WIKINDX Resources
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Bradford, J. B., & Lauenroth, W. K. (2006). Controls over invasion of bromus tectorum: the importance of climate, soil, disturbance and seed availability. Journal of Vegetation Science, 17, 693–704.
Added by: Eric Peterson 2007-10-16 16:35:43
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Abstract
Question: Predicting the future abundance and distribution of
invasive plants requires knowing how they respond to environmental
conditions. In arid and semi-arid ecosystems where
water is a limiting resource, environmental conditions and
disturbance patterns influence invasions by altering acquisition
and utilization of water over space and time. We ask: 1.
How do variations in climatic and soil properties influence
temporal soil water dynamics? 2. How does this variation
affect the establishment of Bromus tectorum (cheatgrass), a
cool-season annual grass that has successfully colonized much
of the U.S. Great Basin?
Location: Short-grass Steppe in northeastern Colorado, USA;
Arid Lands Ecology reserve in southeastern Washington, USA;
and the Patagonian steppe of the Chubut province in Argentina.
Methods: We utilized a soil water model to simulate seasonal
soil water dynamics in multiple combinations of climatic and
soil properties. In addition, we utilized a gap dynamics model
to simulate the impact of disturbance regime and seed availability
on competition between B. tectorum and native plants.
Results: Our results suggest that climate is very important, but
that soil properties do not significantly influence the probability
of observing conditions suitable for B. tectorum establishment.
Results of the plant competition model indicate that
frequent disturbance causes more Bromus tectorum in invaded
areas and higher seed availability causes faster invasion.
Conclusions: These results imply a general framework for
understanding Bromus tectorum invasion in which climatic
conditions dictate which areas are susceptible to invasion,
disturbance regime dictates the severity of invasion and seed
availability dictates the speed of invasion.
Added by: Eric Peterson
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