United States 

Department of Native and Introduced Earthworms from 

Agriculture 

Forest Service Selected Chaparral, Woodland, and 

Pacific Southwest Riparian Zones in Southern California

Research Station 

General Technical

Report PSW-GTR-142 Hulton B. Wood Samuel W. James 
Wood, Hulton B.; James, Samuel W. 1993. Native and introduced earthworms from selected 

chaparral, woodland, and riparian zones in southern California. Gen. Tech. Rep. PSW-GTR142. Albany, CA: Pacific Southwest Research Station, Forest Service, U.S. Department of Agriculture; 20 p. 

Relatively little is known about the earthworm fauna of southern California. Some 20 different

species of earthworms were collected and identified in a survey of various southern California wildland 

habitats. The ecology and biology of earthworms are outlined, and the results of the survey are 

documented. Introduced species belonging to the Lumbricidae family were encountered most often; 

however, native species, primarily of genera Argilophilus and Diplocardia, are widely distributed. 

Several of the natives collected are believed to be new species. Habitats for both the native and 

introduced species ranged from riparian zones to relatively dry chaparral sites. Preference of earthworms for certain types of plant communities began to emerge even in this somewhat limited survey: 

oak and grass being the most preferred, and conifers the least. Geographical separation of the two 

principal native genera occurs at about 34°N. Further research is needed relative to earthworm ecology, 

impacts on soils, ecosystem dynamics, and fire. An appendix includes all collection records by location, 

and vegetation and soil type. 

Retrieval terms: earthworms, Mediterranean ecosystems, southern California, new species, Lumbricidae, 

Megascolecidae, Acanthodrilinae, Ocnerodrilinae, Sparganophilidae, soil, habitat, chaparral, grassland, 

woodland, riparian, aquatic 

The Authors: 

Hulton B. Wood is a Research Forester at the Station's Forest Fire Laboratory, 4955 Canyon Crest 

Drive, Riverside, California 92507. Samuel W. James is Professor of Biology, Maharishi International 

University, 1000 North Fourth Street, Fairfield, Iowa 52557. 

Acknowledgments: 

Invariably we got a chuckle or two when we first approached our many cooperators regarding this 

earthworm project. Once over the "earthworm shock" they provided assistance in numerous different 

ways. Our sincere appreciation goes to Thomas M. Ryan, Angeles National Forest; David A. Larson, 

San Dimas Experimental Forest; John L. Horn, Santa Margarita Ecological Reserve, California State 

University, San Diego; Suzanne Goode, Point Mugu State Park; Francis M. Colwell, Cleveland 

National Forest; Gary P. Bell, Santa Rosa Plateau Preserve, The Nature Conservancy; and Michael P. 

Hamilton, James San Jacinto Mountains Reserve, University of California, Riverside; and numerous 

staff from the Los Padres and San Bernardino National Forests. Special thanks go to Wendy A. 

Weitkamp for technical help in the earlier stages of collecting and identification, and to Jessica L. 

Malloy and John C. Moffitt for all-around assistance. 

We thank our reviewers Sonia Borges, Paul F. Hendrix, Robert W. Parmelee, Thomas M. Ryan, 

Theodore V. St. John, Wendy A. Weitkamp, and Matthew Werner for their helpful comments and 

suggestions. 

To Frank A. Nudge goes our appreciation for the illustrations and to Marcia A. Wood, Peter M. 

Wohlgemuth, Robert G. Tissell, Lola M. Thomas, and Roberta M. Burzynski for putting it all together. 

Publisher: 

Pacific Southwest Research Station 

Albany, California 

(Mailing address: P.O. Box 245, Berkeley, CA 94701-0245 

Telephone: 510-559-6300) 

April 1993 
Native and Introduced Earthworms from 

Selected Chaparral, Woodland, and Riparian 

Zones in Southern California 

Hulton B. Wood Samuel W. James 

Contents 

In Brief...................................................................................................................................................................iii 

Introduction ...........................................................................................................................................1 

An Earthworm Briefing ........................................................................................................................1 

Curiosa .............................................................................................................................................1

Biology Basics ..................................................................................................................................2

Seasonal Activity Patterns.................................................................................................................4

Ecological Strategies and Feeding Behavior .....................................................................................4

Influence on Soils .............................................................................................................................6 

Survey of Southern California Habitats ...............................................................................................6 

Collection Areas ...............................................................................................................................6

Results ..............................................................................................................................................7

Classification of Collected Earthworms .....................................................................................7

Origins and Distributions ...........................................................................................................7

Habitat Preferences ....................................................................................................................9 

Summary and Concluding Remarks...................................................................................................11 

Research and Management Needs ......................................................................................................11 

Appendix--Earthworm Collection Records .....................................................................................13 

Los Padres National Forest ..............................................................................................................13 

Santa Barbara, Ojai, and Mt. Pinos Ranger Districts ................................................................13

Point Mugu State Park .....................................................................................................................13 

Angeles National Forest ..................................................................................................................14

Arroyo Seco and Mt. Baldy Ranger Districts ...........................................................................14

San Dimas Experimental Forest ......................................................................................................15

San Bernardino National Forest .......................................................................................................16 

Arrowhead Ranger District ......................................................................................................16 

San Jacinto Ranger District ......................................................................................................16 

Santa Rosa Plateau Preserve ...........................................................................................................16 

Cleveland National Forest ..............................................................................................................17 

Trabuco Ranger District ..........................................................................................................17 

Santa Margarita Ecological Reserve ...............................................................................................17 

Cleveland National Forest ..............................................................................................................17 

Palomar Ranger District ..........................................................................................................17 

References ............................................................................................................................................19
In Brief ... 

Wood, Hulton B.; James, Samuel W. 1993. Native and introduced earthworms from selected chaparral, woodland,

and riparian zones in southern California. Gen. Tech. 

Rep. PSW-GTR-142. Albany, CA: Pacific Southwest Research Station, Forest Service, U.S. Department of Agriculture; 20 p. 

Retrieval terms: earthworms, Mediterranean ecosystems, southern California, new species, Lumbricidae, Megascolecidae, 

Acanthodrilinae, Ocnerodrilinae, Sparganophilidae, soil, habitat, chaparral, grassland, woodland, riparian, aquatic 

During a recent investigation of soil properties in southern 

California chaparral, earthworms and evidence of significant 

earthworm impact on soil development (Graham and Wood 

1991) were noted. Because earthworms were not known or 

expected to occur in these soils, the findings were of great 

interest and curiosity, leading us to the realization that earthworms may be an overlooked and important component of 

some ecosystems in southern California. 

Earthworms alter soil properties in ways that are beneficial 

to plant growth by improving soil structure for better aeration, 

water intake, and water transmission. They also accelerate 

decomposition and improve nutrient availability to plants, promoting greater plant productivity. 

Until now earthworms have been an unrecognized component of wildland ecosystems in southern California, even though 

they are well documented from many parts of the world. Both 

native and introduced earthworm species were collected and 

identified from a variety of wildland habitats from Santa Barbara County to San Diego County, in spring 1990 and 1991. 

Earthworms were collected from many soil textural types 

ranging from heavy clays to sands, but they seemed to do best 

in loamy soil. Few earthworms live in soils at or below pH 4. 

Collection sites varied from wet streambed sands and riparian zones to dry chaparral and woodland sites. The wetter sites 

invariably contained earthworms. On many of the drier sites no 

earthworms were found. Enough of the drier sites were sampled 

that an earthworm plant-food preference began to emerge: 

grass and oak habitats being the most preferred, ceanothus and 

other mixed chaparral species next, with chamise and pine 

being the least preferred. Some general habitat preferences 

observed suggest the hypothesis that native Argilophilus spp. 

prefer grassland and oak forest. Highest numbers of Diplocardia 

spp. were found in grasslands. Earthworms are usually not 

found under naturally developed conifer stands in southern 

California. 

Earthworms are cylindrical and segmented, with a mouth at 

one end and an anus at the other. They are hermaphroditic, and 

their young are produced in cocoons. Maturation varies from 

months to years among species. 

Earthworms are placed in three ecological categories depending on where they dwell and feed: epigeic--dwell and 

feed at the surface, anecic--dwell in burrows, often very deep 

in the soil, and feed at the surface, and endogeic--dwell and 

feed below the soil surface. Soil organic matter is vital to most 

earthworms primarily as a source of food. Like other detritivores, 

earthworms may derive more nutrition from microbes ingested 

than from the detritus itself. 

Earthworm activity is governed primarily by temperature 

and moisture. Activity peaks at moderate temperatures. Earthworms require a moist body surface for gas exchange and 

hydrostatic pressure for burrowing. They are able to hibernate 

under conditions of extreme temperature and low soil water. 

The 4-5 years of subnormal precipitation preceding our survey 

may have influenced our collections. 

Over 4000 earthworm species are known. Of the 20 species 

encountered in this survey, half of them were native species. 

Some of them are believed to be new species. The predominant 

native species belong to Argilophilus and Diplocardia in the 

Family Megascolecidae. Two other natives found were in genera Ocnerodrilus (Family Ocnerodrilinae) and Sparganophilus 

(Family Sparganophilidae) and are limited to water-saturated 

areas. Finding Sparganophilus was significant because its usual 

range is the Eastern United States. The nonnative species in 

taxa Aporrectodea, Eiseniella, Eisenia, and Allolobophora, however, were by far the most prevalent and widely distributed. 

They are in the Family Lumbricidae and are European in 

origin. Microscolex from South America were also found. We 

did not collect the best-known earthworm species in North 

America, the night crawler. 

Humans are the major distributors of earthworms by transporting plants and soil. Further dispersal methods are many and 

varied. Floodwaters are known to redistribute viable cocoons 

and live earthworms. Birds and other animals have also been 

suggested as dispersal mechanisms. 

The native genera Diplocardia and Argilophilus are of particular interest, not only because they comprise the bulk of the 

native species, but for their apparent separate geographical 

limits in southern California. The northern boundary of 

Diplocardia spp. appears to be about 34° N. The southern limit 

for Argilophilus spp. is also somewhere near 34° N. From this 

survey, the interactions between native and introduced species 

are not clear. Where native species were found, introduced 

species were almost always associated with them. 

Given the potential importance of earthworms from an ecosystem functioning context, virtually nothing is known of their 

biology and ecology, nor of their role in ecosystem processes. 

Therefore, to obtain more information, earthworm research 

should be carried out in southern California in (1) their taxonomy, biology, ecology and population dynamics, (2) their 

influences on soils, (3) their interactions with soil and plants, 

and (4) their role in fire adapted ecosystems. 

USDA Forest Service Gen. Tech. Rep. PSW-GTR-142. 1993. iii 
Introduction 

We are unaware of the nocturnal, hidden, subterranean 

activity of the most important animal biomass that shares 

with us the earth's land surface. This paradoxical situation, this ecological divorce of humanity from the environment, must undoubtedly have some explanation....our knowledge of ecosystems is, fundamentally distorted by our-aboveground, visual perception of nature and our ignorance of 

life below-ground--Bouche (Lee 1985, p. ix). 

During a recent investigation of soil properties in southern California chaparral, earthworms and evidence of

significant earthworm impact on soil development

(Graham and Wood 1991) were noted. Because earthworms 

were not known or expected to occur in these soils, the findings 

were of great interest and curiosity, leading us to the realization 

that earthworms may be an overlooked and important component of some ecosystems in southern California. 

