Report SFRC-85/01 

Litterfall in Pinelands of 

Evergl-ades National Park 

Everglades National Park, South Florida Research Center, PO. Box 279, Homestead, Florida 33030 
Litterfall in Pinelands of Everglades National Park 

Report SFRC-85 10 1 

Alan Herndon and Dale Taylor 

National Park Service 

South Florida Research Center 

Everglades National Park 

Homestead, Florida 3303 0 

March 1985 
Herndon, Alan, and Dale Taylor. 1985. Litterfall in Pinelands of Everglades 

National Park. South Florida Research Center Report SFRC-85/01. 41 p. 
TABLE OF CONTENTS 

Page 

LIST OF TABLES ............................ ii 

LIST OF FIGURES ............................ iii 

INTRODUCTION ............................ 1 

Description of the Study Area .................... 1 

Materials and Methods ....................... 1 

RESULTS ............................... 3 

DISCUSSION .............................. 6 

SUMMARY AND CONCLUSIONS ..................... 7 

ACKNOWLEDGEMENTS ......................... 7 

LITERATURE CITED .......................... 9 
LIST OF TABLES 

Page 

1. Summary of the important characteristics of each leaf litter 

collection plot. . . . . . . . . . . . . . . . . . . . . . . . . . . 10 

2. Monthly litterfall values at each litter collection site. . . . . . . . . . 11 

2 3. Needle fall (gm/m ) in Blocks I and J for calendar years 1979, 1980, 

and 1981. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 

4. Calculation of pine needle fall values for 1981 using measured values 

from the first five months.. . . . . . . . . . . . . . . . . . . . . 26 

5. Herb and hardwood litter collected in each block for the period 

February 1980 - January 1981 with the fire-free period at the start 

of collection. . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 

6. A direct comparison of herb and hardwood litter for two consecutive 

years. There is an increase in this component of litter with firefree period. . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 

2 7. Total basal area of pine trees in 300 m plot overlaying collection 

sites and pine needle fall at site. . . . . . . . . . . . . . . . . . . 29 

8. Summary of litter fall at individual collection sites for the period 

February1980 -February1981.. . . . . . . . . . . . . . . . . . . 30 

2 9. Pine needle fall (gm/m ) in sites under badly scorched pines. . . . . . . 31 
LIST OF FIGURES 

Figure Page 

I. Base map of Long Pine Key showing management blocks (A, B, 

C, etc.) and litter collection sites (1, 2,3, etc.). ............ 32 

2. Base map of Pine Island showing management blocks (M, N, 0, 

etc.) and litter collection sites (1, 2). ................ 33 

3. Average monthly pine needle litter collected in management 

blocks A, B, C, and E, Long Pine Key. ................ 34 

4. Average monthly pine needle litter collected in management 

blocks F, H, and I, Long Pine Key. Missing data indicated by xxxxx. ... 35 

5. Average monthly pine needle litter collected in management 

blocks J (Long Pine ~ey) and N (Pine Island). ............. 36 

6. Total monthly pine needle litter collected at site 54 during 1979, 

1980, and 1981.. ......................... 37 

7. Regression lines used to estimate monthly pine needle fall values at 

collection sites A1 and A2 for November 1980 and at sites J1 and 

J5 for December 1979.. ...................... 38 

8. Relation between pine needle litter for the 'year' (February-January) 

and the litter collected during the first five months of the 'year' 

(February-June). ......................... 3 9 

9. Monthly herb and hardwood litter collected at sites El and E2. 

Note the increase in this component immediately following a 

prescribed burn of Block E in September 1980. ............ 40 

10. Relation between pine needle litter for the 'year' (February-January) 

and the total basal area of pine trees in the immediate vicinity. ..... 41 

iii 

I 7 ,n- -- .. F.!.U. UREAPI G REG. Dr23. -.-. 
INTRODUCTION 

In December 1978, a study was initiated under the Pinelands Fire Ecology project 

to investigate leaf litter fall in the pinelands of Everglades National Park. The 

study had limited aims at this time. We hoped to demonstrate a short-term 

increase in litter fall caused by fire and to compare the effects of cool (with little 

or no scorch of needles in the overstory trees) and hot (with heavy scorch) burns. 

Late in 1979, the scope of the study was expanded to include an examination of 

overall patterns in leaf litter fall throughout Long Pine Key. Leaf litter collection 

was carried out over the whole area during 1980 and the first half of 1981. 

Thereafter, collection was abandoned on various dates at the different sites (see 

below and Table 1) with the last litter collections taking place in June 1982. 

Description of the Study Area 

The pinelands of Everglades National Park represent the southwestern limit of the 

Miami Rock Ridge pinelands. They are dominated by an overstory of Pinus elliottii 

var. densa and a shrub layer of predominantly tropical hardwoods and palms. An 

herbaceous layer is also well developed in openings between the shrubs. The ground 

surface is very rough; eroded oolitic limestone is very commonly exposed at the 

ground surface in Long Pine Key. Soil is very shallow and often confined to 

sinkholes and cracks in the rocks. A thin layer of leaf litter (principally pine straw) 

covers the surface. Frequent fires remove the litter layer before an organic soil 

can be formed except in sinkholes and other protected sites. 

