Structural and functional changes in early successional stages of a semiarid ecosystem

Technical Report · Sat Feb 01 04:00:00 EST 1986

OSTI ID:6063787

Redente, E F; Cook, C W ^[1]

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1. eds.

The objective of our research was to study structural and functional changes that occur within and between ecosystem compartments during secondary succession in disturbed semiarid environments. First year data clearly showed an increase in resource abundance after disturbance which produced not only alteration of the soil surface but a decrease in available organic matter. In addition, marked increases in NO3 and soil water potentials were evident at all depths in the disturbed sites as compared to the undisturbed community. Soil disturbance as well as manipulation of the microflora compartment by fumigation had a significant impact on microflora structure and function. The mycorrhizal population was also drastically reduced by disturbance and fumigation. The floristic composition of the primary producers on the disturbed site was highly correlated with the propagule supply, with composition of the seed bank being the main driving force. Competition studies between bluebunch wheatgrass (Agropyron inerme), western wheatgrass, big sagebrush (Artemisia tridentata), and winterfat (Ceratoides lanata) showed that these four species were able to coexist under a wide range of water availability conditions. The final phase of an experiment designed to determine the effects of retorted shale recarbonation on plant uptake of toxic trace elements was completed. These initial studies indicate that both plant community characteristics and the presence of a functioning belowground community will be important in secondary succession processes which occur in disturbed semiarid environments. 36 figs., 41 tabs.

• Research Organization: Colorado State Univ., Fort Collins (USA). Dept. of Range Science
• DOE Contract Number: AC02-76EV04018
• OSTI ID: 6063787
• Report Number(s): DOE/EV/04018-9; ON: DE86006390
• Country of Publication: United States
• Language: English

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ARID LANDS
ARSENIC
BARIUM
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TRANSITION ELEMENTS
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