Morisita–Horn sample similarity indices (MHSIs) ( Table 1 and SI Appendix, Table S2) and nonmetric multidimensional scaling (NMDS) analysis ( Fig. The bird community of the Amistad International Park, in particular, has a distinct species composition and habitat and diet functional signatures ( Methods) characteristic of extensive primary forest bird communities. Nevertheless, as shown below, in-depth analyses of community composition are more informative on the conservation value of different habitats than species richness estimates alone. Shaded coffee and open coffee Chao 1 estimates overlapped with those of riparian but not of Amistad. The 95% confidence intervals of Chao 1 species richness estimates for Las Cruces, fragments, and secondary forest did not overlap with the 95% confidence intervals of riparian and Amistad Chao 1 species richness estimates. 1 B) were highest for Las Cruces (220), followed by secondary forest (209), fragments (198), shaded coffee (189), open coffee (178), riparian (147), and Amistad (108). Chao 1 estimates of species richness ( Fig. The 95% confidence intervals of species richness values for Las Cruces, fragments, shaded coffee, and secondary forest did not overlap with the 95% confidence intervals of open coffee, riparian, and Amistad species richness values ( Fig. The greatest number of species (179) was recorded at Las Cruces forest sites, followed by forest fragments (162), shaded coffee (161), secondary forest (158), open coffee (146), riparian (134), and Amistad primary forest (85). We had 29,740 captures of 185 species at the coffee sites and 27,515 captures of 230 species at the forest sites. Species accumulation, richness, and similarity. Estimated (Chao 1) species richness values for the Las Cruces forest reserve, forest fragments, and secondary forest are the highest, and Amistad is the lowest, with coffee and riparian sites having intermediate values. Note the differences between actual species accumulation versus expected species richness with Chao 1. ( B) Chao 1 estimates of species richness. Note that for some of the habitats, extrapolated species numbers are higher than the numbers actually recorded. All samples were extrapolated to 179 d to compare them with the full reference sample for Las Cruces, the largest sample in the dataset, with 179 sampling days ( 64). ( A) Species accumulation curves were calculated with Estimates 9.1, using sampling with replacement ( 62). Species accumulation curves indicate the increase in bird species richness (∼20 more species) at shaded coffee sites with higher tree cover than open coffee sites (13% vs. Diversified agricultural landscapes can enhance the biodiversity capacity of tropical countryside, but, for the long-term persistence of all forest bird species, large (>1,000 ha) protected areas are essential.įig. Costa Rican countryside habitats, especially those with greater tree cover, host many bird species and are critical for connecting bird populations in forest remnants. 13%) had more species with increasing capture rates, twice as many forest specialists, and half as many nonforest species. Coffee plantations with higher tree cover (7% vs. ![]() Coffee plantations, although lacking most of the forest specialists, hosted 185 bird species, had the highest capture rates, and supported increasing numbers of some forest species. While 49% of bird species preferred forest to coffee, 39% preferred coffee to forest and 12% used both habitats, indicating that coffee plantations have some conservation value. ![]() High-value forest bird communities were characterized by their distinct species composition and habitat and dietary functional signatures. ![]() There was no relationship between the species richness of a habitat and its conservation value. ![]() Declines were common in resident, insectivorous, and more specialized species. More bird populations (69) were declining than were stable (39) or increasing (4). To investigate the long-term biodiversity capacity of agricultural countryside, we quantified bird population trends in Costa Rica by mist netting 57,255 birds of 265 species between 19 in sun coffee plantations, riparian corridors, secondary forests, forest fragments, and primary forest reserves. Tropical agriculture is a major driver of biodiversity loss, yet it can provide conservation opportunities, especially where protected areas are inadequate.
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