Author
GUO, TIAN - Purdue University | |
ENGEL, BERNARD - Purdue University | |
SHAO, GANG - Purdue University | |
Arnold, Jeffrey | |
SRINIVASAN, RAGHAVAN - Texas A&M University | |
Kiniry, James |
Submitted to: Environmental Modelling & Software
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 8/23/2018 Publication Date: N/A Citation: N/A Interpretive Summary: In this paper we improved the plant variables for hybrid poplar and cottonwood used in a computer simulation model (SWAT). Hybrid poplar grows in the midwestern US, and cottonwood grows in the southern US. We improved how we simulate leaf area and leaf weight. This improved SWAT simulation of hybrid poplar leaf area cover and woody plant material, and simulation of cottonwood plant material, rainfall runoff on the soils, soil losses due to water erosion, and nutrients in the trees. The modified SWAT model is useful for calculating biofuel production of these trees and calculating water use by these trees in these systems. Technical Abstract: Rangeland grasses in the arid western U.S. must grow quickly, set seed, and senesce in a relatively short timeframe in order to survive and reproduce when the limited soil moisture is available. In addition, rangeland management in arid sites can benefit from process-based simulation tools to optimize grazing intensity and duration and for assessing impacts of invasive species and of climate change. In this project, we derived the needed growth parameters for the ALMANAC model to simulate three common cool season grasses and one warm season grass in Montana. The parameters were then used with the model to simulate three typical ecological sites near Miles City. Model parameters such as radiation use efficiency and potential leaf area index showed expected trends with the four grasses. Once the parameters were used with the ALMANAC model, simulations showed reasonable agreement with published NRCS grass yields for normal years, wet years, and dry years. Thus this process-based model and parameters such as those described herein will be valuable for assessing various management scenarios and climate variables in these types of low rainfall, western U.S. range sites. |