Context-dependence of plant-soil feedback: Environment matters
Environmental factors (e.g. moisture, light, nutrients, natural enemies) are known to affect plant interactions with soil and soil organisms, leading to an expectation of environmental context-dependence in plant-soil feedback. Such context-dependence could have strong implications for the role of feedback in species coexistence and community structure and dynamics. We develop a conceptual framework to predict variation in the strength and direction of plant-soil feedback with abiotic or biotic factors. Then, we present case studies from the literature and from our own work that address context dependence of plant-soil feedback, and suggest key future directions.
Although few relevant studies have been conducted in this emerging research area, results to date suggest that the strength and direction of plant-soil feedback shows strong environmental context-dependence. Examples from the literature show that plant-soil feedback is sensitive to abiotic factors, such as nutrients, as well as biotic factors, such as above- and belowground herbivory. Our conceptual framework predicts that light availability interacts with other environmental factors to modulate the strength and direction of feedback. We present case studies demonstrating that the strength and direction of plant-soil feedback is indeed context dependent with respect to light, but that feedback-light relationships can vary with system and feedback mechanism (e.g. abiotic vs. biotic). We suggest how future experiments can further clarify our understanding of context dependence in plant-soil feedback and the role of light as a modulating factor.