Abstract
Simulation of changes in production within an Andropoqon-Paspalum dominated grassland ecosystem of east-central Texas was based on 36 months of environmental and 20 months of biomass data. Simulation models utilizing sub-models for green and standing dead biomass accounted for 84% of the variation in production. Environmental parameters recorded were reduced to monthly averages or totals. These monthly data were assumed to be practical estimates of the effect of environmental parameters on the vegetation and characteristic of the local climate. Variation of most environmental parameters reflected an annual cyclic pattern related to solar radiation. Water, when introduced into the ecosystem by precipitation, acted as a major absorber of both solar and terrestial radiate energy. Eighty-two percent of the variation in available soil water could be accounted for by using a seasonal function of soil temperature at 5 cm. Biomass harvested for 20 consecutive months was assumed to represent the average state of production within the ecosystem. Green biomass followed an annual cyclic pattern strongly correlated to many environmental parameters. Standing dead biomass exhibited an annual cyclic pattern lagging green biomass by 3-4 months. The initial sub-model accounted for 93% of the green biomass. Green biomass was accounted for by utilizing a thermal-seasonal model based on the curvilinear response of green biomass to monthly averages of soil temperature at 5 cm. This biomass component was then utilized to predict standing dead biomass..
Pardue, John Lawrence (1978). Aerial biomass production and environment of a grassland ecosystem: a model. Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -199065.