Intermediate herbivory intensity of an aboveground pest promotes soil labile resources and microbial biomass via modifying rice growth
Intermediate herbivory intensity of an aboveground pest promotes soil labile resources and microbial biomass via modifying rice growth
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地上害虫的中等食草强度通过改变水稻生长来促进土壤不稳定资源和微生物生物量
DOI：
10.1007/s11104-012-1480-4
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发表时间：
2013-06-01
期刊：
影响因子：
4.9
通讯作者：
Hu, Feng
中科院分区：
文献类型：
--
作者：
Huang, Jinghua;Liu, Manqiang;Hu, Feng
背景与目的地上食草动物对改变地下生态系统的重要性已经引起了大量的研究；然而，研究可能会受到环境依赖条件的影响，从而导致极不一致的结果。目前，水稻重要害虫的取食强度对稻田土壤生态系统的影响尚缺乏研究。本研究的目的是验证褐飞虱（Nilaparvata lugensstatal）的中等食草强度可以通过调节水稻生长来促进土壤稳定资源和微生物生物量，而高食草强度则相反。本研究也将有助于害虫综合治理的发展。方法采用4种不同密度处理（每株0、4、8和12若虫）和2种侵染时间处理（n后9和15 d）。在温室试验中建立了lugensin侵染菌，DAI 9和DAI 15。对4个重复的土壤和植物进行破坏性采样，分别分析土壤活性资源有效性、土壤微生物生物量和植物生长性能。结果侵染密度对水稻茎、根质量、土壤溶解有机碳（DOC）和氮（DON）、微生物生物量碳（MBC）和氮（MBN）均有显著影响（P< 0.05），且随着侵染时间的延长，影响进一步增强。与未施氮对照（CK）相比。低（LD）和中等（MD）密度处理下，光合速率、植株干质量、DOC、DON、MBC和MBN均有所增加，高密度处理下则有所降低。此外，LD处理对dai15的促进作用最大。水稻根冠比在草食处理中普遍升高。在不同处理中，稳定资源和微生物生物量与茎部和根质量关系密切，特别是与DAI 15的根质量关系密切。这一趋势表明，光合分配向地下转移导致了土壤资源有效性和微生物生物量的变化。结论中等草食强度对水稻幼苗生长性能有积极影响，进而提高土壤稳定资源有效性和微生物生物量。强调了外推时间和空间尺度的重要性，即从短期温室试验到田间整个水稻生长季节。
Background and AimsThe importance of aboveground herbivores for modifying belowground ecosystems has prompted numerous studies; however, studies can be biased by context dependent conditions which lead to extremely inconsistent results. So far, the impacts of herbivory intensity by important rice pests on rice paddy soil ecosystems are lacking. The aim of this study was to test the hypothesis that intermediate herbivory intensity of the brown planthopper (Nilaparvata lugensStål) could promote soil labile resources and microbial biomass, while high intensity would show a reverse pattern, by mediating rice plant growth. This study will also help the development of integrative pest management.MethodsFour hopper infestation density treatments (0, 4, 8 and 12 nymphs per rice plant) and two infestation duration treatments (9 and 15 days afterN. lugensinfestation, DAI 9 and DAI 15) were established in a glasshouse experiment. Soil and plant were sampled destructively from four replicates and analysed for soil labile resources availability, soil microbial biomass and plant performance, respectively.ResultsThe infestation density significantly affected both shoot and root mass of rice (P< 0.05), soil dissolved organic carbon (DOC) and nitrogen (DON), and microbial biomass carbon (MBC) and nitrogen (MBN), and the effects were further enhanced by prolonged infestation duration. Compared to the control (CK) withoutN. lugens, plant dry mass, DOC, DON, MBC and MBN increased under low (LD) and moderate hopper densities (MD) but decreased under high density (HD) on DAI 9. Moreover, the LD treatment exerted the most promotional effects on DAI 15. Rice root to shoot ratio generally increased in treatments subjected to herbivory. The labile resources and microbial biomass showed close relationships with both shoot and root mass across treatments, in particular with root mass on DAI 15. Such a trend indicated that the shift of photosynthate allocation to belowground contributed to changes of soil resource availability and microbial biomass.ConclusionsIntermediate herbivory intensity showed positive effects on rice seedling performance and, further, promoted soil labile resource availability and microbial biomass. The importance of extrapolating temporal and spatial scale, i.e. from the short-term greenhouse experiment to an entire rice growing season in the field, was highlighted.