Plant‐Soil Processes in Eriophorum Vaginatum Tussock Tundra in Alaska: A Systems Modeling Approach

• Published in: Ecological Monographs
• Main Authors: Miller, P. C., Miller, P. M., Blake-Jacobson, M., Chapin, F. S., Everett, K. R., Hilbert, D. W., Kummerow, J., Linkins, A. E., Marion, G. M., Oechel, W. C., Roberts, S. W., Stuart, L.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1984
• Subjects: Ecology, Evolution, Behavior and Systematics; Arctic; albedo; Eriophorum; Tundra; Alaska
• Online Access: http://dx.doi.org/10.2307/1942593; http://api.wiley.com/onlinelibrary/tdm/v1/articles/10.2307%2F1942593; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.2307%2F1942593; https://onlinelibrary.wiley.com/doi/pdf/10.2307/1942593; https://esajournals.onlinelibrary.wiley.com/doi/pdf/10.2307/1942593

The Arctic Tundra Simulator (ARTUS) is a computer—based simulation model of Eriophorum vaginatum tussock tundra ecosystems found in north central Alaska. ARTUS simulates the annual patterns of heat and water balance, carbon fixation, plant growth, and nitrogen and phosphorus cycling. ARTUS runs in 1—d time steps for a growing season from 1 May to 17 September and is intended to run for several years. The abiotic section of ARTUS encodes the seasonal input of the environmental driving variables and calculates the resultant thermal and water regimes to define the heat and water environments for the tussock tundra system. The primary driving variables are daily total solar radiation, air temperature, precipitation, surface albedo, wind, and sky conditions. The soil compartment contains three organic horizons, which are recognized by their state of physical and chemical decomposition, and one mineral horizon. Six vascular plant species and four moss species are simulated. The model has seven compartments for each vascular plant species: total nonstructural carbohydrates, total nitrogen, total phosphorus, leaves grown in the current season, leaves grown in previous years, conducting and storage stems plus roots, and absorbing roots. In ARTUS the functional unit of the plant is the shoot system or ramet. Each shoot system consists of leaves, stems, fine roots (which do not have secondary growth and have a limited life—span), and larger roots, which have secondary growth and an extended life—span. Although plant processes are based on individual shoots, the ARTUS model as a whole is based on a square metre of ground. Values per square metre are calculated from the values per shoot by multiplying by the shoot density of each species. The model was validated by comparing calculated and measured peak season biomasses and nutrient contents, and the seasonal progression of environmental processes, biomass, carbohydrate contents, and nutrient contents. ARTUS successfully simulated the seasonality of the physical environment, ...