Soil-vegetation feedbacks as a driver for early ecosystems development in the context of mine site rehabilitation

摘要

Highly disturbed ecosystems may undergo rapid changes due to the interaction between vegetation and soil that play a pivotal role for the water balance. This is particular true for -water-limited ecosystems for which water availability determines biomass. Based on a review of how vegetation growth affects soil hydraulic properties, the authors propose a simple conceptual model that captures the feedbacks between soil water storage in soil and soil hydraulic behaviour and vegetation biomass. The feedbacks that were considered are ft) vegetation biomass and soil water storage, (ii) root growth and infiltration capacity, (Hi) vegetation biomass and bare soil evaporation, and (iv) root growth and soil water drainage. In water-limited environments, these feedbacks are responsible for highly organised vegetation patterns in space and may also lead to oscillating behaviour of soil water storage and vegetation biomass in time. Biomass overshooting as a result of initially high soil water content is predicted, which is consistent with observations made in forested catchments after clearing or during revegetation of mine tailings. Implications of these feedbacks for predicting the early development of rehabilitated sites will be discussed.