The Author 

William B. Leak is principal silviculturist for the Northeastern Forest 

Experiment Station, USDA Forest ServiceyForestry Sciences Laboratory at 

Durham, New Hampshire. 

Manuscript received for publication 25 April 1981 

Abstract 

Recommendations are gi*n on the classification of forest land in New 

England on the basis of physiographic region, climate (elevation, latitude), 

mineralogy, and habitat. A habitat map for the Bartlett Experimental Forest 

in New Hampshire is presented based on land form, vegetation, and soil 

materials. For each habitat or group of habitats, data are presented on 

stand composition, understory vegetation, biomass, volume, and diameter 

development by species. - -- 
In this paper I describe 

methodology and approaches for 

the classification and mapping of 

forest habitats in New England. " 

Then, I give an example of habitat 

mapping on the Bartlett Experimental Forest in central New Hampshire with interpretations on 

species composition, productivity, 

and silvicultural approaches. 

Classification Approaches 

Many fobst land-classification 

systems have been described for 

the United States and Canada, and 

other parts of the world. Bailey and 

others (1978) emphasize the distinction between taxonomic pr placeindependent classifications and 

place-dependent classifications. 

Taxonomic classifications are systems for grouping objects into 

homogeneous classes without regard for their geographic affinities. 

Place-dependent classifications are 

designed to subdivide existing landscapes into homogeneous geographic units. These systems are 

designed to segregate forest land 

into parcels with distinct characteristics or use potentials. I'll discuss 

four different approaches to classifying forest land: 

1. Biological 

2. Physicallchemical 

3. Production-oriented 

4. Biophysical 

Biological approaches emphasize natural associations of flora or 

fauna. Typical examples are the 

habitat types of Pfister and Arno 

(1980) or Daubenmire (1952) and the 

ground vegetation types of Westveld (1951). Maps of major forest regions and cover types (Society of 

American Foresters 1980) also fall 

within this category. The biological 

approach to forest land classification employs the concept that natural associations of plants or animals reflect or integrate the important factors that affect forest use 

and production. 

Physicallc hemical approaches 

depend upon the classification of 

nonliving factors of the environment. Soil classifications are taxonomic systems falling within this 

category. Approaches based primarily upon elevation (Bormann et al. 

1970) or landform are integrated 

(taxonomic and place-dependent) 

systems of the physicallchemical 

type. This approach assumes that 

nonliving factors influencing forest 

use and protection can be determined, measured, and mapped. The 

approach does not depend upon the 

availability of suitable, existing 

vegetation-an advantage in heavily 

disturbed areas. 

Production-oriented approaches 

are taxonomic systems that relate 

directly to the land's capacity to 

produce certain products. These are 

sometimes referred to as technical 

or artificial classifications (Bailey et 

al. 1978). Classifications of areas by 

average site index, merchantable 

height, or volume are examples of 

the production-oriented approach. 

Within this category I also include 

methods based on indirect estimates of productivity, for example, 

regression equations that predict 

site index. Production-oriented approaches often are closely related 

to the interests and needs of practicing foresters. 

Biophysical approaches are integrated systems where the units 

are classified by both biological and 

physicallc hemical criteria. The holistic system of Hills (1953) is a pioneering example. The habitat types 

described by Mueller-Dombois 

(1965) on the basis of tree-shrub 

vegetation, soils, and glacial deposit 

also typify the biophysical approach. The approach is based upon 

the concept that biological and 

physicallchemical conditions can be 

correlated on the ground so that all 

criteria will share common boundaries. If this can be done successfully, biophysical schemes provide a 

fairly broad base for evaluating resource use and protection. 

Forest land systems are classified in other ways as well. Many 

systems are hierarchical to some 

degree. This means that they allow 

for the definition of large, general 

units useful for broad planning purposes as well as smaller, more 

homogeneous subdivisions useful 

for conducting project work. Some 

systems are based on single factors; others are multifactor classif ications (Bailey et al. 1978). Within 

the multifactor category, some factors may be considered as criteria 

necessary for the classification of 

units, and others may be given less 

weight as associated characteristics. 

The habitat classification described in this paper is a biophysical scheme. Vegetation within New 

England varies, first of all, because 

of climate; we see obvious differences in species mixes in northern 

and southern New England, along 

the seacoast, in the high elevation 

zones, and so on. Next, we find differences in vegetation because of 

the mineralogy of the glacial drift: 

granite versus schist versus limestone, for example. Finally, within 

areas of similar climate and mineralogy, vegetation varies between habitats defined primarily by parent soil 

materials or glacial process. 

So a habitat is a small unit of 

land from a few to over 100 acres lying within a given climaticmineralogical zone and supporting a 

distinct successional sequence of 

vegetation growing on a unique type 

of soil material. Habitats also are 

associated with certain landforms, 

surface conditions, and types of 

ground flora; these characteristics 

are useful in mapping. Habitats, 

thus defined, reflect productivity in 

terms of species combinations and 

growth rates, as well as certain 

management limitations such as 

windthrow and machine operability. 

Diagramatically, the system may be 

represented as: 

Climatic regions (geographic su bdivision) 

i 

Mineralogy (taxonomic subdivision) 

i 

Habitats (taxonomic sites having 

characteristic soils, landforms 

and chronosequences of vegetation) 
Climati~~mineralogicai Zones Physiographic Regions 

A detailed classification of the 

important climatic-mineralogical 

zones in New England and adjacent 

states is impossible at this time. 

However, available information indicates that the region might be subdivided on the basis of physiographic zones, elevation, latitude, and 

broad mineralogical classes. 

Lull (1968) published physioiraphic regions (Fig. 1) adapted 

from Fenneman (1938) for New England and adjacent states. These 

physiographic regions are based on 

broad differences in relief or geomorphology, climate, and proximity 

to water bodies and, thus, represent 

a reasonable starting point for 

segregating and studying the forest 

vegetation. These physiographic regions correlate to some extent with 

the major forest regions (Fig. 2) published by Lull (1968). But the correlations are limited because most of 

the physiographic regions cover a 

broad range in elevation or latitude, 

or both, and should be subdivided 

by these two variables. 

Figure 1.-Physiographic regions in the Northeast (Lull 1968). 
Elevation 

In the mountainous physio- . graphic regions such as the White 

Mountains, Green Mountains, and 

Adirondacks there is a wellrecognized change from hardwood 

to spruce-fir types above an elevation of 2,500 to 2,700 feet (Siccama 

1974, Leak and Graber 1974). If we 

superimpose this elevational effect 

on the Green Mountain, Adirondack, 

and the southern part of the White 

Mountain physiographic regions, it 

will account for spruce-fir on Lull's 

map of the major forest regions 

(Fig. 2). 

% 

Major Forest Regions 

The influence of elevation is 

tempered to some extent by aspect: 

spruce-fir types tend to grow at 

lower elevations on colder aspects 

and higher elevations on warmer aspects. However, this pattern is often 

upset by habitat condition. For example, the spruce-fir cap on the 

south side of Mt. Chocorua in New 

Hampshire begins at 1,800 feet; this 

is because of habitat condition 

(shallow bedrock) rather than climatic effect. 

Aspect has some additional effects on species mixes. On dry habitats such as shallow bedrock or outwash, oak tends to grow on southerly or westerly aspects in northern 

New England. And hemlock tends to 

predominate over red spruce as the 

aspect gets warmer (Leak 1976). 

However, I do not regard aspect as 

a major factor in classifying forest 

land because its effects are easily 

overshadowed by the habitat conditions discussed later, and because 

it is responsible for fairly minor 

shifts in the abundance of certain 

species near the limits of their 

range. 

Spruce - Fir 

. -- 

Beech - Birch - Maple 

Figure 2.-Major forest regions in the Northeast (Lull 1968). 
There is some evidence that as 

elevation decreases there are increases in productivity and volume 

(Bormann et al. 1970), the proportion 

of beech (Leak and Graber 1974), 

and the ratio of hemlock to red 

spruce (Leak 1976). However, in 

classifying forest land in New England, the major distinction is between stands above and below 2,500 

feet. 

Latitude pr 

Some of the physiographic regions outlined by Lull (Fig. 1) span 

several (up to 7) degrees latitude. A 

comparison with Lull's map of forest regions (Fig. 2) indicates that 

some of the larger physiographic regions extend across two or three 

forest regions. For example, the 

New England seaboard is spruce-fir 

in the northern part and white pine 

(with hemlock and hardwoods) in 

the southern part. The White Mountain physiographic region is sprucefir in the north and partly northern 

hardwoods in the south. Although 

these differences may be partly due 

to mineralogy and the prevailing 

types of glacial deposit, we also see 

evidence of a climatic effect related 

to latitude. Differences in latitude of 

about 1" seem important. This 

means that stands growing on a 

given mineralogy and soil material 

in a given physiographic region will 

be different in species composition 

and productivity if they differ in 

position by 1 " latitude. For forest 

land classification purposes, we 

should divide physiographic regions 

into zones that extend no further 

than 1" latitude: for example, the 

northern and southern New England 

seacoast in Maine. 

Mineralogy 

We have known for some time 

that distinct differences in mineralogy affect species and productivity 

(Lutz 1958). Some scientists believe 

that in glaciated regions such as 

New England the influence of bedrock mineralogy is lost by thorough 

mixing of the glacial drift. However, 

Goldthwaite (1948) mapped the 

glacial drift in New Hampshire into 

three basic types derived from granite, slaty schist, and crystalline 

qchist (Fig. 3). This was possible because most drift is moved by the 

glacier only a few miles from its 

source, though occasionally 

boulders move many miles. The distinctions among these mineralogies 

are reflected by differences in general soil texture, rock types, 

abundance of mica in the soil, and 

forest vegetation (Leak 1978b). Thus, 

mineralogy of the drift provides a 

further breakdown that should be 

recognized in any biophysical classification of forest land in New England. 

