Jones Alice R, Jessop Tim S, Ariefiandy Achmad, Brook Barry W, Brown Stuart C, Ciofi Claudio, Benu Yunias Jackson, Purwandana Deni, Sitorus Tamen, Wigley Tom M L, Fordham Damien A
The Environment Institute and School of Biological Sciences The University of Adelaide Adelaide SA Australia.
Department for Environment and Water Adelaide SA Australia.
Ecol Evol. 2020 Sep 15;10(19):10492-10507. doi: 10.1002/ece3.6705. eCollection 2020 Oct.
The Komodo dragon () is an endangered, island-endemic species with a naturally restricted distribution. Despite this, no previous studies have attempted to predict the effects of climate change on this iconic species. We used extensive Komodo dragon monitoring data, climate, and sea-level change projections to build spatially explicit demographic models for the Komodo dragon. These models project the species' future range and abundance under multiple climate change scenarios. We ran over one million model simulations with varying model parameters, enabling us to incorporate uncertainty introduced from three main sources: (a) structure of global climate models, (b) choice of greenhouse gas emission trajectories, and (c) estimates of Komodo dragon demographic parameters. Our models predict a reduction in range-wide Komodo dragon habitat of 8%-87% by 2050, leading to a decrease in habitat patch occupancy of 25%-97% and declines of 27%-99% in abundance across the species' range. We show that the risk of extirpation on the two largest protected islands in Komodo National Park (Rinca and Komodo) was lower than other island populations, providing important safe havens for Komodo dragons under global warming. Given the severity and rate of the predicted changes to Komodo dragon habitat patch occupancy (a proxy for area of occupancy) and abundance, urgent conservation actions are required to avoid risk of extinction. These should, as a priority, be focused on managing habitat on the islands of Komodo and Rinca, reflecting these islands' status as important refuges for the species in a warming world. Variability in our model projections highlights the importance of accounting for uncertainties in demographic and environmental parameters, structural assumptions of global climate models, and greenhouse gas emission scenarios when simulating species metapopulation dynamics under climate change.
科莫多巨蜥（）是一种濒危的岛屿特有物种，分布范围自然受限。尽管如此，此前尚无研究尝试预测气候变化对这一标志性物种的影响。我们利用广泛的科莫多巨蜥监测数据、气候和海平面变化预测，为科莫多巨蜥构建了空间明确的种群动态模型。这些模型预测了该物种在多种气候变化情景下的未来分布范围和数量。我们使用不同的模型参数运行了超过一百万个模型模拟，使我们能够纳入来自三个主要来源的不确定性：（a）全球气候模型的结构，（b）温室气体排放轨迹的选择，以及（c）科莫多巨蜥种群动态参数的估计。我们的模型预测，到2050年，科莫多巨蜥在整个分布范围内的栖息地将减少8% - 87%，导致栖息地斑块占有率下降25% - 97%，整个物种分布范围内的数量下降27% - 99%。我们表明，科莫多国家公园中两个最大的受保护岛屿（林卡岛和科莫多岛）上的科莫多巨蜥灭绝风险低于其他岛屿种群，在全球变暖的情况下为科莫多巨蜥提供了重要的避难所。鉴于预测的科莫多巨蜥栖息地斑块占有率（占用面积的替代指标）和数量变化的严重性和速度，需要采取紧急保护行动以避免灭绝风险。这些行动应优先集中于管理科莫多岛和林卡岛的栖息地，反映出这些岛屿在气候变暖世界中作为该物种重要避难所的地位。我们模型预测的变异性突出了在模拟气候变化下物种集合种群动态时，考虑种群动态和环境参数的不确定性、全球气候模型的结构假设以及温室气体排放情景的重要性。
