Summer and winter drought in a cold desert ecosystem (Colorado Plateau) part I: effects on soil water and plant water uptake

Document Type

Article

Journal/Book Title/Conference

Journal of Arid Environments

Volume

60

Issue

4

First Page

547

Publisher

Elsevier

Last Page

566

Publication Date

2005

Abstract

We investigated the effects of winter and summer drought on plants of the Colorado Plateau in western North America. This winter-cold, summer-hot desert region receives both winter and summer precipitation. Droughts were imposed for two consecutive years using rainout shelters. Here, we examine drought effects on the hydrologic interactions between plants and soil. We chose three perennial species for this study, representing different rooting patterns and responsiveness to precipitation pulses: Oryzopsis hymenoides, a perennial bunch grass with shallow roots; Gutierrezia sarothrae, a subshrub with dimorphic roots; and Ceratoides lanata, a predominantly deep-rooted woody shrub. Drought effects on plant water status were qualitatively similar among species, despite morphological differences. Summer drought affected the water status of all species more negatively than winter drought. Isotopic analysis of stem water revealed that all three species took up deeper soil water under drought conditions and shallow soil water after a large rainfall event in summer. Thus all three species appeared to use the same water sources most of the time. However, after a particularly dry summer, only the deepest-rooted species continued to take up soil water, while the more shallow-rooted species were either dead or dormant. Our study suggests therefore that increased occurrence of summer drought could favor the most deep-rooted species in ecosystem.

Comments

This article may be accessed here.

The publisher retains the copyright to this work and may require a subscription to access the published version.

Please use publisher's recommended citation.

This document is currently not available here.

Share

COinS