Browsing by Subject "theoretical ecology"

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    Constraints and tradeoffs: Toward a predictive, mechanism-based understanding of ecological communities
    (2017-08) Clark, Adam
    It is easy to forget how far ecology has come in a very short time. Less than two decades ago, it was unclear whether predictive models of species-level dynamics in diverse ecological communities would ever be possible. Today, an abundance of methods can accurately forecast these dynamics, driven by explosive growth in the availability of data and modern analytical tools. However, most of these methods rely on matching patterns from historical dynamics to current trends. Thus, while predictions have become much easier, understanding why behavior occurs – and extrapolating predictions to novel circumstances – remains elusive. Here, we apply theoretical insights from tradeoffs to better understand how species in ecological communities assemble and coexist. Tradeoffs describe physiological and ecological constraints that limit the traits and roles of individual organisms. These constraints therefore contain substantial information about species ecological and evolutionary histories, and how they are likely to interact with one another and their environments. We show that information contained in tradeoffs can be used to identify important mechanisms governing community dynamics, and to constrain viable parameter space in otherwise intractable models. These methods could substantially improve mechanism-based predictions in diverse communities, resulting in better understanding of how these complex systems function, and better extrapolations of predictions under novel circumstances.
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    Living close to your neighbors – the importance of both competition and facilitation in plant communities
    (Ecological Society of America, 2014) Wright, Alexandra; Schnitzer, Stefan A; Reich, Peter B
    Recent work has demonstrated that competition and facilitation likely operate jointly in plant communities, but teasing out the relative role of each has proven difficult. Here we address how competition and facilitation vary with seasonal fluctuations in environmental conditions, and how the effects of these fluctuations change with plant ontogeny. We planted three sizes of pine seedlings (Pinus strobus) into an herbaceous diversity experiment and measured pine growth every two weeks for two growing seasons. Both competition and facilitation occurred at different times of year between pines and their neighbors. Facilitation was important for the smallest pines when environmental conditions were severe. This effect decreased as pines got larger. Competition was stronger than facilitation overall and outweighed facilitative effects at annual time scales. Our data suggest that both competition and the counter-directional effects of facilitation may be more common and more intense than previously considered.