Warming increased feeding of a root-chewing insect at the soil surface and enhanced its damage on a grass
Warming increased feeding of a root-chewing insect at the soil surface and enhanced its damage on a grass
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变暖增加了土壤表面食根昆虫的摄食并增强了其对草的损害
DOI：
10.1016/j.soilbio.2018.09.009
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发表时间：
2018
影响因子：
9.7
通讯作者：
Kaneko Nobuhiro
中科院分区：
文献类型：
--
作者：
Tsunoda Tomonori;Makoto Kobayashi;Suzuki Jun-Ichirou;Kaneko Nobuhiro
空气和土壤变暖对植物和食草根性昆虫都有影响，但变暖如何改变它们的相互作用在很大程度上是未知的。由于食草性的强度和植物对食草性的敏感性都依赖于温度，因此很难预测在变暖条件下昆虫食草性对植物生长的影响。为了分析变暖引起的地下植物-昆虫相互作用的变化，我们进行了一项盆栽实验，使用了一种草本植物Loliumperene和一种甲虫GRubAnomala cuprea。对盆栽土壤的温度(17 °C或20.3 °C)、是否有幼虫以及是否有有机质(OM)进行了控制。土壤表层有机质是幼虫的重要资源，含有中性脂肪脂肪酸(NLFA)，可作为细菌标志物。NLFA可以作为一种示踪剂来确定幼虫是否以OM为食，因此我们评估了幼虫对变暖的消耗和垂直移动。在没有幼虫的情况下，植物生物量随着气温的升高而增加，但不受OM处理的影响。在幼虫存在的情况下，植物生物量显著下降。此外，温度和幼虫处理之间的交互作用项显著，说明温度越高，对幼虫的危害越严重。幼虫死亡率不受任何处理的影响。添加OM的幼虫中细菌NLFA的检出率显著高于未添加OM的幼虫中的NLFA含量，且随温度升高而增加。这表明，在两种温度条件下，幼虫都在土壤表面附近取食，但在较温暖的条件下，幼虫的摄食率增加。较暖条件下的土壤平均相对含水量显著低于对照条件下的土壤相对含水量。OM还增加了土壤水分，但对草食性损害没有影响，这表明植物对草食性的敏感性不是土壤水分造成的。这些结果表明了气候变暖对植物的生物背景依赖性的重要性。温度的变化不是通过改变植物对草食的敏感性，而是通过增加对幼虫的消耗来改变根-食草动物的相互作用。
Air and soil warming influences both plants and root herbivorous insects, but how warming alters their interactions is largely unknown. Because both the intensity of herbivory and plant susceptibility to the herbivory depend on temperature, it is difficult to predict the effects of insect herbivory on plant growth under warming. To analyse changes in belowground plant-insect interaction due to warming, we conducted a pot experiment using one grass species,Loliumperrene,and one beetle grubAnomala cuprea. Temperature (17 °C or 20.3 °C), presence or absence of a grub, and presence or absence of organic matter (OM) on the surface of the potted soil were manipulated. OM at the soil surface is an important resource for grubs, and contains neutral lipid fatty acids (NLFA) that can serve as a bacterial marker. NLFAs can be used as a tracer to determine whether grubs had fed upon OM, so we evaluated the consumption and vertical movement of a grub in response to warming. In the absence of grubs, plant biomass increased with warming, but was not affected by the OM treatment. In the presence of grubs, plant biomass was significantly decreased. Moreover, the interaction term between the temperature and grub treatments was significant, demonstrating that grub damage was more severe under warmer conditions. Grub mortality was not affected by any treatment. The bacterial NLFAs in a grub were significantly more detectable when OM was added relative to those without OM, and the amount increased with warming treatments. This suggests that the grub fed near the soil surface under both temperature conditions, but increased consumption rates under the warmer condition. The mean relative soil moisture content in the warmer conditions was significantly lower than that in the control conditions. OM additionally increased soil moisture, but it had no effect on herbivory damage, suggesting that plant susceptibility to herbivory was not attributable to soil moisture. These results show the importance of biological-context dependency of warming on a plant. Temperature changes will alter the root-herbivore interactions not by changing the plant susceptibility to herbivory but by increasing the consumption of the grub.