Forecasts of habitat suitability improve habitat corridor efficacy in rapidly changing environments

Authors

  • Stephen D. Gregory,

    Corresponding author
    1. Environment Institute and School of Earth and Environmental Sciences, University of Adelaide, Adelaide, SA, Australia
    2. Salmon and Trout Research Centre, Game and Wildlife Conservation Trust, East Stoke, Dorset, UK
    • Correspondence: Stephen Gregory, Salmon and Trout Research Centre, Game and Wildlife Conservation Trust, East Stoke, Dorset BH20 6BB, UK.

      E-mail: stephendavidgregory@gmail.com

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  • Marc Ancrenaz,

    1. Hutan, Kinabatangan Orang-utan Conservation Program, Sabah, Malaysia
    2. North England Zoological Society, Chester Zoo, Chester, UK
    3. Sabah Wildlife Department, Wisma Muis, Kota Kinabalu, Sabah, Malaysia
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  • Barry W. Brook,

    1. Environment Institute and School of Earth and Environmental Sciences, University of Adelaide, Adelaide, SA, Australia
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  • Benoit Goossens,

    1. Sabah Wildlife Department, Wisma Muis, Kota Kinabalu, Sabah, Malaysia
    2. Organisms and Environment Division, School of Biosciences, Cardiff University, Cardiff, UK
    3. Danau Girang Field Centre c/o Sabah Wildlife Department, Wisma Muis, Kota Kinabalu, Sabah, Malaysia
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  • Raymond Alfred,

    1. Borneo Conservation Trust, Wisma Muis, Kota Kinabalu, Sabah, Malaysia
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  • Laurentius N. Ambu,

    1. Sabah Wildlife Department, Wisma Muis, Kota Kinabalu, Sabah, Malaysia
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  • Damien A. Fordham

    1. Environment Institute and School of Earth and Environmental Sciences, University of Adelaide, Adelaide, SA, Australia
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Abstract

Aim

Habitat fragmentation threatens species’ persistence by increasing subpopulation isolation and vulnerability to stochastic events, and its impacts are expected to worsen under climate change. By reconnecting isolated fragments, habitat corridors should dampen the synergistic impacts of habitat and climate change on population viability. Choosing which fragments to reconnect is typically informed by past and current environmental conditions. However, habitat and climate are dynamic and change over time. Habitat suitability projections could inform fragment selection using current and future conditions, ensuring that corridors connect persistent fragments. We compare the efficacy of using current-day and future forecasts of breeding habitat to inform corridor placement under land cover and climate-change mitigation and no mitigation scenarios by evaluating their influence on subpopulation abundance, and connectivity and long-term metapopulation abundance. Our case study is the threatened orangutan metapopulation in Sabah.

Location

Sabah, Malaysian Borneo.

Methods

Using coupled niche–population models that capture a metapopulation distribution and its major processes, we forecast the effect of current-day and future-informed habitat corridor implementations under two scenarios where (1) land cover and climate change continue unabated (no mitigation) and (2) local and international cooperation mitigates their synergistic impact (mitigation).

Results

We show that Future-informed corridor placement maximizes long-term metapopulation abundance when human-driven land cover and climate change alter the spatio-temporal composition of suitable habitat. By contrast, there is no apparent benefit in using future forecasts of breeding habitat to inform corridor placement if conditions remain comparatively stable. For the Sabah orangutan under unabated land cover and climate change, habitat corridors should connect current-day populated eastern habitat fragments with vacant fragments in the state's west.

Main conclusions

The efficacy of habitat corridors can be improved by using habitat-suitability model projections to inform corridor placement in rapidly changing environments, even for long-lived, low-fecundity, philopatric species such as orangutan.

Ancillary