Leslie T W, Biddinger D J, Rohr J R, Hulting A G, Mortensen D A, Fleischer S J
Department of Biology, Long Island University, 801 Metcalfe Bldg., 1 University Plaza, Brooklyn, NY 11201, USA.
Environ Entomol. 2014 Feb;43(1):18-28. doi: 10.1603/EN13099. Epub 2013 Dec 16.
Northeastern U.S. farms are often situated adjacent to forestland due to the heterogeneous nature of the landscape. We investigated how forested areas influence Carabidae diversity within nearby crop fields by establishing transects of pitfall traps. Trapping extended across a forest-agriculture ecotone consisting of maize, an intermediate mowed grass margin, and a forest edge. Carabidae diversity was compared among the three habitats, and community and population dynamics were assessed along the transect. We used a principal response curve to examine and visualize community change across a spatial gradient. The highest levels of richness and evenness were observed in the forest community, and carabid assemblages shifted significantly across the ecotone, especially at the forest-grass interface. Despite strong ecotone effects, population distributions showed that some species were found in all three habitats and seemed to thrive at the ecotone. Based on similarity indices, carabid assemblages collected in maize adjacent to forest differed from carabid assemblages in maize not adjacent to forest. We conclude that forest carabid assemblages exhibit high degrees of dissimilarity with those found in agricultural fields and forested areas should thus be retained in agricultural landscapes to increase biodiversity at the landscape scale. However, ecotone species found at forest edges can still noticeably influence carabid community composition within neighboring agricultural fields. Further studies should determine how these shifts in carabid assemblages influence agroecosystem services in relation to ecosystem services observed in fields embedded in an agricultural matrix.
由于景观的异质性，美国东北部的农场常常毗邻林地。我们通过设置陷阱样带，研究了森林区域如何影响附近农田内步甲科昆虫的多样性。诱捕范围跨越了一个由玉米地、中间经过修剪的草地边缘和森林边缘组成的森林 - 农业交错带。我们比较了这三种栖息地的步甲科昆虫多样性，并沿着样带评估了群落和种群动态。我们使用主响应曲线来检验和可视化群落沿空间梯度的变化。森林群落中观察到的丰富度和均匀度最高，步甲类群在交错带显著变化，尤其是在森林 - 草地交界处。尽管交错带效应强烈，但种群分布表明，一些物种在所有三种栖息地都能被发现，并且似乎在交错带茁壮成长。基于相似性指数，在毗邻森林的玉米地中收集的步甲类群与不毗邻森林的玉米地中的步甲类群不同。我们得出结论，森林中的步甲类群与农田中的步甲类群表现出高度的差异，因此在农业景观中应保留森林区域，以增加景观尺度上的生物多样性。然而，在森林边缘发现的交错带物种仍然可以显著影响邻近农田内的步甲群落组成。进一步的研究应该确定这些步甲类群的变化如何影响农业生态系统服务，以及与嵌入农业基质中的农田所观察到的生态系统服务之间的关系。
