Throop, Heather L. and Holland, Elisabeth A. and Parton, William J. and Ojima, Dennis S. and Keough, Cynthia A. (2004) Effects of nitrogen deposition and insect herbivory on patterns of ecosystem - level carbon and nitrogen dynamics: results from the CENTURY model. Global Change Biology, 10 (7). pp. 1092-1105. ISSN 1354-1013
Full text not available from this repository.Abstract
Atmospheric nitrogen deposition may indirectly affect ecosystems through deposition-induced changes in the rates of insect herbivory. Plant nitrogen (N) status can affect the consumption rates and population dynamics of herbivorous insects, but the extent to which N deposition-induced changes in herbivory might lead to changes in ecosystem-level carbon (C) and N dynamics is unknown. We created three insect herbivory functions based on empirical responses of insect consumption and population dynamics to changes in foliar N and implemented them into the CENTURY model. We modeled the responses of C and N storage patterns and flux rates to N deposition and insect herbivory in an herbaceous system. Results from the model indicate that N deposition caused a strong increase in plant production, decreased plant C:N ratios, increased soil organic C (SOC), and enhanced rates of N mineralization. In contrast, herbivory decreased both vegetative and SOC storage and depressed N mineralization rates. The results suggest that herbivory plays a particularly important role in affecting ecosystem processes by regulating the threshold value of N deposition at which ecosystem C storage saturates; C storage saturated at lower rates of N deposition with increasing intensity of herbivory. Differences in the results among the modeled insect herbivory functions suggests that distinct physiological and population response of insect herbivores can have a large impact on ecosystem processes. Including the effects of herbivory in ecosystem studies, particularly in systems where rates of herbivory are high and linked to plant C:N, will be important in generating accurate predictions of the effects of atmospheric N deposition on ecosystem C and N dynamics.
| Item Type: | Journal Article |
|---|---|
| Subjects: | G Geography. Anthropology. Recreation > GE Environmental Sciences Q Science > Q Science (General) |
| Divisions: | Pacific Centre for Environment and Sustainable Development (PACE-SD) |
| Depositing User: | Harmindar Kaur |
| Date Deposited: | 01 Jun 2023 00:08 |
| Last Modified: | 01 Jun 2023 00:08 |
| URI: | https://repository.usp.ac.fj/id/eprint/13969 |
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