Effects of landscape composition, configuration, and vegetation structure on bird communities of the pine-oak forests of El Salvador

Abstract

We assessed the effects on habitat loss and fragmentation at the landscape level in the pine-oak forests of El Salvador, which is an important global biodiversity hotspot and currently endangered. We defined four regions in pine-oak forests across northern El Salvador (Montecristo, Miramundo, El Manzano, and Morazán regions). We established 20 point-counts (five point-counts per region), where we surveyed birds and made vegetation plots for three months in 2021. We created four buffers around each point-count (100, 300, 500, and 1000 m of radii) and calculated nine landscape metrics for each buffer; we made a regression analysis to evaluate the predicting power of vegetation structure and the landscape variables over the bird community. We found that bird communities responded strongly to landscape variables; we did not find any relationship with vegetation structure. We found that Montecristo and Miramundo regions share similar bird communities. El Manzano and Morazán regions also share similar bird communities, being the former regions different from the latter regions. Our results suggest that bird communities at the pine-oak forest are affected by forest fragmentation, especially highland birds, frugivorous and forest-dependent birds. We highlight the importance of continuing with systematic studies in northern areas of El Salvador since these areas are key are for biodiversity but long understudied.