A complex-systems approach to improve understanding of the biodiversity-landscape structure relationship

我们目前正在经历一场全球性的生物多样性危机。国际报纸头版的头版是25%的物种被列为濒危物种的消息。除了气候变化、外来物种入侵和野生动物犯罪等全球环境变化问题外，我们管理景观的方式也在产生负面影响。虽然减少自然栖息地的数量将对野生动物产生负面影响几乎是常识，但不太清楚的是，剩余自然土地覆盖的空间安排是如何影响的。与数量变化无关的自然土地面积的分裂称为碎片化。然而，我们对碎片化的影响的理解存在广泛的争论，缺乏一致的证据基础。如果我们观察单独的自然土地斑块，我们可能会得出结论，较小的斑块包含的个体和物种较少，这些物种可能对斑块外发生的事情不那么敏感。然而，如果我们看一幅由多个小块组成的整体景观，情况就更复杂了。每一小块斑块可能栖息着几个物种，但它们彼此隔离的事实可能意味着这些斑块之间的物种存在差异--可能是因为物种之间的竞争较少。我们还需要考虑这些补丁之间的内容。被砍伐用于低强度农业的森林可能会开辟一些不同的栖息地类型，因此对生物多样性有积极的影响。另一方面，为道路和城市发展而砍伐的森林可能会构成更大的威胁，因为它将通过改变行为和增加死亡率来限制个人的行动。人类干预既可以阻碍也可以促进扩散，这取决于栖息地的碎片化程度和碎片化的原因。在拟议的研究中，我将汇集不同尺度的研究--从观察单个斑块的特征，到这种关系如何在景观尺度和更广泛的范围内表现出来。我将从功能的角度考虑这一点--根据我们是观察大型食肉动物还是小型食谷鸟类，影响有何不同？我还将考虑影响如何变化，这取决于自然栖息地被什么打破了。这是一个多尺度的问题，需要复杂的系统方法。复杂系统方法是一种允许我们考虑系统的组成部分如何协同工作以创建我们可能通过仅单独查看每个部分而看不到的结果的方法。

We are currently experiencing a global biodiversity crisis. Adorning front pages of international newspapers is the news that 25% of species are listed as threatened. In addition to global environmental change issues such as climate change, invasive species introductions and wildlife crime, the way we manage landscape is also having a negative effect. While it almost seems like common sense that reducing the amount of natural habitat will negatively impact wildlife, what is less clear is how the spatial arrangement of any remaining natural land cover factors in. The breaking apart of areas of natural land independent of the change in the amount is known as fragmentation. However, our understanding of the effects of fragmentation is widely debated and lacks a consistent evidence base. If we look at individual patches of natural land, we are likely to conclude that smaller patches contain fewer individuals and species, and that those species may be those that are less sensitive to what is happening outside of the patch. However, if we look at a whole landscape, made up of multiple small patches, the picture is more complicated. Each small patch may inhabit few species, but the fact they are isolated from each other could mean that there are differences in those species among the patches - perhaps because there is less competition between species. We also need to consider what is between those patches. Forest that has been cleared for low intensity agriculture may open up some different habitat types and therefore have a positive effect on biodiversity. On the other hand, forest cleared for roads and urban developments will likely pose a greater threat as it will limit the movement of individuals through behaviour change and increased mortality. Human intervention can both impede and assist dispersal depending on how habitat is fragmented and what it is fragmented by. In the proposed research, I will bring together research at various scales - from looking at characteristics of individual patches, to how this relationship manifests at the landscape scale and broader. I will consider this from a functional perspective - how do the impacts differ depending on whether we look at large carnivores or small grain-eating birds? I will also consider how the impacts change depending on what the natural habitat has been fragmented by. This is a multiscale problem, that requires a complex systems approach. A complex systems approach is one which allows us to consider how the constituent parts of a system work together to create a result which we may not have seen by only looking at each part individually.