Vegetation as affected by groundwater depth and microtopography in a shallow aquifer area of the Great Basin

Abstract

This study was designed to better define the nature of the relationship among vegetation, groundwater level and microtopography in an arid area where depth to groundwater (DTW) was 0–4 m. Plant cover, DTW and relative elevations were jointly measured along 67 vegetation transects throughout the Owens Valley, CA, USA. These transects were dominated by major species of the area: Artemisia tridentata, Atriplex torreyi, Ericameria nauseosa, Distichlis spicata, Juncus arcticus, Leymus triticoides, Sarcobatus vermiculatus and Sporobolus airoides. Plant species occurrence was associated with different DTW. J. arcticus and D. spicata occurred more frequently in areas with the shallowest groundwater (<1·5 m). A. torreyi, L. triticoides and E. nauseosa dominated areas with intermediate DTW (1·5–2·0 m); whereas S. airoides, S. vermiculatus and A. tridentata dominated areas with deeper water tables (>2·0 m). Species were also linked to different microtopographic positions: L. triticoides and J. arcticus were mainly restricted to depressions whereas A. torreyi and A. tridentata were widely distributed in higher positions on the microtopographical gradient. Only 6% of the variation in vegetation cover was accounted for by DTW throughout the study area (N = 820). Cover of individual species was usually unaffected by DTW variation. Results suggest that species distribution is linked to groundwater conditions, but cover of vegetation is only partially affected by DTW variation. This is possible because water tables in our study area are within the rooting depth of most species and plants appear to be well adapted to shallow DTW variations. Copyright © 2011 John Wiley & Sons, Ltd.

Reprint of: ``Climate change effects on water-dependent ecosystems in south-western Australia'' [J. Hydrol. 434--435 (2012) 95--109]

“…Similar to other reported studies, the effect of groundwater abstraction may be more significant than changes in climate conditions (Elmore et al, 2003;Muñoz-Reinoso, 2001;Mata-González et al, 2011). Under drought conditions and an increase in the demand for groundwater resources, the combined effect on groundwater-dependent ecosystems may become severe.…”

“…This replacement may be most obvious when wetland species such as rushes are replaced by woodland species; and less so when water-dependent shrubs are replaced by more-xeric species as demonstrated in other regions of the world (Cooper et al, 2006;Mata-González et al, 2011).…”

“…In addition, in many regions with an arid or semi-arid climate, such as some areas of the Mediterranean coast, some regions of the USA and some areas in China (e.g. Bernaldez et al, 1989;Zhu et al, 2004;Mata-González et al, 2011), where rainfall is highly seasonal, shallow groundwater promotes the establishment of groundwater-dependent ecosystems. In these regions, where groundwater is relied on as a water resource, drying climatic conditions also lead to a greater dependency on groundwater resources thus causing an additional stress to water-dependent ecosystems.…”

Indigenous knowledge on development and management of shallow dug wells of Dodoma Municipality in Tanzania

“…Thus, locals would dig SDWs in such areas and often locate water (FOs, FGDs). Interestingly, the practice of using the status of the vegetation health as an indicator of groundwater and/or soil moisture is constant with modern science (Mata-González et al 2012;Nocco et al 2013;Sommer and Froend 2014). Locals in ancient times also used vegetation and soil moisture as indicators of groundwater (Kent 2001).…”

Drip irrigation enhances shallow groundwater contribution to crop water consumption in an arid area

“…Reduced extraction from surface water and groundwater can also preserve native groundwater‐dependent vegetation. Therefore, in areas where groundwater promotes the growth of vegetation or natural plants, water use efficiencies will protect and preserve the environment by reducing irrigation losses (Doody et al, ; Mata‐González, McLendon, Martin, Trlica, & Pearce, ).…”