Data from: Edge effects on components of diversity and above-ground biomass in a tropical rainforest

1. Edge effects are among the most significant consequences of forest fragmentation. Therefore, understanding the impacts of edge creation on biodiversity is crucial for forest management and biological conservation. 2. In this study, we used trait-based and phylogenetic approaches to examine the effects of fragmentation on components of diversity and above-ground biomass of rainforest tree communities in Madagascar in forest edge vs. interior habitats. 3. Tree communities in forest edges showed lower phylogenetic diversity relative to those in interior habitats, suggesting that some clades may be more vulnerable to environmental filtering than others. Functional diversity was also significantly lower on the edge for productivity traits, but not for dispersal traits. Tree communities in the forest edge showed higher divergence of dispersal traits and lower divergence in productivity traits than expected by chance, while functional diversity in interior forest did not differ from random expectations. This suggests separate mechanisms affect productivity traits vs. dispersal traits in edge habitat. 4. There was no significant difference in above-ground biomass between edge and interior habitats, suggesting that edge effects have not yet negatively influenced the forest’s potential for carbon storage. However, these changes may not have occurred yet, given the slow turnover of tree communities. 5. Synthesis and applications: Our results highlight the role of edge effects in the erosion of functional and phylogenetic diversity of highly diverse tree communities. While above-ground biomass did not appear to be affected by forest edge in our study, we suggest long-term monitoring of forests for potential changes in ecosystem functioning. Given the prevalence of forest fragmentation globally, these findings indicate the need for more holistic biodiversity studies to better understand local consequences of forest fragmentation.11-Jul-2017

1. 边缘效应（edge effects）是森林破碎化（forest fragmentation）最显著的后果之一。因此，厘清生境边缘形成对生物多样性（biodiversity）的影响，对于森林经营与生物保护工作至关重要。2. 本研究采用基于功能性状的（trait-based）系统发育分析方法（phylogenetic approaches），对比了马达加斯加（Madagascar）热带雨林树木群落在林缘与林内生境中的多样性组分及地上生物量（above-ground biomass）特征。3. 相较于林内群落，林缘树木群落的系统发育多样性（phylogenetic diversity）显著更低，提示部分支系（clades）相较于其他支系更易受到环境过滤（environmental filtering）作用的影响。功能多样性（functional diversity）在生产力相关性状（productivity traits）上同样显著偏低，但扩散相关性状（dispersal traits）的功能多样性无此差异。与随机预期（random expectations）相比，林缘树木群落的扩散相关性状呈现更高的分化程度，而生产力相关性状的分化程度则更低；林内群落的功能多样性则与随机预期无显著差异。这表明林缘生境中，作用于生产力相关性状与扩散相关性状的环境调控机制存在分化。4. 林缘与林内生境的地上生物量并无显著差异，说明目前边缘效应尚未对森林的碳储存（carbon storage）潜力产生负面影响。不过考虑到树木群落的周转速率较慢，这类生态变化可能尚未显现。5. 总结与应用：本研究结果凸显了边缘效应在高度多样树木群落的功能与系统发育多样性衰减过程中的作用。尽管本研究中森林边缘未对地上生物量造成显著影响，我们仍建议对森林开展长期监测，以追踪其生态系统功能（ecosystem functioning）的潜在变化。鉴于全球范围内森林破碎化现象普遍存在，本研究结果表明，亟需开展更具整体性的生物多样性研究（holistic biodiversity studies），以更深入地理解森林破碎化的局域生态后果。2017年7月11日