Climatic~mineralogical Zones Summarized 

In studying, classifying, or comparing forest vegetation in New England, account for the influence of 

climate and mineralogy. One likely 

approach is to begin with large 

physiographic regions (Fig. 1). The 

physiographic regions should be 

divided into subregions that extend 

no more than 1" latitude. Distinguish between areas above and below the critical elevational level, 

which is about 2,500 feet. Finally, 

distinguish broad mineralogical 

classes. These subdivisions result 

in zones that might include several 

hundred thousand contiguous or 

noncontinguous acres which is 

about the size of the zone that we 

discuss: granitic drift below an elevation of 2,500 feet in the southern 

half of the White Mountains. Much 

smaller units than these are required in planning and conducting 

forestry operations. The definition 

and mapping of these smaller units, 

called habitats, are discussed in the 

remainder of the paper. 

Habitats 

A habitat is a smatl unit of land, 

from a few acres up to a few 

hundred acres in size, with a given 

type of soil material (reflecting a 

given glacial process), landform and 

surface condition, and forest vegetation (climax-successional sequence). These are defined within 

given climatic-mineralogical zones 

because a certain soil material-for 

example, wet compact till-will support different vegetation in different 

climatic-mineralogical zones. 

Habitats can be defined broadly 

or narrowly. For general planning 

purposes, habitats can be defined 

on the basis of soil substrate to a 

depth of 10 to 15 feet, general iandform as interpreted from aerial 

photographs, and climax forest association. These broad units correspond to the ecological land types 

(ELT) being mapped on the White 

and Green Mountain National Forests. 

In this paper, however, habitats 

are defined more narrowly on the 

basis of soil materials to a depth of 

2 to 4 feet, landform plus surface 

conditions, and climax plus successional vegetation. I consider soil 

material to be the major variable: 

through its physical and chemical 

properties, soil material has a direct 

cause and effect on the nature and 

productivity of the vegetation. In 

classifying habitats, the soil materials at the base of the B horizon are 

examined to assess the original 

nature of the parent material; the 

objective is to determine what materials gave rise to the solum (surface and subsoil horizons). Materials 

within the solum are examined only 

to confirm the conclusions drawn 

from C-horizons materials. However, 

in two cases (enriched and poorly 

drained habitats), organic matter or 

excess water in the solum overrides 

the influence of C-horizon materials. 

Early research leading to this 

habitat taxonomic classification was 

directed toward understanding the 

relation of soil materials to species 

composition and productivity of the 

vegetation (Leak 1976, 1978a). On 

the basis of this early research, 

which included 68 plots in old 

stands and 151 plots in successional stands on granitic drift, correlations between soil materials, 

species, and landformlsurface conditions were developed. Currently, 

in mapping the taxonomic units, 

vegetation and landformlsurface 

conditions are most useful because 
they can be readily observed. Occasional checks on soil materials are 

made to confirm the designations. 

The goal is to obtain compatible 

and consistent relationships and 

common boundaries among all 

these variables. 

A description is given for all 

habitats now recognized in the 

granitic drift below an elevation of 

2,500 feet on the southern White 

Mountains. The descriptions are 

numbered according to the map 

designations used throughout this 

paper. The types of soil materials 

and landformlsurface conditions will 

be found in most all glaciated regions, though it is possible that 

some additional classes would be 

required to meet local conditions. 

However, the associated vegetation 

will vary considerably depending 

upon climate and mineralogy. For 

example, the sirccessional and 

climax vegetation found on granitic 

drift in the southern White Mountains of New Hampshire (Fig. 4) differs appreciably from the vegetation 

on schistose drift only a few miles 

away at the same latitude (Leak 

197813). The schistose drift supports 

noticeably more sugar maple and 

less beech in most habi4ats. 

Habitat Descriptions (Taxonomy) 

1. Poorly drained-This area is 

level with gray or heavily mottled mineral soil throughout 

the solum. Currently there are 

pools of standing water or 

free water in the upper Solum. 

The climax is red spruce 

greater than hemlock. Successional stands are generally 

softwood greater than hardwood mixtures of red spruce, 

eastern hemlock, balsam fir, 

red maple, and birches (paper 

and yellow). Areas that have 

been cleared or repeatedly cut 

may be mostly red maple. 

Areas that are wet enough to 

preclude full occupancy to 

trees are better classed as 

wetlands. 

Figure 3.-Mineralogy of glacial drift in New Hampshire, adapted from 

Goldthwaite (1948). Successional stands result 

from clearcutting or heavy 
Poorly 

10 

a, 

0 Outwash 1-1 ~~1 lo t f I I & i 

Wet 

compact 

- Dry 

compact 1 , - till 

Silty 2 

sediments 

Sandy 21 - sediments I-- 

Washed 

-finetill -1 

- Coarse till 

,. Fine till 

- Enriched - - 

Figure 4.-Basal area in rn21ha by species and habitat for successional 

stands on granitic drift in the southern White Mountains of New Hampshire. Number 1 refers to the most abundant and number 2 refers to the 

second most abundant species in older, climax stands. 
partial cutting. Climax stands 

are defined as those stands 

composed primarily of 

tolerant species with the * 

understory of similar species 

composition as the overstory. 

Shallow bedrock- Bed rock, 

angular boulders, or nearly 

pure grus (weathered granite) 

is found as deep as 2 feet (65 

cm) below the surface of the 

mineral soil. This area was 

plucked and scoured by the 

glacier, and may be on steep 

or moderate slopes. Ledges 

and rectangular boulders (not 

glacially worn) often are evident. Red spruce greater than 

hemlock is c~imak. Successional stands commonly have 

softwood greater than or 

equal to hardwood mixtures 

of red spruce, hemlock, red 

maple, and birches. On southern exposures, oak. is, often 

noticeably present; sometimes hophornbeam and white 

pine as well. 

2A. Shallow loose rock-A matrix 

of partly rounded boulders is 

found up to 2 feet below the 

surface of the mineral soil. 

This condition apparently results from heavy rinsing action along streams or lakeshores. In some cases, the 

loose rock is sharp angled; 

apparently, this is colluvium 

for upslope. This habitat occurs on moderate to flat 

slopes often associated with 

drainage ways, or at the base 

of rocky slopes. The species 

are similar to those in 2, but 

productivity and the proportion of hardwoods are generally higher. 

28. Exposed ledge-In this area 

shallow bedrock and expanses of exposed ledge are 

very evident, resulting in 

scattered openings in the tree 

canopy. This area may have 

originated the same as shailow bedrock (2) and was followed by fire and erosion that 

exposed areas of ledge. The 

species are similar to those in 

2, but stocking and productivity are lower. 

Outwash-This habitat consists of sands or gravels that 

have been stratified, at least 

to some extent, and deposited 

by moving water. This definition includes both true outwash and ice-contact 

materials. Stones at the base 

of the B horizon are generally 

clean without silt caps. Outwash areas are flat to gently 

rolling or hummocky, free of 

surface rocks, and associated 

with streams or old drainage 

ways. The climax vegetation 

is red spruce greater than 

hemlock. Successional stands 

are softwood greater than or 

equal to hardwood mixtures 

of red spruce, hemlock, white 

pine, balsam fir, red maple 

and birches (especially paper 

birch). White pine is very characteristic of this habitat. 

4. Wet compact till- Platy basal 

till compacted by the glacier 

is found at the base of the 8 

horizon, and mottling or free 

water is very evident in the B 

horizon. This habitat is flat or 

concave and gently sloping 

, with boulders pressed into 

the surface. The climax is 

eastern hemlock greater than 

red spruce. Successional 

stands are softwood greater 

than or equal to hardwood 

mixtures of hemlock, red 

spruce, red maple, and 

birches. Some ash is present 

but is moderate to low quality 

5. Dry compact till-This is 

basal till compacted by the 

glacier, but contains very little 

evidence of mottling or free 

water in the B horizon. C-horizon material usually is mottled and obviously supports 

water. This habitat is found 

on moderate upper slopes and 

knolls, usually above areas of 

wet compact till. The climax 

is hemlock greater than red 

spruce. Successional stands 

are hardwood greater than 

softwood mixtures of red 

maple, birches, beech, hemlock, and red spruce. Successional stands on this habitat 

contain noticeably more hardwoods than those on wet 

compact till (4). 

5A. Dry cemented till- Hard crisp 

till is evident at the base of 

the 6 horizon. There is little 

or no evidence of free water 

or water-caused mottling. The 

habitat is found on low ridges 

or undulating topography but 

is not very common or widespread. The origin of this material is somewhat uncertain, 

but it seems to be cemented 

into a somewhat porous platy 

mass. The vegetation is similar to that in 5. 

6. Silty sediment-This is very 

uniform (poorly graded) silt 

and fine sand deposited in 

slack water; up to 80 percent 

by weight is silt or finer particles. This material is somewhat sticky and massive and 

sometimes displays impeded 

drainage. Coarse fragments 

and stones are sometimes 

present, but lie within a 

matrix of sediments. The topography is level to gently 

sloping with mostly rock-free 

surfaces. The climax is eastern hemlock greater than red 

spruce. Successional stands 

are hardwood greater than 

softwood mixtures of red 

maple, birches, beech, hemlock, and red spruce; sometimes the softwoods are barely evident. 
Figure 5.-A red maplelbeechlpaper birchlaspen stand growing on sandy 

sediments. Climax is hemlocklspruce, though few softwoods are evident 

in this successional stand. Biomass and cubic-foot production are adequate, but sawtimber production is low. 

