Exploring the role of intraspecific trait variation in assembly of terrestrial plant communities

(124671, 2017 - 2021, running project)
Coordinator or leader of the project: 
Botta-Dukát Zoltán
Responsible person at MTA ÖK: 
Short description: 

Using traits offers a theory-driven, functional approach to understand assembly of communities. In the last decade there was a great development in this field: new methods emerged, lot of case studies were published; moreover this part of community ecology has been linked to modern coexistence theory. Most of the methods and consequently the case studies neglected the intraspecific trait variation. However, few case studies that measured ITV proved that sometimes it is not significantly lower than interspecific variation and thus it may play important role in community assembly: ITV may contribute to both adaptation to local abiotic environment and avoiding competitive exclusion.
Intraspecific trait variation can be decomposed into three main components: variation between populations, variation between individuals within the same population, and variation within individuals. In the project we will consider the first two components.
Absolute and relative amount of ITV components will be estimated and the drivers of differences between species in ITV will be explored. We will check if results based on local trait measurement could be extrapolated into sites with similar environmental conditions and overlapping species pool in spite of ITV between populations. We will improve our existing individual-based model to allow ITV, and will use it for checking statistical properties (type I error rate and power of the test) of different methods for detecting assembly rules considering ITV. We will apply methods proved to be suitable in the previous step to field data and compare their results with each other and with results of previous study neglecting ITV. We will check if within population ITV is fully stochastic or it has a deterministic part driven by environmental filtering and competition between co-occurring species.
Our main questions are the following:
1. What is the amount of ITV in the studied system? How is it structured?
2. Which method is the most appropriate for integrating ITV into community assembly studies?
3. Does considering ITV change our conclusion considerably?
4. Does trait variation between sites hinder extrapolation of our results and predictions received by using methods neglecting ITV?