Download Full Text (664 KB)
Dr. Jordan Marshall
Department of Biology
Indiana University – Purdue University Fort Wayne
In the Midwest region of the United States, forested areas have been removed to make way for agriculture and settlement. In the southern Midwestern states, including Indiana, cultivated and pasture agriculture lands account for 80-90% of rural landscapes. The remaining forests have been fragmented into small, often privately owned, woodlots. Due to their size, these forests typically have a high edge to interior ratio, which creates a greater influence of the surrounding agricultural land matrix upon the forest itself. Fragmentation influences the species in these forests through the distance between, size, age, and shape of the forest in addition to management. By quantifying the intensity of these factors on plant species, management strategies could be modified to improve the ecological function of the fragments. We surveyed thirty forest fragments in Adams, Wells, and Allen County Indiana, identifying plants to species in stratified 25m2 understory plots. Richness, evenness, and Shannon Entropy Index were used to quantify understory biodiversity of each forest. These were compared using linear and logistic regression against the size of the forest and environmental characteristics including soil moisture and compaction, canopy cover, and forest age determined by incremental boring. Positive linear regression was noted with forest patch size and biodiversity with no relationship between size and evenness or any environmental factors. Through use of aerial photography, distance between sampled forest and nearest neighbor as well as neighbor count within 2km was calculated, showing no relationship. Analysis by use of Kriging prediction models visually displayed location-based increases in understory biodiversity surrounding managed forest patches. As noted by landowners, these forests were selectively harvested every 10-30 years, depending on the forest patch. Management strategies including overstory thinning through selective harvests approximately every 20 years may be important to increase understory biodiversity.
Forest Sciences | Life Sciences
Fuelling, Rachel R., "Diversity and Distribution of Plant Communities Related to Forest Fragment Size, Shape, Age, and Structure" (2014). 2014 IPFW Student Research and Creative Endeavor Symposium. 55.