Moss Ellen D, Evans Darren M
School of Natural and Environmental Sciences, Newcastle University, Newcastle Upon Tyne, United Kingdom.
School of Biological, Biomedical and Environmental Sciences, University of Hull, Hull, United Kingdom.
Front Plant Sci. 2022 Feb 23;13:826205. doi: 10.3389/fpls.2022.826205. eCollection 2022.
Declines in pollinating insects and wildflowers have been well documented in recent years. Climate change is an emerging threat to insect pollinators and their food plants, but little is known about how whole communities of interacting species will be affected or what impacts there may be on ecosystem services such as pollination. Using a novel open-air field experiment, we simulated an increase in temperature of 1.5°C and rainwater of 40% for two growing seasons to investigate how climate change may impact several within-field features of temperate arable agro-ecosystems: (1) wildflower floral resources; (2) insect visitation; (3) flower-visitor network structure; and (4) wildflower seed set. Experimental warming reduced total floral abundance by nearly 40%, and nectar volumes by over 60% for two species. The species richness of the visiting insects and flowering plants (dominated by annuals) were unaffected by warming, and while a negative impact on visitor abundance was observed, this effect appears to have been mediated by different community compositions between years. Warming increased the frequency of visits to flowers and the complexity of the flower-visitor interaction networks. Wildflower seed set was reduced in terms of seed number and/or weight in four of the five species examined. Increased rainwater did not ameliorate any of these effects. These findings demonstrate the adverse impacts that climate warming might have on annual wildflowers in arable systems and the pollinating insects that feed on them, highlighting several mechanisms that could drive changes in community composition over time. The results also reveal how cascading impacts within communities can accumulate to affect ecosystem functioning.
近年来，传粉昆虫和野花数量减少的情况已有充分记录。气候变化正对昆虫传粉者及其食物植物构成新的威胁，但对于相互作用的物种整个群落将如何受到影响，以及对诸如授粉等生态系统服务可能产生何种影响，人们知之甚少。我们利用一项新颖的露天田间试验，在两个生长季节模拟了温度升高1.5°C和降雨量增加40%的情况，以研究气候变化可能如何影响温带耕作农业生态系统的几个田间特征：（1）野花的花卉资源；（2）昆虫访花情况；（3）花-访花者网络结构；（4）野花结实率。实验性变暖使两种野花的总花量减少了近40%，花蜜量减少了60%以上。访花昆虫和开花植物（以一年生植物为主）的物种丰富度不受变暖影响，虽然观察到对访花者数量有负面影响，但这种影响似乎是由不同年份的群落组成差异介导的。变暖增加了访花频率和花-访花者相互作用网络的复杂性。在所研究的五个物种中，有四个物种的野花结实率在种子数量和/或重量方面有所降低。降雨量增加并未改善这些影响中的任何一种。这些发现表明气候变暖可能对耕作系统中的一年生野花以及以它们为食的传粉昆虫产生不利影响，突出了几种可能随着时间推移推动群落组成变化的机制。研究结果还揭示了群落内部的连锁影响如何累积起来影响生态系统功能。