General descriptions of the pinelands vegetation in southern Florida can be found in 

Harshberger (19141, Harper (19271, and Davis (1943). More details on the pinelands 

in Everglades National Park can be found in Robertson (1953), Loope et al. (1979), 

Taylor and Herndon (1 981), and Olmsted et al. (1983). 

It is important to remember that the litter collection sites are in very diverse 

surroundings. There is a general trend in Long Pine Key with high, well developed 

pineland toward the eastern end and lower-lying stunted pinelands in the west. In 

addition, there are numerous local variations in topography and substrate which 

profoundly influence the mix of pines, hardwoods, and herbaceous plants at a given 

site. 

Materials and Methods 

Each litter collection site consisted of 20 plastic trays laid out in a more-or-less 

regular grid pattern covering approximately 180 square meters. The grids were 

laid out in four rows of five trays each with approximately 3 m separation between 

adjacent trays and adjacent rows. 

Three different tray sizes were used in setting up the collection sites. Those first 

obtained '(used at sites 12, J1, 52, J4, and J5) were 4 by 51 cm with 6 cm high t 2 sides. This gave a collecting surface of .I224 m per tray or 2.448 m per 

collection site. All sites set out later (with the exception of E3) had trays with 

dimensions 33 by 46 cm with 8 cm high sides. At these sites, the collecting 
2 2 surface was .I518 m per tr4y or 3.036 m per gte. The trays at E3 had a 

' collecting surface of .I935 m per tray or 3.870 m for the site. All trays had 

drainage holes in the bottom. The largest drainage holes were approximately 1 cm 

by K cm in size. Of the various units which made up the leaf litter, only the seeds 

of Pinus elliottii and Dodonaea viscosa could pass through this size hole easily. 

These were a negligible component of the litter, so measurement inaccuracy from 

this source was of no consequence. 

?'he grids were placed so the trays were 10 m or more distant from roads to 

minimize edge effect. Grids were paced off and the trays set on as nearly level an 

area as possible near the grid point. Owing to the very rough nature of the ground 

surface at some sites, it was impossible to lay out a very regular grid. With a few 

exceptions, the trays were left at their original locations throughout the study. 

The exceptions came in Block E where all trays had to be taken up to allow a 

prescribed burn in the block. The grids were reestablished in their original 

locations, but no attempt was made to ensure that trays were returned to the same 

positions. 

0 

Trays of the size used are adequate to measure leaf litter in the pinelands due to 

the nature of the vegetation. Air movement near the surface is almost eliminated 

by the combined effects of the pine canopy and the shrub layer. Furthermore, the 

major components of the leaf litter fall (Pinus elliottii, Guettarda scabra, 

Tetrazygia bicolor, and Myrsine florida leaves) are quite heavy and have little or no 

tendency to drift. The walls of the trays were considered adequate to hold 

material in the tray which fell in and to exclude materials which fell outside. 

Four collection sites were established in Block J of Long Pine Key (see Fig. 1, sites 

J1, J2, 54, and J5) following a prescribed burn (backing fire with no scorch) on 

December 18, 1978. A ltcontroll' plot was established at the same time in Block I 

(Fig. 1, site 12). The pinelands at this site had last been burned two years 

previously (in January 1977). Soon thereafter, two additional collection sites were 

set up in Block N (Fig. 2) following a prescribed burn. A head fire was used in this 

burn which left several areas of badly scorched pines. The litter collection sites 

were set deliberately under badly scorched pines. Fifteen new collection sites 

were established in the pinelands (Fig. 1) in November and December 1979 and in 

January 1980 when the scope of the study was expanded. Also, a collection site 

was later set up in Block E (Fig. 1, site E3) for a short time. This collection site 

was in an area of badly scorched trees and was intended to measure the short-term 

effect of fire on pine needle fall. Important data associated with each collection 

site are given in Table 1. 

Leaf litter collections continued at all sites through June 1981. Blocks A and B 

were burned in July of 1981 and the collection sites in those blocks were abandoned 

at that time. In August 1981, Tropical Storm Dennis inundated the low pinelands 

in the western half of Long Pine Key. Many of the litter collection sites were 

flooded. These sites were abandoned at that time. Collection at sites in Block N 

was discontinued a short time thereafter. And, finally, all remaining collection 

was suspended in June 1982, 

In general, litter was collected every two or three weeks. Often, it was collected 

more frequently following a prescribed burn in order to study any effect the fire 

might have on leaf litter fall in more detail. The major methodological problem 

encountered in litter collection was deciding when to collect fronds from Sabal 
palmetto, Serenoa repens, and Pteridium aquilinum. In each of the species, the old 

frond is not shed at a single point in time, rather, it bends slowlv closer to the 

ground over a period of weeks or months. But,.a dead frond near the ground 

affects fire behaviour in substantially the same manner as a dead frond on the 

ground, so the parts of dead fronds over a litter tray which were close enough to 

the ground were clipped and added to the litter sample. We had to choose an 

arbitrary height below which these fronds would be considered litter. A height of 

30 cm was chosen as the cutoff point since dead grass clumps and draped pine 

needles could often be found at that height but not much above. 

