Spatial modeling of biological soil crusts to support land management decisions
Bowker MA and Belnap J. 2008. Spatial modeling of biological soil crusts to support land management decisions. Department of Environmental Science, Northern Arizona University and U.S. Geological Survey
Biological soil crusts (BSCs) are potentially a highly informative indicator of rangeland health and ecosystem function in dryland ecosystems. These crusts are communities of cyanobacteria, mosses and lichens, among other organisms which aggregate the mineral soil surface. We modeled the potential abundance, function and biodiversity of BSCs across steep climate gradients and heterogenous soils captured in five national monuments of Northern Arizona: Wupatki, Walnut Canyon, Sunset Crater, Montezuma Castle and Tuzigoot. Specifically, we created spatial models of ten indicators of BSC development (lichen cover, light cyanobacterial cover, dark cyanobacterial cover, and chlorophyll a, soil slaking, nitrogen fixation index, functional richness, species richness, evenness, and functional redundancy), then created combinations of these indicators in overlays depicting potential BSC abundance, function and biodiversity. Our best individual models were those pertaining to indicators of biodiversity, lichen cover, and light cyanobacterial cover which performed 54- 81% better than random null models. Chlorophyll a was our most problematic model, performing only 34% better than a random null model. In general, we found that limestone-derived soils tended to have moderate to high BSC potential, basalt-derived and non-bentonitic fine soils had very low BSC potential, and calcareous sandy soils were highly variable and intermediate. Of the national monuments examined, Montezuma Castle and Tuzigoot had the greatest potential for BSCs. Walnut Canyon had moderate to high BSC potential, and Wupatki had low potential. Sunset Crater was essentially lacking in available BSC habitat. We propose that potential BSC abundance indicators can be used in multi-indicator rangeland assessment protocols. Our indicators also enable users to determine where on the landscape BSCs have the greatest conservation or restoration value. (Copied verbatim from the published report.)
- Type
- Published Report
- Authors
- Bowker, Matthew; Belnap, Jayne
- Date of Issue
- 2008
- Publisher
- Department of Environmental Science, Northern Arizona University and U.S. Geological Survey
- Units
- MOCA , SCPN , TUZI , WACA , WUPA
- Keywords
- 1, Biological Soil Crusts, Conservation, Core, Distribution (Biodiversity), Indicators, Montezuma Castle National Monument, NRCA, Observations, Presence (Biodiversity), range health, Restoration, Soil crusts, Soils, Tuzigoot National Monument, Walnut Canyon National Monument, Wupatki National Monument