Earthworms are well documented from many parts of the 

world, particularly Europe and many of the British Commonwealth countries (Darwin 1881, Gates 1982, Lee 1985, 

Stephenson 1930). Extensive areas, notably portions of France, 

Italy, Spain, South Africa, Western Australia, Chile, and California have Mediterranean-type climates characterized by cool, 

wet periods followed by hot, dry seasons of 6 months or more. 

With the exception of a few locations in the Mediterranean 

(Bouche 1972, Diaz-Cosin and others 1980, Omodeo 1959, 

1960, 1982), Africa (Ljungstrom 1972, Pickford 1937), and 

Australia (Abbott 1984, 1985; Barley 1959), information is 

lacking on earthworm populations in Mediterranean climates 

and is particularly sparse for southern California. 

Nearly a hundred years ago Eisen (1900) described species 

from southern California and Baja California, Mexico. Collection records that do exist for southern California are relatively 

few (Eisen 1900, Gates 1967), and are primarily species descriptions and location records. The bulk of the earthworm 

literature for the Pacific Coast States (Fender 1985, Fender and 

McKey-Fender 1990, Gates 1967, Macnab and McKey-Fender 

1947, McKey-Fender 1970) generally lacks information from 

southern California locations. Except for a few of the introduced earthworm species, virtually nothing is known of the 

biology and ecology of most earthworm species found in southern California, native or introduced. 

Where present in sufficient numbers, earthworms can have 

major beneficial impacts on physical and chemical soil properties (Darwin 1881, Edwards and Lofty 1977, Lee 1985, 

Satchell 1967). In the decades just before and after World 

War II, southern California was perhaps a Western center for 

the commercial promotion of earthworm farming. The virtues of "domesticated" earthworms for increasing soil fertility, soil humus development, soil porosity, and soil drainage 

were widely acclaimed for farmers, orchardists, and backyard gardeners (Barrett 1947). 

The potential loss of native earthworm species by habitat 

destruction through urbanization or from competition with introduced European or Asian species has been a concern for a 

long time (Eisen 1900, Gates 1977b, Ljungstrom 1972, Smith 

1928, Stebbings 1962). It is now a moot point in southern 

California, after some two centuries of landscape and cultural 

impacts, that endemic species may have been replaced by 

introduced ones. The reason is no baseline or precolonization 

data exist for comparison. What is important now, however, is 

to determine what species are extant, regardless of origin, and 

their ecological importance to edaphic and plant functions. 

We conducted-what is to the best of our knowledge--the

first survey on earthworms in southern California. The geographical area that we are calling southern California is essentially the area west and south from the midribs of the Transverse and Peninsular Ranges (fig. 1). It comprises portions of 

seven counties and for the most part has a Mediterranean 

climate. The northernmost collection zone was in Santa Barbara County, and the southernmost was in San Diego County. 

Sampling was confined to nonurban mountain and park areas. 

The survey results set the stage for future work on assessing 

what ecological role native or introduced earthworms play in 

these ecosystems. 

This paper does the following: (1) introduces a general 

outline of the biology, ecology, and taxonomy of earthworms 

to those readers unfamiliar with their fascinating and complex 

nature; (2) provides the first-ever data from selected wildland 

areas of southern California on species, locations, and habitat 

of native and introduced earthworms; (3) documents the dis

covery of new earthworm species; (4) discusses the ecological

implications of earthworms in many of our wildland habitats,

and (5) identifies some of the research and management needs

relative to this major but "unseen" portion of the ecosystem.

An Earthworm Briefing 

Curiosa 

The following selection of earthworm facts and oddities 

answers frequently asked questions about earthworms (Adis 

and Righi 1989, Bouche 1983, Edwards and Lofty 1977, James 

1988, Lee 1985, Satchell 1967). 

• It is not clear why many species of earthworms come to 

the surface after a rain storm. Earthworms can survive in water 

for many days. 

• Species that are surface or near-surface feeders are active 

only at night; long exposures to ultraviolet light are lethal to 

most species. 

• Several different species of earthworms often occur in the 

same habitat. 

USDA Forest Service Gen. Tech. Rep. PSW-GTR-142. 1993. 1 
Figure 1-Earthworms were collected from a variety of vegetation and soil habitats in the Tranverse and Peninsular Ranges of southern 

California. 

• Earthworms are not randomly distributed; obtaining popu­-

lation estimates is extremely difficult. 

• In some areas it is not uncommon to have earthworm

population densities in the range of 100 to 500 per square 

meter. 

• There are usually considerably more juveniles in any

given population than there are adults. 

• Some species can regenerate severed tail sections. 

• Some are luminescent. Some exhibit changes in body

colors depending on diet. 

• Some may even produce a plant growth hormone. 

• Earthworms are voracious ingesters of soil and decomposed organic material. A rough estimate for some of the 

common European species is that they ingest soil and organic 

matter equivalent to about 30 percent of their 1- to 2-gram body 

weight daily. 

• They are capable of burying plant seeds and bringing

seeds to the surface. 

• Some climb trees. 

• Populations in some ecosystems may benefit from fire. 

These tidbits of information imply a wealth of knowledge

about earthworms; however, relatively little is known of the

biology and ecology of most earthworm species. 

Biology Basics

This section outlines some of the basics of earthworm biology, which may or may not serve as appropriate models for the 

earthworms in Mediterranean ecosystems in southern California. Though people have been observing earthworms for millenia, 

the first detailed written account of their biology and ecology 

was by Charles Darwin (1881). Earthworms belong to the 

Phylum Annelida, Class Oligochaeta (fig. 2). The Oligochaeta 

include aquatic and terrestrial groups, the latter composed largely 

of the Opisthopora, which are commonly known as earthworms. Opisthopora are so called because the pores from which 

sperm exit are behind the segments containing the female 

gonads. About 4300 species of earthworms exist worldwide 

(Reynolds and Cook 1976, 1981, 1989). Many general zoology 

texts provide a good summary of earthworm anatomy, but 

Edwards and Lofty (1977) and Reynolds (1977) provide introductions directed specifically to the individual interested in 

earthworm studies. 

In North America there are five families of earthworms: 

the Lumbricidae, Megascolecidae, Komarekionidae, 

Sparganophilidae, and Lutodrililidae (Gates 1982, James 1990). 

The last two are found exclusively in saturated or submerged 

soils under or next to lakes and rivers. The Komarekionidae 

have a limited distribution within the Appalachian Mountains. 

2 USDA Forest Service Gen. Tech. Rep. PSW-GTR-142. 1993. 
Figure 2-The earthworms collected in southern California represent three families in the phylum Annelida. 

The most commonly encountered earthworms in the United 

States are Lumbricidae, usually species accidentally imported 

from Europe. However, the two genera, Bimastos and 

Eisenoides, are native to eastern North America. A good key 

to their identification is by Schwert (1990). The bulk of the 

earthworm ecology and biology literature is concerned with 

European Lumbricidae. 

Megascolecid earthworms are represented by several genera naturally occurring in the United States, plus a few genera 

of Asian or South American origin (Fender and McKeyFender 1990). The native genera include Diplocardia, 

Arctiostrotus, Argilophilus, Chetcodrilus, Kincaidodrilus, 

Driloleirus, Macnabodrilus, Toutellus, Nephrallaxis, and 

Drilochaera. In addition, there are some species of the 

megascolecid subfamily Ocnerodrilinae, but they are new 

taxa and not yet assigned to a genus. 

The gross external morphology of all earthworms is essentially the same (fig. 3). Earthworms have a mouth at the head or

anterior end and an anus at the tail or posterior end. They have

no eyes. Their bodies are cylindrical and are composed of 

individual sections or segments, often numbering a hundred or

more. Each segment contains setae (hairs) that can be extended

or retracted. Mature earthworms have a clitellum, a ring-like or 

saddle-shaped collar that functions in reproduction, near the 

anterior end of the body. The location of the clitellum, relative

to the number of segments it is from the anterior end, is an aid to

species identification in the Lumbricidae and Megascolecidae

(fig. 4). The visible external sex organs are all located in the

anterior region; their prominence and positioning by segments

are also important taxonomically. 

Earthworms are hermaphroditic, though there are cases of

parthenogenesis. Generally earthworms reproduce by exchanging sperm, which is stored in spermatophores or spermathecae. 

The sperm fertilize eggs which are deposited in an ovate sac 

containing eggs (one to many) and a food source for the developing embryo(s). The sac or cocoon is secreted by the clitellum 

(fig. 3) and deposited in a small cavity in the soil. Development 

time varies among species, and can be prolonged by drought or 

cold. A general figure for common species during the growing 

season is 3 to 4 weeks from deposition to hatching. 

After hatching, the period of growth to maturation may be 

short, a matter of 5 or 6 months in some small species living on 

rich organic substrates, or much longer in the cases of large 

species living on relatively low-quality diets. The largest earthUSDA Forest Service Gen. Tech. Rep. PSW-GTR-142. 1993. 3 
Figure 3--All earthworms have essentially the same external morphology. 

worms are not from California, but are found in Brazil, South

Africa, and Australia. They are over a meter long, with reports 

of some up to 2 meters, and weigh 500 grams (fresh weight).

Such species may take a few years to reach maturity. 

Seasonal Activity Patterns 

Given habitable soils and an adequate food supply, earthworm activity is primarily governed by temperature and moisture. Low soil temperatures limit activity, though active earthworms have been observed just below snow cover in unfrozen soil. However, maximal activity usually takes place at 

moderate temperatures. For most European Lumbricidae, activity peaks between 10 and 20 °C (Daugbjerg 1988, Edwards 

and Lofty 1977, Laverack 1963). Some Diplocardia are known 

to tolerate close to 30 °C, and tropical species generally 

tolerate higher temperature optima than do temperate species 

(Madge 1969). When temperatures become too low for activity, earthworms become dormant. Similarly, when high 

temperatures are encountered, and depending on the species, 

a worm may enter a true diapause state lasting for a fixed 

period of time, or simply cease activity until temperatures 

return to lower levels (Edwards and Lofty 1977). In temperate zones with spring and summer rainfall, activity may 

close in midsummer due to high soil temperature, even with 

adequate soil moisture (e.g., James 1991). 

Soil moisture is the other primary factor controlling activity. 

Earthworms are fundamentally aquatic in body plan, requiring 

a moist surface for gas exchange. Thus there must be free water 

present in soil for them to be active. Earthworms are 65-90 

percent water by weight, and depend on hydrostatic pressure 

for their ability to burrow (Dales 1963, Lee 1985). A loss of 10 

percent of body water can prevent movement (Satchell 1967). 

Water leaves earthworms through the cuticle, in castings, through 

the nephridia in urine, and through dorsal pores in the species 

having them. Daily water turnover can be 10-20 percent of the 

total body weight (Lee 1985). 

When soil moisture begins to fall towards some critical 

value, earthworms burrow deeper into the soil to find moisture, or enter a dormancy called quiescence. This state is 

indistinguishable from the dormant states induced by high 

temperatures; the two often occur together. When earthworms cease activity in drought, they void their guts within a 

roughly spherical cavity and roll themselves in a ball. Thus 

encased with a plastering of their castings, they can remain 

inactive for long periods, losing up to 75 percent of their 

body water and slowly metabolizing their reserves (Edwards 

and Lofty 1977). This quiescence can be quickly broken with 

the introduction of water. 

Ecological Strategies and Feeding

Behavior 

Being so dependent on soil moisture, earthworms are influenced by soil texture. They are found in all textural types, but 

they seem to do best in loamy soils, followed by clays and 

coarse sands (Guild 1948). Unless precipitation is steady, very 

coarse-textured soils do not retain enough water to support 

earthworm activity. Soil pH tolerance ranges vary among species, but in general few earthworms are able to live in soils at or 

below pH 4. The upper limit is weakly alkaline, in the neighborhood of pH 8 (Edwards and Lofty 1977). 

