10.5061/DRYAD.J4H5C
Yu, Kailiang
University of Utah
University of Virginia
D'Odorico, Paolo
University of Virginia
University of California System
Carr, David E.
University of Utah
Personius, Ashden
Villanova University
Collins, Scott L.
University of New Mexico
Data from: The effect of nitrogen availability and water conditions on
competition between a facultative CAM plant and an invasive grass
Dryad
dataset
2017
National Science Foundation
https://ror.org/021nxhr62
DBI-1052875
2017-09-18T13:47:55Z
2017-09-18T13:47:55Z
en
https://doi.org/10.1002/ece3.3296
65440 bytes
1
CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
Abstract Plants with crassulacean acid metabolism (CAM) are increasing
their abundance in drylands worldwide. The drivers and mechanisms
underlying the increased dominance of CAM plants and CAM expression (i.e.,
nocturnal carboxylation) in facultative CAM plants, however, remain poorly
understood. We investigated how nutrient and water availability affected
competition between Mesembryanthemum crystallinum (a model facultative CAM
species) and the invasive C3 grass Bromus mollis that co-occur in
California's coastal grasslands. Specifically we investigated the
extent to which water stress, nutrients, and competition affect nocturnal
carboxylation in M. crystallinum. High nutrient and low water conditions
favored M. crystallinum over B. mollis, in contrast to high water
conditions. While low water conditions induced nocturnal carboxylation in
9-week-old individuals of M. crystallinum, in these low water treatments,
a 66% reduction in nutrient applied over the entire experiment did not
further enhance nocturnal carboxylation. In high water conditions M.
crystallinum both alone and in association with B. mollis did not perform
nocturnal carboxylation, regardless of the nutrient levels. Thus,
nocturnal carboxylation in M. crystallinum was restricted by strong
competition with B. mollis in high water conditions. This study provides
empirical evidence of the competitive advantage of facultative CAM plants
over grasses in drought conditions and of the restricted ability of M.
crystallinum to use their photosynthetic plasticity (i.e., ability to
switch to CAM behavior) to compete with grasses in well-watered
conditions. We suggest that a high drought tolerance could explain the
increased dominance of facultative CAM plants in a future environment with
increased drought and nitrogen deposition, while the potential of
facultative CAM plants such as M. crystallinum to expand to wet
environments is expected to be limited.
Nitrogen experiment data