Land use type, forest cover and forest edges modulate avian cross‐habitat spillover

Abstract

Natural habitats adjacent to agricultural areas are often considered sources of species that provide beneficial regulating ecosystem services through cross‐habitat spillover. Both inter‐habitat matrix and landscape configuration can influence spillover by controlling organismal ability to disperse through landscapes, and affecting the provision of additional or supplementary resources that impact organism survival. To understand how landscape structure in terms of matrix land use type, forest cover and edge density might facilitate avian cross‐habitat spillover, we sampled avian communities in forest patches and adjacent land use types (coffee plantations or cattle pastures) using a well‐replicated study design across 92 sampling sites across a landscape‐context forest cover gradient (6%–60%). Land use type was a key factor influencing avian cross‐habitat spillover, facilitating species movement into coffee plantations and acting as a barrier to spillover into cattle pastures. We found that 24% of the forest‐dependent species pool was capable of spillover into coffee plantations, while spillover was nearly non‐existent in cattle pastures. Forest cover was also the main driver of spillover into coffee plantations. There was a positive relationship between forest cover and spillover, potentially due to processes related with (1) a higher density of organism in‐patches, (2) decreased isolation among patches facilitating species movement and (3) higher landscape supplementation processes. Finally, we found edge density had an additive effect with forest cover on spillover. Spillover was higher in high‐forested landscapes with many forest‐matrix edges, possibly due to increased structural connectivity for species able to move through edges, and to improved access for forest‐dwelling species to different resource types (complementation processes). Synthesis and applications. We demonstrate that land use type is a key factor facilitating species spillover into agricultural matrices and that the influence of land use type on spillover is further modulated by a combination of native habitat amount and edge density. These results should be considered in efforts to design or manage sustainable agricultural landscapes in order to enhance both bird persistence and the provision of bird‐mediated ecosystem services.

Biodiversity extinction thresholds are modulated by matrix type

“…First, as organismal movements between patches can be affected by land-use types (Ricketts 2001, Prevedello et al 2016, Biz et al 2017, matrix composition may rival the importance of remnant patch size and spatial arrangement in maintaining landscape connectivity (Tubelis et al 2007, Driscoll et al 2013. Higher-contrasting matrices, such as cattle pastures, can strongly prevent organismal dispersal among patches and consequently increase extinction rates in-patches, while reducing (re)colonization rates (Antongiovanni and Metzger 2005, Castellon and Sieving 2006, Neuschulz et al 2013, Boesing et al 2017a). Second, matrix composition also plays important role modulating microclimate conditions at habitat edges (Saunders et al 1991), and consequently might influence native species survival and reproductive success (Ewers and Didham 2006), particularly for the small fragments dominated by edge habitat that are characteristic of landscapes with low native cover.…”

“…The presence of coffee plantations is often associated to a more permeable and a biodiversity friendly matrix for forest species (Moguel andToledo 1999, Smith et al 2015) compared to high-contrasting land uses such as cattle pastures. Even though shaded-coffee are better for biodiversity conservation compared to sun coffee plantations (Perfecto et al 1996, O'Connell 2003, according to a previous study, around 24% of forest-dependent species pool can spillover into sun coffee plantations, while these movements are extremely rare into pastures, occurring only in short-gap crossing events in highly forested landscapes (Boesing et al 2017a). We test two related hypothesis: 1) that matrix type is a key factor influencing the placement of thresholds along the forest cover gradient (Fig.…”

Species‐specific responses to habitat conversion across scales synergistically restructure Neotropical bird communities

“…It is also thought that species responses to local land cover may depend on landscape configuration, with species more likely to use agriculture in more fragmented landscapes (Boesing et al. ). The rationale underlying both hypotheses likely applies well to habitat generalists that can use both forested and cleared habitats.…”

“…But confronting this heterogeneity could lead to new insights; for example, variation in species mobility may underlie scale-dependence, with more vagile organisms influenced by habitat amount and configuration at larger scales (Gonthier et al 2014 (Tscharntke et al 2012); in completely cleared landscapes, conservation interventions may be ineffective because source populations may not exist to send colonists to any restored sites (Duelli and Obrist 2003). It is also thought that species responses to local land cover may depend on landscape configuration, with species more likely to use agriculture in more fragmented landscapes (Boesing et al 2018). The rationale underlying both hypotheses likely applies well to habitat generalists that can use both forested and cleared habitats.…”

Mediation of area and edge effects in forest fragments by adjacent land use

“…), in contrast to Boesing et al. (), who found minimal spillover of birds into cattle pasture in the Atlantic Forest. Our results suggest community integrity in matrix transects increases as forest patch area increases (Fig.…”