Researchers have developed a mathematical model that aims to maximise the conservation of global forested biodiversity under budget and time constraints. By Amelia Macho.
Very little of the natural world has been left untouched by humanity. According to the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), global habitats have experienced significant decline in the last century, with an estimated 70% of land exposed to human activities and interventions [1]. The impact of such actions has been particularly pronounced on global forests, which, post industrialisation, have worsened widespread deforestation. An estimated 80,000 acres of rainforests alone are destroyed every day [2]. The loss of forest ecosystems around the world has severe implications for biodiversity. Importantly, as an enormous proportion of flora and fauna are supported by these environments, their destruction risks the endangerment and extinction of countless native species. Despite the detrimental impact of deforestation, the global response to reduce it has been sparse; just 15% of global landmass is protected, with a priority given to minimising disruption to human exploitation, rather than maximising biodiversity conservation [3].
Widespread interventions are necessary to prevent the accelerated loss of biodiversity in global forests. However, there are various barriers that must be overcome to do so, including access to the resources required to implement them. Hence, it seems unfeasible to conserve vast ecosystems such that species biodiversity does not decline. Rather, for sake of practicality, conservation efforts should be directed towards specific areas to instead maximise species numbers. So how can it be decided where to implement such interventions?
A recent study by Ian Luby and his team may just inch us closer to a solution [4]. Previous research had largely been conducted at a regional level and considered priority conservation areas on the basis of existing threats to biodiversity and conservation costs [5][6]. Luby’s team extended this by considering forested regions around the world. Using a metric that assigned a threat level given the extent of forest coverage between the year 2000 and 2018, i.e. deforestation rates, they identified 458 ecoregions as candidates for conservation funding [4]. Additionally, they considered both the number of plant species in each region and the cost of protecting the land, as well as the extent to which the forest was already protected, as identified by the United Nations Environment Programme and International Union for Conservation of Nature (UNEP-IUCN). These factors were used together in a dynamic mathematical model that aimed to maximise plant species diversity at the end of a 50-year period, with a $1 billion target budget. Luby’s team concluded that to actualise this goal, only 127 of the 458 ecoregions identified could be protected, resulting in the conservation of 23,680 species that would otherwise face endangerment or extinction [4]. Interestingly, they found that funding was most effective when targeted to lower income regions such as South and South-East Asia, as well as South and Central America. This was largely due to the lower conservation costs incurred, as well as an abundant biodiversity and a historic lack of investment in these regions. Additionally, the team’s approach demonstrated that staggered global investments maximised conservation efficiency. For example, just 18 of these 127 ecosystems would receive funding in the first year of investment, with this number rising to 46 within the first decade [4]. In this way, “temporal patterns”could be identified and adjusted for, ensuring flexibility in the event of various ecological setbacks.
There were, however, some limitations to the findings of this paper. For example, it considered only the conservation of plant biodiversity, potentially at the expense of animal biodiversity. This is exemplified by the fact that earlier papers that solely considered animal biodiversity came to somewhat different conclusions as to where funding was best diverted [7][8]. Moreover, given its nature, the study was limited by the fact that it could only consider known species; what of the conservation of species that are yet to be identified? However, the largest barrier to Luby’s proposed solution was, at its heart, one of practicality. Conservation policy is largely decided at a national level. Although recent climate summits, like COP22, have marked the beginnings of global initiatives in the fight against climate-related losses of biodiversity, there is generally a lack of international cooperation in global conservation planning. To maximise conservation efforts by implementing models proposed in research such as this, there is a much greater need for global coordination in the coming years. Only time will tell how this may transpire.
Citations:
[1] Díaz, S. 2019. Pervasive human-driven decline of life on earth points to the need for transformative change. Science 366, eaax3100
[2] Scientific American. 2009. Measuring the Daily Destruction of the World's Rainforests. [online] Scientific American. Available at: <https://www.scientificamerican.com/article/earth-talks-daily-destruction/> [Accessed 3 September 2022].
[3] UNEP-WCMC and IUCN. 2020. Protected Planet: The World Database on Protected Areas (WDPA) http://www.protectedplanet.net
[4] Luby, I.H., Miller, S.J. & Polasky, S. 2022. When and where to protect forests. Nature 609, 89–93.
[5] Ando, A., Camm, J., Polasky, S. & Solow, A. 1998. Species distributions, land values, and efficient conservation. Science 279, 2126–2128
[6] Sarkar, S. 2006. Biodiversity conservation planning tools: present status and challenges for the future. Annu. Rev. Environ. Resour. 31, 123–159
[7] Dinerstein, E. 2020. A ‘Global Safety Net’ to reverse biodiversity loss and stabilize Earth’s climate. Sci. Adv. 6, eabb2824.
[8] Pollock, L. J., Thuiller, W. & Jetz, W. 2017. Large conservation gains possible for global biodiversity facets. Nature 546, 141–144.
