Does large-scale N fertilization have time-delayed effects on insect community structure by changing oak quantity and quality?
Does large-scale N fertilization have time-delayed effects on insect community structure by changing oak quantity and quality?
复制标题
大规模施氮肥是否会通过改变橡树的数量和质量对昆虫群落结构产生延时效应？
DOI：
10.1007/s11829-016-9485-1
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发表时间：
2017
影响因子：
1.6
通讯作者：
Hiura T
中科院分区：
文献类型：
--
作者：
Lee J;Nakamura M;Hiura T
大气氮沉降的增加可能通过沉降引起寄主数量和质量的变化而间接影响植食性昆虫。为了避免小规模氮肥施用中可能发生的“灯效应”，大规模氮肥施用（约200万吨）可能会导致氮肥施用量增加。9公顷，100公斤氮公顷-1年-1）的实验进行了落叶，阔叶，冷温带森林。通过测定成年栎冠层树木（皱皮栎）的生长和叶片质量，研究了皱皮栎及其植食性昆虫对施氮的初始反应。测定了施氮前（2012年）和施氮后（2013-2014年）对照地和施肥地植食性昆虫的取食功能团和群落结构。2014年，氮肥促进了植物生长。在2013年，而不是2014年，氮肥增加了叶片中的N含量，降低了碳/氮（C/N）比。尽管在2013年的植物性状的这些变化，N施肥没有影响无论是取食公会（咀嚼食草动物，galler密度，矿工密度）或群落结构（物种丰富度，多样性指数，相对丰富度）的食草昆虫在同一年。然而，在2014年，多样性指数显著下降，而物种丰富度和丰度没有变化。这表明，种特异性的反应，改变昆虫繁殖力的形式，改变叶片质量氮施肥，影响草食性昆虫的多样性指数，虽然有1年的滞后时间。因此，我们的大规模氮肥试验显示了氮肥对昆虫群落结构的延迟自下而上的影响。
The increased atmospheric deposition of nitrogen (N) may indirectly affect herbivorous insects by deposition-induced changes in host quantity and quality. To avoid the “lamp effect” that can occur in small-scale N fertilizations, large-scale N fertilization (ca. 9 ha, 100 kg N ha−1year−1) experiments were performed in a deciduous, broad-leaved, cool temperate forest. The initial responses of mature oak canopy trees (Quercus crispula) and their herbivorous insects to N fertilization were evaluated by measuring the growth and leaf qualities of the trees. The feeding guilds and community structures of the herbivorous insects at control and fertilized sites before (2012) and after (2013–2014) N fertilization were then determined. In 2014, N fertilization enhanced plant growth. In 2013 but not 2014, N fertilization increased N content and decreased the carbon/nitrogen (C/N) ratio in leaves. Despite these changes in plant traits in 2013, N fertilization had no effect on either feeding guilds (chewing herbivory, galler density, and miner density) or community structures (species richness, diversity index, and relative abundance) of herbivorous insects in the same year. However, in 2014, the diversity index decreased significantly, whereas species richness and abundance were unchanged. This suggests that species-specific responses to changes in leaf qualities following N fertilization, in the form of altered insect fecundity, impact the diversity index of herbivorous insects, albeit with a 1-year lag time. Thus, our large-scale N fertilization experiment show the time-delayed bottom-up effects of N fertilization on insect community structure.