Cosset Cindy C P, Gilroy James J, Srinivasan Umesh, Hethcoat Matthew G, Edwards David P
Department of Animal and Plant Sciences University of Sheffield Sheffield UK.
School of Environmental Sciences University of East Anglia Norwich UK.
Ecol Evol. 2020 Feb 29;10(6):2803-2812. doi: 10.1002/ece3.6066. eCollection 2020 Mar.
Selective logging dominates forested landscapes across the tropics. Despite the structural damage incurred, selectively logged forests typically retain more biodiversity than other forest disturbances. Most logging impact studies consider conventional metrics, like species richness, but these can conceal subtle biodiversity impacts. The mass-abundance relationship is an integral feature of ecological communities, describing the negative relationship between body mass and population abundance, where, in a system without anthropogenic influence, larger species are less abundant due to higher energy requirements. Changes in this relationship can indicate community structure and function changes.We investigated the impacts of selective logging on the mass-abundance scaling of avian communities by conducting a meta-analysis to examine its pantropical trend. We divide our analysis between studies using mist netting, sampling the understory avian community, and point counts, sampling the entire community.Across 19 mist-netting studies, we found no consistent effects of selective logging on mass-abundance scaling relative to primary forests, except for the guild where there were fewer larger-bodied species after logging. In eleven point-count studies, we found a more negative relationship in the whole community after logging, likely driven by the guild, showing a similar pattern.Limited effects of logging on mass-abundance scaling may suggest high species turnover in logged communities, with like-for-like replacement of lost species with similar-sized species. The increased negative mass-abundance relationship found in some logged communities could result from resource depletion, density compensation, or increased hunting; potentially indicating downstream impacts on ecosystem functions. . Our results suggest that size distributions of avian communities in logged forests are relatively robust to disturbance, potentially maintaining ecosystem processes in these forests, thus underscoring the high conservation value of logged tropical forests, indicating an urgent need to focus on their protection from further degradation and deforestation.
选择性采伐在热带地区的森林景观中占主导地位。尽管会造成结构破坏，但与其他森林干扰相比，经过选择性采伐的森林通常保留了更多的生物多样性。大多数采伐影响研究考虑的是常规指标，如物种丰富度，但这些指标可能会掩盖生物多样性的细微影响。质量-丰度关系是生态群落的一个基本特征，描述了体重与种群丰度之间的负相关关系，即在没有人为影响的系统中，由于能量需求较高，较大的物种数量较少。这种关系的变化可以表明群落结构和功能的变化。我们通过进行一项荟萃分析来研究选择性采伐对鸟类群落质量-丰度比例关系的影响，以检验其泛热带趋势。我们将分析分为使用雾网采样林下鸟类群落的研究和使用点计数法采样整个群落的研究。在19项雾网研究中，我们发现相对于原始森林，选择性采伐对质量-丰度比例关系没有一致的影响，除了一个类群，采伐后大型物种较少。在11项点计数研究中，我们发现采伐后整个群落的关系更呈负相关，可能是由一个类群驱动的，呈现出类似的模式。采伐对质量-丰度比例关系的有限影响可能表明采伐群落中物种更替率较高，失去的物种被类似大小的物种同类替代。在一些采伐群落中发现的质量-丰度负相关关系增加可能是由于资源枯竭、密度补偿或捕猎增加；这可能预示着对生态系统功能的下游影响。我们的结果表明采伐森林中鸟类群落的大小分布对干扰相对具有抗性，有可能维持这些森林中的生态系统过程，从而强调了采伐热带森林的高保护价值，表明迫切需要关注对其的保护，防止其进一步退化和森林砍伐。