Sandy sediment-This sediment is similar to that in 6 in 

origin and occurrence. But the 

materials tend to be dry and 

single grained due to higher 

proportions of sand. However, 

there are too many fine particles for outwash. The climax 

apparently is eastern hemlock 

greater than red spruce. Suecessionai stands are hardwood greater than softwood 

mixtures of red maple, 

birches (especially paper 

birch), beech, hemlock, and 

spruce. Balsam fir or white 

pine may be present (Fig. 5). 

8. Fine washed till-The washed 

tilts (8 and 9) apparently are 

ablational tills that were 

heavily water worked during 

deposition so that they contain sections of partially 

sorted material. The fine 

washed tills contain sufficient 

fine particles to produce very 

prominent silt caps on the 

buried rocks. These are loose 

tills which resemble a transition between sandy sediments and till. The topography is sloping or undulating with some surface rocks. 

The climax apparently is 

beech. Successional stands 

are mostly beech, red maple, 

and birches. 

9. Coarse washed till-This is 

the most common of the 

washed tills. Rinsing action 

removed most of the silt and 

finer particles so that the remaining material is loose, 
Figure 6.-Typical northern hardwoods on fine till. A good area for sawtimber production of sugar maple, yellow birch, and beech. 

coarse, and sandy. However, 

minimal silt caps are found on 

buried stones. The topography is sloping or hummocky 

with moderate numbers of 

surface rocks. The climax is 

beech. Successional stands 

support beech, birches, and 

red maple. Hemlock and 

spruce may be present but 

not predominant. 

10. Fine till-This till was 

dumped in place with little 

evidence of waterworking. The 

topography is irregular and often steep with many surface 

rocks. The climax is typical 

northern hardwoods characterized by beech and sugar 

maple. Successional stands 

contain beech, sugar maple, 

and birches (Fig. 6). 

10C. Fine till over compact tillThis recently recognized habitat is typical fine till underlaid 

with compacted till. The compacted layer generally is below the base of the B line or 

is discontinuous. The vegetation is similar to that in 10, 

but may have a few more ash 

and slightly higher site 

capacity. This habitat was recognized because of possible 

logging limitations caused by 

this habitat in the spring. 

10s. Silty fine till-Fine tills may 

exhibit a noticeable silty feeling. Further research might 

indicate that these silty tills 

often are associated with 10C. 

The vegetation is similar to 

that in 10, but possibly with a 

slightly higher productive 

capacity. 

11. Enriched-This habitat is 

small coves and benches in 

association with tills and 

compact tills. Organic matter 

or organic-coated fine materials are incorporated into 

the mineral soil. Horizonization is poor; the white A2 generally is absent. Drainage 

varies from well to somewhat 

poor. Apparent1 y, these areas 

are enriched by leaf litter, fine 

materials, or nutrient-rich 

water continually moving in 

from upslope. The climax is 

sugar maple. Successional 

stands are characterized by 

white ash and sugar maple 

with miscellaneous associated species. 

A few additional habitat conditions were observed, but our experience with them is limited. Clay sediments are sometimes found and 

may be quite common in other climatic-mineralogical zones. These 

are similar to silty sediments, but 

the materials are much more plastic. 

A very compact layer may form 

in silty or even sandy sediments. 

This layer acts as a barrier to water. 

Until further information becomes 

available, interpret this condition as 

similar to a wet compact till. 

Relationships of Species Cornposition to Habitats 

Climax vegetation is closely related to the soil conditions repre- 
sented by groups of habitats. We 

used discriminant analysis to 

analyze differences in species composition for 63 prism plots in old 

climax stands composed mostly of 

tolerant species. First, a function 

was developed to segregate several 

habitats with a softwood climax 

(shallow bedrock, shallow loose 

rock, outwash, dry and wet compact 

tills, poorly drained) from those with 

a hardwood climax (qoarse washed 

till, fine till, enriched). 

The following discriminant 

function was developed: 

Where: 

Z = Function value with midpoint 

- 9.3614 

X, = Easaf area (m21ha) in softwood 

X2 = Basal area (m21ha) in tolerant *- 

hardwoods (beech and sugar maple) 

By inserting values of XI and X2, a 

value of Z is predicted. Values 

greater than - 9.3614 denote rock, 

outwash, compact till, or poor drainage. Values less than - 0.3614 denote tills or enriched sites. 

The function was highly significant with a calculated F of about 

240. The probability of misclassification was estimated at about .005, 

equivalent to 2.75 standard deviations. All 63 plots in the data set are 

correctly classified using this functioa. 

A second discriminant function 

was developed for the 7 plots in 

coarse washed or fine till versus the 

24 plots on enriched sites: 

Where: 

Z = Function value with midpoint 

,2501 

X1 = Basal area (m2/ha) in sugar 

maple 

X2 = Basal area (m21ha) in beech 

The function was again highly 

significant with an F of about 15. 

Values of Z less than -2501 denote 

enriched sites. The probability of 

misclassification was estimated at 

about 10 percent. Four (all were enriched plots) of the 31 plots were 

misclassified using this function, an 

actual misclassification rate of 13 

percent. 

~6cause of the practical value 

of being able to recognize habitats 

on the basis of species composition 

alone, I developed a list of seven 

species groups that characterize the 

major stand conditions in New 

Hampshire and probably in adjacent 

states as well (Table 1). Recognition 

of these groups, coupled with a 

general assessment of soil 

moisture, provides some indication 

of likely habitats, climax species 

composition, best species, and possible management limitations, For 

silvicultural purposes, foresters may 

find it more convenient to assess 

stand potentials based on species 

composition alone-without examining soil materials or landform. 

Mapping 

Procedures 

A strong taxonomic framework 

is a prerequisite to mapping. Although earlier plotwork showed that 

soil materials was the primary criterion for habitat definition, landform and tree species composition 

are the most useful criteria in the 

mapping phase. 

Habitat mapping is best done 

with aerial photos on a scale of 

1115,000 to 1120,000. Larger scales, 

though useful for a detailed examination of previously delineated 

areas, tend to obscure differences 

in landforms. Smaller scales mask 

certain small landform distinctions 

useful in detecting habitats; however, scales of about 1140,000 are 

best for defining larger planning 

units at the ecologic land type level. 

The photos need to show sharp dist inctions between softwoods and 

hardwoods; thus, leaf-free or infrared photography seems best. 
Table 1.-Characteristics of seven forest types that represent major 

stand conditions in New Hampshire. 

0t her Check for these 

Climax Best species productive management 

species 

Forest a Soil Likely 

type moisture habitats 

Adequate 

Wet 

Enriched Sugar maple Sugar maple Most hardash woods 

Sugar maple, Most hardash woods 

Possible excess water 

in spring 

Excess water and possible 

occurrence of excess 

competition following 

clearcutting. 

Possibly steep slopes 

and rocks 

Sugar maple1 

ash 

Enriched Sugar maple 

Fine, or Beech 

washed fine sugar maple 

till, dry 

compact till 

Coarse washed Beech or 

till, sandy softwoods 

sediments 

Washed fine Beech or 

Sugar maple, Any hardwood 

yellow, and except ash 

paper birches 

Beec hlbirc hl 

sugar map te 

Adequate 

Paper birch Red maple, 

(or possibly beech, aspen 

oak) 

Paper birch, Red maple 

possibly beech, aspen 

yellow birch 

Beechlbirchl 

red maple 

Dry 

Adequate 

None 

Possibly excess water 

till, dry com- softwoods in spring 

pact till, 

silty sediments 

Wet compact Probably 

till softwoods 

Yellow birch Red maple 

paper birch 

softwoods 

White pine, Red maple, 

other soft- aspen 

woods, paper 

birch, possibly oak 

Softwoods, Red maple, 

birches aspen 

Excess water and excess 

competition following 

clearcutting. 

Possible shallow bedrock 

Wet 

Hardwood1 

hemlock1 

spruce 

Sandy sedi- Softwoods 

ments, outwash 

shallow to rock 

Possibly excess 

water in spring 

Adequate 

Wet - -- 

Dry 

Silty sedi- Softwoods 

ments, dry compact till 

Wet compact Softwoods 

till, poorly 

drained 

Outwash, sandy Softwoods 

sediments, 

shallow to rock 

Softwoods, Red maple 

birches 

Excess water, windthrow, 

and excess competition 

following clearcutting 

Hardwoodl Possibly shallow bedrock 

white pine 

White pine, Red maple, 

other soft- aspen, beech 

woods, paper 

birch, 

perhaps oak 

White pine Uncertain 

in present 

stand 

Adequatewet 

Any Uncertain 

Present 

stand 

probably 

old-field 

Outwash, Softwoods 

sandy 

sediments 

Possibly excess water 

Aspen1 None 

paper birch 

Paper birch, Red maple, 

white pine, aspen 

other softwoods, oak 

Paper birch Uncertain 

in present 

stand 

Adequatewet 

Any Uncertain. 

