Towards a new generation of vegetation models

May 11, 2020

Plants and vegetation play a critical role in supporting life on Earth, but there is still a lot of uncertainty in our understanding of how exactly they affect the global carbon cycle and ecosystem services. A new IIASA-led study explored the most important organizing principles that control vegetation behavior and how they can be used to improve vegetation models.

We rely on the plants that make up our planet's ecosystems to release oxygen into the atmosphere, absorb carbon dioxide (CO2), and provide habitat and food for wildlife and humans. These services are critical in the future management of climate change, especially in terms of CO2 uptake and release, but due to the many complex, interacting processes that affect the ability of vegetation to provide these services, they remain difficult to predict.

In an IIASA-led perspective published in the journal Nature Plants, an international team of researchers endeavored to address this problem by exploring approaches to master this complexity and improve our ability to predict vegetation dynamics. They explored key organizing principles that govern these processes - specifically, natural selection; self-organization (controlling collective behavior among individuals); and entropy maximization (controlling the outcome of a large number of random processes). In general, an organizing principle determines or constrains how components of a system, such as different plants in an ecosystem or different organs of a plant, behave together. Mathematically, such a principle can be seen as an additional equation added to a system of equations, allowing one or more previously unknown variables in the system to be determined and thereby reducing the uncertainty of the solution.

A lot of research has gone into understanding and predicting how plant processes combine to determine the dynamics of vegetation on larger scales. To integrate process understanding from different disciplines, dynamic vegetation models (DVMs) have been developed that combine elements from plant biogeography, biogeochemistry, plant physiology, and forest ecology. DVMs have been widely used in many fields including the assessment of impacts of environmental change on plants and ecosystems; land management; and feedbacks from vegetation changes to regional and global climates. However, previous attempts to improve vegetation models have mainly focused on improving realism by including more processes and more data. This has not led to the expected success because each additional process comes with uncertain parameters, which has in turn caused an accumulation of uncertainty and therefore unreliable model predictions.

"Despite the ever-increasing availability of data, and the fact that vegetation science, like many other scientific fields, is benefitting from increasing access to big data sets and new observation technologies, we also need to understand governing principles like evolution to make sense of the big data. Current models are not able to reliably predict long-term vegetation responses," explains lead author Oskar Franklin, a researcher in the IIASA Ecosystems Services and Management Program.

The study found that by representing the principles of evolution, self-organization, and entropy maximization in models, they could better predict complex plant behavior and resulting vegetation as an emerging result of environmental conditions. Although each of these principles had previously been used to explain a particular aspect of vegetation dynamics, their combined implications were not fully understood. This approach means that a lot of complex variation and behavior at different scales, from leaves to landscapes, can now be better predicted without additional understanding of underlying details or more measurements.

The authors expect that apart from leading to better tools for understanding and managing the biosphere, the proposed "next-generation approach" may result in different trajectories of projected climate change that both policy and the general public would have to cope with.
-end-
Reference

Franklin O, Harrison S, Dewar R, Farrior C, Bra?nnstro?m A, Dieckmann U, Pietsch S, Falster D, et al. (2020). Organizing principles for vegetation dynamics. Nature Plants DOI: 10.1038/s41477-020-0655-x

Contacts:

Researcher contact

Oskar Franklin
Research scholar
Ecosystems Services and Management Program
Tel: +43 2236 807 251
franklin@iiasa.ac.at

Press Officer

Ansa Heyl
IIASA Press Office
Tel: +43 2236 807 574
Mob: +43 676 83 807 574
heyl@iiasa.ac.at

About IIASA:

The International Institute for Applied Systems Analysis (IIASA) is an international scientific institute that conducts research into the critical issues of global environmental, economic, technological, and social change that we face in the twenty-first century. Our findings provide valuable options to policymakers to shape the future of our changing world. IIASA is independent and funded by prestigious research funding agencies in Africa, the Americas, Asia, and Europe. http://www.iiasa.ac.at

International Institute for Applied Systems Analysis

Related Climate Change Articles from Brightsurf:

Are climate scientists being too cautious when linking extreme weather to climate change?
Climate science has focused on avoiding false alarms when linking extreme events to climate change.

Mysterious climate change
New research findings underline the crucial role that sea ice throughout the Southern Ocean played for atmospheric CO2 in times of rapid climate change in the past.

Mapping the path of climate change
Predicting a major transition, such as climate change, is extremely difficult, but the probabilistic framework developed by the authors is the first step in identifying the path between a shift in two environmental states.

Small change for climate change: Time to increase research funding to save the world
A new study shows that there is a huge disproportion in the level of funding for social science research into the greatest challenge in combating global warming -- how to get individuals and societies to overcome ingrained human habits to make the changes necessary to mitigate climate change.

Sub-national 'climate clubs' could offer key to combating climate change
'Climate clubs' offering membership for sub-national states, in addition to just countries, could speed up progress towards a globally harmonized climate change policy, which in turn offers a way to achieve stronger climate policies in all countries.

Review of Chinese atmospheric science research over the past 70 years: Climate and climate change
Over the past 70 years since the foundation of the People's Republic of China, Chinese scientists have made great contributions to various fields in the research of atmospheric sciences, which attracted worldwide attention.

A CERN for climate change
In a Perspective article appearing in this week's Proceedings of the National Academy of Sciences, Tim Palmer (Oxford University), and Bjorn Stevens (Max Planck Society), critically reflect on the present state of Earth system modelling.

Fairy-wrens change breeding habits to cope with climate change
Warmer temperatures linked to climate change are having a big impact on the breeding habits of one of Australia's most recognisable bird species, according to researchers at The Australian National University (ANU).

Believing in climate change doesn't mean you are preparing for climate change, study finds
Notre Dame researchers found that although coastal homeowners may perceive a worsening of climate change-related hazards, these attitudes are largely unrelated to a homeowner's expectations of actual home damage.

Older forests resist change -- climate change, that is
Older forests in eastern North America are less vulnerable to climate change than younger forests, particularly for carbon storage, timber production, and biodiversity, new research finds.

Read More: Climate Change News and Climate Change Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.