Effects of structural heterogeneity on the diurnal temperature range in temperate forest ecosystems
Effects of structural heterogeneity on the diurnal temperature range in temperate forest ecosystems
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DOI：
10.1016/j.foreco.2018.10.008
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发表时间：
2019-01-15
影响因子：
3.7
通讯作者：
Seidel, Dominik
中科院分区：
文献类型：
--
作者：
Ehbrecht, Martin;Schall, Peter;Seidel, Dominik
由于森林经营或自然森林开发，林分结构的改变可以改变森林生态系统的小气候。中欧和北美目前的森林管理做法旨在促进结构异质性和维持森林树冠覆盖，这被认为是森林小气候的一个主要驱动因素。在这里，我们研究了森林经营和结构异质性对中欧三个气候不同地点(Swabian Alb，Hainich-Diin和Schorfheide-Chorin)的128个受管理林分的日温度差(DTR)的影响。通过促进树木大小的多样性和分化来增加结构的异质性，增加了垂直分层，导致植被期间的DTR受损。以地理位置、海拔高度、冠层开度和构造异质性度量为解释变量的线性回归模型可以解释DTR的79.4-80.9%的变异。然而，结构异质性对DTR的总体影响很小。不同树种样地DTR的差异可归因于树冠开度和透光率的差异，而树种多样性对DTR没有显著影响。未经管理的森林的DTR显著低于经管理的、甚至是年龄较大的森林。在单木选择下经营的异龄林的DTR与未经营的林分相当。地面激光扫描(TLS)测量的树冠开度和垂直结构可以解释考虑地理位置和海拔高度的DTR的79.4%的变异，这也可以通过TLS与GPS和高度计相结合的方法进行评估。我们得出结论，林分的结构特征而不是林冠开度对森林小气候的变化有轻微的贡献。然而，结构-小气候分析表明，林分结构对植被期间降水量较少的地区DTR的影响可能更为明显。
The microclimate in forest ecosystems can be altered by modifications of stand structure due to forest management or natural forest development. Current forest management practices in Central Europe and North America aim to promote structural heterogeneity and maintain forest canopy cover, which is known to be a major driver of forest microclimate. Here, we investigated the impacts of forest management and structural heterogeneity on the diurnal temperature range (DTR) in 128 managed forest stands in three climatically different locations (Swabian Alb, Hainich-Diin and Schorfheide-Chorin) in Central Europe. Increasing structural heterogeneity by promoting tree size diversity and differentiation increased vertical stratification and resulted in an impaired DTR during the vegetation period. Linear regression models with geographic location, elevation above sea level, canopy openness and measures of structural heterogeneity as explanatory variables explained 79.4-80.9% of variance in DTR. However, the overall effect of structural heterogeneity on DTR was small. Differences in DTR between plots of different main tree species could be attributed to differences in canopy openness and light transmission, whereas tree species diversity had no significant effect on DTR. Unmanaged forests were characterized by a significantly lower DTR than managed, even-aged forests. DTR in uneven-aged stands managed under single tree selection was comparable to unmanaged stands. Terrestrial laser scanning (TLS) derived measures of canopy openness and vertical structure allowed to explain 79.4% of variance in DTR considering geographic location and elevation, which can also be assessed by TLS with integrated GPS and an altimeter. We conclude that structural characteristics of forest stands other than canopy openness contribute marginally to variation in forest microclimate. However, the analyses of structure-microclimate analyses indicate that effects of stand structure on DTR might be more pronounced in regions with low precipitation during the vegetation period.