TREELANDS – Trees as Islands – on the phylogenetic isolation of trees in mixed forests

在生产林中混交是营林管理的核心工具之一。在生物多样性探索站，针叶树比例的增加是森林土地使用强度的主要决定因素。然而，驱动嵌入不同进化邻域的树冠多样性的生态机制仍然知之甚少。与进化距离增加的树种的邻近作为系统发育隔离可以以多种方式影响目标树及其居民：首先通过改变冠和叶特征，其次通过与邻近物种的隔离。在这里，我们测试的假设，系统发育隔离的主机树影响节肢动物群落的四个主要树种在中欧，山毛榉，栎，樟子松和云杉。我们将结合联合收割机林冠节肢动物雾化样本，地面激光扫描，小气候测量，叶片测量和创新的条形码方法，以测试四个研究领域的八个预测。首先，我们将调查系统发育隔离是否直接通过隔离或间接通过树冠结构的变化影响昆虫群落。其次，我们将研究系统发育隔离树内变异的影响，这种变化对昆虫群落的影响。第四，我们将研究系统发育隔离对植食性，不同功能团的多样性和种内变异的影响。这将使我们能够首次测试橡树的先前结果可以推广到其他树种，并更深入地了解森林土地利用梯度混合成分背后的生态机制。

Mixing trees in production forests is one of the core tools of silvicultural forest management. In the Biodiversity Exploratories the increasing proportion of conifers is a major determinant of the land-use intensity in the forests. However, the ecological mechanisms driving the diversity in the canopy of trees embedded in different evolutionary neighbourhoods is still poorly understood. The neighbourhood to tree species with an increasing evolutionary distance as the phylogenetic isolation can affect the target tree and it inhabitants in many ways: first by changing the crown and leaf characteristic, second via isolation from neighbour with increasing distance. Here we test the hypothesis that phylogenetic isolation of a host tree affects the arthropod communities for the four major tree species in Central Europe, Fagus sylvatica, Quercus petrae, Pinus sylvestris and Picea abies. We will combine canopy arthropod fogging samples, Terrestrial Laserscanning, microclimate measurements, Leaf measurements and innovative barcoding methods to test eight predictions in four research fields. First, we will investigate if phylogenetic isolation affects insect communities directly via isolation or indirectly by changes in crown structures. Second we will study the effects of phylogenetic isolation on within tree variation and third the effects of this variation on insect communities. Fourth, we will study the effect of phylogenetic isolation on herbivory, diversity of different guilds and within species variation. This will allow us to test for the first time how far previous results from oaks can be generalised to other tree species and give a deeper insight into the ecological mechanisms behind the mixing component of the land use gradient in forests.