Stepwise Ecological Restoration: A framework for improving restoration outcomes

Ecosystem degradation is one of the critical constraints for the sustainable development of our planet. However, recovering an ecosystem to a pre-impairment condition is often not practical. The International Restoration Standards provide the first framework for practical guidance on what constitutes the process of ecological repair and how this repair process can be influenced to improve net ecological benefits. In these Standards, Restorative Continuum is highlighted and it recognises that many do not, yet there is still value in aspiring to improvements to the highest extent possible, with some sites potentially being able to be improved in a stepwise manner. Here we elaborate on these Standards by providing a cross-ecosystem theoretical framework of stepwise ecological restoration (STERE) for promoting higher environmental benefits. STERE allows the selection of suitable restorative modes by considering the degree of degradation while encouraging a transition to a higher state. These models include environmental remediation for completely modified and degraded ecosystems, ecological rehabilitation for highly modified and degraded ecosystems, and ecological restoration for degraded native ecosystems. STERE requires selecting tailored restorative modes, setting clear restorative targets and reference ecosystems, applying a systematic-thinking approach, and implementing a continuous monitoring program at all process stages to achieve a resilient trajectory. STERE allows adaptive management in the context of climate change, and when the evidence is available, to "adapt to the future" to ensure climate resilience. The STERE framework could assist in initiating and implementing restoration projects worldwide, especially in developing countries.