Department of Entomology, Purdue University, West Lafayette, Indiana, 47907, USA.
Department of Forestry and Natural Resources, Purdue University, West Lafayette, Indiana, 47907, USA.
Ecol Appl. 2018 Oct;28(7):1853-1866. doi: 10.1002/eap.1780. Epub 2018 Aug 20.
The study of functional diversity, or the range of species' ecological roles in a community, is a rapidly expanding area in ecology. Given the extent that ecosystems are being altered, effort should shift toward assessing variation in functional diversity across landscapes with the goal of improving land use management decisions. We construct a workflow that creates three-dimensional surfaces and maps of functional diversity to examine changes in beetle functional diversity across an Indiana, USA landscape. We sampled 105 prey wood-borer and predator beetle species along a gradient of forest fragmentation across Indiana and used a number of functional traits from literature sources to capture their functional roles. We developed newly measured functional traits to estimate several traits relevant to beetles' ecological function that was unknown and not easily measured. Functional diversity indices (FRic, FDis, FDiv, and FEve) were calculated from species abundance and functional traits and used to assess changes in functional diversity along the fragmentation gradient. We predicted that habitat fragmentation would have a greater negative impact on predator beetle functional diversity than prey wood-borer functional diversity. Landscape metrics most important to the functional diversity of both wood-borer and predator beetle communities were landscape division index (LDI, an assessment of landscape subdivision) and mean shape index (MSI, a measure of patch shape complexity). Overall, three-dimensional surfaces of functional diversity and functional diversity maps across the Indiana landscape revealed that beetle functional diversity was greatest with minimal landscape subdivision. Opposite to what we predicted, we found that the prey wood-borer functional diversity was more negatively impacted by LDI than the predator beetle functional diversity. Furthermore, predator beetle functional diversity was greater with increasing MSI. The map predicted predator FRic to be highest in forested areas with intact habitat and also less sensitive to habitat fragmentation adjacent to more continuous forest. We propose that land management may be guided by revealing landscapes that are most appropriate for maximizing functional diversity of multiple communities or shifting the relative abundance within prey and beneficial predator beetle functional groups with the use of three-dimensional plots or maps.
功能多样性的研究，即物种在群落中的生态角色范围，是生态学中一个迅速发展的领域。鉴于生态系统正在发生变化，应该努力评估景观中功能多样性的变化，以期改善土地利用管理决策。我们构建了一个工作流程，创建了三维表面和功能多样性图，以研究美国印第安纳州景观中甲虫功能多样性的变化。我们在印第安纳州沿着森林破碎化梯度对 105 种猎物蛀木虫和捕食性甲虫进行了采样，并从文献来源中使用了许多功能特征来捕捉它们的功能角色。我们开发了新的测量功能特征，以估计几个与甲虫生态功能相关的特征，这些特征是未知的，不容易测量。从物种丰度和功能特征中计算出功能多样性指数（FRic、FDis、FDiv 和 FEve），并用于评估功能多样性沿着破碎化梯度的变化。我们预测，栖息地破碎化对捕食性甲虫功能多样性的负面影响将大于对猎物蛀木虫功能多样性的负面影响。对猎物蛀木虫和捕食性甲虫群落的功能多样性最重要的景观指标是景观分割指数（LDI，对景观细分的评估）和平均形状指数（MSI，衡量斑块形状的复杂性）。总体而言，印第安纳州景观的功能多样性三维表面和功能多样性图表明，甲虫的功能多样性在最小的景观细分下最大。与我们的预测相反，我们发现猎物蛀木虫的功能多样性受 LDI 的影响比捕食性甲虫的功能多样性更大。此外，捕食性甲虫的功能多样性随着 MSI 的增加而增加。该地图预测，捕食者 FRic 在森林覆盖区最高，在与更连续的森林相邻的地方对生境破碎化的敏感性较低。我们提出，通过使用三维图或地图，揭示最适合最大化多个群落功能多样性或改变猎物和有益捕食性甲虫功能组相对丰度的景观，可能指导土地管理。
