Visually assessing the level of development and soil surface stability of cyanobacterially dominated biological soil crusts

Belnap, J.; Phillips, S. L.; Witwicki, D. L.; Miller, M. E.

Abstract:

Biological soil crusts (BSCs) are an integral part of dryland ecosystems and often included in long-term ecological monitoring programs. Estimating moss and lichen cover is fairly easy and non-destructive, but documenting cyanobacterial level of development (LOD) is more difficult. It requires sample collection for laboratory analysis, which causes soil surface disturbance. Assessing soil surface stability also requires surface disturbance. Here we present a visual technique to assess cyanobacterial LOD and soil surface stability. We define six development levels of cyanobacterially dominated soils based on soil surface darkness. We sampled chlorophyll a concentrations (the most common way of assessing cyanobacterial biomass), exopolysaccharide concentrations, and soil surface aggregate stability from representative areas of each LOD class. We found that, in the laboratory and field, LOD classes were effective at predicting chlorophyll a soil concentrations (R2=68-81%), exopolysaccharide concentrations (R2=71%), and soil aggregate stability (R2=77%). We took representative photos of these classes to construct a field guide. We then tested the ability of field crews to distinguish these classes and found this technique was highly repeatable among observers. We also discuss how to adjust this index for the different types of BSCs found in various dryland regions.

Genre:

Article

ProdID:

70033243

Citation Author:

Belnap, J.; Phillips, S. L.; Witwicki, D. L.; Miller, M. E.

Citation Contributing Office:

Citation Datum:

Citation Day:

Citation Edition:

Citation Editor:

Citation End Page:

1264

Citation Issue:

Citation Keywords:

Citation Language:

English

Citation Larger Work Title:

Journal of Arid Environments

Citation LatN:

Citation LatS:

Citation LonE:

Citation LonW:

Citation Month:

Citation No Pagination:

Citation Number Of Pages:

Citation Online Only Flag:

Citation Phsyical Description:

Citation Projection:

Citation Public Comments:

Citation Publisher:

Citation Series:

Citation Series Code:

Citation Series Number:

Citation Search Results Text:

Visually assessing the level of development and soil surface stability of cyanobacterially dominated biological soil crusts; 2008; Article; Journal; Journal of Arid Environments; Belnap, J.; Phillips, S. L.; Witwicki, D. L.; Miller, M. E.