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Title: Press–pulse interactions and long‐term community dynamics in a Chihuahuan Desert grassland
Abstract Questions

Reordering of dominant species is an important mechanism of community response to global environmental change. We asked how wildfire (apulseevent) interacts with directional changes in climate (environmentalpresses) to affect plant community dynamics in a Chihuahuan Desert grassland.

Location

Sevilleta National Wildlife Refuge, Socorro County, New Mexico, USA.

Methods

Vegetation cover by species was measured twice each year from 1989 to 2019 along two permanently located 400‐m long line intercept transects, one in Chihuahuan Desert grassland, and the second in the ecotone between Chihuahuan Desert and Great Plains grasslands. Trends in community structure were plotted over time, and climate sensitivity functions were used to predict how changes in the Pacific Decadal Oscillation (PDO) affected vegetation dynamics.

Results

Community composition was undergoing gradual change in the absence of disturbance in the ecotone and desert grassland. These changes were related to the reordering of abundances between two foundation grasses,Bouteloua eriopodaandB. gracilis, that together account for >80% of above‐ground primary production. However, reordering varied over time in response to wildfire (apulse) and changes in the PDO (apress). Community dynamics were initially related to the warm and cool phases of the PDO, but in the ecotone these relationships changed following wildfire, which reset the system.

Conclusion

Species reordering more » is an important component of community dynamics in response to ecological presses. However, reordering is a complex, non‐linear process in response to ecological presses that may change over time and interact with pulse disturbances.

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Authors:
 ;  ;  ;  ;  ;  ;
Award ID(s):
1655499 1856383
Publication Date:
NSF-PAR ID:
10456960
Journal Name:
Journal of Vegetation Science
Volume:
31
Issue:
5
Page Range or eLocation-ID:
p. 722-732
ISSN:
1100-9233
Publisher:
Wiley-Blackwell
Sponsoring Org:
National Science Foundation
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  2. Abstract

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