Department of Life and Environmental Sciences, Bournemouth University, Poole, UK.
Department of Biology, University of New Mexico, Albuquerque, NM, USA.
Int J Biometeorol. 2022 Jun;66(6):1283-1295. doi: 10.1007/s00484-022-02276-4. Epub 2022 Mar 31.
Climate change is predicted to cause widespread disruptions to global biodiversity. Most climate models are at the macroscale, operating at a ~ 1 km resolution and predicting future temperatures at 1.5-2 m above ground level, making them unable to predict microclimates at the scale that many organisms experience temperature. We studied the effects of forest structure and vertical position on microclimatic air temperature within forest canopy in a historically degraded tropical forest in Sikundur, Northern Sumatra, Indonesia. We collected temperature measurements in fifteen plots over 20 months, alongside vegetation structure data from the same fifteen 25 × 25 m plots. We also performed airborne surveys using an unmanned aerial vehicle (UAV) to record canopy structure remotely, both over the plot locations and a wider area. We hypothesised that old-growth forest structure would moderate microclimatic air temperature. Our data showed that Sikundur is a thermally dynamic environment, with simultaneously recorded temperatures at different locations within the canopy varying by up to ~ 15 °C. Our models (R = 0.90 to 0.95) showed that temperature differences between data loggers at different sites were largely determined by variation in recording height and the amount of solar radiation reaching the topmost part of the canopy, although strong interactions between these abiotic factors and canopy structure shaped microclimate air temperature variation. The impacts of forest degradation have smaller relative influence on models of microclimatic air temperature than abiotic factors, but the loss of canopy density increases temperature. This may render areas of degraded tropical forests unsuitable for some forest-dwelling species with the advent of future climate change.
气候变化预计将对全球生物多样性造成广泛破坏。大多数气候模型都处于宏观尺度，分辨率在 1 公里左右，预测未来地面以上 1.5-2 米的温度，因此无法预测许多生物经历温度的微观气候。我们研究了森林结构和垂直位置对印度尼西亚北苏门答腊锡孔杜尔历史退化热带森林林冠内小气候空气温度的影响。我们在 20 个月内收集了 15 个样地的温度测量值，以及来自同一 15 个 25 × 25 米样地的植被结构数据。我们还使用无人机（UAV）进行了航空调查，以远程记录树冠结构，同时记录样地位置和更广泛区域的树冠结构。我们假设原始森林结构将缓和小气候空气温度。我们的数据表明，锡孔杜尔是一个热力动态环境，树冠内不同位置同时记录的温度差异高达 15°C 左右。我们的模型（R = 0.90 至 0.95）表明，不同地点数据记录器之间的温度差异主要取决于记录高度和到达树冠顶部的太阳辐射量的变化，尽管这些非生物因素和树冠结构之间的强烈相互作用塑造了小气候空气温度变化。与非生物因素相比，森林退化对小气候空气温度模型的影响相对较小，但树冠密度的丧失会增加温度。随着未来气候变化的到来，这可能会使退化热带森林地区不适合某些森林栖息物种。
