New frontiers in soil: Future challenges and knowledge gaps

Background/Question/Methods

Soil is a key regulator of climate, terrestrial ecosystem functions, and ecological services through plant-decomposer feedbacks. All biota depend upon soil for nutrient and water cycling, which itself harbors the highest diversity per unit area of any ecosystem on earth. Further, the decomposition and nutrient mineralization activities of the fungal- and bacterial-dominated soil microbiome is a major determinant of terrestrial greenhouse gas emissions and sequestration. Therefore, accurate understanding of soil process is critical to predicting the responses of terrestrial systems to ongoing environmental changes — including rapidly shifting climate conditions, nutrient enrichment, and altered land use practices. Recognizing the unique and critical role of soil in the earth system, researchers have increasingly sought to integrate empirical and modeling studies to mechanistically describe soil biogeochemical processes that cross scales. This goal has spurred rapid growth in both micro-resolution measurements of soil functions, edaphic properties, and communities, as well as macro-scale, remote measurements spanning from the regional to global scales.

Results/Conclusions

While these innovations have greatly increased our knowledge of terrestrial systems, they have also spurred novel challenges to bridge the spatial and temporal scales encompassed by soil processes. Non-linear and indirect feedbacks to perturbations further complicate our ability to project soil responses to global change factors. These challenges shape the new frontier of soil ecology. This talk will explore three cutting edge and cross-scale areas of soil research: 1) Recognizing the relative importance of direct and indirect effects of global change disturbances on terrestrial biogeochemical function; 2) Understanding the role of legacy effects on soil biota and ecosystem function under climate and land use change scenarios; and 3) Identifying which soil processes are essential to incorporate into land-surface models in order to strengthen projections of climate change impacts on ecosystem functions and services.