Tree Density and Diversity

Tree density and diversity in a forest is extremely important to an ecosystem. Ecosystems are very complex. Individuals should know and learn the history of any ecosystem they are attempting to study, including its soil type, moisture, structure, and composition (Thompson et al. 2002). Many factors play a role in the composition of these forests. Affecting the forest in negative and positive ways. I had the opportunity to study, measure and compare an upslope site and a down a down slope site in the same forest. I used two different sections of Rugar woods, Plattsburgh New York, surveyed and compared them, an upslope site and a downslope site were chosen. A 10 by 10 meter section of each site was measured out and the trees with in this section that were larger than 10cm were measured at breast height and the species were determined based on the bark and remaining leaves. Forest are affected by many different abiotic and biotic factors (Satake et al. 1989). Abiotic factors may include the amount of sunlight that reaches through the canopy to the forest floor to provide seedlings with sunlight to grow. Another factor may be soil moisture and nutrients, which is extremely detrimental to various seedlings growth and survival. Biotic factors include the herbivores that inhabit the forest. Herbivores may include deer, rabbits and squirrels. These animals help spread seedlings through out the forest creating a greater diversity of trees and other shrubs in various areas. Also herbivores help provide nutrients to the forest floor through the work of their digestive tracts, their feces can provide essential nutrients to the soil to help seedlings thrive and grow in to trees and other shrubs. Herbivores have a strong correlation to light availability with in forest (Rosenthal et al. 1994). After grazing of herbivores there becomes more light availability to the forest. Therefore the forest is able to regenerate itself. 

Figure 1. Relative density (trees/ha) of three species of trees sampled at a down-slope site in Rugar woods, Plattsburgh New York February 2013.  

  

Figure 2.  Relative density (trees/ha) of three species of trees sampled at an upslope site in Rugar woods, Plattsburgh New York February 2013.   

   

Figure 3. Relative dominance of trees sampled in Rugar woods, Plattsburgh New York February 2013.   

Key

THU OCC- Northern White Cedar

PIN STR- White Pine

FRA AME- White Ash

PIN RIG- Pitch Pine

Works Cited

Adams, Dwight E., and Roger C. Anderson. "Species Response to Moisture Gradient Forest." Species Response to Moisture Gradient Forest 67.3 (1980): n. pag. Botanical Society of America. Web.

Thompson, Jill, Nicholas Brokaw, and Jess K. Zimmerman,' "Land Use History, Environment, And Tree Composition In a Tropical Forest." Land Use History, Environment, And Tree Composition In a Tropical Forest. (2002): n. pag. Ecological Society of America. Web.