Perceptions and reality in ecological restoration and the use of seasonal forecasting
By Valerie Hagger (University of Queensland)
The need to restore the world’s ecosystems and landscapes to protect biodiversity and vital ecosystem services has resulted in significant international commitments over the last decade. Governments and non-government organisations are now looking at ways to scale up restoration efforts to meet those commitments (see Decision Point #68).
Efforts to restore native vegetation have had mixed outcomes. Some have worked, some haven’t, and there are many diverse opinions on the factors behind these successes and failures. However, not much is known about how these factors are perceived, and whether perceptions match realities.
We surveyed 307 people involved in the restoration of native vegetation to identify their perceptions on the factors influencing the success of restoration projects
The survey identified that weather (particularly drought and flooding) has affected the outcomes of restoration projects, but is not perceived to be an important risk when planning new projects
We demonstrated that seasonal forecasts provided by the Predictive Ocean Atmosphere Model for Australia detected unfavourable weather with sufficient skill and lead time to be useful for restoration projects
We set out to throw some light on this. We surveyed 307 people who are involved in restoring native vegetation across Australia to find out what their perceptions were about the factors that influence a successful restoration project.
Restoration projects are influenced by a range of ecological, financial and social factors. These include invasive plant species, animals that consume or displace native plant species, existing conditions of the site, timeframes and funding, public acceptance, weather – the list is long and varied.
We asked the survey respondents to rate how strongly they agree that restoration success is limited by each factor on a five-point scale. The factors perceived by respondents to most strongly limit the success of restoration projects were financial constraints (Probability [P] = 0.9), weed invasion (P = 0.85), time constraints (P = 0.85), and pest animals (P = 0.82).
We also asked survey respondents to provide a case study of a specific restoration project for which they have been involved, and asked them which factors, if any, limited success in that project. Two hundred and twenty of the 307 respondents provided a case study example of a restoration project. Factors commonly identified as most important were financial constraints (22%), local climate (16%), natural events (15%), and weeds (13%).
One hundred and thirty six respondents reported being involved in a restoration project that failed to deliver the expected outcomes. The main reasons reported were local climate (32%), weeds (17%) and natural events (15%). Other reasons reported were lack of maintenance (29%) and low plant survival rates (15%).
We found discrepancies between perceived risks to restoration projects in general and realised risks from specific case studies after implementation. People did not perceive local climate and natural events as important risks, but they recognised them as major reasons limiting the success of specific case studies. They also cited local climate as the main cause of failure of restoration projects.
While the impacts of weather, particularly drought and flooding on restoration projects, are well known, we found they are not considered to be an important risk in planning new restoration projects. This highlights the need for better recognition and management of weather risks, and the potential role of seasonal forecasting.
Forty five of the restoration case studies reported weather as a primary or secondary constraint to success. We were able to obtain further information for 16 of the case studies, across Queensland, New South Wales, Victoria and Western Australia, on location of the restoration site, the date of revegetation, what the weather issues were and when they occurred, and how restoration outcomes were affected. For example a restoration site at Chambers Flat in Queensland was affected by three different weather events over several years (Figure 1).
Using these restoration case studies, we assessed the ability of seasonal forecasting from the Predictive Ocean Atmosphere Model for Australia (POAMA-2) to detect unfavourable weather with sufficient skill and lead time to be useful for restoration projects.
We found that rainfall and temperature variables in POAMA-2 predicted 88% of the weather issues encountered in restoration case studies, apart from strong winds and cyclones. Of those restoration case studies with predictable weather issues, POAMA-2 had the forecast skill to predict the dominant or first-encountered issue in 67% of cases.
Through consultation with restoration practitioners, we explored the challenges associated with the uptake of forecast products to develop a prototype forecast product (Figure 2).
The establishment success of restoration could be improved by integrating seasonal forecasting into decision making through identifying risk management strategies during restoration planning, accessing the forecast a month prior to revegetation activities, and adapting decisions if extreme weather is forecasted.
Seasonal forecasting has potential to reduce uncertainty in decision making and improve the success and cost-efficiency of restoration projects. It could also be useful for other conservation actions that rely on weather for successful implementation.
More info: Valerie Hagger email@example.com
Hagger V, J Dwyer, L Shoo & K Wilson (2018). Use of seasonal forecasting to manage weather risk in ecological restoration. Ecological Applications. https://doi.org/10.1002/eap.1769