A model for studying the ecology and evolution of plant communities
Responding to the need among vegetation researchers for a flexible toolbox for investigating the eco-evolutionary dynamics of vegetation, the IIASA Evolution and Ecology Program (EEP) co-developed the Trait Ecology and Evolution Plant model, a comprehensive software package for studying the ecology and evolution of plant communities.
The new PLANT model shows how community evolution in two functional traits can give rise to species-rich communities matching empirical observations (Figure 1).
The research also shows, for the first time, the emergence of neutral fitness ridges in niche models of plant communities, thereby demonstrating an assumption previously used a priori by the neutral theory of biodiversity.
Figure 1. The PLANT model generates realistic vegetation patterns matching observations in dependence on a site’s environmental conditions. The vegetation’s biodiversity is shown in terms of the successional dynamics of different species (distinguished by color) after a disturbance.
1. Population dynamics in forests are strongly size-structured: larger plants shade smaller plants while also expending proportionately more energy on building and maintaining woody stems. Although the importance of size structure for demography is widely recognized, many models either omit it entirely or include only coarse approximations.
2. Here, we introduce the plant package, an extensible framework for modelling size- and trait-structured demography, ecology and evolution in simulated forests. At its core, plant is an individual-based model where plant physiology and demography are mediated by traits. Individual plants from multiple species can be grown in isolation, in patches of competing plants or in metapopulations under a disturbance regime. These dynamics can be integrated into metapopulation-level estimates of invasion fitness and vegetation structure. Because fitness emerges as a function of traits, plant provides a novel arena for exploring eco-evolutionary dynamics.
3. Plant is an open source R package and is available at github.com/traitecoevo/plant. Accessed from R, the core routines in plant are written in C++. The package provides for alternative physiologies and for capturing trade-offs among parameters. A detailed test suite is provided to ensure correct behaviour of the code.
4. Plant provides a transparent platform for investigating how physiological rules and functional trade-offs interact with competition and disturbance regimes to influence vegetation demography, structure and diversity.
Falster DS, FitzJohn RG, Brännström Å, Dieckmann U, & Westoby M (2016). PLANT: A package for modelling forest trait ecology and evolution. Methods in Ecology and Evolution 7 (2): 136-146. DOI:10.1111/2041-210X.12525.
Falster DS, Brännström Å, Westoby M, & Dieckmann U (2017). Multi-trait successional forest dynamics enable diverse competitive coexistence. Proceedings of the National Academy of Sciences of the USA 114 (13): E2719-E2728. DOI:10.1073/pnas.1610206114.