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Biodiversity is under threat due to human-induced changes in land use. While various aspects of biodiversity are increasingly studied in response to these changes, there is limited understanding of their effects on the structure and composition of bird communities in dryland regions. We examined the impacts of land use change on birds in the semi-arid area of the Longxi Loess Plateau by considering taxonomic diversity, functional diversity, and phylogenetic diversity. We analyzed both the α- and β-diversity of avian communities across different dimensions of diversity and calculated functional and phylogenetic structures using the net relatedness index. Our findings revealed that species richness was highest in farmland and abandoned farmland, while artificial mixed forests exhibited the highest number of unique species. Functional and phylogenetic α-diversity was greater in farmland and abandoned farmland when compared to the other four land use types. Moreover, the taxonomic diversity in artificial mixed forests, artificial Caragana korshinskii forests, and artificial Platycladus orientalis forests surpassed that in typical grasslands, but no differences were observed in functional and phylogenetic diversity. Regarding β-diversity, turnover patterns dominated multidimensional dissimilarity, with taxonomic turnover and total dissimilarity lower than their functional counterparts but higher than phylogenetic counterparts. Based on the present findings, we emphasize the long-term cessation of ongoing silvicultural initiatives to safeguard bird diversity in the semi-arid region of the Longxi Loess Plateau. This is crucial for narrowly distributed species such as Alectoris magna, as they face heightened vulnerability to losses.

Studying the spatio-temporal niche partitioning among closely related sympatric species is essential for understanding their stable coexistence in animal communities. However, consideration of niche partitioning across multiple ecological dimensions is still poor for many sympatric pheasant species. Here, we studied temporal activity patterns and spatial distributions of the Blue Eared Pheasant (EP, Crossoptilon auritum) and Blood Pheasant (BP, Ithaginis cruentus) in the Qilian Mountains National Nature Reserve (QMNNR), Northwestern China, using 137 camera traps from August 2017 to August 2020. Kernel density estimation was applied to analyze diel activity patterns, and the Maxent model was applied to evaluate their suitable distributions and underlying habitat preferences. Eight Galliformes species were captured in 678 detection records with 485 records of EP and 106 records of BP over a total of 39,206 camera days. Their monthly activity frequencies demonstrate temporal partitioning but their diel activity patterns do not. Furthermore, 90.78% of BP distribution (2867.99 km2) overlaps with the distribution of EP (4355.86 km2) in the QMNNR. However, BP manifests a high dependence on forest habitats and shows larger Normalized Difference Vegetation Index (NDVI) values, while EP showed obvious avoidance of forest with NDVI greater than 0.75. Hence, differentiation in monthly activity patterns and partitioning in habitat preference might facilitate their coexistence in spatiotemporal dimensions. Conservation actions should give priority to highly overlapping areas in the center and east of the QMNNR and should strengthen forest landscape connectivity, as they provide irreplaceable habitats for these threatened and endemic Galliformes.