Ecology And Environment

The Fundamental Principles of Ecology

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The Diversity, Abundance, and Distribution of Living Things In Their Environment:
IS "Ecology" defined.

What is Ecology?

The Diversity, Abundance, and Distribution of Living Things In Their Environment:
IS "Ecology" defined. Therefore, it is necessary to observe a given environment in order to understand how organisms adapt to alter, to survive in, or to perish in their environment. The most fundamental means by which an environment can be studied is through the discussion of the richness and diversity of the environment. Richness refers to the number of species within a large, representative area. Diversity refers to the species richness of an area in association with the evenness or equitability of distributed species abundance. By examining these factors with regard to a type of environment, one can begin to develop an understanding of the ecology of an environment. (V.E. Wamback, VE, 2007).

A study was conducted to determine the richness, dominance, and diversity of species within a one hundred meter square plot of a forest community (the forest on the SUNY Fredonia College campus). Observations were made regarding the density, richness, and estimated cover of vegetation, shrubbery, and herb life as well as soil invertebrates within the plot in order to mathematically calculate the diversity of species within the plot using the Shannon Diversity Index.

Because it is not conceivable to determine the richness and abundance within an entire community, it is necessary to use a plot approach by which a representative sample of the community is studied in order to make inferences about the community as a whole. This approach was used for the present study.

Methods: A 100 meter-square plot was flagged off in a Forest Community (the woods on the SUNY Fredonia College campus) in order to look at the richness and diversity of species within the forest environment. To examine the vegetation of the plot, the number of species of trees (tree richness) over 2.5 cm in diameter as well as the number of trees of each type (abundance) was recorded. Also, the tree trunk diameter at breast height (DBH) was measured and recorded. This data was used to calculate the Tree DBH diversity. Also, the percent cover of the trees was estimated according to the total cover of trees over the plot as well as with regard to each tree species over the plot. This estimated data was also used to calculate diversity of vegetation over the plot.

Within the plot, a representative 2 meter-square quadrant was flagged off to examine the shrubbery density, coverage, and diversity of the plot. Cover was again estimated according to total cover as well as cover by each shrub species. This data was used to calculate shrub cover diversity. Also, shrub density was determined according to the richness of shrubs as well as the abundance of each shrub species within the 2 meter-square quadrant.

Another quadrant of 1meter-square was used to examine the cover and density of herbs according to the richness and abundance of herbaceous species. This information was used to calculate the herb density within the plot according to both estimated cover and calculated density.

Finally, the edaphic analysis of the plot was conducted by collecting a soil sample from within a 0.5 meter-square quadrant. The richness and abundance of invertebrate species was recorded and the diversity of these species was calculated.

Results: Data collected for the 100 meter-square plot is shown in table 1. From this data, the diversity for each of the strata sampled was determined according to the Shannon Diversity Index (H'). For trees, the diversity was found to be 0.5 based on DBH and 0.563 based percent cover. For shrubs, diversity was found to be 1.06 based on density and 0.954 based on percent cover. For herbs, diversity was found to be 1.19 based on density and 0.924 based on percent cover. Finally, the diversity of invertebrates was found to be 1.041. This data was compiled with the data from other plots to create a quantitative representation of the Forest Community (SUNY Fredonia College forest. Table 2.).

Discussion: In examining the data collected, it appears that there is an overall equitable distribution of species within the Forest Community (forest on the SUNY Fredonia College campus), however within each sub-group sampled, there appears to be different distributions depending upon the plot. For example, in examining the data found for tree diversity based on DBH, there appears to be a wide distribution of diversity ranging from zero to 1.46 across the six plots. This demonstrates that the density of certain species of trees within some plots, as is seen in plot #1, is high and the diversity of species of trees within the plot is low. Similarly, in plot #4, based on the diversity index of 1.46, it is seen that the diversity of different tree species is high and the spread of these species is even.

Diversity indices for plot #6 show little difference between calculations based on diversity versus those based on cover across the four sampling categories. This may be due to the fact that the plot demonstrated a low level of richness and density, thus allowing for accurate estimations of cover per species.


Freeman, Scott. (2005). Biological Science, Second Edition. Prentice Hall, Upper Saddle,

SUNY Fredonia Biology Department. (2005). Richness, Diversity, Dominance: Vegetation and Soil Invertebrate Analysis. SUNY Fredonia College, Fredonia, NY.

Wamback, Victoria E. (2007); Victoria E. Wamback, Biologist. (2007). The Diversity, Abundance, and Distribution of Living Things In Their Environment: Ecology Defined.
State University of New York, College at Fredonia, NY, Biology Department. May 2007.

Table 1.
Richness, density, and estimated cover for vegetation, shrubs, herbs, and invertebrates in a 100 meter-square plot in the Forest Community

Vegetation Shrubs Herbs Invertebrates
Richness 2 3 4 2

Density 4 Maples 1 Hickory 4 Honeysuckle 3 Hickory 2 Baby oak 9 Daisy
"1" Moss 4 Grasses 7 "Other" 2 Crustacea 2 Enchytraeid Worms
Total Cover Per-cent 80 % 35 % 58 %

Cover per-cent for each species 60 % Maple20 % Hickory 20 % Honeysuckle10 % Hickory
5 % Baby oak 5 % Daisy 40 % Moss 10 % Grass 3 % "Other"

Table 2.
Quantitative representation of the Forest Community. Data was collected from six 100 meters-square plots to examine the diversity of vegetation, shrubs, herbs and invertebrates species within the forest.
Plot #
(density) Tree Diversity (coverage) Shrub Diversity (density) Shrub Diversity (coverage) Herb Diversity (density) Herb Diversity (coverage) Invertebrate

1 0.000 0.000 0.760 0.650 1.070 1.080 0.000
2 0.866 0.922 0.951 0.191 1.036 0.806 1.386
3 0.693 0.693 0.000 0.000 0.860 1.040 0.347
4 1.460 1.070 1.550 1.470 0.530 0.660 1.090
5 0.500 0.546 0.617 0.540 0.955 1.348 0.562
*6 0.500 0.563 1.060 0.954 1.190 0.924 1.041

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