Predicted distributions of avian specialists: A framework for conservation of endangered forests under future climates

Abstract

Aim: Forested regions are of global importance for a multitude of ecosystem functions and services and are critical for biodiversity. Anthropogenic climate-change compounds negative effects of land-use change on forest persistence and forestdependent biodiversity. Habitat loss and climate change have an additive effect and drive species' extinctions in similar ways, resulting in a homogenization of biodiversity. Connectivity is key in conservation planning for mitigating climate change effects and facilitating species' abilities to disperse throughout remnant habitat and track their climate niches. We used three forest-specialized and habitat-specific bird species as focal species to understand avian connectivity and conservation of each of South Africa's three threatened forest classes, as each species is range-restricted to its respective forest type.Location: South Africa. Methods:We created ensemble models of species' distributions and combined core home-and breeding-range patches with a hybrid of least-cost pathways and ecological circuit theory linkages to assess the success of corridors in facilitating connectivity of each of the three forest types. We then predicted the likelihood of niche persistence for each species under future climate-change scenarios, and the efficacy of our connectivity modelling to facilitate range expansion or climate-niche tracking. Results:The projected habitat loss under climate-change scenarios impacted corehabitat patch distribution, size and connectivity, exacerbated habitat fragmentation and increased resistance and the severity of pinch points and barriers along dispersal corridors. Forest systems and associated focal species projected to experience the highest levels of habitat loss/contraction occurred at mid-to high elevations.Climate-change resilience across ecosystems, and persistence of species therein, was dependent on connectivity, facilitating species' ability to track specific climate niches. Main conclusions:Climate-change resilience of ecosystems, and persistence of biodiversity therein, is most likely to be a product of high functional biodiversity, connectedness and the ability of species to track specific climate niches. | 653 COLYN et aL.

Species–landscape interactions drive divergent population trajectories in four forest‐dependent Afromontane forest songbird species within a biodiversity hotspot in South Africa

“…Stronger performance of the LCP models of native forest and dense thicket configuration over respective IBR models for P. stellata (Figure 7e ), as well as B. capensis and C. dichroa (Tables 2 and 3 ) demonstrate the potential utility of conservation corridors in the Eastern Cape and southern KwaZulu‐Natal to preserve genetic integrity within regional Afromontane forest birds. Such corridors should promote resilience anthropogenic climate change, as recommended by Colyn et al ( 2020 ). The highest priority forests for conservation are the scarp forests present along the Wild Coast, as well the eastern Amatole Afromontane forests, and Afromontane (eastern mistbelt) forests in southern KwaZulu‐Natal.…”

Predicted distribution of plains spotted skunk in Arkansas and Missouri

“…In contrast to early work on plains spotted skunks that revealed high densities in highly anthropogenic agricultural landscapes (Crabb 1948), most recent researchers have reported that both plains and eastern spotted skunks select for denser forests within large forest stands at the microhabitat scale (Hackett 2008;Lesmeister et al 2008Lesmeister et al , 2013Thorne et al 2017). We continue to lack a clear understanding of how habitat fragmentation at the landscape level could limit dispersal, which could affect metapopulation dynamics and population persistence across the range (Ims and Andreassen 2002, Sgro et al 2011, Colyn et al 2019. Despite high to medium-high predicted presence of the species in large portions of northern, western, and southern Arkansas and southern Missouri predicted by our models, there are significant spatial gaps predicted by our models that suggest remaining populations could be isolated.…”

Climate refugia for three Afromontane forest‐dependent bird species in south‐eastern South Africa

“…Climatic resilience of Afromontane forests within the MPA Hotspot, however, may rely upon elevational shifts of forests (see Figure 4). Given that anthropogenic landscape transformation impedes the expansion of forest tree communities (Botzat et al, 2015; Ivory et al, 2019), wildlife corridors may be necessary to mitigate the impact of anthropogenic climate change on sensitive forest taxa (Colyn et al, 2020; Mulvaney et al, 2021). Our palaeodistributional modelling demonstrates the utility that such corridors served in promoting forest connectivity under different climatic regimes (Figure 4), which may be of conservation importance in the Anthropocene.…”