Plant-soil feedback: The past, the present and future challenges

Background/Question/Methods

Plant-soil feedback is the concept that is being developed in order to understand the reciprocal influences between plants and the biotic and abioic properties of soil. Plant-soil feedback is unifying research from a variety of backgrounds in plant-soil interactions: decomposition, symbioses, herbivory, pathogens, food webs, aboveground-belowground interactions, biogeochemistry and soil structure. Plant-soil feedback interactions can be studied to (re)address a large number of long-standing and novel concepts in ecology: succession, biodiversity-ecosystem functioning, plant rarity and invasiveness, climate warming, atmospheric and land use change. Plant-soil feedback has enormous applied and theoretical implications for a range of topical issues including sustainable agriculture/forestry, persistence of invasive species, plant community dynamics, adaptation to climatic change, range shifts and evolutionary ecology. The question addressed in this presentation is where the concept originated from, what exciting current developments there are and what may be future challenges in this field of research.

Results/Conclusions

Plant-soil feedback is both a field of inquiry and a specific methodological technique to examine the complex interactions between soils, soil organisms and plants. Negative plant-soil feedbacks from accumulation of pathogens or herbivores prevents species from persisting at fixed locations or at high abundances and also promote species co-occurrence, while positive plant-soil feedbacks are mechanisms for persistence, local adaptation, or becoming invasively abundant. As such, plant-soil feedbacks determine plant community development during primary and secondary succession, with consequences for biodiversity maintenance, biodiversity-productivity relationships, plant rarity, and plant invasiveness. We will discuss the basic mechanisms underlying plant-soil feedback and their unifying principles. We will also discuss our capacity to predict and what trait-based characteristics, or environmental conditions, may be explored to further improve such predictions.

For the future, we see a major challenges. The first is to consider plant-soil feedback under more realistic conditions in the field and to quantify its contribution proportional to other factors that may structure the composition of plant communities and changes therein. Further, insights in plant-soil feedback interactions may be used to understand and predict consequences of global changes (climate warming, invasions, and land use changes). We also foresee that plant-soil feedback interaction approaches may be used to enhance the sustainability of food production and other soil-based systems, for example to be used in a more bio-based economy. Growing monocultures of fast-growing species involves a risk of magnifying negative plant-soil feedbacks and one of the challenges will be to enhance the sustainability of these production systems.