|DRENOVSKY, REBECCA - John Carroll University|
|RICHARDS, JAMES - University Of California|
Submitted to: Journal of Arid Environments
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/26/2010
Publication Date: 11/1/2010
Citation: Drenovsky, R.E., James, J.J., Richards, J.H. 2010. Variation in nutrient resorption by desert shrubs. Journal of Arid Environments. 74(11):1564-1568.
Interpretive Summary: Recycling nutrients from leaves before leaves die (resorption) is an important way for desert plants to conserve nutrients but factors that influence the ability of plants to resorb nutrients are poorly understood. Over a three year period we investigated the influence of evolutionary relatedness and soil salinity on nutrient resorption of 13 shrub species. We found that evolutionary relatedness and soil salinity influenced resorption but effects were species specific. This means effects of soil salinization and changes in land use on resorption will be difficult to predict. Detailed studies will be required to understand how these impacts will influence particular plant communities and nutrient cycling.
Technical Abstract: Plant nutrient resorption prior to leaf senescence is an important nutrient conservation mechanism for aridland plant species. However, little is known regarding the phylogenetic and environmental factors influencing this trait. Our objective was to compare nitrogen and phosphorus resorption in a suite of species in the Asteraceae and Chenopodiaceae and assess the relative impact of soil salinity on nitrogen resorption. Although there were no significant differences in N resorption proficiency between asters and chenopods, chenopods were more proficient than asters at resorbing P. Plant responses to natural salinity gradients were species-specific and likely were related to the different salt-tolerance physiologies of the species. During the course of our three year study, precipitation varied 6.4- and nearly 10-fold from the long term average at our two desert sites; despite this variation, annual variation in nutrient resorption was not linked to annual precipitation. More detailed studies are required to better understand environmental influences on resorption patterns. Understanding controls on this trait may give insight into how species will respond to anthropogenic soil salinization and desertification.