TY - JOUR
T1 - The role of climate in the dynamics of annual plants in a Chihuahuan Desert ecosystem
AU - Ignace, Danielle D.
AU - Huntly, Nancy
AU - Chesson, Peter
N1 - Funding Information:
We thank Morgan Ernest for providing long-term climate data collected at an adjacent research site and acknowledge the Bureau of Land Management for permission to use the site for research. We thank Stephanie Hovatter and Krista Robinson for assistance in the field. This work was supported by the National Science Foundation (DEB 8615028, 9307658, 0816231, and 1119784). All opinions, findings, and conclusions or recommendations expressed in this article are those of the authors and do not necessarily reflect the views of the National Science Foundation.
PY - 2018/5
Y1 - 2018/5
N2 - Question: What is the role of temporal climate fluctuations in the dynamics of desert winter annual plants in the Portal Bajada, and in the sustained irruption of the non-native annual plant species, Erodium cicutarium? Field site: Portal Bajada, San Simon Valley, Arizona, USA. Methods: We counted plants at flowering over a 21-year period on twelve permanent plots and related these numbers to weather data collected at an on-site weather station, supplemented by observations from the National Climate Data Center. Specific summary climate variables considered most relevant to annual plant biology were developed as candidate predictors of plant response variables. Statistical techniques: We removed trends in the data associated with the irruption of E. cicutarium, removed temporal autocorrelation, and applied a technique that sought the strongest climatic predictors of vegetation response variables by testing climate variables against each other in bivariate regression analyses. The validity of this technique was demonstrated by simulation. We supplemented our analysis with multivariate regression for simultaneous tests on multiple response variables. Conclusions: Winter rainfall was the strongest predictor of total annual plant abundance, but number of species was more strongly predicted by average temperature over the total growing season (fall and winter), with cooler weather favouring more species. Average size of a rainfall event, although often thought important in desert plant biology, did not emerge as a significant predictor of the community-level variables, total abundance and number of species, but winter event size did emerge as a significant predictor of differences between the abundances of native species. Our analyses do not support a role for climate in the sustained irruption of E. cicutarium.
AB - Question: What is the role of temporal climate fluctuations in the dynamics of desert winter annual plants in the Portal Bajada, and in the sustained irruption of the non-native annual plant species, Erodium cicutarium? Field site: Portal Bajada, San Simon Valley, Arizona, USA. Methods: We counted plants at flowering over a 21-year period on twelve permanent plots and related these numbers to weather data collected at an on-site weather station, supplemented by observations from the National Climate Data Center. Specific summary climate variables considered most relevant to annual plant biology were developed as candidate predictors of plant response variables. Statistical techniques: We removed trends in the data associated with the irruption of E. cicutarium, removed temporal autocorrelation, and applied a technique that sought the strongest climatic predictors of vegetation response variables by testing climate variables against each other in bivariate regression analyses. The validity of this technique was demonstrated by simulation. We supplemented our analysis with multivariate regression for simultaneous tests on multiple response variables. Conclusions: Winter rainfall was the strongest predictor of total annual plant abundance, but number of species was more strongly predicted by average temperature over the total growing season (fall and winter), with cooler weather favouring more species. Average size of a rainfall event, although often thought important in desert plant biology, did not emerge as a significant predictor of the community-level variables, total abundance and number of species, but winter event size did emerge as a significant predictor of differences between the abundances of native species. Our analyses do not support a role for climate in the sustained irruption of E. cicutarium.
KW - Chihuahuan Desert
KW - Climate change
KW - Erodium cicutarium
KW - Global warming
KW - Non-native invasives
KW - Seasonal precipitation
KW - Species diversity
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M3 - Article
AN - SCOPUS:85067700595
VL - 19
SP - 279
EP - 297
JO - Aegyptus
JF - Aegyptus
SN - 0001-9046
IS - 3
ER -