Recovering nature: building on Georgina Mace's work to ensure a biodiverse and liveable future

The Red List Index (RLI) was first developed 20 years ago by a group of conservation scientists including Georgina Mace. It shows trends over time in aggregate survival probability (the inverse of extinction risk) for sets of species. It is calculated from the number of species in each IUCN Red List category, and the number moving between categories between assessments owing to genuine improvement or deterioration in status. The global RLI is aggregated across multiple taxonomic groups, and can be disaggregated to show trends for different subsets of species (e.g. pollinating, migratory, or wetland species), or to show trends driven by particular factors (e.g. international trade, invasive alien species’ impacts, or fisheries). National RLIs have been generated through either repeated assessments of national extinction risk in each country, or through disaggregating the global index and weighting each species by the proportion of its range in each country. The indicator has achieved wide policy uptake, including by the Convention on Biological Diversity, Convention on Migratory Species, Ramsar Convention on Wetlands, Convention on the International Trade in Endangered Species, Sustainable Development Goals, and Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services. Future developments include expanding the taxonomic coverage, applying the RLI to the goals and targets of the Kunming-Montreal Global Biodiversity Framework, projecting the RLI under different scenarios, incorporating uncertainty in the underlying Red List assessments, and more sophisticated analysis of the factors driving RLI trends.

The Living Planet Index (LPI) is one of a suite of indicators used to measure changes in biodiversity globally. Based on vertebrate population data collected from monitoring sites around the world, it can provide a sensitive tool for analysing trends at different scales. The LPI was originally developed a quarter of a century ago to provide an insight into trends in species globally. This was at a time when threats to nature were increasing but very few indicators existed to measure the anthropogenic impact on biodiversity. In 2006, a partnership between the Zoological Society of London (ZSL) and WWF was initiated to continue development of the LPI with instrumental support from Georgina Mace, then Director of Science at ZSL. Since then, the indicator and data set supporting the LPI has been expanded to develop a detailed understanding of patterns in vertebrate populations. This talk will outline the LPIs contribution to the field of biodiversity indicators, and how it has been used to measure the changing status of global biodiversity through applications in research. The LPI has informed many policy instruments by documenting evidence of progress towards national and global targets. Whilst to date the LPI has recorded overall declines in biodiversity around the world, this talk will explore its utility in also measuring the recovery of nature. 

The global, independent Dasgupta Review on the Economics of Biodiversity explored how and why we have failed to integrate nature into decision-making and what we can do about it. Georgina Mace participated on the Dasgupta Review’s Advisory Panel, and provided counsel to Professor Dasgupta and his team throughout the drafting of the Review, including on her areas of expertise in biodiversity science and valuing biodiversity. This talk will introduce the Dasgupta Review, Georgina Mace’s contributions, the options for change it set out, and its recommendations for institutional change in the financial system.

Many of the options for change set out in the Dasgupta Review are now being put into practice, as well as generating further research and increasing understanding among economic and financial decision-makers. The Dasgupta Review included chapters on management of nature-related financial risk and uncertainty, and finance for sustainable engagement with nature. Its recommendations are now being taken forward by the Taskforce on Nature-related Financial Disclosures (TNFD) who are developing a risk management and disclosure framework for organisations to report and act on evolving nature-related risks, with the ultimate aim to support a shift in global financial flows away from nature-negative outcomes and toward nature-positive outcomes.  This talk will introduce the ‘beta version’ of the framework and outline how it is already being used globally by corporates and financial institutions through pilot testing. Critical areas for further research identified through the TNFD framework development process will be outlined, including on data, metrics, targets, scenarios and transition plans. 

Georgina Mace urged the global community to aim higher to bend the curve of biodiversity loss. She then convened the most ambitious ensemble of global biodiversity models to show the types and magnitude of policy interventions that bending the curve would require. This talk focuses on some of the obstacles that the new global biodiversity monitoring framework must overcome if such ambitious targets for nature are to be met. Meeting time-bound targets efficiently requires adaptive management, which in turn requires a ‘sat-nav’ for nature. The two main pillars of such a sat-nav are (1) models that predict future consequences of today’s choices, and (2) rapid feedback from monitoring to enable course corrections and model improvements. The same elements are needed by organisations wishing to ensure that their actions are nature-positive, but neither is yet written into the global biodiversity monitoring framework. Some of the obstacles ahead are purely scientific. For example, whereas developing climate models were able to use rich time series from the instrumental record and proxies, no comparable data are available for developing biodiversity models. Some obstacles, such as the lack of a Biodiversity Model Intercomparison Program analogous to CMIP for climate models, could be overcome relatively rapidly with funding. The cultures within biodiversity science and science-policy have themselves thrown up some obstacles, such as a leaky pipe for data and disincentives for improving indicators, which also need addressing if we are to bend the curve of biodiversity loss.

Climate change drives biodiversity change, causing range shifts that alter species richness and composition with negative impacts on ecosystem services, and the question of species' ability to adapt remains unresolved. Here, Assistant Professor Daru will explore the effect of climate change on global plant diversity using species distribution models and climatic projections. He will investigate changes in geographic distribution of plant species worldwide and predict the extent to which global plant diversity will change under current and future climate, including range shift velocities required for plant species to keep up with future climate change. In his research, he found that there will be widespread reductions in areas climatically suitable for plant growth in the future, with a global median reduction of 1.49%. Areas of plant diversity in the present are projected to experience increases in weighted endemism, supporting the projected decrease in range size for most species. His findings also predict plant communities across the Arctic, Eurasia, and the tropics, especially in west and central Africa, will experience pronounced losses in the spatial composition of β-diversity due to simultaneous local disappearance and introduction of new species. The velocities of range shifts across latitudes and elevations will vary across regions and plant clades. Assistant Professor Daru's study highlights the importance of predicting and conserving diversity at other trophic levels, as plants are foundation species that sustain food chains and drive terrestrial ecosystem productivity.

In this talk Professor Lewis will describe some recent changes to intact tropical forests from large-scale and widely distributed long-term inventory plot networks from across the tropics, and then present some new research on the common species in tropical forests. The conclusion of which is that African, South American and Southeast Asian tropical forests are remarkably similar in terms of their proportion of common species. Remarkably, just ~1,000 tree species account for ~50% of all of the ~800 billion trees (>=10 cm trunk diameter) in Earth’s closed-canopy tropical forests. This is a tractably small number of tree species to understand their autecology and their likely responses to environmental change. This new understanding can open new research avenues in terms of tracking and modelling limited numbers of species that constitute >50% of the trees in a tropical forest to make improved predictions of the behaviour of tropical forests under today’s rapid environmental change. These results may also reveal fundamental mechanisms of ecosystem assembly that apply to all tropical forests, despite their differing biogeographical, environmental and anthropogenic histories.