All material collected in the trays was taken to the lab and oven dried. 

Afterwards, it was separated into components and weighed to the nearest .1 gm. 

Initially, the litter was divided into "pine needle" and "other litter" categories, but 

starting in January 1980, "pine other" was separated out. The categories finally 

used then were !'pine needle", "pine other", and "herb and hardwood". 

"Herb and hardwood" litter was composed mostly of hardwood leaves with 

Pteridium aquilinum fronds supplying the only important herbaceous component. 

However, the Pteridium aquilinum fronds were a major source of litter in a few 

localities. 

2 

Raw litter fall values for each category were converted to litter fall per m per 

day values which were summed to provide total litter fall values for each calendar 

month. 

A complete set of litter fall values is available for all sites only from February 

1980 on, so most of our analysis involving all sites uses litter fall values for the 

twelve month period February 1, 1980 - January 31, 1981 rather than a calendar 

year. In fact, values for the February-January period will differ little from 

calendar year values since litter fall is relatively low during the winter months. On 

occasion, we will use other periods in comparisons. 

RESULTS 

Pine needle fall was the major source of input to the litter lay? in Long Pinepey. 

At our collection sites, total needle fall ranged from 100 gm/m to 350 gm/m for 

the 12 month period, February 1980-January 1981. This accounted for approximately 70 percent of the total litter fall. 

In Table 2, monthly values of pine needle fall for each collection site are given. 

Average values of needle fall were also calculated for each block in Long Pine Key 

which contained collection .sites. These averages are shown as bar graphs in 

Figures 3-5. 

Pine needle fall exhibits a seasonal pattern with a broad peak occurring in the 

period April-November, and a period of depressed needle fall from DecemberMarch (Fig. 3-5). No one month stands out as the peak month for needle fall. 

Casual observations suggest that local rainstorms and their accompanying winds 

were important factors in determining the timing of needle fall at any given 

location. In fact, the general annual pattern in pine needle fall corresponds roughly 

to the pattern of rainfall in South Florida. However, needle fall begins to increase 

approximately one month before the wet season typically begins. 
. Using the three year record of litter fall from collection sites 12, J1, 52, 54, and 

55, we can get some idea of the year-to-year variation in needle fall. Calendar 

year needle fall for each of these sites is given in Table 3. A large increase in 

needle fall for the year 1981 relative to 1979 and 1980 is immediately apparent. 

The increase is also striking if we look at a graph of monthly pine needle fall for 

site 54 for the same three years (Fig. 6). Note that the increase was spread over 

the whole year and not confined to any particular season. 

In calculating the yearly totals for Table 3, it was necessary to estimate values for 

data missing in December 1979 at sites Jl and J5. This was done for site Jl by 

calculating a regression line between the monthly needle fall at site 52 and Jl and 

using the observed needle fall at 52 to estimate the missing value. The same 

procedure was followed to estimate the missing value for site 55. The graphs in 

the right half of Figure 7 show the regression lines used to make the estimates and 

the scatter of observed points about the regression line. 

We then used the litter fall data collected at all sites during the five months, 

February-June 1981, to determine whether the increase in needle fall observed at 

the I and J sites was local. First, we constructed a graph of needle fall for the 

period February 1980-January 1981 versus needle fall for the period February-June 

1980 (Fig. 8). From this graph, it is apparent that the needle fall in the five 

months (February-June) of the year is strongly related to needle fall for the entire 

year (February-January). 

In obtaining the yearly totals for needle fall, we had to estimate needle fall at sites 

A1 and A2 for August 1980. This was done in the manner outlined above for sites 

Jl and 55 using site 82 as our standard. The regression lines used and the scatter 

of observed values about them are shown in the left half of Figure 7. 

On calculating yearly (February-January) needle fall for all plots using a regression 

line derived from ye graph in Figure 8, w? estimate an average needle fall for 

1981 of 241 gm/m versus the 208 gm/m measured in 1980 (Table 4). This 

corresponds to an average 15 percent increase in needle fall over Long Pine Key. 

At the I and J sites, where a direct comparison could be made, the average 

increase was 30 percent. This suggests the increase in needle fall was unevenly 

distributed with the bettersites (for pines) showing more response, but we do not 

have enough data to investigate this possibility. The significance of the observed 

increase in needle fall was tested using the Wilcoxon matched-pairs signed-ranks 

test (Sokol and Rohlf 1969). There is less than 1 percent probability that the 

observed increase could be due to sampling error. 