Present 

stand 

may be of 

fire origin 

Washed Oak or softcoarse till, woods 

outwash, sandy 

sediments, 

shallow bedrock 

Possibly excess water 

Oaklwhite Possibly shallow bedrock 

pine 

Oak, white Red maple, 

pine, tolerant aspen 

softwoods 

a Forest types: In general, the stand should contain at least 50 percent by basal area of the listed species. However, some judgment is needed In applying this rule. For example, a stand of hardwoods with an apprecrable component of softwoods in the 

seedling understory should be considered hardwood-softwood or hardwood-white p~ne-because these softwoods could be featured in regenerating the stand. 

Soil Moisture: Dry-This condition occurs on areas of coarse sandy or gravelly outwash, sediments (sandy), and coarse 

washed till, as well as areas shallow to bedrock or boulders. The soils are loose, coarse, and always dry. Ground flora characteristics of dry areas are sometimes present: blueberries, wintergreen, bracken fern, several clubmosses, w~ld lily-of-the-valley. 

Wet-This condition occurs on poorly drained areas and wet compact tills. Ev~dence of excess water is evident at, or just under, 

the surface. Adequate-This condition occurs where soil texture is reasonably fine, a sandy loam or better. A well- to moderatelywell drained pan may also occur. 
A sample map of the Bartlett 

Experimental Forest (2,600 acres) is 

shown in Figure 7. Most of the habitats described earlier are found on 

this map. However, notice that 

some map units are combinations 

of associated habitats that cannot 

be separately mapped. In such 

cases, the habitat listed first is the 

predominant one. Since this map 

was completed, it has been suggested that classification and subsequent mapping of seas by broad 

percent-slope classes would assist 

in making interpretations. 

Predefineation is the first step 

in habitat mapping. This consists of 

drawing lines around and tentatively 

naming logical map units based on 

steroscopic examination of photographs. Mapping is done directly on 

the photos, or overlays, with easily 

erasable marking pencil. Before predelineation work it is necessary to 

know or to determine through reconnaissance the types of materials 

in the area, their mode of occurrence, and their relationships with 

the tree vegetation. Elevational conditions on the Bartlett Forest are 

shown in Figure 8. The following 

guidelines were followed in predelineating habitats on the Barlett For- 

, est. 

Poorly drained (7 )-This habitat 

is a flat area in low topographic 

positions. Stocking may be sparse 

or clumped. Softwoods are 

abundant in both young and old 

stands. 

Shallow bedrock (2) and ledge 

(;IS)-These habitats are in the uppermost elevationat positions, or 

Figure 7.-Habitat map of the Bartlett Experimental Forest, New Hampshire. 
Figure 

Bart let 

8.-Topographic model ( 

t Experimental Forest. 

>i the 

they may extend down from the upper elevations as fingerlike units. 

The ledge is visible in places. 

Spruce, fir, andlor hemlock are 

abundant in both young and old 

stands. 

Shallow loose rock @A)-This 

habitat usually is found along existing stream banks or old drainageways. Old stands are softwood and 

young stands are mixed wood. 

Outwash (3)-An outwash area 

is a high, hummocky bank along 

existing streams (ice-contact materials) or mounded topography in 

the major valleys. Softwoods including some white pine are abundant in 

both young and old stands. 

Wet compact till (4)-This material is on uniform, gently sloping 

areas at lower topographic positions. Softwoods are abundant in 

old stands, and mixed woods predominates in young stands. Drainage lines due to overland flow are 

sometimes evident. Streams are 

shallowly entrenched. 

Dry compact till (5)-This compact till usually is found adjacent to 

and slightly above wet compact till. 

Topography can be gently sloping 

to convex and uniform. Old stands 

are softwood, but young stands are 

mixed wood or mostly hardwood. 

- Dry cemented till (5A)-This 

habitat was not mapped on the Bartlett Forest. It is commonly an area 

of softwood (old stands) or mixed 

wood (younger stands) on low 

ridges. This habitat is difficult to 

distinquish on photographs. 

Silty (6) and sandy (7) sediments-These habitats are found on 

gently sloping or rolling, well 

drained topography at lower elevations. Old stands are softwood and 

young stands are mixed wood or 

hardwood. Streams are steep 

banked and deeply entrenched. 

Washed tills (8, 9)-Washed 

tills are characterized by hardwood 

stands with some softwood admixture on sloping or rolling topography at mid to lower elevations. On 

the Bartlett Forest, most of the 

washed tills are found just above 

and below the major slope break between the upper and lower elevations of the forest (Fig. 8). Streams 

are uncommon within these units, 

though well entrenched streams 

may border them. 

Fine till (10, IOC, 70s)-This 

habitat has hardwood stands on 

moderately steep and irregular topography at mid to upper elevations. 

Enriched (1 1)-Enriched habitats commonly are too small to be 

detected on photographs. On the 

Bartlett Forest, this habitat usually 

occurs at the slope break between 

the upper and lower elevations. In 

other areas, the alluvial soils with 

hardwoods adjacent to major 

streams commonly are typed as enriched. 

After predelineation, each 

mapped unit or a sample of the 

units is examined in the field to 

confirm the boundaries and the 
habitat designations. Boundaries 

generally are quite accurate; however, habitat names frequently are 

revised in the field. In each mapped 

unit examined, a pit is dug to determine the nature of the soil materials; additional auger borings are 

taken to check for uniformity of materials throughout the unit. lt is during field checking that one or two 

associated habitats often are recognized and designated along with the 

primary habitat designqtion. 

Based on a random 1,050-point 

sample of the finished map, the primary habitat conditions on the Bartlett Forest are shallow bedrock, wet 

compact till, coarse washed till, aqd 

fine till. These each account for 

about 18 percent of the forested 

area (Table 2). Poorly drained and 

enriched habitats each account for 

less than 1 percent of the area. The 

remaining habitats each account for 

2 to 5 percent of the area. 

Relation of Habitat Map Units to 

Other Map Units 

Two other land classification 

schemes are used in the area of the 

Bartlett Forest: the ecologic land 

types mapped by the White Mountain National Forest and the standard soil survey using soil series or 

associations mapped by the Soil 

Conservation Service (SCS). Recent 

maps of both systems were available for the Bartlett area. The soils 

Table 2.-Percentage of the Bartlett Experimental For. 

est in each habitat 

based on 1,050 points. . 

Habitat Percentage 

of area - 

Poorly drained(1) 

Shallow to bedrock 

(2 and 28) 

Loose rock(2A) 

Outwash(3) 

Wet compact till(4) 

Dry compact till(5) 

Silty sediments(6) 

Sandy sediments(7) 

Fine washed till(8) 

Coarse washed ti 11 (9) 

Fine till (lo, 10C, 10s) 

Enric hed(l1) 

Total 100.0 

Table 3.-Numbers of points falling within each habitatlsoil series combinationa 

Habitats 

Well-drained Well-drained 

till Well-drained to moderately Moderately Shallow to Pan well-drained bedrock (LVF, (BVCp HOE) BV, BVF, (BEE, MEE, MEF) pan (MFC) pan (PLC) LYF, RPF, CDE) 

Poorly drained(1) 

Shallow to bedrock(2) 

Loose rock(2A) 

Outwash(3) 

Wet compact till(4) 

Dry compact till(5) 

Silty sediments(6) 

Sandy sediments(7) 

Fine washed tiJl(8) 

Coarse washed till(9) 

Fine tilt(j0, IOC, 10s) 

Enrichedfl 1) 

a Soil association definitions: 

BEE-Becket very stony fine sandy loam association, steep 

BVC-Berkshire very stony fine sandy loam association, sloping 

BVE-Berkshire very stony fine sandy loam association, steep 

BVF-Berkshire very stony fine sandy loam association, very steep 

CDE-Canaan-Redstone very rocky gravelly fine sandy loam association, steep 

HaE-Hermon very stony fine sandy loam association, steep 

LVE-Lyman-Berkshire very rocky fine sandy loam association, steep 

LYF-Lyman-Rock outcrop association, very steep 

MEE-Marlow very stony fine sandy loam association, steep 

MEF-Marlow very stony fine sandy loam association, very steep 

MFC-Marlow-Peru very stony fine sandy loam association, sloping 

PLC-Peru very stony fine sandy loam association, sloping 

RPF-Rock outcrop-Lyman association, very steep 
of the area were described by Diers 

and Vieira (1977) and by Pilgrim and 

Harter (1 977). By drawing a map 

sample of 1,050 points, we wera 

able to compare habitats, ecologic 

land types, and soil associations. 

Examination of areas in the field 

provided at least a partial explanation for some of the discrepancies 

among mapping approaches. 

Habitats versus soil associations-Habitats (Fig. 7) and soil associationWFig. 9) followed similar 

boundaries: similar units of land 

were designated under both approaches. The similarity between 

mapped unit designations is shown 

in Table 3. The soil associations 

were grouped into general classes 

of parent materials. 

The few points that fell in the 

poorly drained habitat were crossclassified as well-drained to moderately well-drained soils with a pan. 

This is a reasonable association because poorly drained areas are generally surrounded by moderately 

drained to somewhat poorly drained 

pan soils. 

The shallow-to-bedrock habitat 

is similar to the soil associations reflecting shallowness to bedrock; 70 

percent of the points are similar. 

The habitats classed primarily 

as loose rock were predominately 

cross-classified as well-drained to 

moderately well-drained soils with a 

pan. This association was not surprising because most of the loose 

rock was mapped along waterways 

at lower elevations, and loose rock 

supports vegetation somewhat similar to that of pans. However, because loose rock is a reasonably 

common habitat, which often occurs in association with other habitats and has different hydrologic 

Figure 9.-Soil survey map of the Bartlett Experimental Forest. 
properties than pan, the importance 

of loose rock in determining forest 

composition and utilization should 

be evaluated further. 