Soil organic matter is vital to most earthworms, primarily as 

a source of food. The North American lumbricid genus Bimastos 

is an exception, since most of its species inhabit rotting logs 

rather than soil. Other groups of earthworms, as described 

below, are relatively independent of soil organic matter. 

4 USDA Forest Service Gen. Tech. Rep. PSW-GTR-142. 1993. 
Most earthworm species can be placed into one of three 

basic types by ecological, niches: (1) epigeic--surface feeders 

and surface dwellers, (2) anecic--surface feeders that dwell in 

burrows sometimes deep within the soil, and (3) endogeic

subsurface feeders and subsurface dwellers (Bouche 1977, 1983; 

Lavelle 1983; Lee 1959, 1985). 

The first type, the epigeic earthworms, feed on surface litter 

or other forms of organic matter above the mineral soil, such as 

logs or accumulations in rock crevices or tree limb crotches. 

Typically they are darkly pigmented, relatively small, have 

high reproduction rates, and flee rapidly to avoid capture. Such 

species may retreat to the soil to avoid intolerably dry or hot 

conditions in the surface litter, but ordinarily would not be 

found in the soil except as transients. 

The second type, the anecic earthworms, create deep vertical burrows or burrow systems from which they emerge to 

feed on surface organic matter, such as dead leaves, seeds, or 

small twigs. The most familiar example is the nightcrawler 

(Lumbricus terrestris). A few native North American species 

are known or suspected to be deep burrowers. Among these 

are the largest Diplocardia, D. fusca, and D. biprostatica, 

and some large species endemic to the Pacific Northwest. 

Anecics are usually large, long-lived, darkly pigmented on 

the anterior dorsal surface, and capable of rapid escape by 

Figure 4-Lumbricidae (a) and Megascolecidae (b) from southern California can often be distinguished by their opacity or translucence, segment 

position of the clitellum, and by the position and prominence of sex characteristics. 

USDA Forest Service Gen. Tech. Rep. PSW-GTR-142. 1993. 5 
quick contraction and moving down their burrows. This behavior makes them difficult to sample accurately. Special 

techniques such as formalin extraction may have to be used 

(Raw 1959). Dilute solutions of lime sulfur (calcium polysulfide) are effective for large anecic Diplocardia and are used 

by fishermen in south Texas. Soil vibration may also be 

effective on some species, but the accuracy of quantitative 

sampling by this method is poor (Lee 1985). 

The last type, the endogeic earthworms, in general are lightly 

colored to unpigmented, slower moving, may exude fluids 

when irritated, and vary considerably in size. The endogeic 

type is divided into three subgroups: polyhumic, mesohumic, 

and oligohumic, referring to decreasing concentrations and 

lability of organic matter consumed by the earthworms (Lavelle 

1983). Polyhumic species live in the soil proper, but nearer the 

surface than the other two subgroups, and consume partially 

decomposed organic matter in the soil. Oligohumic species live 

deeper in the soil and feed on relatively stable soil organic 

matter. Mesohumic species are intermediate in vertical distribution and organic matter consumed. Those feeding on further 

decomposed material, such as the mesohumic and oligohumic 

types, tend to be larger. The distinctions among the three 

groups of endogeic earthworms are fine, so one may wish to 

lump them together in the early phases of studying earthworms. 

When soil and organic matter are ingested by an earthworm, 

the materials are subjected to mechanical and chemical action. 

The order of events varies among earthworm families, but 

consists of the same basic processes: grinding in a tough muscular gizzard; treatment with earthworm-generated enzymes 

and mucus (Lavelle and others 1983); attack by microbes in the 

ingested soil, or in the gut of the earthworm, or both; absorption 

of nutrients; and excretion of unassimilated material. In some 

species a glandular region produces calcium carbonate which is 

added to the gut contents. Like other detritivores, earthworms 

may derive more nutrition from microbes colonizing ingested 

detritus than from the detritus itself (Cummins 1974). 

Influence on Soils 

Earthworms alter soil both chemically and physically. By 

burrowing and casting, earthworms mix soil horizons (e.g.,

Buntley and Papendick 1960, Langmaid 1964) and change the

physical structure of the soil. Their effects on soil are considered beneficial to plants (Edwards and Lofty 1977). Vertical

mixing between soil horizons is accomplished by the different

ecological types of earthworms. Epigeic species, for example,

break down surface litter and accelerate incorporation of decomposed organic material into the upper few centimeters of

soil. Anecic species bring subsoil material to the surface and

line their deep burrows with highly organic cast material derived from surface plant remains. 

Some structural changes to soil resulting from earthworm

activity are increased porosity, decreased bulk density, changes

in pore size distribution, and increased water stability of soil

aggregates. Air and water move more freely in worm-worked

soils, and root penetration may be facilitated (Lee 1985). Water

entry into the soil is often greatly enhanced by earthworm 

activity (Edwards and others 1989, Ehlers 1975), thereby 

reducing surface water runoff and consequent soil transport. 

Earthworms help reduce crusting of surface soil, a problem in 

many cultivated soils (Kladivko and others 1986). Earthworms 

actually reduced soil erosion in cropland (Hopp 1946). Fresh 

surface casts are easily dispersed by raindrop impact, while 

aged casts are more stable (Marinissen and Dexter 1990, Shipitalo 

and Protz 1989). 

Depending on the feeding and burrowing habits of the earthworm, casts may be deposited as a lining of the burrow, within 

burrows or krotovinas (tunnels made by other burrowing animals), in the soil, or on the surface. Casts are higher in available 

nutrients than the surrounding soil. This does not mean that 

earthworms supply more nutrients to the soil, merely that the 

form of nutrients is more readily accessible to plants (Lee 

1985). Casts contain a myriad of different microbial populations (bacteria, fungi, protozoa), and biological and enzyme 

activity in fresh casts is high, with a rapid decline as the cast 

ages (Edwards and Fletcher 1988, Parle 1963a, b). 

From a plant nutrition standpoint, interactions are not well 

understood among earthworms, plants, and mycorrhizal fungimajor symbionts for plant nutrient uptake. Earthworms may be 

major dispersal agents or detrimental consumers of mycorrhizal fungi (Rabatin and Stinner 1988, Reddell and Spain 1991). 

Another source of available nutrients, primarily nitrogen, is 

earthworm urine, excreted from the nephridia in each segment. 

Additional nitrogen is added to the soil when the earthworm 

dies; slightly over 70 percent of the dry weight of an earthworm 

is protein, and about three-quarters of that is usable nitrogen 

(Satchell 1967). 

Survey of Southern California 

Habitats 

Collection Areas 

Ten broad geographical areas were selected to represent 

Mediterranean climatic zones in essentially wildland settings in 

southern California. The northernmost collection area was the 

Los Padres National Forest near Santa Barbara and the southernmost the Palomar District on the Cleveland National Forest 

in San Diego County (fig. 1). We searched each of these areas 

and collected earthworms from a wide variety of vegetation 

and soil habitats ranging in elevation from 55 to 1876 meters. 

Vegetation types included many different chaparral associations, native and exotic grasslands, oak woodlands, and riparian 

zones containing various mixed hardwoods. A few high elevation mixed oak-conifer sites were also sampled. 

Most of the earthworms were collected by digging into the 

soil with a shovel, hand sorting through the excavated material, 

and picking out specimens. The average maximum sampling 

depth was about 30 cm. On a few occasions we used a formalin 

6 USDA Forest Service Gen. Tech. Rep. PSW-GTR-142. 1993. 
solution extraction procedure (Raw 1959) with limited success.

Other known earthworm collection techniques, such as electric

shock, vibrating metal rods, and "thumping" procedures (Lee

1985) were not used. We did not attempt to quantify earthworm 

populations in any of the areas sampled. A major note of 

caution: "one-time" sampling such as was done for this project

is no assurance that data collected is representative of a particular site or area. Our two major collecting periods were late

March-early April 1990 and late April 1991. Ideally, one would

visit a site at intervals during an entire season and sample more

intensively at every site. 

The live earthworm specimens were placed in plastic vials 

immediately upon collection. Detailed notes taken at each sampling spot included location, date, time, habitat (such as landscape position, plant species), and soil information. Once we 

completed collecting at a site, the live earthworm specimens 

were removed from the collection vials, and quick-killed and 

cleaned by placing them in a 50 percent solution of ethanol for 

a few minutes. The specimens were then placed in a 5 percent 

formalin solution for a minimum of 1 week. Specimens retained for long-term storage were eventually placed in a 70 

percent ethanol solution. 

Identification was a three-stage procedure. The first stage 

was gross field examination sometimes with the aid of a hand 

lens. Relying solely on external morphological characteristics, 

all of the specimens could be identified at the family level, 

about 95 percent to genera, and about 50 percent to species. 

Many of the specimens were juveniles or were fragmented, 

thereby limiting identification or making it impossible. In the 

second stage of identification, specimens were examined in the 

laboratory under a low power microscope, to cross check and 

verify the field classification, based again on external morphological characteristics. In the third stage specimens that could 

not be identified by external features alone were dissected and 

identified using various taxonomic keys based on internal structures (Gates 1977 a, b, James 1990, Michaelson 1900, Schwert 

1990). In a few cases, when a new species was encountered, we 

described and recorded complete external and internal features. 

We searched known taxonomic records for past documentation 

of the same or similar species, to verify possible new species. 

The new species found in this survey will be described in 

separate publications. In this report, the new species are identified by genus name and a temporary label for the species, e.g., 

Argilophilus 2. 

Results 

Classification of Collected Earthworms 

We collected and identified 20 diverse earthworm species 

(table 1). Half of them are native species, including hitherto

undescribed new species or genera. The species collected represent 11 genera, 3 families, and 2 subfamilies (fig. 2). Most of

the specimens collected were nonnative earthworms in the

family Lumbricidae. They were, in fact, the most abundant and

most widely distributed earthworms encountered. 

The earthworms found most often in this survey were the 

introduced species, Aporrectodea trapezoides and Eiseniella 

tetraedra, followed closely by Eisenia rosea and Allolobophora 

chlorotica (table 1). The best known earthworm species in 

North America, the night crawler, was not collected from any 

of our sampling areas. A high percentage of specimens were 

juveniles (without well-formed clitellae) and could be classified only as juvenile Lumbricidae. 

The native earthworms belonged to two different families: 

Megascolecidae and Sparganophilidae (fig. 2). Of special interest are species in two genera, Diplocardia and Argilophilus, 

belonging to the family Megascolecidae (subfamily 

Acanthodrilinae). Several of these species have not been described before. Based on our field observations, these species 

have soil ameliorating behavior comparable to some of the 

nonnative species. We know essentially nothing of their biology. They apparently do not require continually wet or moist 

soil conditions, and are primarily subsurface casters. The two 

other native species collected are small and thin, and are limited 

to water-saturated habitats. These two are represented by species yet unnamed. One is in the Ocnerodrilinae (a subfamily of 

the Megascolecidae), but not assignable to any known genus 

and the other in the genus Sparganophilus (family 

Sparganophilidae). 

Origins and Distributions 

The earthworm fauna of the areas sampled indicate that the 

region has elements of three separate sources. The nonnatives 

are the Lumbricidae introduced from Europe (Gates 1982) and 

Microscolex from southern South America (Michaelsen 1900). 

