A high level of biodiversity in flora and fauna is the basis for well-functioning ecosystems. A world map of plant diversity compiled with AI-supported methods now shows the state of this diversity in global vegetation. It also provides clues as to why plant diversity is more pronounced in some places than in others and which factors are particularly influential.
In the course of evolution, countless plant species and subspecies have formed - always with the aim of being perfectly adapted to their respective environment and thus being able to spread more effectively. Whether tree, palm or grass - every plant species has developed in a unique way and over time has had to adapt to environmental changes or the strategies of competitors or predators. So it's no wonder that after millions of years of evolution we can look at an overwhelming number of plant species.
Pattern recognition with AI
In order to be able to understand and preserve this important part of global biodiversity, detailed maps of plant diversity are needed, which can, for example, establish connections between species diversity and environmental conditions. Such mapping of the diversity of global flora also makes it possible to assess changes in view of the current biodiversity and climate crisis. Although there are already lists and vegetation plots that record the occurrence of different species, these vary greatly in scope, precision and completeness, explain Lirong Cai from the University of Göttingen and his colleagues.
The scientists have therefore set themselves the task of creating a global map of plant diversity, which should form a basis for large-scale monitoring of biodiversity and for research into the origin of plant diversity. As a basis, they use a unique global data set of 830 floras and the distribution of 300,000 plant species, which were compiled over a period of ten years. In order to uncover possible connections to environmental factors, the team used what are known as neural networks, which use machine learning to recognize patterns in complex relationships and are therefore able to show the connection between plant diversity and environmental conditions better than the linear models previously used. By also considering interspecies relationships, Cai and his team were able to incorporate the evolutionary history of plant species found in each geographic region.
How can diversity arise?
The results are promising: "The global forecasts show in unprecedented detail and accuracy how plant diversity is distributed across our planet," reports second author Holger Kreft from the University of Göttingen. The current climatic influences proved to be the most important drivers for plant diversity. The model identified a high abundance of water and solar energy, as well as low seasonal fluctuations in the climate, as conducive to a rich abundance of various plants. The highest plant diversity is thus achieved in tropical areas such as Central America, the Andes, Madagascar, southern China and in some Mediterranean regions such as the Cape of Africa and areas around the Mediterranean.
But apart from the favorable climate, what else makes these areas so special that they have become veritable global centers of plant diversity? According to the researchers, this is due to the geological processes such as mountain building that have taken place in places such as the tropical Andes, the East African highlands or various Asian mountains over the last millions of years. “Orogenic processes are constantly changing soil composition, nutrient content and the local climate in mountain regions. This creates new and heterogeneous habitats in which plant strains can diversify and colonize from neighboring areas," Cai and his colleagues explain.
keep an eye on biodiversity
The world map of plant diversity has not only confirmed these relationships, it also opens up further possibilities for assessing global biodiversity and introducing suitable protective measures. "Knowing where to expect a given number of species under current conditions allows us to anticipate future developments due to changes in climate and land use, as well as identify the impact of overexploitation and introduced invasive species," summarizes senior author Patrick Weigelt from the University of Göttingen.
Source: Georg-August-Universität Göttingen, Article: New Phytologist, doi: 10.1111/nph.18533