We are not sure what led to the observed increase in needle fall. Two possibilities 

are suggested: 

1. The increase in needle fall in 1981 is a consequence of better than average 

growth during 1980, or, 

2. The increase may have been due to shedding of younger than normal leaves as 

a result of drought conditions in early 1981. 
Other pine litter is composed of branches, flakes of bark, and both seed and pollen 

cones. Overall, this component accounted for about 25 percent of the total litter 

fall. Table 2 contains monthly values of other pine litter at each of the collection 

sites. 

This component was much more variable than pine needle fall. There was no 

pattern of maximum litter production in any season. In fact, the litter collection 

sites were too small to measure the other pine component effectively. It is clear, 

however, that rain storms and the associated winds tend to knock dead branches 

and loosely held pieces of bark off the trees. 

It is worth noting that most of the pine branches collected in the litter trays had 

been subjected to a fair amount of weathering on the tree. They are not fresh 

when they reach the ground, and not all are the same age. This should be 

recognized when studying or modelling the decomposition of pine stems on the 

forest floor. 

Herb and hardwood litter was composed primarily of leaves shed by the understory 

shrubs. However, at some sites, fronds from Pteridium aquilinum and/or Serenoa 

repens were very important, even dominant, parts of this component. As discussed 

above, fronds of these two species were collected whenever they fell within 30 cm 

of the ground level. See Table 2 for monthly values of this component at the 

collection sites. 

Litter in this component is primarily dependent on the size and density of the 

shrubs near the collection site. The size of the shrubs is primarily dependent on 

the time they have had to recover from the last fire. All areas of Long Pine Key 

are burned frequently enough (every 3-8 years) that most hardwoods have no 

chance to reach any environmental limit to their growth. In Table 5 herb and 

hardwood litter for the 12-month period, February 1980-January 1981, is given 

along with the corresponding fire-free period. An increase in litter with increasing 

fire-free period is suggested though the relationship is evidently complex. Further, 

in Table 6, herb and hardwood litter for the period February-December 1980 is 

compared directly to herb and hardwood litter for February-December 1981 at all 

sites for which sufficient data were available. There is generally an increase in 

this component from 1980 to 1981, but it is small. Using a Wilcoxon matched-pairs 

signed rank test, it was found that the difference is not significant at the 5 percent 

level. 

An especially interesting case to consider with regard to the influence of fire on 

herb and hardwood litter is that of the two collection sites in Block E. This block 

was burned in September 1980, following several months of litter collection at sites 

El and E2 within the block. As can be seen in Figure 9, at El, which had a low 

herb and hardwood litter level initially, the most obvious effect of the burn is an 

abrupt increase in this component starting right after the burn and lasting some 

three months. At E2, with a high initial herb and hardwood litter level, an increase 

of the same duration is observed followed by an abrupt depression of this 

component some four months after the fire (once most of the fire-killed leaves had 

been shed). 
DISCUSSION 

One of the original motivations for collecting leaf litter was to study the effect of 

hot fires on pine needles. Three collection sites set in areas of heavily scorched 

pines (Nl, N2, and E3) are available to look at this subject. 

In Table 9, the pine needle fall at each site following fire is shown in detail. The 

needle fall for any given period post-fire was obtained by linear interpolation 

between collection dates. Immediately following the fire, a 10-day period is used 

to show maximum detail. Later, a 20-day period is used. 

Note first the similarity between the pattern shown at sites N1 and N2. There is a 

delay between the time of the fire and the period of major needle fall. And, by the 

end of 30 days, some 80 percent of the needles falling within six months of the fire 

had fallen. 

The pattern followed by needle fall at site E3 is hardly similar. Unfortunately, the 

first post-fire dollection was made too late to see if there was any delay between 

the fire and the onset of heavy needle fall. We see that the heaviest needle fall 

occurred within 60 days of the fire, but thereafter, the needle fall at E3 remained 

high. 

There are no clear reasons for the difference in needle fall patterns. However, it 

might be significant that Block N was burned in February while Block E was burned 

in September. 

Considering the predominant influence pine needle fall has on the accumulation of 

leaf litter in Long Pine Key, we looked for a means of predicting needle fall based 

on stand characteristics of the trees surrounding the collection sites. Alsbut the 

two collection sites in Block N fit into a rectangle 15 m by 20 m (300 m ). The 

DBH (diameter at breast height) for each tree within these rectangles was 

measured. Several stand characteristics were computed using these measurements 

and tested as predictors of pine needle fall. 

