| Title: | Herbivore-induced changes in plant carbon allocation: assessment of below-ground C fluxes using carbon-14 |
| Author(s): | Holland JN; Cheng W; Crossley DA; |
| Address: | "Department of Entomology, University of Georgia, 30602, Athens, GA, USA. fsn84016@umiami.ir.miami.edu. Institute of Ecology, University of Georgia, 30602, Athens, GA, USA" |
| ISSN/ISBN: | 1432-1939 (Electronic) 0029-8549 (Linking) |
| Abstract: | "Effects of above-ground herbivory on short-term 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(14)CO(2). During the next 8 h,(14)C 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(14)C recovered from soil. While herbivory increased root and soil respiration, the peak time for(14)CO(2) 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" |
| Keywords: | Carbon allocation Herbivory Photosynthetic rate Rhizosphere respiration Root exudates; |
| Notes: | "PubMed-not-MEDLINEHolland, J Nathaniel Cheng, Weixin Crossley, D A Jr eng Germany 1996/03/01 Oecologia. 1996 Mar; 107(1):87-94. doi: 10.1007/BF00582238" |
