© 1986 Heron Publishing—Victoria, Canada
A conceptual model for primary productivity, decomposition and nitrogen cycling in the Chihuahuan creosotebush desert
Daryl L. Moorhead (1, 2), James F. Reynolds (1, 2) and Walter G. Whitford (1)
1. Biology Department, Box 3AF, New Mexico State University, Las Cruces, New Mexico 88003, USA / 2. Systems Ecology Research Group, San Diego State University, San Diego, CA 92182, USA /
Summary
The conceptual framework for a simulation model of primary productivity, decomposition and nitrogen cycling in a shrub-dominated
desert ecosystem in southern New Mexico is presented. This model is based on our previous attempt to simulate carbon allocation
patterns in the desert shrub Larrea tridentata Cov., which demonstrated that moisture patterns alone are insufficient to predict desert productivity. These results, as
well as others, suggest that mineral nutrients, especially nitrogen, may also be an important determinant of productivity
in arid environments. Our current research in the Chihuahuan desert is directed towards elucidating the numerous biotic and
abiotic interactions that determine the rates and directions of carbon, nitrogen and water fluxes in this ecosystem. The development
of this working model will serve as a tool to accomplish three major objectives: (1) to synthesize the large amount of existing
data on decomposition and nitrogen cycling in deserts, (2) to quantify our present state of knowledge about the structure
and function of ecosystem components important in carbon and nitrogen dynamics in deserts, and (3) to address hypotheses concerning
the complex mechanisms of interactions and feedbacks among the organisms involved in carbon and nitrogen exchanges in deserts.
