Herbivore-induced changes in plant carbon allocation: Assessment of below-ground C fluxes using carbon-14
Herbivore-induced changes in plant carbon allocation: Assessment of below-ground C fluxes using carbon-14
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DOI：
10.1007/bf00582238
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发表时间：
1996-07-01
期刊：
影响因子：
2.7
通讯作者：
Crossley, DA
中科院分区：
文献类型：
--
作者：
Holland, JN;Cheng, WX;Crossley, DA
利用玉米和一种通性蝗虫研究了地上部食草动物对短期植物碳分配的影响。我们假设，地上草食动物刺激当前的净碳同化物分配到地下组件，如根，根分泌物和根和土壤呼吸。将24天龄的玉米植物放牧（c. 25-50%的叶面积被移除），通过将蚱蜢关在单个植物周围，18小时后用（CO2）-C-14脉冲标记。在接下来的8小时，C-14同化物被追踪到芽，根，根加土壤呼吸，根分泌物，根际土壤，和散装土壤使用碳-14技术。植食性和碳分配到根，根分泌物，根和土壤呼吸之间的显着正相关关系，植食性和碳分配到芽之间的显着负相关关系。食草动物和C-14从土壤中回收之间没有关系。虽然草食动物增加根和土壤呼吸，（CO2）-C-14的峰值时间演变为呼吸没有改变，从而表明，草食动物只增加呼吸的幅度，而不是通过时间的转运模式。尽管放牧植物的光合速率比未放牧植物的光合速率有降低的趋势，但放牧和未放牧植物之间没有显著差异。我们得出结论，地上食草动物可以增加植物地下碳通量（根，根分泌物和根际呼吸），从而增加资源（例如，根分泌物）可用于土壤生物，特别是微生物种群。
Effects of above-ground herbivory on shortterm plant carbon allocation were studied using maize (Zea mays) and a generalist lubber grasshopper (Romalea guttata). We hypothesized that above-ground herbivory stimulates current net carbon assimilate allocation to below-ground components, such as roots, root exudation and root and soil respiration. Maize plants 24 days old were grazed (c. 25-50% leaf area removed) by caging grasshoppers around individual plants and 18 h later pulse-labelled with (CO2)-C-14. During the next 8 h, C-14 assimilates were traced to shoots, roots, root plus soil respiration, root exudates, rhizosphere soil, and bulk soil using carbon-14 techniques. Significant positive relationships were observed between herbivory and carbon allocated to roots, root exudates, and root and soil respiration, and a significant negative relationship between herbivory and carbon allocated to shoots. No relationship was observed between herbivory and C-14 recovered from soil. While herbivory increased root and soil respiration, the peak time for (CO2)-C-14 evolved as respiration was not altered, thereby suggesting that herbivory only increases the magnitude of respiration, not patterns of translocation through time. Although there was a trend for lower photosynthetic rates of grazed plants than photosynthetic rates of ungrazed plants, no significant differences were observed among grazed and ungrazed plants. We conclude that above-ground herbivory can increase plant carbon fluxes below ground (roots, root exudates, and rhizosphere respiration), thus increasing resources (e.g., root exudates) available to soil organisms, especially microbial populations.