Author : Abigail Barenblitt
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (992 download)
Book Synopsis Identify the Response of Forest Songbirds to Local Scale Forest Features and Complexity by : Abigail Barenblitt
Download or read book Identify the Response of Forest Songbirds to Local Scale Forest Features and Complexity written by Abigail Barenblitt and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This feature had a positive correlation with the occupancy of about half of the species we examined (n=23) and had the strongest positive correlation with the occupancy of understory associates (=0.35, 95% CrI = 0.00, 0.65). Certain measures of compositional complexity also had a positive correlation with bird species richness.The number of cover types within a 500 m buffer around each point had the strongest positive effect on species richness compared to other measurement of compositional complexity. The number of cover types within a 500 m buffer had an average mean posterior effect size of 0.10, although credible intervals slightly overlapped 0 (95% CrI=-0.01 to 0.21). The number of cover types had the strongest positive correlation with the occupancy of the understory (= 0.14, 95% CrI = -0.11), ground (=0.16, 95% CrI = -0.19, 0.49), and conifer (=0.20, 95% CrI = -0.05, 0.45) groups and had a positive correlation with the occupancy of 45 species. This positive correlation between the number of forest cover types within a 500 m buffer and bird species richness indicates that spatial heterogeneity is also important for maintaining species diversity. The results of our other measurements of compositional complexity provide more evidence supporting the importance of spatial heterogeneity as well. Measurements of local compositional complexity, including tree species and shrub species richness and number of ground cover types did not appear to have a strong positive effect on species richness. Across 47 bird species, tree species richness had an average mean posterior effect of 0.04 with credible intervals largely overlapping 0 (95% CrI=-0.11 to 0.20), and shrub species richness had an average mean posterior effect of -0.04 with credible intervals also overlapping 0 (95% CrI=-0.19 to 0.10). Tree species richness had the strongest positive correlation with the occupancy of midstory-associated species (=0.39, 95% CrI = -0.13, 0.94) and the strongest negative correlation with the occupancy ground-associated species (=-0.12, 95% CrI = -0.43, 0.17), although credible intervals overlap 0. Shrub species richness had the strongest positive correlation with the occupancy of the midstory and understory groups (=0.16, 95% CrI = -0.13, 0.46; =0.23, 95% CrI = -0.06, 0.50) and the strongest negative correlation with the occupancy of the canopy, conifer, and dead wood groups (=-0.26, 95% CrI = -0.67, 0.21; =-0.18, 95% CrI = -0.46, 0.11; =-0.17, 95% CrI = -0.55, 0.19), although credible intervals overlap 0. The number of ground cover types had an average mean posterior effect of -0.05 with credible intervals slightly overlapping 0 (95% CrI=-0.15 to 0.05), however this covariate appeared to have a negligible effect on the occupancy of all groups of co-occurring species. For each of these compositional covariates, the credible intervals largely overlapped 0 and did not appear to affect overall species richness positively or negatively. These results indicate that changes in compositional complexity may lead to changes in forest bird community composition, but not overall richness. The varying effect of measures of compositional complexity on the predicted occupancy of the six groups of interest, as well as our results from the first chapter linking species groups to local forest features, indicate that microhabitats within the forest are important to specific groups of co-occuring species. Therefore, spatial heterogeneity would increase the availability of a variety of these microhabitat features across a landscape and allow managers to maintain biodiversity across forests.Our nestedness results also indicate that managing certain for features that increase species richness, such as the standard deviation of DBH and spatial heterogeneity, stands to benefit the forest bird community as a whole. Of the points we surveyed, species rich and species depauperate points were nested based on the expected nesting from a random distribution (p