Stand characteristics considered included local pine density, the average DBH of 

the trees around the site, the total DBH (or, equivalently, the total basal area) of 

the trees around the site, and the dominance factor defined as (basal area) x 

(density) of the local pines. Of these stand characteristics, the best predictor of 

pine needle fall was total basal area (or DBH). Table 7 gives the values used in 

these calculations. A graph of the relationship found between needle fall and the 

basal area of the pines is shown in Figure 10. The strength of the relationship is 

evident. The only point diverging seriously from the average line is that for 

site N1, which had much lower needle fall than would be predicted from the pine 

DBH. This might be due to a persistent reduction in crown needle weight traceable 

to the severe scorch suffered by the plants in 1979. Note however, that the graph 

only implies that relative needle fall in two areas will be proportional to the 

difference between total DBH of the pines in the areas. A change in needle fall 

such as was seen between 1980 and 1981 can only be detected by maintaining 

collecting sites. 
A summary of the leaf litter fall at each collection site is given in Table 8. 

Perhaps the most important result to be obtained from this table is an appreciation 

for the variability shown by litter fall from site to site. The total litter fall and 

each of the components vary by a factor of three or more across Long Pine Key. 

This has important implications for any fire management program. 

To see the implications of leaf fall variability, assume that pine litter is the only 

source of qurnable fuel in the pinelands and further assume that a fuel density of 

800 gm/m is necessary to carry a fire in the pinelands under prescribed burning 

conditions. Then you see that the pinelands around sites I2 and J1 can potentially 

be burned every two years while the pinelands around site A1 require more than 

five years for sufficient fuel build-up to support a burn. 

The model presented above is greatly oversimplified, but the general conclusion 

that different areas within Long Pine Key burned on different natural frequencies 

is clearly realistic. The current uniform treatment of the blocks under the Fire 

Management Plan has no biological just if ication. 

SUMMARY AND CONCLUSIONS 

Our study of the patterns of leaf litter fall in Long Pine Key has led to several 

important conclusions. 

1: Pine needles make the largest contribution to the litter layer on the forest 

floor. They represent 70 percent of the total litter fall by mass. 

2. It is possible to predict relative pine needle fall at a site from the total basal 

area of the pines around the site. 

3. Litter fall is variable by a factor of about three for our collection sites. 

4. Pine needle fall increased by about 15 percent in 1981 relative to 1980 when 

all sites were considered. The increase at the sites toward the east end of 

Long Pine Key was 30 percent. 

5. The nonuniform distributions of pines in Long Pine Key leads to local 

variations in the rate of fuel accumulation which can greatly affect the 

potential fire frequency at any given site. 

6. Any attempt to burn the different blocks in Long Pine Key according to a 

fixed, uniform schedule is biologically unrealistic. 

ACKNOWLEDGEMENTS 

Most of the seasonal employees connected with the Fire Ecology Program have 

shared in the collection and analysis of the litter fall data. Those who helped set 

out the litter sites and collect the data in the early stages of the program were: 

James Craig, Lynette McLamb, Todd Steiner, and Ken Vernick. Later, help in 

collecting data came from Donna Blake, Anthony Caprio, and Lewis Sharman. 

Anthony Caprio collected the DBH measurements on the trees surrounding the 

collection sites. 
Earlier versions of this report were reviewed by Lance Gunderson, William B. 

Robertson, Jr., Regina Rochefort, and James Snyder. Their comments contributed 

greatly to our understanding of the subject. We also thank Jessie Brundige for 

typing the manuscript. 
LITERATURE CITED 

Davis, J. H., Jr. 1943. The natural features of southern Florida, especially the 

vegetation and the Everglades. Fla. Geol. Surv. Bull. 25. 3 11 p. 

Harper, R. M. 1927. Natural resources of southern Florida. Fla. Geol. Surv., 18th 

Ann. Rept., Tallahassee. p. 25-206. 

Harshberger, J. W. 1914. The-vegetation of south Florida, south of 27, 30' north, 

exclusive of the Florida Keys. Trans. Wagner Free Inst. Sci., Philadelphia 7: 

49-189. 

Loope, L. L., D. W. Black, S. Black, and G. N. Avery. 1979. Distribution and 

abundance of flora in limestone rockland pine forests of southeastern Florida. 

National Park Service, South Florida Research Center Report T-547. Everglades National Park, Homestead, FL. 38 p. 

Olmsted, I., W. B. Robertson, and Jill Johnson. The Vegetation of Long Pine Key, 

Everglades National Park. National Park Service, South Florida Research 

Center Report SFRC-83/05. Everglades National Park, Homestead, FL. 

64 p. 

Robertson, W. B., Jr. 1953. A survey of the effects of fire in Everglades National 

Park. U. S. National Park Service. 169 p. 

Taylor, D. L., and A. Herndon. 1981. Impact of 22 years of fire on understory 

hardwood shrubs in slash pine communities within Everglades National Park. 

National Park Service, South Florida Research Center Report T-640. Everglades National Park, Homestead, FL. 30 p. 
Table 1. Summary of the important characteristics of each leaf litter collection 

plot. 