The Lumbricidae encountered are now widely distributed 

throughout the temperate zones of the world. The indigenous 

component consists of new species of four taxa: Argilophilus, 

Diplocardia, Ocnerodrilus, and Sparganophilus. 

Most earthworm introductions are the result of transporting 

plants and soils from one part of the world to another (Lee 

1985). After the initial introductions, further dispersal mechanisms are many and varied. Humans, of course, are the major 

distributors. In the United States, the shifting and settling of 

millions of people over the centuries likely has been responsible for the spread of nonnative earthworm species. Lakesides 

and stream banks are prime candidate areas for earthworm 

establishment because of discarded earthworm fish bait. Marijuana plantings in remote areas may be another recent introduction mechanism. Colonization, reproduction, and spreading 

then occur. Aside from humans, floodwaters are known to 

carry viable cocoons and live earthworms for redistribution 

elsewhere. Birds and other animals have also been suggested as 

dispersal mechanisms (Schwert 1980). 

These dispersal mechanisms may seem unlikely for some of 

the sites and species in this survey. For example, Fern Canyon 

on the San Dimas Experimental Forest is remote and uninhabited, yet had three introduced species. One of them, Eiseniella 

tetraedra, is limicolous (mud-loving) to aquatic, and generally 

is not used as fish bait. It would not be transported with 

ordinary garden plants or by fishermen. How, then, did it reach 

USDA Forest Service Gen. Tech. Rep. PSW-GTR-142. 1993. 7 
••• ••••• ••• 

•••• ••• ••••••••• •• 

••••

••• •• 

•• 

•• •••••• •• 

•• 

•••••••• •• 

•••• 

•• 

••• 

••• 

•••••• 

Table 1 --Native and introduced earthworm species collected in southern California, by general locations 

San Bernardino 

National Forest Arrowhead Ranger District 

San Bernardino National Forest San Jacinto Ranger District 

Santa Rosa Plateau Preserve 

Cleveland National FTrabuco Ranger Dis

Angeles National Forest Arroyo Seco, 

Mt. Baldy Ranger Districts 

San Dimas Experimental Forest 

Earthworm species 

Los Padres 

National Forest 

Santa Barbara, Ojai, Mt Pinos 

Ranger Districts 

Point Mugu 

State Park 

Allolobophora chlorotica • • • Aporrectodea caliginosa • • Aporrectodea trapezoides • • Aporrectodea tuberculara • Aporrectodea sp. • 

*Argilophilus papillifer • 

• 

*Argilophilus 1 • *Argilophilus 2 

• *Argilophilus sp. •

Dendrobaena rubida •

* Di p lo ca rd ia CA1 •*Diplocardia CA2 •

Eisenia rosea • •Eiseniella tetraedra • • • •Lumbricidae juveniles 

• • 

Microscolex dubius Microscolex sp. • 

*Ocnerodrilus 1 *Ocnerodrilus 2 • *Ocnerodrilus 3 *Ocnerodrilus sp. • • • 

Octolasion cyaneum • Octolasion sp. • 

*Sparganophilus 1 

• 

*Native •Different collection sites 

1 "See FIGURE 1 for geographic locations of collection sites, and see APPENDIX for descriptions of collection sites.” 

8 USDA Forest Service 
this site? More detailed knowledge of site histories and earthworm dispersal mechanisms is needed to answer this question. 

The genus Microscolex originated in the Southern Hemisphere (Michaelsen 1900). Two species, Microscolex dubius 

and Microscolex phosphorous, are now widely distributed 

due to human activity. Both are variable, making identification difficult. 

Argilophilus is restricted to the Pacific Coast States of Washington, Oregon, and California (Gates 1977b, Fender and McKeyFender 1990). Prior to the survey reported here, the southernmost record was from Fresno County, California (Eisen 1894). 

Three species were collected; two of them are believed to be 

new. The known species, Argilophilus papillifer, was collected 

from Point Mugu State Park in Ventura County. The others, as 

yet undescribed, were from locations even farther south, in both 

the Angeles and San Bernardino National Forests (table 1, 

app.). They may be widely distributed, but further collecting 

will be required to determine how widely. Juveniles, probably 

also of an Argilophilus species, found on the San Dimas Experimental Forest may belong to one of the new species or even 

to a third. The absence of Argilophilus earthworms from apparently suitable habitats on the San Jacinto Ranger District, San 

Bernardino National Forest region may indicate the boundary 

of the genus is north of there. 

The two new species of Diplocardia found are similar to 

Diplocardia keyesi, known only from Ensenada, Baja California (Eisen 1900). All other members of the genus are from the 

Central and Southern United States and Northeastern Mexico. 

The new species are an important find from a biogeographical 

perspective. It appears their northern limit is at about 34 degrees N., excluding the San Jacinto Peak area of the San 

Bernardino National Forest. The southern California species of 

Diplocardia were found in a system of mountains (Peninsula 

Range) extending from the Santa Ana Mountains south into 

Mexico. Though we have not examined all the potential areas 

for Diplocardia, they likely will be found in suitable habitats of

most sections of the Cleveland National Forest. 

Our finding of Ocnerodrilinae in several aquatic habitats is 

another tie to the earthworm fauna of Mexico, which includes 

many in this subfamily. Some described species in the subfamily, however, are quite variable (Eisen 1900, Gates 1982). We 

are not yet certain that the California species found are distinct 

taxa, but it appears likely. 

Some Sparganophilus were found also. This finding is significant, because other than a few records from northern California, the genus is unknown from California. The bulk of the 

range of Sparganophilus is the eastern United States (Reynolds 

1980). 

We encountered what appears to be a biogeographical boundary separating two elements of the native earthworm fauna of 

southern California. To the north and west of San Gorgonio 

Pass, including the low coastal mountains of Point Mugu, the 

genus Argilophilus was present. No native earthworms were 

found in the San Jacinto Peak area (table 1, San Jacinto District), though some introduced Lumbricidae were collected. 

Diplocardia were found in the Santa Ana Mountains west of 

Lake Elsinore, in foothill grasslands near Temecula, and in the 

vicinity of Palomar Mountain, all south and west of the San 

Jacinto Peak area. Argilophilus, which is primarily a Pacific 

Northwest group, apparently reaches its southern limit at about 

34° N. Presence of Argilophilus in the Santa Lucia and Coast 

Ranges toward Monterey is possible. 

In contrast, Sparganophilus sp. and Ocnerodrilus spp. were 

encountered in sediments of streams north and south of 34° N. 

Habitat Preferences 

The wetter sites (riparian areas) are obviously preferred 

habitats for many of the species encountered during this survey. 

In these wet habitats a wide variety of food sources (organic 

matter) is available. With the exception of the almost aquatic 

genera Ocnerodrilus and Sparganophilus, which exist in saturated soils and mucks, no particular vegetation or soil type was 

noted to be associated with them. In the mesic or "arid" collection sites, or where earthworm activity was evident, a definite 

habitat or plant type community preference began to emerge. 

Soils under oaks (Quercus spp.) and grass (including Avena, 

Bromus, Stipa) had the greatest earthworm activity followed by 

ceanothus (Ceanothus spp.), chamise (Adenostoma fasciculatum), 

and pine (Pinus spp.). 

Our observations generally confirm the earthworm plant 

preferences observed in the soils of the large, unconfined lysimeters on the San Dimas Experimental Forest, which contains monocultures of scrub oak, ceanothus, chamise, and pine. 

The worm-worked A horizon under oak was at least three times 

as thick as any other A horizon, had higher clay contents and 

greater aggregate stability (Graham and Wood 1991). 

Apart from the semi-aquatic species and the riparian forests, 

chaparral plant communities do support earthworm populations to some degree. They are less abundant in chaparral, 

however, and a great many of the chaparral sites appear not to 

support earthworm populations at all. Populations may have 

been reduced by the 4-5 years of subnormal precipitation that 

preceded our collections in 1990-91. 

Most of the introduced species have distributions dependent 

on human activity. It is difficult to draw any conclusions about 

their plant food preferences, although an oak > grass > ceanothus 

> chamise > conifer preference for many of the earthworm 

species might be a good guess. This order assumes adequate 

soil water and does not distinguish between soil types. We did 

find several locations where pine trees had been introduced in 

chaparral environments as roadside amenity plantings or fuel 

breaks, where nonnative earthworm species were present. The 

earthworms were probably introduced to these sites during 

planting of the containerized pine tree stock. Our general observation is that earthworms, introduced or native, are usually not 

found in soils under naturally developed conifer stands in 

southern California. 

The native Argilophilus species were found in grasslands, 

oak forests, and various chaparral types (table 2). A single 

specimen was collected in a sandy soil on the flood plain of the 

West Fork of the San Gabriel River, under mixed hardwoods. 

On the San Bernardino National Forest, Argilophilus sp. was 

USDA Forest Service Gen. Tech. Rep. PSW-GTR-142. 1993. 9 
Table 2--Habitats of the earthworm species collected in southern California 

Earthworm species 

Woodland ass Grass/ 

Woodland 

Gr Chaparral Riparian Aquatic 

Allolobophora chlorotica • • • 

Aporrectodea caliginosa • • • • • 

Aporrectodea trapezoides • • • • • 

Aporrectodea tuberculata • 

Aporrectodea sp. • 

*Argilophilus papillifer • 

*Argilophilus 1 • 

*Argilophilus 2 • • 

*Argilophilus sp. • • • 

Dendrobaena rubida • •

*Diplocardia CA1 • 

*Diplocardia CA2 • 

Eisenia rosea • • • • 

Eiseniella tetraedra • • 

Lumbricidae juveniles • • • • • • 

Microscolex dubius • • •

Microscolex sp. • • • 

*Ocnerodrilus 1 • 

*Ocnerodrilus 2 • 

*Ocnerodrilus 3 • 

• 

• 

• 

• • 

• • 

•

*Ocnerodrilus sp. • • • 

Octolasion cyaneum • 

Octolasion sp. • 

*Sparganophilus 1 • 

*Native 

found at elevations above 1500 m in oak-conifer-grasslands, considerable margin. On some of the cattle-grazed grassland 

but confined primarily to the grassed areas within these zones. sites, cattle droppings (a desirable food source for many

We tentatively offer as an hypothesis that Argilophilus is pri- Lumbricid species) appeared not to be a prime food source for 

marily associated with grasslands and oaks in southern Califor- the Diplocardia. Collection success was no greater under dropnia. Eisen (1894) observed Argilophilus to be confined to pings than elsewhere. 

"heavy adobe or clayey soil." We also collected them in this The habitats where Diplocardia were found on the Santa 

type of soil (grass-covered Vertisols from Point Mugu State Rosa Plateau Preserve illustrate some of the complexities in

Park), but primarily we found them in lighter soil types. attempting to define habitat preferences for these native speDiplocardia spp., the other native species, were collected cies. Diplocardia CA1 was found on Mesa de Colorado near 

from several locations on the Cleveland National Forest's the largest of the vernal pools. The site was wet, soils were 

Trubuco and Palomar Ranger Districts. Although we collected deeper than 30 cm, and vegetation included grasses and a mix 

them from a number of different habitat types (mixed chapar- of wetland species on the fringes of the vernal pool. Diplocardia 

ral, oak, and grassed areas), the highest population numbers CA2 was collected in slightly moist, deep soils in mixed 

were in the grasslands. Where we found them in the oak or chaparral (scrub oak, black sage, chamise) on a slope leading to 

chaparral habitats they were invariably associated with intro- Mesa de Burro. Some earthworm activity was evident on Mesa 

duced species, with the nonnatives outnumbering them by a de Burro at the shrub-grass interface, but not in the herbaceous 

10 USDA Forest Service Gen. Tech. Rep. PSW-GTR-142. 1993. 
vegetation, which was within 50-100 m of the vernal pools 

where the soil depth is generally 20 cm or less. 

