HR: 0800h
AN: H31F-1357    [Abstracts]
TI: The Effect of Anthropogenic Disturbance in the Ecohydrology of Pinyon Juniper Woodlands with Soil Biocrust
AU: * Lebron, I
EM: Inma_lebron@yahoo.com
AF: Utah State University, 4820 Old Main, Logan, UT 84322 United States
AU: Chandler, D G
EM: David.Chandler@usu.edu
AF: Utah State University, 4820 Old Main, Logan, UT 84322 United States
AU: Robinson, D A
EM: darobinson@cc.usu.edu
AF: Utah State University, 4820 Old Main, Logan, UT 84322 United States
AU: Belnap, J
EM: jayne_belnap@usgs.gov
AF: U.S. Geological Survey, Canyolands Field Station 2290 S. West Resource Blvd., Moab, UT 84532 United States
AU: Madsen, M
EM: matt@cc.usu.edu
AF: Utah State University, 4820 Old Main, Logan, UT 84322 United States
AB: The canopy and intercanopy in pinyon-juniper woodlands are intrinsically related and constitute an ecosystem of great importance in the arid lands in the United States. The integrity of this ecosystem is continually challenged by anthropogenic disturbances as oil exploration and recreation activities in these environments. An important feature in the intercanopy of pinyon juniper drylands is the soil biological crust or biocrust. Biocrust is important to the nutrient cycles and hydrology and sediment production of this system. To quantify the effect of disturbances in the soil physical properties in the interspace of a pinion-juniper woodland we measured soil bulk density, water content, and hydraulic conductivity in undisturbed and disturbed areas of sandy soil. The disturbance had minimal impact on the bulk soil properties in the interspace soils. We also analyzed chlorophyll and other pigments related with bacterial activity in top 4mm of the soil and found chlorophyll activity to be almost zero in the disturbed areas while the undisturbed ones showed several orders of magnitude higher concentrations. Subsequent analysis of the soil surface properties indicates that a drastic change in the surface roughness and structure at the surface due to disturbances can alter the microenvironment characteristics critical for the bacterial survival. Since cyanobacteria colonization is the first step in the formation of biocrust, we conclude that surface properties are critical for the preservation and establishment of biocrust in the intercanopy space of the pinyon-juniper woodlands ecosystems.
DE: 1800 HYDROLOGY
DE: 1866 Soil moisture
DE: 1875 Vadose zone
DE: 1899 General or miscellaneous
DE: 9810 New fields (not classifiable under other headings)
SC: Hydrology [H]
MN: Fall Meeting 2005