Impact of management practices on habitat use by birds in exotic tree plantations in northeastern Argentina

Bird habitat use can be influenced by the structural complexity of exotic plantations. Management practices such as pruning and thinning can promote understory development, increasing structural complexity and enhancing ecosystem integrity. Given the rapid expansion of fast-growing tree species, understanding bird responses to different forestry practices is crucial for sustainable management. In northeastern Argentina, we assessed bird habitat use, including trophic guild composition, behavioral patterns, and strata use across native forests and exotic Pinus and Eucalyptus plantations managed to promote or limit understory development. Using non-metric multidimensional scaling (NMDS), hierarchical cluster analysis, and PERMANOVA, we evaluated differences in bird assemblages among these forest types. Our results indicate that plantations with developed understory exhibit habitat use patterns more similar to native forests; however, certain ecologically important species, such as large fruit dispersers, were absent. Among plantation types, Pinus plantations with understory development were the most comparable to native forests in strata use and behavior categories. Birds in both native forests and plantations with developed understory used all available strata and were abundant in the shrub layer, including insectivorous and insectivorous-frugivorous species, whereas plantations lacking understory were functionally similar, exhibiting reduced diversity in trophic guilds. Although Eucalyptus plantations showed greater functional differences from native forests than Pinus plantations, the variation within Eucalyptus plantations based on management practices was particularly striking. We found that although plantations with developed understory cannot fully replicate the ecological functions of native forests, they can mitigate habitat simplification impacts by supporting similar but less abundant trophic guilds with comparable strata use and behaviors. As the demand for exotic plantations increases, effective management practices will become essential for maintaining biodiversity and promoting sustainable land use. Practices such as regular thinning and the establishment of mixed-species plantations can help better replicate the functional roles of native forests, thereby maintaining biodiversity and promoting sustainable land use.