Even minor logging road development can decrease the functional diversity of forest bird communities: Evidence from a biodiversity hotspot

Abstract

Although the effects of major roads and highways on biodiversity have received considerable attention, there is a lack of research considering how smaller and less-used roads might also impact wildlife, especially during the initial re-used development phase of abandoned roads, despite these minor roads being much more extensive and pervasive. Here, we examined how even minor redevelopment of former-abandoned logging roads can impact bird community alpha and beta diversity indices at the taxonomic, functional, and phylogenetic levels in a biodiversity conservation hotspot in central China. The minor redevelopment (i.e., re-paved) of former-abandoned roads generally reduced bird alpha and beta diversity compared to undeveloped abandoned roads, especially at the functional level. Compared with continuous-use roads, minor road redevelopment shows only a slight impact on avian diversity. Notably, compared to old-growth forest reference stands and undeveloped abandoned roads, minor road redevelopments have negative effects on the recovery process of avian diversity. Furthermore, the structure and composition of the high tree layer significantly affected avian functional and phylogenetic diversity, and low shrub layer vegetation mainly influenced taxonomic and phylogenetic diversity. To mitigate the effects of minor forest logging roads on avian biodiversity in priority biodiversity conservation areas, we propose the following: (1) roads that have fallen into disuse should be allowed and encouraged to re-naturalise; (2) roads should only be paved, and cleared back as strictly necessary, allowing grassy or gravel roads to suffice where possible; and (3) if road development is necessary, key umbrella tree species should be planted deliberately to support maximal community diversity and to maintain ecosystem functions and processes.