Several possible explanations emerge. The Diplocardia species may have restricted and specialized distributions or soil 

depth limitations. Conditions at the time of collecting may not 

have been conducive to finding the species present in the grassforb community on Mesa de Burro. Neither species of 

Diplocardia was found in other chaparral sites, grasslands, or 

riparian areas on the Preserve. However, Lumbricidae and 

Ocnerodrilidae were found in the grassland and riparian habitats of the Preserve. Diplocardia CAI was collected from 

numerous grassland sites on the Trabuco and Cleveland Districts of the Cleveland National Forest. 

We repeatedly observed, particularly under oaks, that where 

earthworms, their burrows, and castings were abundant, depth 

of leaf litter was reduced. Also, the leaf litter showed little 

evidence of decomposition throughout its depth profile (classified as an Oi horizon in its entirety). Where earthworms were 

not evident, the leaf litter was often deep, having Oi, Oe, and 

Oa horizons, indicating increased decomposition with depth. 

And depending on the site, the litter below the immediate 

surface on the earthworm-free sites was frequently intertwined 

with abundant fungal mycelia. We never found earthworms 

and a thick litter layer, except where steep slopes deposited 

extra litter at their bases. We never found earthworms and the 

abundant mycelia just mentioned in the same spot. 

Earthworm activity, by reducing litter volume, probably 

does not reduce surface fuel loads enough to be a significant 

factor in reducing fire initiation and propagation. On the 

other hand, this accelerated decomposition process may provide a greater soil nutrient capital, promoting greater plant 

productivity. 

Summary and Concluding Remarks 

We are encouraged by our discoveries in this somewhat 

rudimentary excursion into the earthworm world of some 

southern California wildland habitats. A wide variety of species were collected from many different habitats. Nonnative 

species far outnumbered the natives. Several new species of 

native earthworms were collected, and work on their taxonomies is being assembled. 

Some harsh chaparral sites contained earthworm populations, many of them native species. The wetter sites, typically 

accepted as the best earthworm habitats, were found to have an 

abundance of species, in most cases, primarily introduced ones. 

Well-defined habitat (food-plant) preferences for the more mesic or dryland areas are not nearly as clear-cut. Our observations lead us to this generalization: the most preferred plant 

habitats on the drier sites are the oaks and grasses, followed by 

ceanothus and numerous other chaparral species, some of the 

least preferred being chamise and buckwheat; conifers seem to 

be the least preferred. 

At this stage nothing definitive can be said regarding soil 

types or soil preferences on the drier sites we sampled. The 

majority of soils were deeper than 35 cm, and textures ranged 

from heavy clays to sands. Soil orders included Mollisols, 

Entisols, Alfisols, Inceptisols, and Vertisols. Most, but not all, 

had mollic or umbric epipedons (diagnostic surface horizons) 

that were darker in color than the subsurface horizons. The 

predominate soil feature indicative of earthworm activity (not 

soil preference) is in the kind and degree of soil structure, 

particularly in the surface horizons. Most earthworm-worked 

soils we investigated had some granular or crumb structure to 

them; loose single spheroids to aggregated spheriods, ranging 

from less than 1 mm to greater than 5 mm. We believe 

earthworm castings are the principal components contributing 

to this distinctive type of structure. It should be possible to 

identify, within certain limits, the earthworm genus or even the 

species, based on characteristics of the observed cast material 

and soil structure (Rusek 1985). 

Soil surveys for southern California contain little mention of 

earthworm-influenced soils (Anderson 1966, Bowman 1973, 

Edwards and others 1970, Knecht 1971, O'Hare and Hallock 

1987, Retelas 1980, Ryan 1991). Many of the soils we encountered, some covering fairly extensive areas, were heavily influenced by earthworms and should be considered worm-worked 

by any standards. These soils probably meet the Soil Taxonomy (USDA 1975) criteria of "verm"; and somewhere in 

their taxonomic classification this fact should be noted. Why a 

major diagnostic soil attribute (thick surface horizons, with 

greater than 50 percent of the soil volume composed of wormworked casts and burrows) has not been recognized until now 

in southern California is somewhat of a puzzle to us. 

Research and Management Needs 

Before this survey was begun we had little idea of what 

earthworm populations and species existed in southern California. We now know that some rather diverse, if not unusual, earthworm habitats are populated by both native and 

introduced earthworm species. From an ecological and biological diversity perspective we find this fact exciting but 

tremendously perplexing and complex, for it raises numerous 

questions of interest to research and management that will 

not necessarily be easy to answer. Some of the answers may 

come if research on earthworms is conducted in the following four areas: 

• Taxonomy, biology, ecology, and population dynamics 

• Impacts on soil physical, chemical, and hydrological properties 

• Interactions with soil and plants 

• Role in fire-adapted ecosystems 

Earthworm taxonomy, biology, ecology, and population dynamics--One of the biggest problems we encountered during 

the general course of this project was obtaining live, adult 

USDA Forest Service Gen. Tech. Rep. PSW-GTR-142. 1993. 11 
specimens from the drier, chaparral sites that we knew contained earthworms based on the presence of cast material. 

Seasonal patterns of activity, growth, and reproduction for both 

selected native and introduced species need to be clearly understood. The winter and early spring rainy period clearly is most 

conducive to earthworm activity, but it is not known whether 

soil temperatures at mid-to-low elevations (1500-300 m) ever 

become low enough to suppress earthworm activity. Soil temperatures below 6 °C terminate activity in many common 

Lumbricidae, including Aporrectodea caliginosa and A. 

trapezoides. The upper limit for activity is about 25 °C. Absolutely nothing is known of the temperature tolerances of any 

Argilophilus, including the species found in this survey. 

Earthworm related impacts on soil physical, chemical, and 

hydrologic properties--Earthworms undoubtedly enhance both 

the chemical and physical condition of soils, often with consequent increases in plant productivity, improved water intake 

rates into the soil, enhanced water and nutrient transmission to 

the lower depths, and increased aggregate stability. The question now is this: are earthworms a major soil ameliorating 

factor in selected wildland sites in southern California? To 

answer this question studies should be initiated comparing 

chemical and physical differences between worm-worked and 

worm-free soils, in both field and laboratory settings, involving 

different soil types and plant species. Both native and introduced earthworm species should be studied. 

Earthworm-soil-plant interactions--Particular emphasis

should be placed on earthworm-generated soil nutrient and soil 

biological effects relative to site productivity and plant growth 

processes. It would be useful to know the sensitivity of chaparral ecosystems to fertilization, the nutrient cycling patterns, and 

plant production in worm-free and worm-inhabited plots. One 

hypothesis is that under major litter-producing plant species 

(such as oaks), earthworms increase the rate of litter decomposition and reduce the importance of fungi in litter decomposition. Another is that earthworms enhance fungal importance by 

dispersing propagules and by speeding up fungal turnover, 

thereby making the fungi more active in nutrient cycling. We 

need to know what the interactions are among earthworms, 

mycorrhizal fungi, and plant nutrient uptake. In the somewhat 

controversial arena of global climate change, studies should be 

aimed at earthworm ecology in specific Mediterranean ecotones relative to plant and soil associations (including carbon 

dynamics). 

Earthworms and fire--For the land manager in southern 

California, both wildfire and prescribed fire and their management are critical issues. Earthworms and fire have obviously 

coexisted in many of these fire-adapted chaparral ecosystems 

for quite some time. Just what role, if any, does the earthworm 

play in the interaction of fire, soil, and plant production and 

species composition or diversity? Earthworms may have a role 

in seed burial or retrieval after fire, or in improving water and 

nutrient transmission into soils that have been burned over, or 

even in breaking soil water repellency, which commonly occurs after fire. 

12 USDA Forest Service Gen. Tech. Rep. PSW-GTR-142. 1993. 
Appendix--Earthworm Collection 

Records 

This appendix lists the geographic locations we surveyed in 

order from north to south (fig. 1). Earthworm species are listed 

alphabetically by geographic location, then collection sites are 

described. 

In site descriptions, the formal soil taxonomic classifications (soil) are based primarily on published and nonpublished 

soil surveys (Anderson 1966, Bowman 1973, Edwards and 

others 1970, Knecht 1971, O'Hare and Hallock 1987, Retelas 

1980, Ryan 1991). Often the soil type described in these surveys did not correspond to the soil type at the sites; in these 

situations we reclassified the soils. Elevation (elev.), latitude 

(lat.), and longitude (long.) were estimated from 7.5-minute 

U.S. Geological Survey quadrangle maps (quad.). Unless rainfall records were available for specific sites, average annual 

precipitation (precip.) was estimated from isohyets (U.S. Geological Survey 1969). 

Los Padres National Forest 

Santa Barbara, Ojai, and Mt. Pinos Ranger Districts 

Species Site 

Allolobophora chlorotica ............................... 1 

Aporrectodea caliginosa ................................ 1, 2, 3 

Aporrectodea trapezoides .............................. 1, 2, 3, 4 

Argilophilus 1 (new species) ........................... 5 

Eisenia rosea ................................................... 4, 6 

Eiseniella tetraedra ........................................ 1, 7 

Lumbricidae (juveniles) ................................... 4 

Microscolex sp ................................................. 2 

Ocnerodrilus 2 (new genus/species) ............... 2 

Ocnerodrilus sp ............................................... 7 

Site 1--About 500 m down old Hwy. 150, off Hwy. 154, 

from Cold Springs Resort. Streambed gravels, wet sands and 

muck; adjacent streambanks moist sandy loamy. Overstory 

Quercus agrifolia and Platanus racemosa. Litter depth 4-8 cm. 

Soil alluvial sands; elev. 473 m; aspect NE.; slope NA; precip. 

640 mm; lat. 34°31'21" N.; long. 119°50'18" W.; quad. San 

Marcos Pass. 

Site 2--Santa Ynez Recreation Area, Forest Service Rd. 

5N 18, end of paved road past Live Oak Campground where 

Santa Ynez River crosses road. Streambed, gravelly muck. 

Scattered Salix lasiolepis and unknown marsh grasses and 

sedges. Soil alluvial sands; elev. 342 m; aspect NA; slope NA; 

precip. 690 mm; lat. 34°32'05" N.; long. 119°42'47" W.; quad. 

Little Pine Mountain. 

Site 3--Wheeler Gorge Campground, north fork Matilija

River, riparian zone. Typical worm-worked A horizon, no 

fungal mycelia in oak litter, mollic epipedon, loam, slightly 

moist, casting evident throughout A horizon and on surface. 

Primarily a Quercus agrifolia overstory, scattered Platanus 

racemosa. Soil probably Mollisols; elev. 616 m; aspect NA; ° slope NA; precip. 760 mm; lat. 34°31'09" N.; long. 119 16'26" 

W.; quad. Wheeler Springs. 

Site 4--Santa Ynez Recreation Area, first major side drainage west of Santa Ynez campground on Forest Service Rd. 

5N18. Mucky, gravelly sands in creek bottom. Soil alluvial 

sands; elev. 323 m; aspect N.; slope NA; precip. 685 mm; lat. 

34°32'14" N.; long. 119°44'47" W.; quad. Little Pine Mountain. 

