Data from: Thermal tolerance and the importance of microhabitats for Andean frogs in the context of land-use and climate change

1. Global warming is having impacts across the Tree of Life. Understanding
species’ physiological sensitivity to temperature change and how they
relate to local temperature variation in their habitats is crucial to
determining vulnerability to global warming. 2. We ask how species’
vulnerability varies across habitats and elevations, and how
climatically-buffered microhabitats can contribute to reduce their
vulnerability. 3. We measured thermal sensitivity (critical thermal
maximum – CTmax) of 14 species of Pristimantis frogs inhabiting young and
old secondary, and primary forests in the Colombian Andes. Exposure to
temperature stress was measured by recording temperature in the understory
and across five microhabitats. We determined the frogs’ current
vulnerability across habitats, elevations and microhabitats accounting for
phylogeny and then ask how vulnerability varies under four warming
scenarios: +1.5⁰C, +2⁰C, +3⁰C and +5⁰C. 4. We found that CTmax was
constant across species regardless of habitat and elevation. However,
species in young secondary forests are expected to become more vulnerable
because of increased exposure to higher temperatures. Microhabitat
variation could enable species to persist within their thermal temperature
range as long as regional temperatures do not surpass +2°C. The
effectiveness of microhabitat buffering decreases with a 2-3°C increase,
and is almost null under a 5°C temperature increase. 5. Microhabitats will
provide thermal protection to Andean frog communities from climate change
by enabling tracking of suitable climates through short distance movement.
Conservation strategies, such as managing landscapes by preserving primary
forests and allowing regrowth and re-connection of secondary forest would
offer thermally buffered microhabitats and aid in the survival of this
group.

1. 全球变暖正在对整个生命之树（Tree of Life）产生广泛影响。厘清物种对温度变化的生理敏感性，以及该敏感性与其栖息地的局地温度变异之间的关联，是判断物种应对全球变暖脆弱性的核心前提。
2. 本研究旨在探究物种的脆弱性如何随栖息地与海拔梯度发生变化，以及气候缓冲微生境（climatically-buffered microhabitats）如何助力降低物种的脆弱性水平。
3. 我们针对栖息于哥伦比亚安第斯山脉（Colombian Andes）的14种离趾蟾属（Pristimantis）青蛙开展了热敏感性（thermal sensitivity）测定，其核心指标为临界热最大值（critical thermal maximum，CTmax），采样生境涵盖幼年次生林、老年次生林与原始林。我们通过记录林下层以及5种微生境的温度，量化了物种所面临的温度胁迫程度。在系统发育（phylogeny）校正的前提下，我们明确了不同栖息地、海拔与微生境下蛙类当前的脆弱性；随后进一步探究了在+1.5℃、+2℃、+3℃与+5℃四种增温情景下，物种脆弱性的变化规律。
4. 研究结果显示，不同物种的临界热最大值无显著差异，且不受栖息地类型与海拔的影响。然而，栖息于幼年次生林的物种，由于暴露于更高温度环境的概率升高，其预期脆弱性将显著提升。只要区域升温未超过+2℃，微生境异质性便可帮助物种维持在其适宜的温度区间内存活。当升温幅度达到2~3℃时，微生境的缓冲效果会逐步减弱；而在升温5℃的情景下，其缓冲作用几乎完全消失。
5. 微生境可通过允许物种进行短距离移动以追踪适宜气候的方式，为安第斯蛙类群落提供应对气候变化的热保护屏障。相关保护策略，例如通过保护原始林、促进次生林的自然恢复与连通性来开展景观管理，可提供具备热缓冲能力的微生境，从而助力该类蛙类的种群存续。