Abstract
To sustainably manage rangelands, it is paramount that all agents of soil health are considered in conservation practices. Yet, our understanding of the extent and importance of biological soil crust (hereafter biocrust) as a component of rangeland health and quality is limited. The objective of this project was to quantify and characterize rangeland biocrusts within a region of New Mexico, USA, for which soil microbes have yet to be considered in rangeland health assessments: the Rio Puerco Watershed. Moreover, we examined the influence of biocrust on soil aggregate stability as key ecosystem service in a landscape prone to erosion. We further assessed the relationships between biocrust abundance and community composition with soil properties. We found that biocrusts covered an average of 41% of plant interspaces throughout all sampling locations (n = 20), with the most abundant types being incipient and light cyanobacterial crusts, which tend to be more cryptic in appearance. Soil surface stability was greater than subsurface stability and biocrust cover was positively related to soil surface stability. Light cyanobacterial and cyanolichen crusts were the primary biocrust types related to soil surface stability, especially on sites with unconsolidated subsurfaces. Physical soil crusts were also a major landscape component covering an average of 21% of the soil and were important for subsurface stability. These findings reflect the importance of biological and physical soil aggregating processes in dryland systems. Several environmental variables were related to biocrust community composition and aggregate stability, with surface soil texture, salt contents, pH, and soil nitrogen ions having the strongest relationships. This study expands the biocrust characterizations of drylands in a region that has received little attention. It further contributes new insights on how biocrust and soil microbial communities may play a role in influencing rangeland health, providing much needed data for a watershed characterized by its high susceptibility to soil loss.
| Original language | English |
|---|---|
| Article number | 115658 |
| Journal | Geoderma |
| Volume | 410 |
| DOIs | |
| State | Published - Mar 15 2022 |
Funding
We thank New Mexico state soil scientist Rick Strait for sharing his rich knowledge and passion for dryland soils, rangeland health, and sustainable management. We could not have carried out this project without his enthusiasm and logistical support. Funding for this research was provided by the USDA NRCS Project 68-8C30-16-503 and NR188C30XXXXC002. Barbara Hunter was instrumental in instructing Megan Stovall on how to run soil physical and chemical analyses, as well as how to perform measurements of nutrient contents. Sergei Shalygin and Paul De Ley were invaluable field assistants. We also thank Scott Ferrenberg for initial guidance to Megan Stovall on the statistics used. Jeffrey Herrick served on Megan Stovall’s master thesis committee and provided valuable insights and feedback to improve the content of this manuscript. We thank Paul De Ley for his invaluable edits on various manuscript versions. We also acknowledge support from the U.S. Department of Agriculture, National Institute of Food and Agriculture, Agriculture and Food Research Initiative under Award Number 2019-67020-29320 to Akasha Faist and Nicole Pietrasiak during the writing of this manuscript. Lastly, we would like to acknowledge the two anonymous reviewers for their valuable feedback.
| Funders | Funder number |
|---|---|
| 2019-67020-29320 | |
| Natural Resources Conservation Service | 68-8C30-16-503, NR188C30XXXXC002 |
Keywords
- Biocrust
- Colorado Plateau
- Cyanobacteria
- Drylands
- Rangeland health
- Soil stability