Biotic plant-soil feedbacks across temporal scales

1. Plant effects on soil biota can result in feedbacks affecting plant performance, with consequences for plant community and ecosystem dynamics on short and long time-scales. In addition, the strength and direction of plant-soil feedbacks depend on temporal shifts in abiotic environmental conditions. 2. We synthesize current knowledge on temporal aspects of plant-soil feedbacks and present new ideas to better understand and predict the effects of plant-soil feedbacks on community and ecosystem properties across temporal scales. 3. Explaining short-term temporal feedback dynamics requires us to better understand mechanistic linkages between plants, soil organisms and locally available resources. On the other hand, we need to refine our understanding of the context-dependency of plant-soil feedbacks, as the strength and direction of feedback interactions are influenced by 'external' temporal ecosystem dynamics, such as variation in soil resource availability after disturbance or during succession. 4. Synthesis. Based on our synthesis of temporal aspects of plant-soil feedbacks, we suggest three main avenues for future research: (i) how plant-soil feedbacks changes with ontogeny, (ii) how plant and soil organism traits drive temporal variation in plant-soil feedbacks and (iii) how environmental changes across temporal scales alter the strength and direction of plant-soil feedbacks

Reinforcing loose foundation stones in trait-based plant ecology

The promise of “trait-based” plant ecology is one of generalized prediction across organizational and spatial scales, independent of taxonomy. This promise is a major reason for the increased popularity of this approach. Here, we argue that some important foundational assumptions of trait-based ecology have not received sufficient empirical evaluation. We identify three such assumptions and, where possible, suggest methods of improvement: (i) traits are functional to the degree that they determine individual fitness, (ii) intraspecific variation in functional traits can be largely ignored, and (iii) functional traits show general predictive relationships to measurable environmental gradients