Journal
JOURNAL OF ARID ENVIRONMENTS
Volume 102, Issue -, Pages 27-33Publisher
ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD
DOI: 10.1016/j.jaridenv.2013.11.006
Keywords
Artemisia tridentata; Distribution range; Facilitation; Great Basin; Mojave Desert; Pinus monophylla; Stress gradient
Categories
Funding
- International Arid Land Consortium
Ask authors/readers for more resources
We examined variations in the relative importance of facilitation vs. competition, in light of the Stress-Gradient Hypothesis (SGH) by assessing plant interactions along an aridity gradient over biogeographic scales. We surveyed the relationship between a shrub species (Artemisia tridentata) and pine seedlings (Pinus monophylla) across the Great Basin and the Mojave Desert, USA, encompassing the entire range of P. monophylla. Using 69 sites we evaluated the spatial association between P. monophylla seedlings and A. tridentata shrubs, quantified with an electivity index, and implemented multiple regression analysis on the effects of macro- and micro-environmental factors: precipitation, temperature, monsoonality index, topography, substrate and litter cover. We identified annual precipitation as a main factor, which was negatively related to shrub-seedling association. Additionally, shrub-seedling association was stronger in the hot- than in the cold-desert, and was negatively related to litter cover. Effects of monsoonality, summer temperature, and bedrock type were not significant. We also considered nonlinear functional forms of a precipitation electivity relationship, but the negative linear model proved most predictive. Our observations match SGH predictions. Studying the role of interspecific interactions in shaping species range shifts may lead to improved predictions of distribution ranges and changes in dryland vegetation under global change scenarios. (C) 2013 Elsevier Ltd. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available