The seedbed microclimate and active revegetation of disturbed lands in the Mojave Desert

• Published in: Journal of arid environments Vol. 73; no. 4; pp. 563 - 573
• Main Authors: Caldwell, T.G., McDonald, E.V., Young, M.H.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.04.2009
• Subjects: climatic factors; deserts; disturbed soils; drought; Drought effects; Ecohydrology; evapotranspiration; Germination; Hydrothermal time; land restoration; microclimate; military lands; Monitoring; Mulch; mulches; Restoration; seed germination; seedbeds; Sensors; soil matric potential; soil temperature; soil water balance; soil water content; sprinkler irrigation; Mojave Desert; California; USA; USA, California, Mojave Desert; Restoration; Germination; Ecohydrology; Mulch; Hydrothermal time; Sensors; Monitoring; Drought effects
• ISSN: 0140-1963; 1095-922X
• DOI: 10.1016/j.jaridenv.2008.12.008

One of the greatest challenges to the U.S. Department of Defense is maintaining the sustainability of military lands while maximizing their use for training activities. Restoration of disturbed lands in the Mojave Desert has proven to be a challenge, particularly revegetation from seed. This study presents soil moisture dynamics from three restoration sites at the National Training Center, Ft. Irwin, CA. The soil microclimate (matric potential, water balance, and temperature) was monitored beneath various surface treatments to better assess their effects on seed germination and establishment. Results show that under the typically hot and dry climatic conditions that prevail, the soil microclimate is a hostile environment. Irrigation had the most positive effect on the seedbed. Surface mulches including gravel, straw, emulsion, and bark had limited benefits often detrimental. Although seedlings germinated, survival after three months was negligible. Results presented here suggest that successful seeding with broadcast sprinkler irrigation in the central Mojave Desert is not possible unless the seedbed area is limited or advantageous environmental conditions prevail. Improved knowledge of the germination requirements and applied numerical modeling would result in more successful seedbed management.