Site 5--Hwy. 33, near marker 41.50, just south of Forest 

Service Rd. 6N06, in Quercus agrifolia grove next to highway. 

Moist, fine sandy loam; litter 6-14 cm. Single specimen also 

collected from adjacent field of Artemisia tridentata, fragmented shallow litter, ochric epipedon. Soil coarse-loamy, mixed, 

mesic Pachic Haploxerolls; elev. 1502 m; aspect N.; slope 7 

pct; precip. 508 mm; lat. 34°38'54" N.; long. 119°22'40" W.; 

quad. Rancho Nuevo Creek. 

Site 6--Sespe River, Hwy. 33. Specimens from an otherwise "sterile" riverbed in moist sands under 2-3 cm Salix sp. 

litter. Soil alluvial sands; elev. 1037 m; aspect NA; slope NA; 

precip. 635 mm; lat. 34°33'47" N.; long. 119°15'48" W.; quad. 

Wheeler Springs. 

Site 7--Wheeler Gorge Campground, north fork Matilija 

River. Riverbed saturated sands and muck; overstory Alnus sp. 

and Populus sp. Soil alluvial sands; elev. 616 m; aspect NA; 

slope NA; precip. 760 mm; lat. 34°31'09" N.; long. 119°16'26" 

W.; quad. Wheeler Springs. 

Point Mugu State Park 

Species Site 

Aporrectodea caliginosa ............................8 

Argilophilus papillifer ................................9 

Argilophilus sp ............................................10 

Argilophilus sp. (juvenile) ..........................11, 12 

Eisenia rosea ..............................................8, 9, 11, 13, 

14,15 

Lumbricidae (juveniles) ...............................16 

Microscolex dubius ....................................8, 9, 12, 14 

Site 8--Wood Canyon/Campground. Overstory Quercus 

agrifolia, mixed grasses and Toxicodendron diversilobum understory. Dry to moist, surface loam, rocky and cobbly, wormworked mollic epipedons under oak litter, otherwise ochric, 

depths quite variable. Soil fine-loamy, mixed, thermic Calcic 

Haploxerolls; elev. 55 m; aspect NE.; slope 1 pct; precip. 330 

mm; lat. 34°08'57" N.; long. 119°57'41" W.; quad. Point Mugu.

Site 9--La Jolla Valley. Native grassland, primarily Stipa 

pulchra, some unidentified exotic grasses. Surface dry, moist to 

slightly moist below surface, light gray, heavy clay, sticky, 

USDA Forest Service Gen. Tech. Rep. PSW-GTR-142. 1993. 13 
some surface cracking. Soil fine, montmorillonitic, thermic 

Chromic Pelloxererts; elev. 244 m; aspect SW.; slope <2 pct;

precip. 330 mm; lat. 34°06'20" N.; long. 119°03'18" W.; quad.

Point Mugu. 

Site 10--Chaparral slope adjacent and west of La Jolla 

Valley (site 9). Mixed chaparral vegetation of Salvia mellifera,

Salvia sp., Rhus sp. plus unidentified others. Dry to slightly

moist below surface, mainly ochric but some inclusions of

mollic epipedons, loam to clay loam surface, sticky. Soil fine,

montmorillonitic, thermic Typic Argixerolls; elev. 259 m; as­-

pect E.; slope 8 pct; precip. 330 mm; lat. 34°06'04" N.; long.

119°03'25" W.; quad. Point Mugu. 

Site 11--Ridge just east of La Jolla Valley (site 9). Mixed 

chaparral and grassland; Stipa pulchra and other unknown 

grasses, Rhus sp., Salvia sp., and other unidentified shrub species. Soil moist to dry, some cobbles, ochric epipedon, vertisollike. Soil fine, montmorillonitic, thermic Abruptic Palexerolls; 

elev. 250 m; aspect NW.; slope 3 pct; precip. 330 mm; lat. 34° 

06'21" N.; long. 119°02'36" W.; quad. Point Mugu. 

Site 12--Last grassland-chaparral interface on road heading 

east from La Jolla Valley (site 9). Mixed grasses including 

Stipa pulchra and others; Rhus sp., Salvia sp. plus other shrubs. 

Soil moisture spotty, dry to slightly moist; dark gray to brown 

heavy clay, vertisol-like. Soil fine, montmorillonitic, thermic 

Abruptic Palexerolls; elev. 237 m; aspect NW.; slope 5 pct; 

precip. 330 mm; lat. 34°06'32" N.; long. 119°01'55" W.; quad. 

Point Mugu. 

Site 13--Drainage cutting southwest through La Jolla Valley grassland (site 9), riparian zone. Under Quercus agrifolia; 

10 cm litter, no fungal mycelia. Moist to very moist, mollic 

epipedon, vertisol-like. Soil fine, montmorillonitic, thermic 

Chromic Pelloxererts; elev. 236 m; aspect W.; slope 5 pct; 

precip. 330 mm; lat. 34°06'13" N.; long. 119°02'36" W.; quad. 

Point Mugu. 

Site 14--Sycamore Valley, about 200 meters west of barn 

just off main road. Mixed grasses of unidentified species, scattered large Platanus racemosa. Deep (>30 cm) sandy loam, 

moist to dry, few rocks. Soil fine-loamy, mixed, thermic Fluventic 

Haploxerolls; elev. 256 m; aspect NW.; slope 1 pct; precip. 558 

mm; lat. 34°08'57" N.; long. 119°57'41" W.; quad. Newbury 

Park. 

Site 15--Chaparral slope adjacent and west of La Jolla 

Valley grassland site (site 9). Mixed chaparral vegetation of

Salvia mellifera, Salvia sp., Rhus sp., plus unidentified others.

Dry to slightly moist below surface, mainly ochric but some

inclusions of mollic epipedons, sticky. Soil fine, montmorillonitic, thermic Typic Argixerolls; elev. 259 m; aspect E.; slope 

8 pct; precip. 330 mm; lat. 34°06'04" N.; long. 119°03'25" W.; 

quad. Point Mugu. 

Site 16--Eastern side of La Jolla Valley Loop Trail, Quercus

agrifolia grove above spring; understory Toxicodendron 

diversilobum. Very slightly moist loam to clay loam, 3-7 cm 

litter depth, shale fragments throughout. Soil fine, montmorillonitic, thermic, Chromic Pelloxerts; elev. 170 m; aspect NW.; 

slope <5 pct; precip. 330 mm; lat. 34°05'55" N.; long. 119°02'20" 

W.; quad. Point Mugu. 

Angeles National Forest 

Arroyo Seco and Mt. Baldy Ranger Districts 

Species Site 

Aporrectodea trapezoides .......................... 17, 18, 19 

Argilophilus 2 (new species)........................ 20, 21, 22, 23 

Dendrobaena rubida .................................. 18, 24 

Eisenia rosea ............................................... 24 

Eiseniella tetraedra .................................... 19 

Lumbricidae (juveniles) ............................... 17 

Microscolex sp............................................. 17, 22 

Octolasion sp .............................................. 17 

Site 17--Glendora Mountain Rd. Close to 9.77-mile post on

firebreak off Forest Service Rd. 1N26. Unidentified grasses. 

Moist, deep (8-22 cm) mollic epipedon. Soil fine, mixed, mesic, Pachic Argixerolls; elev. 750 m; aspect NW.; slope 5 pct; 

precip. 640 mm; lat. 34°10'49" N.; long. 117°50'52" W.; quad. 

Glendora. 

Site 18--Glendora Mountain Road, Fallen Leaf Spring.

Overstory Quercus agrifolia. Creekbed saturated sand and gravel. 

Soil alluvial sands and gravels; elev. 1330 m; aspect N.; slope 

NA; precip. 762 mm; lat. 34°13'02" N.; long. 117°41'50" W.; 

quad. Mt. Baldy. 

Site 19--West Fork San Gabriel River, Forest Service Rd.

2N24, just below Camp Kole, sec. 18, R. 11 W., T. 2 N. 

Overstory Quercus agrifolia, Platanus racemosa, Pseudotsuga 

macrocarpa. Riverbed, saturated sands. Soil alluvial sands; 

elev. 1067 m; aspect N.; slope NA; precip. 762 mm; lat. 34°15'16" 

N.; long. 118°04'13" W.; quad. Chilao Flat. 

Site 20--West Fork San Gabriel River, about 1/2 mile 

northeast of Camp Hi-Hill, around spring on side slope off 

Forest Service Rd. 2N24. Quercus agrifolia overstory. Wet to 

saturated sands with some organics. Soil alluvial sands and 

gravels; elev. 1196 m; aspect S.; slope 20 pct; precip. 762 mm; 

lat. 34°15'27" N.; long. 118°05'00" W.; quad. Chilao Flat. 

Site 21--West Fork San Gabriel River, Forest Service Rd. 

2N24, just below Camp Kole, sec. 18, R. 11 W., T. 2 N. 

Riparian zone streambank and streambed, overstory Quercus 

agrifolia, Platanus racemosa, Pseudotsuga macrocarpa. Riverbed saturated sands and riverbank moist sandy loamy, mollic 

epipedons. Soil alluvial sands and Mollisols; elev. 1067 m; 

aspect N.; slope NA; precip. 762 mm; lat. 34°15'16" N.; long. 

118°04'13" W.; quad. Chilao Flat. 

Site 22--West Fork San Gabriel River, Forest Service Rd. 

2N24, just past first concrete low water road crossing east of 

Valley Forge Campground. Riparian zone, primary overstory 

of Quercus chrysolepis. Moist sandy loam, surface litter continuous, moderately deep. Soil alluvial sand and Mollisols; 

elev. 991 m; aspect NE.; slope NA; precip. 672 mm; lat. 

34°14'55" N.; long. 118°03'47" W.; quad. Mt. Wilson. 

Site 23--Southeast of Newcomb Peak, on Forest Service 

Rd. 2N24, sec. 26, R. 11 W.,T. 2 N. Stand of Quercus chrysolepis 

and dense understory of Toxicodendron diversilobum, scat14 USDA Forest Service Gen. Tech. Rep. PSW-GTR-142. 1993. 
tered Pseudotsuga macrocarpa saplings. Mollic epipedon to 

22 cm, slightly moist, loam, litter depth 12 cm. Soil loamyskeletal, mixed, mesic, Typic Haploxerolls; elev. 1196 m; aspect NE.; slope 8 pct; precip. 762 mm; lat. 34°13'50" N.; long. 

118°00'33" W.; quad. Mt. Wilson. 

Site 24--Chilao Flats, just north of ranger station, Forest 

Service Rd., 3N18. Vegetation type not recorded. Dry gravelly 

loam, litter depth 3-5 cm, mollic epipedon. Soil probably a 

coarse-loamy, mixed, mesic Typic Xerochrepts; elev. 1598 m; 

aspect S.; slope 5 pct; precip. 762 mm; lat. 34°20'05" N.; long. 

118°01'26" W.; quad. Chilao Flat. 

San Dimas Experimental Forest 

Species Site 

Allolobophora chlorotica ............25 

Aporrectodea caliginosa ...............26, 27, 28, 29, 30 

Aporrectodea trapezoides ..............28, 29, 31, 32, 33, 34, 

35, 36, 37 

Aporrectodea tuberculata ..............33 

Argilophilus sp. (juvenile) .............27 

Eiseniella tetraedra .......................34 

Lumbricidae (juveniles) ................29, 30, 32, 33, 34, 35, 

36, 37 

Microscolex sp..............................27, 31, 34, 38, 39, 40 

Ocnerodrilus sp..............................34, 36, 37 

Octolasion cyaneum ......................40 

Site 25--Tanbark Flats, unconfined Quercus dumosa lysimeter. Soil fill material/coarse-loamy, mixed, mesic, Typic 

Xerorthents; elev. 860 m; aspect S.; slope <5 pct; precip. 690 

mm; lat. 34°12'25" N.; long. 117°44'18" W.; quad. Glendora. 

