Multichannel feeding by spider functional groups is driven by feeding strategies and resource availability
Multichannel feeding by spider functional groups is driven by feeding strategies and resource availability
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蜘蛛功能群的多渠道喂养是由喂养策略和资源可用性驱动的
DOI：
10.1111/oik.04500
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发表时间：
2018
期刊：
影响因子：
3.4
通讯作者：
D. Sanders
中科院分区：
文献类型：
--
作者：
Matthew J. Perkins;R. Inger;S. Bearhop;D. Sanders
多渠道喂食，即消费者通过食草动物和有害动物等资源渠道喂食更多的资源，其作用是将食物网的离散隔间与对生态系统功能和稳定性的影响联系起来。然而，目前我们很少了解消费者的哪些喂养策略是多渠道喂养的基础。因此，我们不仅通过量化消费者的饮食，而且还通过量化资源的相对可用性，将蜘蛛官能团和资源密度依赖或非密度依赖的摄食策略与多渠道摄食联系起来。在这里，我们分析了草原蜘蛛群落对食草动物(绿色)和有害动物(棕色)猎物的使用，并测试了有效猎物的生物量比例是否与观察到的蜘蛛食物比例有关。不同的蜘蛛功能群各自连接着绿色和棕色资源通道，但尽管绿色猎物总是按其相对生物量的比例消耗，但棕色猎物的消耗与某些功能群的比例无关。此外，我们发现，当绿色资源相对稀缺时，草蜘蛛在行会内的捕食能力更强，这表明绿色猎物是首选，当绿色资源稀少时，需要进行补偿。总体而言，我们观察到消费者与绿色资源渠道的联系比棕色资源渠道更强，但这种绿色联系更具变异性，因为草原上绿色资源的可获得性范围更大，而且对绿色猎物的消费依赖于密度。因此，蜘蛛的多渠道取食是由密度依赖和密度非依赖的取食策略决定的，不同的蜘蛛功能群和跨资源渠道的取食策略不同。我们的结果表明，蜘蛛多渠道取食在连接不同的食物网隔间中的作用是这些野生草原食物网结构的一个动态组成部分。
Multichannel feeding, whereby consumers feed across resource channels such as upon herbivore and detritivore resources, acts to link discrete compartments of a food web with implications for ecosystem functioning and stability. Currently however, we have little understanding which feeding strategies of consumers underlie multichannel feeding. We therefore link spider functional group and resource density‐dependent or density‐independent feeding strategies to multichannel feeding by quantifying not only consumer diet, but also the relative availability of resources. Here we analysed herbivore (green) and detritivore (brown) prey use by spider communities in grasslands, and tested if available prey biomass proportions were linked to observed spider dietary proportions.Different spider functional groups each linked green and brown resource channels, but while green prey were always consumed in proportion to their relative biomass, brown prey were consumed independently of proportion by some functional groups. Additionally, we found greater intraguild predation by cursorial spiders when green resources were relatively scarcer, suggesting green prey was preferred, and needed to be compensated for when rare. Overall, we observed a stronger consumer connection to the green than brown resource channel, yet this green connection was more variable due to greater range in green resource availability across grasslands and density‐dependent consumption on green prey. Consequently, multichannel feeding by spiders was determined by density‐dependent and density‐independent feeding strategies that varied by spider functional group and across resources channels. Our results demonstrate that the role of multichannel feeding by spiders in linking separate food web compartments is a dynamic component of food web structure in these wild grasslands.
通才捕食者对小麦上蚜虫的控制：捕食者密度和替代猎物存在的影响
影响因子：
1.9
作者：
Oelbermann
通讯作者：
Oelbermann
影响因子：
6.6
作者：
Nakagawa, Shinichi;Schielzeth, Holger
通讯作者：
Schielzeth, Holger
简单的规则描述了具有替代能源途径的食物网中自下而上和自上而下的控制
影响因子：
8.8
作者：
Wollrab;De Roos
通讯作者：
De Roos