Using ecosystem risk assessment science in ecosystem restoration: a guide to applying the Red List of Ecosystems to ecosystem restoration

Recent global initiatives in ecosystem restoration offer an unprecedented opportunity to improve biodiversity conservation and human health and well-being. Ecosystems form a core component of biodiversity. They provide humans with multiple benefits – a stable climate and breathable air; water, food and materials; and protection from disaster and disease. Ecosystem restoration, as defined by the UN Decade on Ecosystem Restoration, includes a range of management interventions that aim to reduce impacts on and assist in the recovery of ecosystems that have been damaged, degraded or destroyed. This Guide promotes the application of the science of ecosystem risk assessment, which involves measuring the risk of ecosystem collapse, in ecosystem restoration. It explores how the IUCN Red List of Ecosystems and ecosystem restoration can be jointly deployed to reduce risk of ecosystem collapse.

Strengthening the Scientific Basis of Ecosystem Collapse Risk Assessments

Progress is being made in assessing the conservation status of ecosystems, notably through initiatives such as the IUCN Red List of Ecosystems (RLE) and the NatureServe Conservation Status Assessment (NCS). Both of these approaches consider conservation status in terms of the risk of ecosystem collapse. However, the scientific understanding of ecosystem collapse is still at a relatively early stage. Consequently, concerns have been raised regarding the scientific basis of ecosystem conservation assessments focusing on collapse risk. Here I explore how these concerns might potentially be addressed by considering how the concept is defined, and by briefly reviewing the theoretical basis of ecosystem collapse. I then examine the implications of recent research results for the design of ecosystem collapse risk assessments, and the challenges identified in those assessments conducted to date. Recommendations are made regarding how collapse risk assessments might be strengthened based on current scientific understanding, and how this understanding could be improved by further research. In addition, I examine the potential implications for conservation policy and practice if the scientific basis of collapse risk assessments is not strengthened in this way.

Interacting Fire, Logging and Climate Change has Sprung a Landscape Trap in Victoria’s Montane Ash Forests

Ecosystems are influenced by multiple drivers which shape ecosystem state and biodiversity. In some ecosystems, interactions and feedbacks between drivers can produce traps that confine an ecosystem to a particular state or condition and influence processes like succession. A range of traps have been recognized, with one of these – “a landscape trap” first proposed a decade ago for the tall, wet Mountain Ash and Alpine Ash forests of Victoria, south-eastern Australia. Under such a trap, young flammable forest is at high risk of reburning at high-severity, thereby precluding stand maturation, and potentially leading to ecosystem collapse. These young forests are more common because recurrent wildfire and widespread clearcutting have transformed historical patterns of forest cover from widespread old-growth with small patches of regrowth embedded within it, to the reverse. Indeed, approximately 99% of the montane ash ecosystem is now relatively young forest. Based on new empirical insights, we argue that at least three key inter-related pre-conditions underpin the development of a landscape trap in montane ash forests. A landscape trap has been sprung in these forests because the pre-conditions for its development have been met: We show how inter-relationships between these pre-conditions, leading to frequent high-severity fire, interacts with life history attributes (e.g. time to viable seed production) to make montane ash forests (e.g. which have been highly disturbed through logging and frequent fire) vulnerable to ecosystem collapse. We conclude with the ecological and resource management implications of this landscape trap and discuss how the problems created might be rectified.