Site 26--Modal soil site "B," through locked gate, first 

finger ridge on left going down to Bell Canyon Dam. Mixed 

chaparral primarily Quercus dumosa and unknown grasses. 

Moist loam to sandy clay loam, mainly ochric but broken and 

scattered mollic/umbric epipedons. Soil loamy, mixed, thermic 

Typic Xerorthents; elev. 793 m; aspect N.; slope 20 pct; precip. 

660 mm; lat. 34°11'45" N.; long. 117°46'46" W.; quad. Glendora. 

Site 27--Tanbark Flats, chaparral slope NE of lysimeter

installation, primarily Quercus dumosa, Adenostoma 

fasciculatum, Ceanothus crassifolius. Litter depth 3-6 cm, moist 

to slightly moist, some mollic but primarily ochric epipedons. 

Soil loamy, mixed, mesic, shallow Typic Xerorthents; elev. 

872 m; aspect SW.; slope 8 pct; precip. 685 mm; lat. 34°12'36" 

N.; long. 1l7°44'15" W.; quad. Glendora. 

Site 28--Tanbark Flats, Quercus dumosa confined lysimeter 20. Soil fill material/coarse-loamy, mixed, mesic Typic 

Xerorthents; elev. 860 m; aspect S.; slope <5 pct; precip. 690 

mm; lat. 34°12'27" N.; long. 117°44'16" W.; quad. Glendora. 

Site 29--Tanbark Flats, Quercus dumosa confined lysimeter 19. Soil fill material/coarse-loamy, mixed, mesic Typic 

Xerorthents; elev. 860 m; aspect S.; slope <5 pct; precip. 690 

mm; lat. 34°12'25" N.; long. 117°44'18" W.; quad. Glendora. 

Site 30--Tanbark Flats, creekbed just northeast of lysimeter 

installation. Quercus agrifolia overstory. Wet decomposed granite with organics. Soil alluvial sands and gravels; elev. 854 m; 

aspect NW.; slope 2 pct; precip. 685 mm; lat. 34°12'31" N.; 

long. 117°44' 18" W.; quad. Glendora. 

Site 31--Spot B. Riparian zone, Quercus agrifolia, Platanus 

racemosa, Umbellularia californica overstory. Stream sides 

and stream bottom, wet to saturated sands and muck. Soil 

alluvial sands and gravels; elev. 778 m; aspect NA; slope NA; 

precip. 762 mm; lat. 34°11'47" N.; long. 117°44'16" W.; quad. 

Mt. Baldy. 

Site 32--Tanbark Flats, adjacent to unconfined Quercus 

dumosa lysimeter. Collections made in both soil and litter. Soil 

fill material/coarse-loamy, mixed, mesic Typic Xerorthents; 

elev. 860 m; aspect S.; slope <5 pct; precip. 690 mm; lat. 

34°12'25" N.; long. 117°44'18" W.; quad. Glendora. 

Site 33--Tanbark Flats, adjacent to pyramid soil storage 

building. Under Quercus agrifolia; side slope, moist sandy 

loam, litter depth 4-9 cm. Soil coarse-loamy, mixed, mesic 

Typic Xerothents; elev. 848 m; aspect NE.; slope 15 pct; 

precip. 690 mm; lat. 34°l2'27" N.; long. 117°44'16" W.; quad. 

Glendora. 

Site 34--Big Dalton Canyon Rd., approximately 500 m 

southwest of Volfe Canyon and gauging station in streambed. 

Vegetation not recorded. Wet coarse sand. Soil alluvial sand; 

elev. 317 m; aspect NW.; slope 2 pct; precip. 635 mm; lat. 

34°10'48" N.; long. 117°47'52" W.; quad. Glendora. 

Site 35--Tanbark Flats, side slopes off creekbed trail just 

northeast of lysimeter installation. Quercus dumosa cover. Sandy 

loam with cobbles, 2-4 cm A horizon. Soil coarse-loamy, mixed, 

mesic Typic Xerorthents; elev. 863 m; aspect S.; slope 25 pct; 

precip. 685 mm; lat. 34°12'33" N.; long. 117°44'16" W.; quad. 

Glendora. 

Site 36--Tanbark Flats, Quercus dumosa confined lysimeter 21. Soil fill material/coarse-loamy, mixed, mesic Typic 

Xerorthents; elev. 860 m; aspect S.; slope <5 pct; precip. 690 

mm; lat. 34°12'25" N.; long. 117°44'18" W.; quad. Glendora. 

Site 37--Tanbark Flats, Bromus mollis and Eriogonum 

fasciculatum unconfined lysimeter. Soil fill material/coarseloamy, mixed, mesic Typic Xerorthents; elev. 860 m; aspect S.; 

slope <5 pct; precip. 690 mm; lat. 34°12'25" N.; long. 117'44'18" 

W.; quad. Glendora. 

Site 38--Hummingbird Creek, just north of Spot B Road. 

Vegetation not recorded. Streambed saturated sands and gravel, 

some muck. Soil alluvial sands and gravels; elev. 808 m; aspect

° S.; slope NA; precip. 762 mm; lat. 34°12'24" N.; long. 117 45'15" 

W.; quad. Glendora. 

Site 39--Waterfall creekbed, second small drainage north 

from Site 31 on Spot B Road. Overstory vegetation not recorded. Creekbed saturated decomposed granite with some 

organics. Soil alluvial sands and gravels; elev. 778 m; aspect 

SW.; slope NA; precip. 762 mm; lat. 34°12'11" N.; long. 

117°44'37" W.; quad. Mt. Baldy. 

Site 40--Big Dalton Canyon Rd., first major cross drainage 

coming from Glendora in northwest corner of sec. 22. Overstory Quercus agrifolia and Umbellularia californica. In 

creekbed, very wet coarse sandy loam. Soil alluvial sands and 

gravels; elev. 427 m; aspect NW.; slope 2 pct; precip. 635 mm; 

lat. 34°09'49" N.; long. 117°47'56" W.; quad. Glendora. 

USDA Forest Service Gen. Tech. Rep. PSW-GTR-142. 1993. 15 
San Bernardino National Forest 

Arrowhead Ranger District 

Species Site 

Aporrectodea caliginosa ............................. 41, 42, 43 

Aporrectodea trapezoides............................ 44 

Aporrectodea sp........................................... 45 

Argilophilus sp............................................. 46, 47 

Site 41--Hwy. 18 gently sloping grass woodland southwest 

of Heaps Peak. Unknown grasses, Polypodium californicum, 

Quercus kelloggii, Pinus coulteri. Moist deep (>30 cm) sandy 

loam, mollic epipedon primarily all cast material. Soil fineloamy, mixed, mesic Mollic Haploxeralfs; elev. 1876 m; aspect 

SW.; slope 5 pct; precip. 889 mm; lat. 34°13'58" N.; long. 

117°08'08" W.; quad. Harrison Mt. 

Site 42--Horseshoe bend in Hwy. 330 at Long Point before 

entering Fredalba. North side of highway in Pinus sp. plantings. 

Deep 5-30 cm mollic epipedon, moist, dark, essentially all cast 

material. Soil fine-loamy, mixed, mesic Mollic Haploxeralfs; 

elev. 1571 m; aspect N.; slope 15 pct; precip. 762 mm; lat. 

34°12'30" N.; long. 117°08'53" W.; quad. Harrison Mt. 

Site 43--Mojave River at entrance to Lake Silverwood off 

Hwy. 138. Overstory riparian vegetation Alnus sp., Quercus 

sp., Platanus racemosa. Riverbottom saturated sands with some 

organics. Soil alluvial sands and gravels; elev. 1092 m; aspect 

W.; slope NA; precip. 635 mm; lat. 34°16'19" N.; long. 117°17'33" 

W.; quad. Silverwood Lake. 

Site 44--City Creek Truck Trail, first creek crossing at 

southern end of Mud Flat, starting from Hwy. 330. Creekbed, 

vegetation not recorded. Saturated coarse sands with some 

surface organics. Soil alluvial sands; elev. 964 m; aspect NA; 

slope NA; precip. 889 mm; lat. 34°12'39" N.; long. 117°12'14" 

W.; quad. Harrison Mt. 

Site 45--Turnout Hwy. 330 near call box 330-346, ridge off 

main highway on old paved road. Chaparral cover of 

Arctostaphylos sp., Salvia mellifera, unknown grasses. Under 

manzanita litter, very slightly moist, coarse sandy loam, ochric 

epipedon. Soil loamy, mixed, nonacid, thermic shallow Typic 

Xerorthents; elev. 897 m; aspect NE.; slope 10 pct; precip. 508 

mm; lat. 34°10'58" N.; long. 117°10'10" W.; quad. Harrison Mt. 

Site 46--Hwy. 138 enroute to Silverwood Lake from 

Crestline, near highway marker 33.93. Mixed conifer-oak-woodland of Quercus kelloggii, Pinus ponderosa, and unidentified 

grasses. Mollic epipedon, moist, cold, dark brown, sandy to 

fine sandy loam. Soil fine-loamy, mixed, mesic, Mollic 

Haploxeralfs; elev. 1388 m; aspect NW.; slope 28 pct; precip. 

762 mm; lat. 34°15'30" N.; long. 117°17'10" W.; quad. Silverwood 

Lake. 

Site 47--Horsehoe bend in Hwy. 330 at Long Point before 

entering Fredalba, southside of highway. Grass woodland of 

unidentified grasses, Pinus coulteri, Polypodium californicum, 

Quercus kelloggii. Moist, mollic epipedons, deep, coarse sandy 

loam; scattered patches of snow. Soil fine-loamy, mixed, mesic 

Mollic Haploxeralfs; elev. 1571 m; aspect N.; slope 20 pct; 

precip. 762 mm; lat. 34°12'30" N.; long. 117°08'53" W.; quad.

Harrison Mt. 

San Bernardino National Forest 

San Jacinto Ranger District 

Species ........................................................... Site 

Aporrectodea caliginosa............................. 48 

Dendrobaena rubida.................................... 48 

Eiseniella tetraedra..................................... 48 

Site 48--James San Jacinto Mountains Reserve (University

of California Natural Reserve System). Indian Creek within 

reserve boundaries; creek area between museum and campground. Overstory Quercus chrysolepsis, Pinus ponderosa, 

Calocedrus decurrens. Creekbed bottom and sides, saturated 

sand and muck. Soil alluvial sands and gravels; elev. 1641 m; 

aspect SW.; slope 3 pct; precip. 635 mm; lat. 33°48'42" N.; 

long. 116°46'22" W.; quad. Lake Fulmor. 

Santa Rosa Plateau Preserve 

Species Site 

Allolobophora chlorotica ...........................49 

Aporrectodea trapezoides.............................49 

Diplocardia CA1 ........................................50 

Diplocardia CA2 .......................................51 

Eisenia rosea.................................................52 

Eiseniella tetraedra ......................................49 

Lumbricidae (juvenile) .................................49, 52 

Ocnerodrilus sp ............................................49 

Site 49--Tenaja between Clinton Keith Rd. and Sycamore 

Trail. Riparian overstory of Salix sp., Quercus agrifolia, Platanus 

racemosa. Creekbed and tenaja, saturated sands and mucks, 

large granitic boulders. Soil alluvial sands; elev. 534 m; aspect 

SW.; slope <3 pct; precip. 406 mm; lat. 33°31'54" N.; long. 

