The effect of mean and variance in resource supply on survival of annuals from Mediterranean and desert environments

Anna A. Sher, Deborah E. Goldberg, Ariel Novoplansky

    Research output: Contribution to journalArticlepeer-review

    45 Scopus citations


    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.

    Original languageEnglish
    Pages (from-to)353-362
    Number of pages10
    Issue number2
    StatePublished - 1 Oct 2004


    • Desert ecology
    • Drought resistance
    • Phenotypic plasticity
    • Pulse dynamics
    • Temporal resource availability

    ASJC Scopus subject areas

    • Ecology, Evolution, Behavior and Systematics


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