The small amount of outwash 

habitat in the forest was mostly 

cross-classif ied as weli-drained 

soils with a pan. This habitat was 

not in the usual position for outwash; it was along a stream at fairly 

high elevations and easily could be 

mistaken. In general, obtwash is 

classified in similar fashion under 

all three systems examined in this 

study. 

Most wet compact till (71 percent) was cross-classified as well-* 

drained to moderately well-drained 

soils with a pan. The dry compact 

till fell mostly (88 percent) into the 

well-drained and well-drained to 

moderately well-drained categories 

of pan. Thus, there is a reasonable 

association between the habitat and -' 

soil association approaches in mapping these categories. 

Both the silty and sandy sediments were primarily crossclassified as well-drained to moderately well-drained soils with a pan. 

In the Bartlett Forest, both of these 

habitats were in lower slope positions where pan commonly is found. 

However, the sediments appear to 

offer different opportunities than 

pan with regard to opeMbility, productivity, and potential for intensive 

management. 

Most of the coarse washed till 

and, to a lesser degree, the fine 

washed till were cross-classified as 

well-draihed to moderately welldrained soils with a pan. About onefifth of the fine washed till fell into 

the soils category of well-drained 

till, which seems like a more logical 

category. One reason why there is 

some discrepancy in the mapping of 

these habitats is that the washed 

tills seem to occur in complex associations. Much of the washed tili ! 

mapped seemed to be underlaid 

with pan, which surfaced occasionally. On the basis of plot work, I feel 

that the washed tills have considerably different management potential than the pans or the typical 

well-drained tills (Berkshire for example). For example, the coarse 

washed tills appear to produce 

heavy amounts of beech; the pans 

lean toward softwoods, and the typical (unwashed) tills produce rich 

notthern hardwoods (sugar 

maplelbeech). 

Approximately 45 percent of the 

fine till habitat was cross-classified 

as well-drained till soils (a logical 

category), and most of the remainder fell into well-drained to 

moderately well-drained soils with a 

pan. Field examination of several 

areas with the SCS state soil scientist, S. Pilgrim, indicated that some 

areas classed as fine till were 

underlaid with a firm, platy till and 

classified as well-drained soils with 

a pan by SCS mapping. I did not 

class these as pans because the 

firm layer seemed to be below the 

rooting depth, and did not seem to 

be mottled or discolored, and because the area supported typical 

northern hardwoods. Since then, a 

new habitat category (10C) was developed to represent fine till over 

compact till. This was done because 

of the possible effects of this pan 

on operability and site potential (a 

positive effect perhaps). However, 

this sort of well-drained pan needs 

to be mapped separately from the 

areas mapped as dry compact till. 

The few points that fell in enriched habitats were cross-classified 

as well-drained to moderately welldrained soils with a pan. Enriched 

habitats are limited in size and number, and apparently there is no analogous soil series. However, enrichment often is mapped in association 

with other habitats. Thus, this condition may be more important than 

its acreage indicates. 

Habitats versus ecologic land 

types-Table 4 gives the association between habitats and ecologic 

land types (ELT). Many changes 

have been made in ecologic land 

typing since these data were developed, so only a brief and general 

comparison will be made. 

The poorly drained and shallowto-bedrock habitats were sirni tar to 

the ELT classifications of imperfectly drained ablational tills and 

shallow-to-bedrock sites, 

Habitats characterized by loose 

rock and outwash were too small 

and scattered to be reflected in the 

ecologic land types, 

The wet compact till habitat 

was similar to the ELT classifications of basal till or imperfectly 

drained basal till. However, a large 

number of points (38 percent) fell 

under well-drained ti1 Is. Pans and 

imperfect drainage sometimes are 

difficult to assess on aerial photographs without intensive ground 

checking. The dry compact till habitats also were split between the 

land types of basal till and welldrained till. 

'Silty and sandy sediments were 

classed both as imperfectly drained 

ablational tills and well-drained tills. 

This is understandable because 

some sediments seem well-drained, 

and others show some evidence of 

imperfect drainage. The concept of 

sedimentation is now built into the 

ELT system. 

Fine washed tills were similar 

to the ecologic land type representing well-drained tills-a logical association. 

Much of the coarse washed till 

habitat was cross-classified as basal 

till or imperfectly drained ablational 

till. As mentioned earlier, the coarse 

washed tills often are complex 

areas, sometimes underlaid with 

pan. The ELT system, which classifies substrata to a depth of abgut 10 

feet, could understandably list these 

as basal till or imperfectly drained 

areas. However, i think that areas 

with shallow versus deep pan can 

be quite different in species, productivity, and operability. 

Habitats classed as fine till 

commonly were cross-classified as 

basal till. This difference again reflects the ELT approach of looking 
Table 4.-Numbers of points falling within each habitatlecologic land type combinationa 

Well-drained Imperfectly 

W&l-drained Well-drained to moderately drained Shallow to 

Habitat tills(5) bouldery well-drained ablational 

tills(5C) bed roc k(2) 

basal ti 1 l(3) till(6B) 

Poorly drained(1) 

Shallow to bedrock(2) 

Loose roc k(2A) 

Outwash(3) 

Wet compact tiil(4) 

Dry compxct till(5) 

Silty sediments(6) 

Sandy sediments(?) 

Fine washed till(8) 

Coarse washed t ill(9) 

Fine till(l0, 10C, 10s) 

Enriched(l1) a 

a Ecologic Land Types: 

ELT 2-Softwood knolls, ridges, and steep side slopes with ledgy, bouldery shallow sites-these typically are shallow to bedrock with a spruce-fir climax at higher elevations, and with more hemlock and oak at lower elevations. 

ELT 3-Hardwood with softwood mountain side'slopes with moderately deep soils to hardpan-these are well-drained to 

moderately well-drained soils underlaid by impermeable basal till. 

ELT 5-Hardwood lower~mountain slopes and broad valley floors with very deep ablational tills-these are well-drained tills 

supporting northern hardwood stands. 

ELT 5C-Hardwood smooth steep upper mountain slopes with deep, very bouldery ablational tills-these are bouldery, welldrained tills, high in coarse fragments, supporting more beech than ELT 5. 

ELT 6B-Hardwood flats and swales with imperfectly drained organic surfaces over wet ablational tills-these are less than 

' well-drained soils, apparently due to the influence of pan and lower slope position, supporting a hardwood-softwood mixture. 

I 

at deeper layers than the habitat 

system. 

The few enriched areas were 

too small to be considered under 

the ELT system. 

Summary on mapping correlations-Keep in mind the uncertainties involved in comparing mapping 

approaches. Apparent discrepancies 

.can arise because of differences in: 

taxoc.omic or mapping criteria, precise definition~ of these criteria, the 

weighting of criteria in multifactor 

systems, and the purity of the mapping systems (the variability allowed 

.within units). Although all of these a sources of uncertainty have not 

been evaluated in detail, it seems 

evident that two technical subjects 

require additional discussion and 

specification. 

Z 

1. We need to look more closely at 

the types of pans that influence 

productivity and operability. The 

problem seems especially important with pans that are welldrained to moderately welldrained. Some pans support rich 

northern hardwoods; others that 

are well-drained to moderately 

well-drained support mediocre 

hardwoods and have a softwood 

climax. 

2. The concept of washed or waterworked till needs additional evaluation. We should reexamine our 

definitions of sediments-what 

they are and how they influence 

vegetation. The problem is that 

areas mapped as well-drained 

tills by the SCS might be classified as sediments or washed tills 

under the ELT or habitat approaches. Because of different 

definitions, the coordination of 

information from the three approaches is difficult. 

Interpretations 

To develop information on 

species relationships and product ivity of the habitats mapped on the 

Bartlett Forest, 145 10-factor prism 

plots were measured. These plots 

were systematically located to sample the range of conditions in 27 

stands representing 12 habitat mapping units. The sample included 

even-aged successional stands 

(mostly about 100 years old) composed of both tolerant and lesstolerant species as well as a few 

uneven-aged climax stands composed primarily of tolerant species. 

The stands were uncut during the 

last 50 years or more. 

On each plot, trees were tallied 

by species and dbh class (over 1.0 

inch). Height and age were determined on one potential site index 

,tree per plot, if available. The pres- 
ence of trees less than 1.0 inch dbh, 

shrubs, and herbs was recorded by 

species on eight 1-m2 plots per 

prism point. 

Species Composition 

Species composition in basal 

area per acre (trees over 1.0 inch 

dbh) was determined for both successional stands (Fig. 10) and 

climax stands (Fig. 11). These results closely follow earlier guidelines on the relation& of species 

composition and succession (Fig. 4) 

to habitat in granitic drift (Leak 

1978a). Softwoods are evident in 

successional stands on poorly 

drained, bedrock, wet compact till, 

and silty sediments habitats; re& 

maple is the predominant hardwood 

on these habitats. The proportion of 

softwoods in these successional 

stands varies considerably, however, depending upon cutting history. If an understory was left in theearly cuttings around 1900, softwoods are abundant. If the cutting 

was complete, hardwoods predominate. 

Dry compact till and sandy 

sediments support red 

maplelbeechlbirch stands. The 

washed tills are primarily hardwood 

stands with beech predominating; 

some hemlock is evident as well. 

