Corcos Daria, Cerretti Pierfilippo, Mei Maurizio, Vigna Taglianti Augusto, Paniccia Dino, Santoiemma Giacomo, De Biase Alessio, Marini Lorenzo
Department of Biology and Biotechnology "Charles Darwin", Sapienza University of Rome, Piazzale Aldo Moro 5, 00185, Rome, Italy.
DAFNAE-Entomology, University of Padova, Viale dell'Università 16, 35020, Legnaro, Padua, Italy.
Oecologia. 2018 Sep;188(1):193-202. doi: 10.1007/s00442-018-4169-4. Epub 2018 May 24.
Elevational gradients are characterized by strong abiotic variation within small geographical distances and provide a powerful tool to evaluate community response to variation in climatic and other environmental factors. We explored how temperature and habitat diversity shape the diversity of holometabolous predator and parasitoid insects along temperate elevational gradients in the European Alps. We surveyed insect communities along 12 elevational transects that were selected to separate effects of temperature from those of habitat diversity. Pitfall traps and pan traps were placed every 100 m of elevation increment along the transects ranging from 120 to 2200 m a.s.l. Sampling took place once a month from June to September 2015. Four groups characterized by having at least one life stage behaving as predator or parasitoid were examined: tachinids (Diptera), hoverflies (Diptera), sphecids (Hymenoptera) and ground beetles (Coleoptera). Species richness and evenness changed with elevation, but the shape and direction of the elevation-diversity patterns varied between groups. The effect of temperature on species richness was positive for all groups except for hoverflies. Habitat diversity did not affect species richness, while it modulated the evenness of most groups. Often, elevational patterns of species richness and evenness were contrasting. Our study indicates that natural enemies characterized by diverse ecological requirements can be differentially affected by temperature and habitat diversity across the same elevational gradients. As climate warming is predicted to increase mean annual temperatures and exacerbate weather variability, it is also expected to strongly influence natural enemies and their ability to regulate herbivore populations.
海拔梯度的特点是在小地理距离内存在强烈的非生物变化，为评估群落对气候和其他环境因素变化的响应提供了一个有力工具。我们探究了温度和栖息地多样性如何塑造欧洲阿尔卑斯山温带海拔梯度上全变态捕食性和寄生性昆虫的多样性。我们沿着12条海拔样带调查昆虫群落，这些样带的选择是为了区分温度和栖息地多样性的影响。在海拔从120米到2200米的样带上，每隔100米的海拔增量设置陷阱诱捕器和盘式诱捕器。采样于2015年6月至9月每月进行一次。我们研究了四类至少有一个生命阶段表现为捕食者或寄生者的昆虫：寄蝇（双翅目）、食蚜蝇（双翅目）、胡蜂（膜翅目）和步甲（鞘翅目）。物种丰富度和均匀度随海拔变化，但海拔 - 多样性模式的形状和方向在不同类群之间有所不同。除食蚜蝇外，温度对所有类群的物种丰富度都有正向影响。栖息地多样性不影响物种丰富度，但调节了大多数类群的均匀度。通常，物种丰富度和均匀度的海拔模式形成对比。我们的研究表明，具有不同生态需求的天敌在相同海拔梯度上可能受到温度和栖息地多样性的不同影响。由于预计气候变暖将使年平均温度升高并加剧天气变异性，因此预计也会强烈影响天敌及其调节食草动物种群数量的能力。