117°16'12" W.; quad. Wildomar. 

Site 50--Mesa de Colorado, southwest outer fringe of vernal pool/plateau. Mixed unidentified grasses, Lupinus sp., Juncus 

sp., Ranunculus californicus, plus others. Red-brown silty clay 

loam, moist to wet, slightly sticky; single granule cast material 

1-8 cm deep. Soil loam, fine, montmorillonitic, thermic, Typic 

Rhodoxeralfs; elev. 595 m; aspect SW.; slope 2 pct; precip. 406 

mm; lat. 33°30'28" N.; long. 117°17'30" W.; quad. Wildomar. 

Site 51--Southwest chaparral rim of Mesa de Burro and 

southwest chaparral side slope. Mixed chaparral of Salvia 

mellifera, Quercus dumosa, Adenostoma fasciculatum, Quercus 

engelmannii. Litter depths 2-5 cm, cast material 5-10 cm in 

umbric/mollic A horizon; slightly moist clay loam on plateau to 

fairly heavy clay to loam near bottom. Soil top--stony clay 

loam, clayey, montmorillonitic, thermic, Lithic Haploxeralfs; 

bottom--loam, fine, montmorillonitic, thermic, Typic 

Rhodoxeralfs; elev. 594 m; aspect SW.; slope 5-25 pct; precip. 

410 mm; lat. 33°31'35" N.; long. 117°14'28" W.; quad. Murrieta. 

16 USDA Forest Service Gen. Tech. Rep. PSW-GTR-142. 1993.
Site 52--Ranch Rd. heading northeast from Preserve main 

gate. Collections made on an approximately 200-meter line 

transect between zones of introduced grasses (Bromus mollis, 

Avena barbata) and native grass (Stipa pulchra). Slightly moist, 

clay loam, ochric epipedon, surface castings very evident. Soil 

fine-loamy, mixed, thermic, Typic Haploxeralfs; elev. 549 m; 

aspect S.; slope 2 pct; precip. 406 mm; lat. 33°31'49" N.; long. 

117°16'00" W.; quad. Wildomar. 

Cleveland National Forest 

Trabuco Ranger District 

Species Site 

Aporrectodea caliginosa ............................ 53 

Aporrectodea trapezoides ......................... 53,54 

Argilophilus sp............................................ 55 

Diplocardia CA1 ....................................... 53, 54, 55 

Eisenia rosea ............................................. 53, 54 

Microscolex dubius ................................... 55 

Ocnerodrilus sp .......................................... 56 

Site 53--Falcon Campground area, Forest Service Rd. 6S05. 

Grass woodland; grasses unidentified, Quercus agrifolia. Slightly 

moist to dry, clay loams to gravelly and sandy clay loams, 

generally ochric surfaces, some compacted areas. Soil coarseloamy, mixed, thermic Typic Xerochrepts; elev. 1007 m; aspect W.; slope 5 pct; precip. 508 mm; lat. 33°39'30" N.; long. 

117°26'44" W.; quad. Alberhill. 

Site 54--In general proximity of Tenaja Campground and 

Forest Service Rds. 7S01 and 7SO4. Approximately 500 ha of 

grass-woodland-chaparral, seasonally grazed; 90 percent of 

area in unidentified grasses and forbs, scattered Quercus agrifolia, 

Quercus dumosa, Adenostoma fasciculatum. Deep (>25 cm), 

moist sandy loam, generally ochric epipedons but some umbric/ 

mollic epipedons in a few locations. Soil fine-loamy, mixed, 

thermic Typic Haploxeralfs; elev. 595 m; aspect W.; slope 2 

pct; precip. 406 mm; lat. 33°31'03" N.; long. 117°22'22" W.; 

quad. Wildomar. 

Site 55--Long Canyon, at intersection of Hwy. 74 and 

Forest Service Rd. 6S05. Grass-oak woodland, species not 

identified. Very deep (>75 cm), fine sandy loam, dry under 

grassland, slightly moist under oak litter; traces of surface 

casting in grassland. Soil loamy, mixed, thermic Pachic 

Haploxerolls; elev. 726 m; aspect SE.; slope 2 pct; precip. 457 

mm; lat. 33°38'15" N.; long. 117°25'25" W.; quad. Alberhill. 

Site 56--San Juan Creek, Lower San Juan Picnic Area, 

Hwy. 74. Riparian overstory vegetation Quercus sp. and Alnus 

sp. Creekbed saturated sands and muck. Soil alluvial sands and 

muck; elev. 381 m; aspect SW.; slope 1 pct; precip. 381 mm; 

lat. 33°35'54" N.; long. 117°27'39" W.; quad. Sitton Peak. 

Santa Margarita Ecological Reserve 

Species Site 

Allolobophora chlorotica ........................... 57, 58 

Aporrectodea trapezoides ......................... 59 

Lumbricidae (juvenile) ................................ 57 

Ocnerodrilus 1 ........................................... 57 

Ocnerodrilus 3 ........................................... 60 

Ocnerodrilus sp .......................................... 61 

Sparganophilus 1 (new species) ................ 61 

Site 57--Temecula Canyon, Santa Margarita River crossing, southwest along river from Reserve road. Overstory riparian vegetation not recorded. Riverbottom saturated medium to 

fine sands, some banding of muck. Soil alluvial sands and 

muck; elev. 236 m; aspect NE.; slope <5 pct; precip. 279 mm; 

lat. 33°26'52" N.; long. 117°08'22" W.; quad. Temecula. 

Site 58--Temecula Canyon, Santa Margarita River crossing, southwest along river from Reserve road, northwest side of 

river in riparian area. Vegetation primarily Salix lasiolepis. 

Moist medium sand under 1-7 cm of undecomposed willow 

leaf litter. Soil alluvial sands; elev. 236 m; aspect SE.; slope <5 

pct; precip. 279 mm; lat. 33°26'52" N.; long. 117°08'22" W.; 

quad. Temecula. 

Site 59--Approximately 500 m northeast along road from 

southwest Reserve gate in northeast corner of sec. 4, T. 9 S., R. 

3 W. Quercus agrifolia woodland, Toxicodendron diversilobum 

understory. Slightly moist loam to fine sandy loam, litter depth 

3-13 cm, mollic epipedon. Soil loamy, mixed, non-acid, thermic, Typic Xerorthents; elev. 159 m; aspect N.; slope 5 pct; 

precip. 279 mm; lat. 33°25'48" N.; long. 117°11'00" W.; quad. 

Temecula. 

Site 60--Just outside main entrance to Santa Margarita 

Ecological Reserve where "spring" creek crosses paved road. 

Overstory riparian vegetation primarily Quercus sp., collections in creekbed. Saturated sand and muck. Soil alluvial sands 

and muck; elev. 351 m; aspect NE.; slope <5 pct; precip. 279 

mm; lat. 33°27'56" N.; long. 117°10'12" W.; quad. Temecula. 

Site 61--Temecula Canyon, Santa Margarita River crossing, southwest along river from Reserve road. Collections from 

exposed rock outcrops midstream; vegetation includes tule 

(Scirpus olney), cat-tail (Typha domingensis), bur-reed 

(Sparganium eurycarpum), yerba mansa (Anemopsis californica). 

Saturated fibrous mats and mucks with traces of sand, 1-8 cm 

deep, hydrogen sulfide odor, on granite boulder substrates. Soil 

muck--Histosols; elev. 236 m; aspect NA; slope NA; precip. 

279 mm; lat. 33°26'52" N.; long. 117°08'22" W.; quad. Temecula. 

Cleveland National Forest 

Palomar Ranger District 

Species Site 

Aporrectodea caliginosa ........................... 62 

Aporrectodea trapezoides ......................... 63, 64 

Diplocardia CA1 ....................................... 63, 65 

Eisenia rosea ............................................. 63, 64 

USDA Forest Service Gen. Tech. Rep. PSW-GTR-142. 1993. 17 
Site 62--Creekbed adjacent to Mount Palomar Hwy. west 

of Jeff Valley, in southeast comer of sec. 14, T. 10 S., R. 1 E. 

Mixed conifer/hardwood overstory of Pinus ponderosa, Abies 

concolor, Quercus sp. and a Toxicodendron diversilobum understory. Saturated decomposed granite and muck. Soil alluvial 

sands and gravels; elev. 1562 m; aspect SW.; slope 15 pct; 

precip. 584 mm; lat. 33°18'08" N.; long. 116°51'45" W.; quad. 

Palomar Observatory. 

Site 63--Love Valley, southeast border large grazed grassland with watering pond. Mixed grasses and forbes of unknown 

species. Moist, mollic or umbric surface to 20 cm, sandy loam 

to sandy clay loam, fine granular surface structure. Soil loamy, 

mixed, mesic Ultic Haploxerolls; elev. 1024 m; aspect NW.; 

slope 5 pct; precip. 558 mm; lat. 33°15'10" N.; long. 116°46'17" 

W., quad. Palomar Observatory. 

Site 64--Love Valley, southeast edge of watering pond. 

Cattle grazed rangeland, mixed grasses and forbs of unknown 

species. Moist, clay loam to sandy clay loam, sticky, ochric 

epipedon. Soil loamy alluvium; elev. 1024 m; aspect NW.; 

slope 5 pct; precip. 558 mm; lat. 33°15'10" N.; long. 116°46'24" 

W.; quad. Palomar Observatory. 

Site 65--Just below Mount Palomar Observatory a few 

meters off main highway adjacent to Upper French Valley gate 

entrance. A grassland of unidentified species and dead bracken 

fern (Polypodium californicum), a few scattered Pinus ponderosa and Calocedrus decurrens. Moist, surface ochric/umbric 

to 20 cm, sandy loam, unusually warm. Soil coarse-loamy, 

mixed, mesic, Ultic Haploxerolls; elev. 1623 m; aspect W.; 

slope 5 pct; precip. 609 mm; lat. 33°21'10" N.; long. 116°52'14" 

W.; quad. Palomar Observatory. 

18 USDA Forest Service Gen. Tech. Rep. PSW-GTR-142. 1993. 
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USDA Forest Service Gen. Tech. Rep. PSW-GTR-142. 1993. 
The Forest Service, U.S. Department of Agriculture, is responsible for Federal leadership in forestry. 

It carries out this role through four main activities: 

• Protection and management of resources on 191 million acres of National Forest System lands 

• Cooperation with State and local governments, forest industries, and private landowners to help 

protect and manage non-Federal forest and associated range and watershed lands 

• Participation with other agencies in human resource and community assistance programs to 

improve living conditions in rural areas 

• Research on all aspects of forestry, rangeland management, and forest resources utilization. 

The Pacific Southwest Research Station 

• Represents the research branch of the Forest Service in California, Hawaii, American Samoa 

and the western Pacific. 

Persons of any race, color, national origin, sex, age, religion, or 

with any handicapping conditions are welcome to use and enjoy 

all facilities, programs, and services of the U.S. Department of 

Agriculture. Discrimination in any form is strictly against agency

policy, and should be reported to the Secretary of Agriculture, 

Washington, DC 20250. 
Forest Service Native and Introduced Earthworms from Selected Chaparral, 

Pacific Southwest Woodland, and Riparian Zones in Southern California Research Station General Technical Report 

PSW-GTR-142