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Seed banks in a degraded desert shrubland: Influence of soil surface condition and harvester ant activity on seed abundance

Journal of Arid Environments

By:
, , ,
DOI: 10.1016/j.jaridenv.2009.04.017

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Abstract

We compared seed banks between two contrasting anthropogenic surface disturbances (compacted, trenched) and adjacent undisturbed controls to determine whether site condition influences viable seed densities of perennial and annual Mojave Desert species. Viable seeds of perennials were rare in undisturbed areas (3-4 seeds/m2) and declined to <1 seed/m2 within disturbed sites. Annual seed densities were an order of magnitude greater than those of perennials, were one-third the undisturbed seed densities on compacted sites, but doubled on trenched sites relative to controls. On trenched sites, greater litter cover comprising the infructescences of the dominant spring annuals, and low gravel content, enhanced seed densities of both annuals and perennials. Litter cover and surface ruggedness were the best explanations for viable perennial seed densities on compacted sites, but litter cover and the presence of a common harvester ant explained annual seed densities better than any other surface characteristics that were examined. Surface disturbances can have a varied impact on the condition of the soil surface in arid lands. Nevertheless, the consistently positive relationship between ground cover of litter and viable seed density emphasizes the importance of litter as an indicator of site degradation and recovery potential in arid lands.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Seed banks in a degraded desert shrubland: Influence of soil surface condition and harvester ant activity on seed abundance
Series title:
Journal of Arid Environments
DOI:
10.1016/j.jaridenv.2009.04.017
Volume
73
Issue:
10
Year Published:
2009
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
First page:
885
Last page:
893
Number of Pages:
9