The enriched habitats are characterized by sugar maple and white ash. 

Results from the climax stands indicate that beech and sugar maple 

characterize the fine tills; these species together with birches also typify successional stands. Hemlock 

and red spruce are climax on the 

other habitats represented in Fig. 

11. 

Climax species composition is 

not necessarily static, however. 

General observations1 indicated that 

beech and sugar maple on fine till 

habitats tend to alternate in abundance. Results from two climax 

stands on fine till illustrate this phenomenon: 

' Personal communication, Stanley M. 

Filip, retired research forester. 

Poorly 

50 FApact 

0 till 

- Dry compact till 

- Silty 

_, sediments 

- 

Sandy 

- sediments - 

0 finetill - 

Washed 

coarse till 1-1 

Figure 10.-Basal area per acre by habitat and species for successional 

stands on the Bartlett Experimental Forest. 

Beech Sugar maple 

2-8 inches 10 inches 2-8 inches 10 inches 

dbh dbh + dbh dbh + 

Compartment 22 6.7 86.7 16.7 6.7 

Compartment35 11.7 26.7 1.7 45.0 
- 

- Badrock t i a 1 

- 

- Loose rock - - 

- 

- Outwash 

- 

Silty 

- sediment 

- 

- Fine till - f==~nI- a I. 

Figure 11.-Basal area per acre by habitat and species for climax stands 

on the Bartlett Experimental Forest. 

On Compartment 22, beech is abundant in the overstory and sugar 

maple predominates in the understory. On Compartment 35, the situation is reversed. Apparently, species alternation is characteristic of 

northern hardwoods on fine till, but 

additional long-term observation will 

be needed to confirm this hypothesis. 

Although species of shrubs and 

herbs have proved to be of diagnostic value for western habitats 

(Pfister and Arno 1980) and some 

earlier eastern classifications (Westveld 1951), these species have not 

yet been recognized as criteria for 

defining habitats in the White Mountains. 

Results from the Bartlett Forest 

indicate that certain habitats support a much richer flora (greater 

numbers of species) than others. 

The greatest numbers of herbaceous species are found on enriched, sandy sediment, and wet 

and dry compact till habitats; in several instances, these same habitats 

Table 6.-Average frequency (percent occurrence on I-m plots) of tree, shrub (including small trees

species per stand, by habitat and successional stage (includes only those species grea

equal to 5 percent frequency on all areas in each habitatlsuccessional category). 

Habitat and stand category 6 

Enriched Fine Coarse Fine Sandy Silty sediments Dry Wet 

till washed washed sedi- (6) compact compact Out- Bed- 

("I (lo, lOC till (9) till (8) ments (7) -- Succes- till(5) till(4) wash rock 

sional 10s) Succes- Succes- Succes- Climax Success- SUCC~~S- SUCC~S- (3) (2) 

Climax sional sional sional ,sional sional sional Climax Climax 

Species 

TREES 

68 69 57 25 44 45 17 - - 15 22 10 - - - - - - 

15 37 3 1 22 -- - 14 - - 

Beech 

Sugar maple 

Red maple 

Yellow birch 

White ash 

Red spruce 

E. hemlock 

Balsam fir 

SHRUBS 

42 35 16 33 - 12 44 64 42 11 - 

36 40 - - 16 5 - 34 40 - 11 

- - - - - - - - - - - 

Hobble bush 

Striped maple 

Canada yew 

Blueberry 

Wintergreen 

Sheeplaurel 

Wildraisin 

HERBS 

Wildoats 

Indian 

cucumber 

Wild lily-oft he-val ley 

Starflower 

Sarsaparilla 

CIu bmoss 

Trillium 

Clintonia 

Wood sorrel 

Moccasin 

flower 

Woodfern 
number 8 to 10) and softwood habitats (softwood climax now supporting hardwoods, mixed wood, or softwoods: habitats number 2 to 7) (Fig. 

12). Climax hardwood stands2 averaged about 40,000 dry pounds per 

acre heavier than softwood stands 

though there were too few obsewations to detect a significant difference. The white ashlsugar maple 

stands characteristic of enriched 

habitats averaged reatest in biomass; one softwoo ?!l stand on a 

poorly drained habitat averaged 

These climax stands contained trees 

of up to about 200 years old, so climax 

stand age in Figure 12 was set at 200 

years. B 

least. The equations for hardwood 

and softwood standing aboveground 

dfy biomass in thousands of pounds 

per acre are: 

Hardwood:Dry Wt. = 1.2955 + 

3.21 82 (age) - 15.4854 (age2/ 1000) 

n = I1 

R2 = .97 

Softwood:Dry Wt. = - 0.8552 + 

3.1728 (Age) - 14.8337 (Age211000) 

n = 28 

R2 = '94 

These equations were fitted to 

points representing stands of varying size and age. Thus, the R2 

Enriched 

Hardwood habitats 

(excluding enriched) LC--@ 

-4-- 

LC- - c- /-- 

-- rc- ---2--- 

---31t..I 

Softwood habitats 

(excluding poorly drained) 

- 

C I I I I I I I I 1 - 

6 Poorly drained 

values provide a rough measure of 

goodness of fit. 

Note that these curves of biomass over age are substantially different from the living biomass accumulation curve reported by Bormann and Likens (1979, Fig. 2, 

Chapter 6). The Bormann-Likens 

curve peaks sharply at about age 

175; whereas, my curves generally 

flatten off at age 100 to 120. The 

Bormann-Likens curve is essentially 

a straight line from origin to peak; 

whereas, my curves represent the 

more natural parabolic growth form. 

The Bormann-Likens model shows a 

substantial drop from peak biomass 

accumulation to the climax or 

0 

20 40 60 80 100 120 140 160 180 Climax 

Figure 12.-Aboveground biomass (stems and branches) in dry weight 

over stand age by habitat groups. 
steady state. My curves indicate a 

slight drop in biomass of climax 

softwood stands and a slight increase in biomass of hardwoods. * 

The Bormann-Likens curve peaks at 

about 490 metric tons per hectare of 

living biomass, which equals 

437,000 pounds per acre. If we reduce this by approximately 20 percent to account for roots, twigs, and 

leaves, the aboveground biomass in 

stems and branches is about 

350,000 pounds per acre. On the 

Bartlett ForeM, the estimated maximum aboveground biomass per acre 

for climax northern hardwoods is 

200,000 pounds; though, it is indicated that stands on enriched habitats are considerably higher-to at 

least 250,000 pounds. 

Volumes by habitat followed a 

different pattern than that of biomass. Whereas softwoods and hardwoods were similar in biomass production, softwoods were considerably more productive in both cubic 

feet and board feet. Softwood 

stands (including mixed wood 

stands with 24 percent softwood or 

more) supported significantly more 

cubic volume by age 70 to 90 or 

older than hardwoods growing on 

either hardwood habitats (numbers 

8 to 10) or softwood habitats (numbers 2 to 7). Enriched stands were 

about equal to softwood stands in 

cubic volume (Fig. 13). In board-foot 

volume, softwood (including mixed 

wood) stands and hardwood stands 

on enriched habitats were much 

more productive than the other 

Hardwoods on softwood habitats (f~~iud~i~g poorly cfra~necf) 

Hardwoods on hardwood habitats (e~~l~ld~ng tnrz~hfa') 

Softwoods and mixed wood 

Poorly drained 

Enriched 

Climax 

Age (years) 

Figure 13.-Average cubic-foot volume per acre by habitat groups and 

stand age. 
stands, Hardwoods growing on 

hardwood habitats produced more 

(40 percent at age 90 to 110) boardfoot volume than the successional 

hardwoods found on softwood habitats (Fig. 14), though this difference 

was not significant. 

Species Productivity 

On the basis of past work (Leak 

1978a), average site index by species and habitat bparently provides 

some basis for comparing the suitability of habitats for growing given 

species. Additional work in sapling 

and poletimber stands (Leak 1979) 

indicated that certain species differed among habitats in mearf annual diameter growth. 

In the present study on the 

Bartlett Forest, site index by species was extremely variable; only 

very demanding species such as. 

white ash showed any noticeable 

trends in site index by habitat. Apparently, when an entire stand 

"(rather than individual plots) is classified by habitat, there is substantial 

within-stand variation in site index. 

The use of diameter-growth differences of unmanaged stands 

seemed to be a better possibility for 

evaluating species productivity. The 

use of mean diameter of all trees 1 

inch dbh and larger did not work because diameter development was 

obscured by the small trees; even 

heavy sawtimber stands exhibited 

mean diameters of only 8 to 10 

inches. Mean diameter of trees 8 

inches dbh and larger provided a 

better indication of species development, but even with this measure 

there was high variability. Finally, I 

calculated average diameters of the 

largest trees per species, based on 

an average of one large tree per 

plot. For example, if we had seven 

plots in a stand, the average was 

based on the seven largest trees per 

species. Mean diameter was calculated by this method, corrected to a 

base age of 100 yearq3 and showed 

some reasonably distinctive differences among habitats (Table 7). 

However, none of these differences 

proved significant due to the small 

numbers of areas (samples) represented. Sugar maple and white ash 

grew best on the enriched habitats; 

mean diameters were 4 112 to 7 

inches larger on the enriched habitat. Beech grew largest on welldrained sites such as the washed 

tills and sandy sediments. Red 

maple and paper birch grew fairly 

well on all habitats, a pattern that 

has been noted before (Leak 1979). 

