Effects of historical land-use change on species richness and community composition in fragmented and newly created habitats (HiLUCC)

历史上的土地利用变化可能对当前生态系统的组成、结构和功能产生相当大的影响。过去的当地土地利用可能对社区产生持久的遗留影响，例如通过改变场地条件、土壤种子库或持续存在的物种。在景观尺度上，土地利用变化可显著改变生境的空间配置，如斑块大小、景观中各生境类型的总体数量和连通性。众所周知，生境结构会影响群落的聚集和多样性。因此，在生境配置因土地利用变化而发生重大变化的情况下，历史生境配置可能对当前群落产生重大影响。我们将利用草原实验区（EP）的植物和节肢动物数据，以及所有三个探索站1870-2010年（将在本项目中完成）的土地利用/土地覆盖图，模拟过去土地利用和历史栖息地配置对物种丰富度和群落特征组成的影响。土地利用/土地覆盖图以及从这些图中得出的景观指标将通过BExIS提供给生物多样性探索项目的所有参与者，以支持进一步研究历史土地利用变化对生态系统功能和服务的影响。因此，本项目的目标是：1.)历史土地利用和景观分析：我们将从历史地图中对土地利用/土地覆盖进行数字化，分析当地和景观尺度上的土地利用轨迹，并计算景观指标，以量化Schorheide-Chorin和Schwäbische Alb Exploratories的历史景观结构。这已经在一项初步研究中为hainich - d<e:1>完成。2)。模拟历史景观动态对植物和节肢动物物种丰富度的影响：在这里，我们将验证历史栖息地配置影响当前物种丰富度的假设，并且如果有明显的草地变化（增加或减少），它比当前配置更重要。此外，我们将具体分析栖息地的创造和扩展（例如在hainich - d<e:1>）和破碎化的案例，后者包括可能的灭绝债务模型。3)。过去土地利用和历史生境配置对群落性状组成的模拟效应：在此目标下，我们将模拟历史对多元性状组成、某些物种群体（如生境专家）比例和群落（加权）性状的影响。4)。物种特征与过去土地利用和历史栖息地配置之间相互作用的定量建模：为此，我们将使用一种基于广义线性混合模型的新建模方法来量化某些特征对物种发生与过去土地利用和历史栖息地配置之间关系的影响程度。

Historical land-use change may have considerable influence on current ecosystem composition, structure and function. Past local land use can have persistent legacy effects on communities, e.g. through alterations of site conditions, soil seed banks or persisting species. At landscape scale, land-use change may drastically alter the spatial configuration of habitats, such as patch size and overall amount and connectivity of the respective habitat type in the landscape. Habitat configuration is known to affect assembly and diversity of communities. Thus, in cases where habitat configuration changed substantially due to land-use change, the historical habitat configuration may have a significant influence on current communities.We will use data on plants and arthropods from the Experimental Plots (EP) in grasslands together with land use/ land cover maps from 1870-2010 (to be completed in this project) of all three Exploratories to model the effects of past land use and historical habitat configuration on species richness and community trait composition. The land use/ land cover maps as well as landscape metrics derived from these maps will be made available to all participants of the Biodiversity Exploratories through BExIS to support further studies on effects of historical land-use change on, e.g., ecosystem functions and services.Thus, the objectives of this project are: 1.) Historical land-use and landscape analysis: we will digitise land use/ land cover from historical maps, analyse land-use trajectories at local and landscape scale, and calculate landscape metrics to quantify historical landscape structure in the Schorheide-Chorin and Schwäbische Alb Exploratories. This has already been completed for Hainich-Dün in a preliminary study. 2.) Modelling the effects of historical landscape dynamics on species richness of plants and arthropods: here, we will test the hypotheses that historical habitat configuration affects current species richness and that it is more important than the current configuration if there was a marked change of grasslands (increase, decrease). Further, we will specifically analyse cases of habitat creation and expansion (e.g. in Hainich-Dün), and fragmentation, the latter including modelling of possible extinction debt. 3.) Modelling effects of past land use and historical habitat configuration on trait composition of communities: under this objective, we will model historical effects on multivariate trait composition, proportion of certain species groups (e.g. habitat specialists) and on community (weighted) means of traits. 4.) Quantitative modelling of interactions between species traits and effects of past land use and historical habitat configuration: for this purpose, we will use a new modelling approach based on Generalized Linear Mixed Models to quantify how much certain traits modify the relationships of species occurrence to past land use and historical habitat configuration.