The effects of forestry and agroforestry plantations on bird diversity: A global synthesis

Abstract

The increasing expansion of productive lands around the world during the last decades constitutes a strong driver of biodiversity loss, as they are usually established near to high diversity areas. Despite many studies that have compared bird diversity between natural and productive systems, a global synthesis is still missing and important for understanding how biodiversity is being altered. We conducted a meta‐analysis based on 144 case studies to assess the effects of four types of plantations (forestry, oil palm, coffee, and cacao) on bird species richness and abundance. We examined those effects in function of plantation type, latitudinal zone (temperate or tropical), geographical context (mainland or island), zoogeographic zone, and biodiversity hotspots. Plantations presented negative effects on both bird species richness and abundance. Oil palm plantations showed more negative effects followed by forestry plantations, whereas coffee and cacao agroforestry plantations had no significant effects. Those effects were geographically variable, being more pronounced in islands and temperate zones, as well as at the Oriental, Palearctic, and Neotropical zoogeograghic regions, and at the Sundaland and Mediterranean Basin biodiversity hotspots. Our results showed that productive systems reduce both species richness and abundance of bird species, being insular species particularly susceptible. Exotic monocultures with low structural heterogeneity (e.g., oil palm plantations) derive in highly impoverished bird communities dominated by generalist species. We identified South East Asia, tropical South America, and the Mediterranean Basin as the most threatened regions because of the sensitivity of their bird communities and the increasing rates of native forest replacement.

Conservation ecology of birds in Mt. Hilong-hilong, a Key Biodiversity Area on Mindanao Island, the Philippines

“…Declining strict forest-dwelling species at a regional scale is widely associated with human disruption to habitats that reduce the space occupied by and affect the foraging grounds of a diverse set of species (Brooks et al 1999;Renjifo 2001). Global meta-analyses showed that bird species richness and abundance were particularly susceptible to decline in areas with low structural heterogeneity such as plantations and farmland conversions (Bohada-Murillo et al 2020). The continuous conversion within or near intact habitats for agricultural expansions during the last decades has driven high biodiversity loss in many hotspot regions including the Philippines (Brooks et al 2002).…”

The best bang for the bucks: rethinking global investment on biodiversity conservation

“…4). For example, the Brazilian Atlantic rainforest, the Indian peninsula, and the south-east Asia archipelago have the largest proportions of threatened birds, but protected areas are negligible at those locations (Peh et al, 2006;Barlow et al, 2007;Bohada-Murillo et al, 2020). A similar pattern is observed for mammals of south-east Asia and amphibians of eastern China.…”

The Best Bang for the Bucks: Rethinking Global Investment in Biodiversity Conservation

“…If we examine this pattern at the global scale, we observe a moderate correspondence of protected areas with biodiversity hotspots (Figure 3), which is even lower when we examine threatened species instead (Figure 4). For example, the Brazilian Atlantic Rainforest, the Indian Peninsula, and the Southeast Asian archipelago have the largest proportions of threatened birds, but protected areas are negligible at those locations [44][45][46]. A similar pattern is observed for mammals of Southeast Asia and amphibians of Eastern China.…”