TY - JOUR
T1 - The effect of mean and variance in resource supply on survival of annuals from Mediterranean and desert environments
AU - Sher, Anna A.
AU - Goldberg, Deborah E.
AU - Novoplansky, Ariel
N1 - Funding Information:
Acknowledgements We would like to thank Karen Vitkay and Shi Qian for technical help. Shachar Shem-Tov and Laurie Flowers provided invaluable comments on this manuscript, and it was much improved by edits from two anonymous reviewers. Thanks also to Cindy Tejral of the Denver Botanic Gardens for proofing the manuscript. This research was funded by the Fulbright Foundation (US-Israel) and the Blaustein International Center for Desert Research (Ben Gurion University of the Negev, Israel). This is publication no. 398 of the Mitrani Department of Desert Ecology, Ben Gurion University of the Negev.
PY - 2004/10/1
Y1 - 2004/10/1
N2 - Resource availability is often characterized by mean annual amounts, while ignoring the spatial variation within habitats and the temporal variation within a year. Yet, temporal and spatial variation may be especially important for identifying the source of stress in low productivity environments such as deserts where resources are often pulsed and resource renewal events are separated by long periods of low resource availability. Therefore, the degree of stress will be determined in part by the length of time between recharge events. Here, we investigated the effect of timing and total amount of water application on two congeneric pairs, each with a population from a low (desert) and a high (Mediterranean) productivity habitat. As expected, highest survival and greatest growth were found at low or intermediate recharge intervals, and the magnitude of response to increases in total seasonal amounts was greater for Mediterranean species than desert species. The species that had greater survival switched in the hierarchy under high total water depending on interval length. These results demonstrate that temporal variation in resource availability can be as important as annual total amounts for plant performance and that response to temporal dynamics can vary between species. This has implications for community-level processes, as competitive hierarchies may switch based on resource dynamics rather than only total availability.
AB - Resource availability is often characterized by mean annual amounts, while ignoring the spatial variation within habitats and the temporal variation within a year. Yet, temporal and spatial variation may be especially important for identifying the source of stress in low productivity environments such as deserts where resources are often pulsed and resource renewal events are separated by long periods of low resource availability. Therefore, the degree of stress will be determined in part by the length of time between recharge events. Here, we investigated the effect of timing and total amount of water application on two congeneric pairs, each with a population from a low (desert) and a high (Mediterranean) productivity habitat. As expected, highest survival and greatest growth were found at low or intermediate recharge intervals, and the magnitude of response to increases in total seasonal amounts was greater for Mediterranean species than desert species. The species that had greater survival switched in the hierarchy under high total water depending on interval length. These results demonstrate that temporal variation in resource availability can be as important as annual total amounts for plant performance and that response to temporal dynamics can vary between species. This has implications for community-level processes, as competitive hierarchies may switch based on resource dynamics rather than only total availability.
KW - Desert ecology
KW - Drought resistance
KW - Phenotypic plasticity
KW - Pulse dynamics
KW - Temporal resource availability
UR - http://www.scopus.com/inward/record.url?scp=6044229774&partnerID=8YFLogxK
U2 - 10.1007/s00442-003-1435-9
DO - 10.1007/s00442-003-1435-9
M3 - Article
AN - SCOPUS:6044229774
SN - 0029-8549
VL - 141
SP - 353
EP - 362
JO - Oecologia
JF - Oecologia
IS - 2
ER -