1977 Breeding Bird Censuses and Vegetation Surveys in Two Successional Stages of Oak--Pine Forest

摘要

As part of a program to characterize the plant and animal life of the Laboratory site and surrounding areas, two breeding bird census plots were established in 1977 to document the occurrence and abundance of breeding species in two extreme successional stages of Long Island oak-pine forest. A 9.3-hectare plot located near the northeastern corner of the Laboratory site is composed of second growth oak-pine forest in a late successional stage. The second plot measures 9.7 hectares and is located in the scrub oak-pitch pine barrens at Westhampton. Each plot was surveyed with a transit and steel tape and marked with wooden stakes at 100-foot intervals. Quantitative vegetational surveys were made in each plot and all plant species identified. Tree composition was measured as a function of species and size. Shrub density, percent of ground cover and percent of canopy were also measured. The Laboratory plot contained 2100 trees of five species per hectare, 72% ground cover and 84% canopy coverage. The Westhampton plot contained only one tree species, Pitch Pine, at 366 trees per hectare, 92% ground cover and no canopy. Twelve census trips, mostly of two to three hour duration, were made in each plot. Each bird observed was located on a scale map of the plot. At the end of the season, the number of territories was determined from the distribution of sightings. Eighteen territorial bird species were found in the Laboratory plot with between 479 and 629 territorial males per km exp 2 . In Westhampton, only five breeding species were present. Density was between 312 and 374 males per km exp 2 . The Rufous-sided Towhee was the most common species in both plots. Future studies will document changes in both bird and plant species composition and abundance. (ERA citation 03:043591)