Exploring conservation co-benefits to biodiversity and carbon storage and sink capacity across forests to improve practice.

保护全球森林是预防气候和生物多样性危机努力的核心。森林在减缓气候变化方面发挥着基础性作用，吸收了大约三分之一的人为排放，但也是80%陆地生物多样性的家园。现代森林管理主要针对保护和增加碳储量，以减缓气候变化，通常假设生物多样性将同时得到保护，作为一种共同利益。虽然有证据表明，在大规模的热带森林中，这些变量之间存在正向关系，但最近的研究表明，温带森林可能并非如此。为了设计未来的管理政策，我们需要了解生物多样性和碳动态之间的这种关系可能如何以及为什么会在不同的空间尺度和森林使用中发生变化。就像生物多样性和碳动态可能在空间上相关一样，它们也可能在时间上相关，一个变量的扰动可能会危及另一个变量。例如，过度捕杀导致全球森林中大型脊椎动物的损失，因为这些脊椎动物往往是最有价值的肉类、贸易和文化。因此，负责传播大种子的物种被从生态系统中移除，从而减少了大种子树的分散和再生，而大种子树往往具有更高的碳储量。更新动态的这种变化导致了森林组成的变化，形成了以风散种为主的群落，这些树种通常具有较低的木材密度，因此碳储存能力也较低。该项目将使人们更好地了解分类群、生物多样性与碳储量和封存能力之间的多方向关系(图1)。此外，有人认为，脊椎动物和树木的多样性不足以替代栖息地的总生物多样性，因此我将调查各种分类群，以提供对森林生物多样性和碳相互作用的更全面的了解。了解碳动态保护和生物多样性保护之间的共同利益，将有助于根据英国净零排放计划制定保护战略。

Conservation of global forests is at the centre of the climate and biodiversity crisis prevention efforts. Forests play a fundamental role in mitigating climate change, absorbing around 1/3 of anthropogenic emissions, but are also home to 80% of terrestrial biodiversity. Modern forest management is mainly directed at protecting and increasing carbon stocks to mitigate climate change, often assuming biodiversity will be simultaneously protected as a co-benefit. While there is evidence for a positive relationship between these variables in tropical forests at large scales, recent studies suggest this may not be the case for temperate forests. In order to design future management policies, we need understand how and why this relationship between biodiversity and carbon dynamics may change across different spatial scales and forest uses. In the same way that biodiversity and carbon dynamics may be related across space, they may also be related through time, with disturbances in one variable having the potential to compromise the other. Overhunting, for instance, causes the loss of large vertebrates across forests globally, as these tend to be the most valuable for meat, trade and culture. Thus, species responsible for dispersing large seeds are removed from ecosystems, consequently reducing dispersion and regeneration of large-seeded trees, which tend to have higher carbon stocks. This alteration of regeneration dynamics causes a shift in forest composition, creating communities dominated by wind-dispersed species which typically have a lower wood density, and thus low carbon storage capacity. This project will generate a greater understanding of the multidirectional relationship between taxa biodiversity and carbon stocks and sequestration capacity (Figure 1). In addition, it has been suggested that vertebrate and tree diversity are insufficient surrogates for total habitat biodiversity, therefore I will investigate various taxa, providing a more comprehensive understanding of forest biodiversity and carbon interactions. The understanding of co-benefits between conservation of carbon dynamics and biodiversity from this project will help to inform conservation strategies in line with the UK Net Zero program.