Desert rangelands, degradation and nutrients

TitleDesert rangelands, degradation and nutrients
Publication TypeBook Chapter
Year of Publication1999
AuthorsHavstad K, Herrick JE, Schlesinger W.H
EditorArnalds O., Archer SR
Book TitleRangeland Desertification
PublisherKluwer Academic Press
CityDordrecht, The Netherlands
ARIS Log Number095861
Keywordsdesert grassland, desertification, nitrogen, nutrient dynamics, phosphorus

It is well recognized that rangeland environments, especially degraded environments, are relatively infertile. Though arid lands are moisture limited, it is often stated that they are nutrient regulated. A discussion of rangeland soil nutrients relative to landscape degradation should include: (1) dynamics of nutrient distributions; (2) soil properties affecting nutrient fluxes; (3) indicators of soil quality; and 4) nutrient based strategies for remediation. Nutrient distribution is strongly influenced by vegetation structure, and spatial nutrient patterns are closely linked to aspects of primary productivity and species composition. Effects of vegetation on nutrient spatial patterns can persist for decades, even if vegetation is altered by natural or anthropogenic disturbances. Though abiotic processes strongly shape physical features of arid landscapes, biotic activities directly affect soil nutrients. Unfortunately, assessment and monitoring technologies based on soil properties which quantify integrity of nutrient related processes have not been fully developed. Approaches for remediating degraded conditions need to exploit nutrient spatial and temporal heterogeneities. Remediation should be targeted to the most fertile sites, even if these are only relatively small parts of the overall landscape. Understanding nutrient dynamics is a key to triggering autogenic remediation of degraded rangelands.