Department of Forestry and Natural Resources, Purdue University, 715 West State Street, West Lafayette, Indiana, 47907, USA.
Department of Environmental Science and Policy, Drake University, 2507 University Avenue, Des Moines, Iowa, 50311, USA.
Ecol Appl. 2017 Jun;27(4):1064-1081. doi: 10.1002/eap.1532. Epub 2017 May 2.
Contemporary forest management offers a trade-off between the potential positive effects of habitat heterogeneity on biodiversity, and the potential harm to mature forest communities caused by habitat loss and perforation of the forest canopy. While the response of taxonomic diversity to forest management has received a great deal of scrutiny, the response of functional diversity is largely unexplored. However, functional diversity may represent a more direct link between biodiversity and ecosystem function. To examine how forest management affects diversity at multiple spatial scales, we analyzed a long-term data set that captured changes in taxonomic and functional diversity of moths (Lepidoptera), longhorned beetles (Coleoptera: Cerambycidae), and breeding birds in response to contemporary silvicultural systems in oak-hickory hardwood forests. We used these data sets to address the following questions: how do even- and uneven-aged silvicultural systems affect taxonomic and functional diversity at the scale of managed landscapes compared to the individual harvested and unharvested forest patches that comprise the landscapes, and how do these silvicultural systems affect the functional similarity of assemblages at the scale of managed landscapes and patches? Due to increased heterogeneity within landscapes, we expected even-aged silviculture to increase and uneven-aged silviculture to decrease functional diversity at the landscape level regardless of impacts at the patch level. Functional diversity responses were taxon-specific with respect to the direction of change and time since harvest. Responses were also consistent across patch and landscape levels within each taxon. Moth assemblage species richness, functional richness, and functional divergence were negatively affected by harvesting, with stronger effects resulting from uneven-aged than even-aged management. Longhorned beetle assemblages exhibited a peak in species richness two years after harvesting, while functional diversity metrics did not differ between harvested and unharvested patches and managed landscapes. The species and functional richness of breeding bird assemblages increased in response to harvesting with more persistent effects in uneven- than in even-aged managed landscapes. For moth and bird assemblages, species turnover was driven by species with more extreme trait combinations. Our study highlights the variability of multi-taxon functional diversity in response to forest management across multiple spatial scales.
当代森林管理在生境异质性对生物多样性的潜在积极影响与森林栖息地丧失和林冠穿孔对成熟森林群落的潜在危害之间提供了一种权衡。虽然分类多样性对森林管理的响应已经受到了广泛的关注，但功能多样性在很大程度上仍未得到探索。然而，功能多样性可能代表了生物多样性与生态系统功能之间更直接的联系。为了研究森林管理如何在多个空间尺度上影响多样性，我们分析了一个长期数据集，该数据集记录了鳞翅目（鳞翅目）、长角甲虫（鞘翅目：天牛科）和繁殖鸟类的分类和功能多样性在栎-山核桃硬木林中的当代抚育系统下的变化。我们使用这些数据集来回答以下问题：与构成景观的单个采伐和未采伐森林斑块相比，同龄林和异龄林抚育系统如何影响管理景观尺度上的分类和功能多样性，以及这些抚育系统如何影响管理景观和斑块尺度上的组合的功能相似性？由于景观内的异质性增加，我们预计同龄林抚育会增加，而异龄林抚育会降低景观水平的功能多样性，而不论斑块水平的影响如何。功能多样性的响应与变化的方向和收获后的时间有关，具有分类特异性。在每个分类单元中，响应在斑块和景观水平上也是一致的。蛾类组合的物种丰富度、功能丰富度和功能发散受到收获的负面影响，异龄管理的影响比同龄管理更强。长角甲虫组合的物种丰富度在收获后两年达到峰值，而功能多样性指标在采伐和未采伐斑块以及管理景观之间没有差异。鸟类繁殖组合的物种和功能丰富度对收获作出响应而增加，而异龄管理的影响比同龄管理更持久。对于蛾类和鸟类组合，物种更替是由具有更极端特征组合的物种驱动的。我们的研究强调了多分类功能多样性在多个空间尺度上对森林管理的响应的可变性。