Area of Collecting Period of 

Date Surface qt Site Litter 

Block Site Established (m Collect ion 

13 Dec 79 

13 Dec 79 

Jan 80 - Jun 81 

Jan 80 - Jun 81 

11 Dec 79 

11 Dec 79 

13 Dec 79 

Jan 80 - Jul81 

Jan 80 - Jul81 

Jan 80 - Jun 81 

19 Dec 79 Jan 80 - Jul81 

Jan 80 - Jul81 

Jan 80 - Jul81 

Oct 80 - Jun 81 

11 Dec 79 

11 Dec 79 

23 Sep 80 

29 Nov 79 

29 Nov 79 

29 Nov 79 

Jan 80 - Jul81 

Jan 80 - Jun 81 

Jan 80 - Jun 81 

10 Dec 79 

17 Dec 79 

10 Dec 79 

Jan 80 - Jun 81 

Jan 80 - Jul82 

Jan 80 - Jul81 

17 Dec 79 

18 Dec 78 

Jan 80 - Jul82 

Jan 79 - Jul82 

18 Dec 78 

18 Dec 78 

18 Dec 78 

18 Dec 78 

Jan 79 - Jul82 

Jan 79 - Jul82 

Jan 79 - Jul82 

Jan 79 - Jul82 

6 Feb 79 

6 Feb 79 

Mar 79 - Aug 81 

Mar 79 - Aug 81 
Table 2. Monthly litterfall values at each litter collection site. 

Pine Other Herb and 

Needle Pine Hardwood 

Month Year Litter Litter Litter 

Collection Site A1 

January 1980 

February 

March 

April 

May 

June 

July 

August 

September 

October 

November 

December 

January 1981 

February 

March 

April 

May 

June 

Collection Site A2 

January 1980 

February 

March 

April 

May 

June 

July 

August 

September 

October 

November 

December 

January 1981 

February 

March 

April 

May 

June 

Total 

Litter 
Table 2 continued. 

I Month Year 

Collection Site B1 

January 1980 

February 

March 

April 

May 

June 

July 

August 

September 

October l 

November 

December 

January 1981 

February 

March 

April 

May 

June b 

July 

Collection Site B2 

January 1980 

February 

March 

April 

May 

June 

July 

August 

September 

October 

November 

December 

January 1981 

February 

March 

April 

May 

June 

July 

Pine 

Needle 

Litter 

Other 

Pine 

Litter 

Herb and 

Hardwood 

Litter 

Total 

Litter 
Table 2 continued. 

Month Year 

Collection Site B3 

January 1980 

February 

March 

April 

May 

June 

July 

August 

September 

October 

November 

December 

January 1981 

February 

March 

April 

May 

June 

Collection Site C1 

January 1980 

February 

March 

April 

May 

June 

July 

August 

September 

October 

November 

December 

January 1981 

February 

March 

April 

May 

June 

July 

Pine 

Needle 

Litter 

Other 

Pine 

Litter 

Herb and 

Hardwood Total 

Litter Litter 
. Table 2 continued. 

Month Year 

I Collection Site E 1 

January 1980 

February 

March 

April 

May 

June 

July 

August 

September 

October I 

November 

December 

January 1981 

February 

March 

April 

May 

June 

July 

Collection Site E2 

January 1980 

February 

March 

April 

May 

June 

July 

August 

September 

October 

November 

December 

January 1981 

February 

March 

April 

May 

June 

July 

Pine 

Needle 

Litter 

Other 

Pine 

Litter 

Herb and 

Hardwood 

Litter 

Total 

Litter 
Table 2 continued. 

Month Year 

Collection Site E3 

October 1980 

November 

December 

January 1981 

February 

March 

April 

May 

June 

Collection Site F1 

January 1980 

February 

March 

April 

May 

June 

July 

August 

September 

October 

November 

December 

January 1981 

February 

March 

April 

May 

June 

July 

Collection Site F2 

Pine 

Needle 

Litter 

Other 

Pine 

Litter 

Herb and 

Hardwood 

Litter 

Total 

Litter 

January 1980 

February 

March 

April 

May 

June 

July 
Table 2 continued. 

Month Year 

August 

September 

October 

November 

December 

January 1981 

February 

March 

April 

May 

June I 

Collection Site F3 

January 1980 

February 

March 

April 

May 

June 

July 

August 

September 

October 

November 

December 

January 1981 

February 

March 

April 

May 

June 

Collection Site H1 

January 1980 

February 

March 

April 

May 

June 

July 

August 

September 

Pine 

Needle 

Litter 

Other 

Pine 

Litter 

Herb and 

Hardwood 

Litter 

Total 

Litter 
Table 2 continued. 

Month Year 

October 

November 

December 

January 1981 

February 

March 

April 

May 

June 

Collection Site H2 

January 1980 

February 

March 

April 

May 

June 

July 

August 

September 

October 

November 

December 

January 1981 

February 

March 

April 

May 

June 

July 

August 

September 

October 

November 

December 

Collection Site H3 

Pine Other 

Needle . Pine 

Litter Litter 

Herb and 

Hard wood Total 

Litter Litter 

January 1980 

February 

March 

April 
b 

Table 2 continued. 