Yellow birch did well on the enriched habitat, and tree sizes in the 

Corrected = F x 100 

stand age 

Hardwoods on softwood habitats (e.~cfudi~g poorry d~~~in~d) 

50-70 70-90 90-110 Climax 

Age (years) 

Figure 14.-Average board-foot volume per acre by habitat groups and 

stand age, 
Table 7.- Mean diameter of largest trees (average of one tree per plot) at 100 years and 

in climax stands by species and habitat, in inches. D 

Habitat Yellow Sugar Red Paper White Red Eastern 

Beech birch maple maple birch ash spruce hemlock 

Enriched(1) 

Washed tills(9 and 8) 

Sandy sedimen ts(7) 

Silty sediments(6) 

Dry compact ti l(5) 

Wet compact tr C l(4) 

Poorly drained(1) 

Fine tills(lO,lOC, 10s) 

Silty sediments(6) 

Outwash(3) 

Bedroc k(2) 

Loose roc k(2A) 

A t 100 years - - 

13.4 15.4 

17.0 13.6 

16.9 

14.6 13.8 

16.8 14.3 - - Climax - - - - 20.0 - - 10.0 

17.7 - 

climax stands indicate that thisspecies also does well on fine till. Yellow birch performance on the 

washed tills was higher than expected, but perhaps because the 

fine washed till was predominant or 

present in all of these areas. Earlier 

work (1978a) indicated that site index of yellow birch was higher than 

that of paper birch on wet compact 

till, but that the reverse was true on 

dry compact till. However, the diameter information in Table 7 indicates 

that the compact tills are mediocre 

in comparison to the enriched sites 

and fine till for growing yellow 

birch. 

Silvicultural Implications 

-The information presented so 

far on the relationship of habitat to 

species composition, stand productivity, and species performance provides some logical silvicultural implications for the Bartlett stands. 

These implications, which follow, 

are consistent with the general silvicultural directions previously defined for stands on granitic drift in 

the White Mountains (Leak 1980). 

11. Enriched-This habitat is 

well-suited to the production 

of sugar maple and white ash 

sawlogs and veneer. Shelterwood seems the best regeneration technique for ash, and 

either shelterwood, selection, 

or group selection would be 

best for sugar maple. Early 

weedings or cleanings to 

favor increased proportions of 

these species should be economically worthwhile. These 

would be followed later by 

commercial thinnings. Cultural work around sugar maple 

should be light enough or delayed long enough so that low 

live branches are not 

abundant. 

Paper and yellow birch also 

regenerate and grow well on 

these sites. Strips or small 

clearcuttings are the appropriate regeneration method. 

Openings should be small in 

low-lying or wet areas to prevent excess herbaceous 

growth and frost damage; logging or roading activity may 

need to be controlled on 

these wetter enriched sites 

during the spring. 

10. Fine till-This habitat is well10C. suited to the production of 

10s. northern hardwood sawtimber-sugar maple, yellow 

birch, and paper birch. Beech 

often will occupy up to 50 percent of the stand. Any regeneration method suited to the 

desired species is acceptable. 

Early cultural work should be 

economically worth while provided that it improves species 

or product potential. Roading 

and logging restrictions are 

minimal, except when fine till 

is underlaid by a compact layer (1 OC). 

9. Coarse washed till-Beech is 

abundant and well formed on 

this habitat. Paper birch is capable of producing bolts and 

small to medium sawtimber. 

Although results are somewhat conflicting, I still favor 

paper birch over yellow birch 

based on both productivity 

and regeneration possibilities. 

Red maple is a much better 

possibility than sugar maple. 

Early cultural work directed 

toward increasing the proportion of paper birch should be 

economically acceptable. 

Roading and logging restrictions are minimal. 

8. Fine washed till-This habitat 

has a potential similar to the 

coarse washed till. It could 

produce small to medium 
sawtimber, bolts, and cordwood of primarily beech, red 

maple, and the birches. Yellow birch has a higher potential on this habitat than the 

previous one. Cultural work 

that favors increased proportions of birch with sawtog or 

boltwood potential should be 

worthwhile. Operating restrictions are minimal. 

Sandy sedimem-Softwoods 

(including hemlock, spruce, 

white pine, and some balsam 

fir) are the most productive on 

this habitat in terms of boardand cubic-foot volume. Because hardwoods often are* 

abundant in successional 

stands, carefully designed 

shelterwood cuts probably 

would be needed to increase 

the softwood component. The 

best hardwood species are 

beech, red maple, and paper - 

birch; yellow birch seems unproductive on these very welldrained materials. Hardwood 

product objectives should be 

fiber, boltwood, and small or 

lower-grade sawlogs. Cultural 

investments in young stands 

to increase the proportion of 

paper birch might be worthwhile. Operational constraints 

are minimal. 

6. Silty sediments -Softwoods, 

especially hemlock and 

spruce, are more productive 

in board- and cubic-foot 

volume than the hardwoods. 

Hardwoods are abundant in 

successional stands and sheltewood systems may be 

needed to increase the softwood component. Paper 

birch, yellow birch, and red 

maple are moderately productive on this habitat. Beech is 

common but seems less productive here than on drier 

sites. These habitats may be 

too wet for fogging or roading 

in early spring and after heavy 

rains. 

5. Dry compact till-Sof twoods 

again are the best volume producers. The best hardwoods 

are maple and paper birch; the 

- logical product objectives are 

fiber, boltwood, and small or 

lower-grade sawlogs. Yellow 

birch seems less productive 

than paper birch on this habitat, though results are somewhat conflicting. Cultural efforts in young hardwoods 

should favor paper birch. 

Beech, though abundant, is 

not as productive here as on 

drier sites with unrestricted 

rooting. Operational problems 

often occur in spring and after heavy rains. 

4. Wet compact till-Softwoods 

are most productive and 

usually are abundant. The 

best hardwoods are red maple, yellow birch, and paper 

birch; product objectives for 

hardwoods should be limited 

to fiber, bolts, and srnail to 

medium sawlogs. Cultural investments to increase the proportion of paper and yellow 

birch in young stands may be 

worthwhile. Operational problems are common, and this 

might limit logging and roading activities to winter. 

Outwash -Softwoods are productive, and white pine is especially suitable on this habitat. The best hardwoods are 

red maple and paper birch; 

bolts, fiber, and small sawlogs 

are reasonable objectives. 

Cultural work in hardwoods 

should favor paper birch. 

Early cultural work to favor increased growth and sawlog 

production in white pine has 

economic potential. Operational problems are minimal. 

Shallow bedrock-Despite the 

shallow soil, softwood stands 

on this habitat may have high 

cubic- and board-foot volume. 

The best hardwoods are red 

maple and paper birch; fiber 

and boltwood are the logical 

product objectives. Because 

of the shallow soils and difficulties in logging, I suggest 

minimal management effort: 

light selection or group selection cutting of the accessible 

areas to maintain the softwoods. 

2A. Loose rock-Softwood stands 

again are more productive 

than hardwoods. Red maple 

and paper birch are the best 

hardwood species, although a 

few good yellow birch are 

found associated with waterways. Fiber, boltwood, and a 

few small sawlogs are logical 

hardwood products. Logging 

restrictions are minimal unless the slopes are steep. Cutting methods may include 

small clearcuttings or stripcuttings for birch as well as 

selection and shelterwood 

cuttings. 

Poorly drained-Softwoods 

are more productive than 

hardwoods. However, even 

softwood productivity in 

weight and volume is limited 

by excess water. I recommend 

minimal timber management: 

light selection or group selection cuttings during winter. 

Large openings may result in 

frost damage and herbaceous 

competition. 

Applications 

Approaches 

Recognition of habitats such as 

those defined in this paper provides 

guidance on species to grow, regeneration cutting methods, potential 

productivity, and managerial constraints (problems with windthrow, 

logging, and roading). In the granitic 

areas of the southern White Mountains, the habitat definitions and interpretations in this publication 

should apply quite well. In other climaticfmineratogical zones, the definitions and interpretations will vary, 

and an effort will be required to develop and implement a habitat classification. Because of the great diversity that exists in New England 

in types of ownership and objec- 
tives of management, the effort will 

vary in intensity and detail. At least 

three approaches are possible depending upon the expertise and re* 

sources available. 

1. Biophysical classification -Map 

a forest property (or the commercial forest land) into habitats or 

land types based on landform, 

vegetation, and soil materials. A 

small-scale map can be prepared 

for planning purposes, and it can 

be used Mh a more detailed 

map for project work. This approach requires both soilslgeologic and botanical skills. A .considerable amount of reconnaissance or plot work will be required to develop the habitat taxonomy and mapping criteria. 

Forest type classification -Evalu 

ation of stand potential may be 

based on forest type alone. The 

types listed in Table I provide a 

reasonable starting pointljecause our work has already indicated that they are common 

species associations that sometimes reflect differences in site. 

However, the main limitations on 

the use of forest types alone are 

(1) lack of information on operability, and (2) differences that are 

not site related and cannot be 

readily duplicated because of 

past cutting history and other 

types of disturbances. 

This approach can be slightly refined through an assessment of 

soil moisture adequacy (Table 1). 

This soil moisture assessment 

provides a sharper definition of 

species suitability and operation- 

. al constraints. 

Both approaches can be applied 

either through mapping of the 

forest property or by evaluating 

each stand as it is scheduled for 

silvicultural treatment. 

