Land-use components, abundance of predatory arthropods, and vegetation height affect predation rates in grasslands
Land-use components, abundance of predatory arthropods, and vegetation height affect predation rates in grasslands
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DOI：
10.1016/j.agee.2018.10.015
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发表时间：
2019-02
期刊：
影响因子：
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通讯作者：
S. Meyer;Lisa Heuss;H. Feldhaar;W. Weisser;M. Gossner
中科院分区：
文献类型：
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作者：
S. Meyer;Lisa Heuss;H. Feldhaar;W. Weisser;M. Gossner
土地利用是包括巨型多样化节肢动物在内的许多类群生物多样性丧失的主要驱动因素，但节肢动物介导的过程的后果仍知之甚少。使用快速生态系统功能评估（REFA），我们通过量化对人工哨兵猎物的捕食尝试来近似捕食。在德国两个地区的 83 个管理温带草原的土壤表面放置了假人，这些草原的土地利用强度范围广泛（放牧强度、割草频率和施肥量）。此外，我们还测量了植被高度，并使用陷阱评估了地面节肢动物的丰度。我们记录了节肢动物、啮齿动物和鸟类留下的捕食痕迹。具有捕食标记的假人比例（即捕食率）因地区而异。在我们的研究中，植被高度是捕食的最强预测因子，但与土地利用的相关性很弱。对于啮齿动物和所有捕食者群体来说，捕食率随着植被高度的增加而增加。所有三个土地利用组成部分都会影响捕食，其中对节肢动物捕食最为突出。节肢动物捕食随着放牧强度的增加而增加，随着割草频率和施肥强度的增加而减少。此外，地面节肢动物的丰富度也影响了捕食。虽然捕食率通常随着步甲丰度的增加而增加，并随着蚂蚁丰度的增加而减少，但蜘蛛丰度的影响与区域相互作用。我们的结果表明，土地利用的不同组成部分可能会对捕食率产生抵消作用，同时还会影响不同捕食者群体的丰度和植被高度的变化。这表明，维持高植被和地面捕食者丰度的土地利用做法会增加草原的捕食率，从而增加以害虫防治形式提供生态系统服务的潜力。
Land use is a major driver of biodiversity loss in many taxa including the mega-diverse arthropods, but consequences for arthropod-mediated processes are still little understood. Using a rapid ecosystem function assessment (REFA), we approximated predation by quantifying predation attempts on artificial sentinel prey. Dummies were placed on the soil surface of 83 managed temperate grasslands across a broad range of land-use intensities (grazing intensity, mowing frequency, and the amount of applied fertiliser) in two regions of Germany. Additionally, we measured vegetation height and assessed the abundance of ground-dwelling arthropods using pitfall traps. We documented predation marks left by arthropods, rodents, and birds. The proportion of dummies with predation marks (i.e. predation rates) differed between regions. Vegetation height was the strongest predictor for predation in our study but correlated only weakly with land use. Predation rates increased with increasing vegetation height, for rodents and for all predator groups combined. All three land-use components affected predation, which was most prominent for arthropod predation. Arthropod predation increased with higher grazing intensity and decreased with higher mowing frequency and higher fertilisation intensity. Also, the abundances of ground-dwelling arthropods affected predation. While predation rates generally increased with a higher abundance of carabids and decreased with higher abundance of ants, the effects of spider abundance interacted with region. Our results demonstrate that different components of land use can have counteracting effects on predation rates acting together with changes in the abundance of different predator groups and vegetation height. This suggests that land-use practices that sustain high vegetation and ground-dwelling predator abundances increase predation rates in grasslands and consequently the potential to provide ecosystem services in the form of pest control.