Pine 

Needle 

Month Year Litter 

May 

June 

July 

August 

September 

October 

November 

December 

January 

February 

March 

April 

May 

June 

July 

Collection Site I1 

January 

February 

March 

April. 

May 

June 

July 

August 

September 

October 

November 

December 

January 

February 

March 

April 

May 

June 

July 

August 

September 

October 

November 

December 

Other 

Pine 

Litter 

Herb and 

Hardwood 

Litter 

Total 

Litter 
Table 2 continued. 

Month Year 

Collection Site I2 

January 1979 

February 

March 

April 

May 

June 

July 

August 

September 

October 

November 

December 

January 1980 

February 

March 

April 

May 

June 

July 

August 

September 

October 

November 

December 

January 1981 

February 

March 

April 

May 

June 

July 

August 

September 

Octobei 

November 

December 

Collection Site J1 

January 1979 

February 

March 

Pine 

Needle 

Litter 

Other 

Pine 

Litter 

Herb and 

Hardwood 

Litter 

Total 

Litter 
Table 2 continued. 

Month Year 

April 

Fvlay 

June 

July 

August 

September 

October 

November 

December 

January 1980 

February 

March I 

April 

May 

June 

July 

August 

September 

October • 

November 

December 

January 1981 

February 

March 

April 

May 

June 

July 

August 

September 

October 

November 

December 

Collection Site J2 

Pine 

Needle 

Litter 

16.96 

17.08 

35.09 

44.99 

46.78 

37.07 

26.56 

25.63 

18.82 

15.58 

23.12 

22.34 

50.03 

62.46 

27.60 

18.50 

25.96 

24.75 

28.64 

32.45 

14.80 

17.05 

27.79 

27.29 

25.66 

53.31 

52.80 

54.20 

48.83 

51.75 

55.42 

29.13 

21.46 

Other 

Pine 

Litter 

Herb and 

Hardwood 

Litter 

Total 

Litter 

January 1979 

February 

March 

April 

May 

June 

July 
Table 2 continued. 

Month Year 

August 

September 

October 

November 

December 

January 1980 

February 

March 

April 

May 

June 

July 

August 

September 

October 

November 

December 

January 1981 

February 

March 

April 

May 

June 

July 

August 

September 

October 

November 

December 

Collection Site J4 

January 1979 

February 

March 

April 

May 

June 

July 

August 

September 

October 

November 

December 

January 1980 

Pine 

Needle 

Litter 

29.09 

29.02 

24.97 

17.58 

14.47 

10.56 

9.02 

8.76 

3 1.96 

52.18 

24.44 

30.43 

28.07 

24.39 

32.63 

22.39 

11.73 

10.46 

13.87 

17.56 

38.53 

65.3 9 

47.75 

42.46 

31.28 

26.52 

32.89 

18.79 

22.44 

Other Herb and 

Pine Hardwood Total 

Litter Litter Litter 
Table 2 continued. 