3. Forest typelforest soils classification-If sails maps are available, they can be used as a starting basis for assessing habitat 

conditions. This approach can be 

undertaken as a mapping project 

or as a means to assess stands 

scheduled for silvicultural treatment. With a soils map in hand, a 

reconnaissance of the property 

will show how forest types such 

as those in Table 1 change in relation to changes in soil types or 

associations. Concentrate on fairly significant changes in forest 

type: valuable hardwoods, less 

valuable hardwoods, mixed 

woods, and softwood. And, it 

may be necessary to subdivide or 

lump soils units to reflect important change in forest condition. 

Notes should be taken on 

species and condition of overstory and understory; estimates 

of stocking and site index also 

can be taken if time warrants. 

Soils limitations are available 

from the soils map interpretations. Given this information, a 

forester can recognize and list 

the major soils-vegetation associations and develop logical interpretations on: species to favor, 

cutting methods to regenerate 

favored species, potential problems with competition from 

weeds, trees and shrubs, areas 

suited to intensive management, 

wildlife considerations, and limitations on roading and logging. 

Agricultural Areas 

The classification of habitat 

conditions in areas disturbed by agriculture requires special consideration because the vegetation often is 

different than usual. Old-field or 

pastured stands frequently contain 

more white pine, spruce, or hemlock 

than would usually be found on a 

given soil material. In evaluating 

such areas, the composition and 

quality of the existing vegetation 

can be used as a guide on how to 

treat the present stand. However, regeneration cutting practices should 

be based on an evaluation of soil 

materials and understory tree vegetation. It seems that such disturbed 

areas will begin to revert to the natural forest vegetation by the second 

rotation. For example, old-field 

white pine growing on a hardwood 

site will seldom regenerate successfully or easily to white pine because 

of hardwood competition. 

Literature Cited 

Bailey, R. G.; Pfister, R. D.; Henderson, J. A. Nature of land and resource classification-a review, 

J. For. 76:650-655; 1978. 

Bormann, F. H.; Likens, G. E. Pattern 

and process in a forested ecosystem. New York: Springer-Verlag; 

1979. 253 p. 

Bormann, F. H.; Siccama, T. G.; 

Likens, G. E.; Whittaker, R. H. The 

Hubbard Brook ecosystem study: 

composition and dynamics of the 

tree stratum. Ecol. Monogr. 

40:373-388; 1970. 

Daubenmire, R. Forest vegetation of 

northern Idaho and adjacent 

Washington, and its bearing on 

concepts of vegetation ciassification. Ecoi. Monogr. 22:301-330; 

1952. 

Diers, R. W.; Vieira, F. J. Soil survey 

of Carroll County, New Hampshire. Washington, DC: USDA Soil 

Conservation Service and USDA 

Forest Service; 1977. 161 p. 

Fenneman, N. M. Physiography of 

eastern United States. New York: 

McGraw Hill; 1938. 714 p. 

Goldthwaite, L. Glacial till in New 

Hampshire. Mineral Resource Survey Part 10. New Hampshire State 

Planning and Development Committee. 1948; 11 p. 

Hills, G. A. The use of site in forest 

management. For. Chron. 29(2): 

128- 136; 1953. 

Leak, W. B. Relation of tolerant 

species to habitat in the White 

Mountains of New Hampshire. 

1976; USDA For. Serv. Res. Pap. 

NE-351. 10 p. 

Leak, W. B. Relationship of species 

and site index to habitat in the 

White Mountains of New Harnpshire. 1978a; USDA For. Serv. Res. 

Pap. NE-397. 9 p. 
Leak, W. B. Relationships of forest 

vegetation to habitat on two types 

of glacial drift in New Hampshire. 

1978b; USDA For. Sew. Res. Note 

NE-257. 5 p. 

Leak, W. B. Effects of habitat on 

stand productivity in the White 

Mountains of New Hampshire. 

1979; USDA For. Sew. Res. Pap. 

NE-452. 8 p. 

Leak, W. B. The infeence of habitat 

on silvicultural prescriptions in 

New England. J. For. 78:329-333; 

1980. 

Leak, W. B.; Graber, R. E. Forest 

vegetation related to elevatiop in 

the White Mountains of New 

Hampshire. 1974; USDA For. Serv. 

Res. Pap. NE-299. 7 p. 

Lull, H. W. A forest atlas of the 

Northeast. Upper Darby, PA: 

Northeast. For. Exp. Stn.; 1968. 46 

P 

Lutz, H. J. Geology and soil in relation to forest vegetation. Proceedings First North American Forest 

Soils Conference; Michigan State 

University, East Lansing, Mi; 1958: 

75-85. 

Mueller-Dombois, D. Eco-geographic 

criteria for mapping forest habitats in southeastern Manitoba. 

For. Chron. 41(2):188-206; 1965. 

Pfister, R. D.; Arno, S. F. Classifying 

forest habitat types based on potential climax vegetation. For. Sci. 

26(1):52- 70; 1980. 

PilgrimJ S. A. L.; Harter, R. D. Spodic 

horizon characteristics of some 

forest soils in the White Mountains, New Hampshire. 1977; N.H. 

Agr. Exp. Stn. Bull. 507. 26 p. 

Siccama, T. G. Vegetation, soil, and 

climate on the Green Mountains 

of Vermont. Ecol. Monogr. 

441325-349; 1974. 

Siccama, T. G.; Bormann, F. H.; 

Likens, G. E. The Hubbard Brook 

ecosystem study: productivity, nutrients, and phytosociology of the 

herbaceous layer. Ecol. Monogr. 

40:389-402; 1970. 4 

Society of American Foresters. Forest cover types of the United 

States and Canada. Washington, 

D.C.: Society of American Foresters; 1980.148 p. 

Trees: 

Westveld, M. Vegetation mapping as 

a guide to better silviculture. 

Ecology 32508-517; 1951. 

List of Species 

Scientific name 

Shrubs and small trees: 

Whittaker, R. H.; Bormann, F. H.; 

Likens, G. E.; Siccama, R. G. The 

Hubbard Brook ecosystem study: 

forest biomass and production. 

Ecol. Monogr. 44:233-252; 1974. 

A bies balsamea (L.) Mill . Acer rubrum L. 

Acer saccharum Marsh. 

Betula alleghaniensis Britton 

Betula papyrifera Marsh. 

fagus grandifolia Ehrh. 

Fraxinus americana L. 

Picea rubens Sarg . Pinus strobus L. 

Tsuga canadensis (L.) Carr. 

Acer pensylvanicum L. 

Gaultheria procumbens L. 

Kalmia angustifolia L. 

Taxus canadensis Marsh. 

Vaccinium angustifolium Ait. 

Viburnum alnifolium Marsh. 

Viburnum cassinoides L. 

Herbs: 

Aralia nudicaulis L. 

Clin tonia borealis (Ai t .) Raf . Coptis groenlandica (Oeder) Fern. 

Cypripedium acaule Ait. 

Dryopteris spinulosa (0. F. Muell.) Watt. 

Lycopodium annotinum L. 

clavatum L. 

lucidulum Michx. 

Maianthemum canadense Desf, 

Medeola virginiana L. 

Oxalis montana Raf. 

Trientalis borealis Raf . Trillium erectum L. 

undulatum Wiltd. 

Uvularia sessilifolia L. 

Sphagnum spp. 

Common name 

Balsam fir 

Red maple 

Sugar maple 

Yellow birch 

Paper birch 

American beech 

White ash 

Red spruce 

White pine 

Eastern hemlock 

Striped maple 

Wintergreen 

Sheep laurel 

Canada yew 

Low, sweet blueberry 

Wobblebush 

Wild raisin 

Sarsaparilla 

Clintonia 

Goldthread 

Moccasin-flower 

Wood fern 

Clubmoss 

Wild lily-of-the-valley 

Indian cucumber 

Wood sorrel 

Starf lower 

Trillium 

Wild oats 

Sphagnum 

7'U.S. GOVERNMENT PRINTING OFFICE: 1982-505-012:6 
teak, W. B. Habitat mapping and interpretation in New England. Broomall, PA: Northeast. For. Exp. Stn.; 1982; USDA 

For. Serv. Res. Pap. NE-496.28 p. 

Recommendations are given on the classification of forest land 

in New England on the basis of physiographic region, climate 

(ekevation, latitude), mineralogy, and habitat. A habitat map for 

the Bartlett Experimental Forest in New Hampshire is presented based on landform, vegetation, and soil materials. For each 

habitat or group of habitats, data are presented on stand composition, understory vegetation, biomass, volume, and diameter 

development by species. 

ODC: 182.22:114.33 

Keywords: land classification, site, soils, northern hardwoods. 
Headquarters of the Nodheastern Forest Experiment Station are in 

Bmmall, Pa. Fkld laboratories are maintained at: 

'h b 

Amhew, Massachusetts, in cooperation with the University of 

* Berea, Kentucky, in cooperation with Berea College. 

@ Brylinmn, Vermont, in cooperation with the University of 

Vermont. 

Delaware, Ohio. 

Durham, New Wampstrire, in cooperation with the University of 

New Hampshire. 

111 , Conllecticut, in coopration with Yale University. 

Morgantown, West Virginia, in cooperation with West Virginia 

University, Morgantown. 

Orom, Maine, in cooperation with the ZJniversity of Maine, 

Orono. 

Parsons, West Virginia. * Princeton, West Virginia. 

@ Syracuse, New York, in cooperation with the State University of 

New York Cokge of Environmental Sciences and Forestry at 

Syracuse University, Syracuse. 

University Park, Pennsylvania, in cooperation with the 

Pennsylvania State Univenity . Warren, Penwylvania. I 

I