A meta-analytical review of the effects of elevated CO2 on plant-anthropod interactions highlights the importance of interacting environmental and biological variables

An extensive meta-analysis of plant and animal responses to elevated CO2 was conducted. Over 5000 data points were extracted from 270 papers published between 1979 and 2009. These metadata were extracted from an exhaustive review and collection of relevant literature and attempted to synthesize and examine generalizations about herbivore response to CO2 across the literature. This study addressed the responses of insect herbivores to elevated carbon dioxide (CO2) across numerous insect orders and feeding guilds. The changes in 19 animal response variables to the main effect of elevated CO2 was examined. The study also addressed underlying plant mechanisms by quantifying those plant growth and metabolite responses most relevant to insect herbivory and examined how such responses were altered by numerous biotic and abiotic factors. Examined were the main effects of elevated CO2 on: six plant growth and allocation responses, seven primary metabolite responses, eight secondary metabolite responses, and four physical defense responses. These response variable changes were examined under two-way and three-way interactions between CO2 and: soil nitrogen, ambient temperature, drought, light availability, photosynthetic pathway, reproductive system, plant growth rate, plant growth form, tissue type, and nitrogen fixation.

本研究针对动植物对升高浓度二氧化碳（CO₂）的响应开展了大规模元分析。研究从1979年至2009年发表的270篇学术文献中，提取了超过5000个数据点。上述元数据通过对相关文献的全面梳理与系统汇总获取，旨在整合并检验现有文献中关于草食动物对CO₂响应的一般性结论。本研究聚焦于不同昆虫目级类群及取食功能群中的昆虫草食动物对升高CO₂的响应，考察了19项动物响应变量在升高CO₂主效应下的变化情况。本研究同时通过量化与昆虫草食作用密切相关的植物生长及代谢物响应，探究了介导该过程的潜在植物生理机制，并检验了各类生物与非生物因素对这些响应的调控效应。研究还分析了升高CO₂的主效应对以下类别的影响：6项植物生长与分配响应、7项初级代谢产物响应、8项次级代谢产物响应以及4项物理防御响应。上述响应变量的变化情况，在CO₂与以下因素的双向及三向交互作用条件下得到了检验：土壤氮素、环境温度、干旱、光照有效性、光合途径、生殖系统、植物生长速率、植物生长型、组织类型以及固氮作用。