Pine 

Needle 

Month Year Litter 

February 9.19 

March 12.42 

April 47.64 

May 51.76 

June 30.18 

July 34.94 

August 32.31 

September 21.76 

October 27.15 

November 30.27 

December 14.44 

January 1981 11.98 

February 19.60 

March 18.41 

April 29.27 

May 66.41 

June 60.07 

July . 52.77 

August 41.08 

September 28.30 

October 35.96 

November 24.37 

December 27.00 

Collection Site 55 

January 1979 

February 

March 

April 

May 

June 

July 

August 

September 

October 

November 

December 

January 1980 

February 

March 

April 

May 

Other 

Pine 

Litter 

Herb and 

Hardwood 

Litter 

4.16 

1.30 

1.12 

1.44 

.94 

.01 

.74 

.64 

1.04 

.13 

1.42 

1.39 

.66 

1.25 

1.17 

.95 

.44 

.33 

.oo 

.18 

.48 

.82 

1.81 

Total 

Litter 

20.13 

17.23 

66.20 

58.09 

32.76 

37.87 

35.51 

26.99 

29.92 

31.85 

16.82 

14.94 

24.85 

49.16 

31.29 

70.34 

62.55 

58.81 

196.37 

31.22 

41.81 

27.78 

30.33 
Table 2 continued. 

Month Year 

June 

July 

August 

September 

October 

November 

December 

January 1981 

February 

March 

April 

May 

June 

July 

August 

September 

October 

November 

December 

Collection Site N1 

March 1979 

April 

May 

June 

July 

August 

September 

October 

November 

December 

January 1980 

February 

March 

April 

May 

June 

July 

August 

September 

October 

November 

Pine 

Needle 

Litter 

Other 

Pine 

Litter 

Herb and 

Hardwood 

Litter 

1.52 

.67 

1.10 

3.08 

-5 1 

.64 

.56 

.99 

1.18 

2.54 

4.09 

2.58 

1.26 

.98 

1.53 

.87 

1.57 

1.53 

2.45 

Total 

Litter 

21.60 

28.55 

29.88 

20.62 

19.42 

24.00 

25.21 

24.21 

31.57 

33.50 

28.35 

48.49 

40.46 

40.93 

36.08 

40.30 

60.55 

27.59 

23.95 
Table 2 continued. 

Month Year 

December 

January 1981 

.February 

March 

April 

May 

June 

July 

August 

Collection Site N2 

March 

April 

May 

June 

July 

August 

September 

October 

November 

December 

January 

February 

March 

April 

May 

June 

July 

August 

September 

October 

November 

December 

January 

February 

March 

April 

May 

June 

July 

August 

Pine 

Needle 

Litter 

Other 

Pine 

Litter 

Herb and 

Hardwood Total 

Litter Litter 
2 Table 3. Needle fall (gm/m ) in Blocks I and J for calendar years 1979, 1980, 

and 1981. 

Block Site 1979 1980 1981 

I 2 363.41 323 .OO 424.56 

* Data missing for December 1979, value estimated as described in text. 
Table 4. Calculation of pine needle fall values for 1981 using measured values 

from the first five months. 

Calculated 

Block Site Needle Fall Needle Fall Needle Fall Needle Fall 

2180-5/80 2180-4/81 2/81 -9181 2181-3/82 

(gmlm ) (gmlm 1 (gm/m ) (gmlm ) 

2 Needle Fall (2180-1/81) = 1.4829" Needle Fall (2180-6/80) +90.46 gm/m . 

* data missing for November 1980, value estimated as explained in text. 
Table 5. Herb and hardwood litter collected in each block for the period February 

1980 - January 1981 with the fire-free period at t h e s t a r t of collection. 

Number Total Herb and Mean Herb and Months since 

Block Of sites Hardwood Litter Hardwood Litter Last Fire as of 

2180-1 191 2180-1/91 January 1980 

(gm/m (gmlm 

** earlier records not clear, but at least 60 months. 
b 

Table 6. A direct comparison of herb and hardwood litter for two consecutive 

years. There is an increase in this component of litter with fire-free 

period. 

Block 

Herb and Herb and 

Site Hardood Litter Hardwood Litter 

2180-1290 2/81-1291 

(gmlm 1 (gmlm 1 
2 Table 7. Total basal area of pine trees in 300 m plot overlaying collection sites 

and pine needle fall at site. 

Density Pine Needle Pine Needle 

Block Site Bas9 Area (Trey Per Fall, 2/8021 181 Fall, 2/8126/81 

(m /ha) 300 m plot) (gm/m ) (gmlm 
. Table 8. Summary of litterfall atlndividual collection sites for the period February 

1 980 - February 198 1. 

Pine Pine Pine Herb and Total 

Block Site Need15 Othe5 Total2 Hardwyd Litte? 

(gm/m ) (gmlm 1 (gm/m ) (gm/m 1 (gmh ) 
2 Table 9. Pine needle fall (gm/m ) in sites under badly scorched pines. 

Days 

Post Fire 

Collecting Site 

Nl N2 E3 

-- 

30 (first collection) 

3 7 

143 

65 

60 

2 6 

63 

57 

66 
f 0 PINELAND HAMMOCK 

, IKM , 

N u . . . . . GLADE FORMER FARMLAND 

Figure I. Base map of Long Pine Key showing management blocks (A, B, C, 

and litter collection sites (1, 2, 3, etc.). 
8z 

B 

Z 

3 

P 

e 

Z 

W 

PlNE ISLAND PlNE BLOCKS 

Figure 2. Base map of Pine Island showing management blocks (M, N, 0, etc.) and 

litter collection sites (1, 2). 
Block 

Block 

Block 

JFMAMJJASONDJFMA

1980 198

Figure 3. Average monthly pine needle litter collected in management bloc

B, C, and E, Long Pine Key. 
" JFMAMJJASONDJFM

Figure 4. Average monthly pine needle litter collected in management bl

Hy and I, Long Pine Key. Missing data indicated by xxxxx. 
(gm.m-*) FALL NEEDLE PINE 
€ JFMAMJ JASON0 

JFMAMJJASOND 

MONTH 

Figure 6. Total monthly pine needle litter collected at site J4 during 1979, 1980, 

and 1981. 
82 - 1980 J5-1979 

PINE NEEDLE FALL (gm.m-2) 

Figure 7. Regression lines used to estimate monthly pine needle fall values at collection sites 

November 1980 and at sites J1 and J5 for December 1979. 
NEEDLE FALL, FEB -JUNE 1980 

(gm*m-2) 

Figure 8. Relation between pine needle litter for the 'year' (February-January) 

and the litter collected during the first five months of the 'year' 

(February- June). 
Figure 9. Monthly herb and hardwood litter collected at sites El and E2. Note the 

component immediately following a prescribed burn of Block E in September 1980
BASAL AREA (m2*ho-'1 

Figure 10. Relation between pine needle litter for the 'year' (February-January) 

and the total basal area of pine trees in the immediate vicinity.