USP Electronic Research Repository

Effects of nitrogen deposition and insect herbivory on patterns of ecosystem - level carbon and nitrogen dynamics: results from the CENTURY model

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: http://repository.usp.ac.fj/id/eprint/13969
UNSPECIFIED

Actions (login required)

View Item View Item