Dear Colleagues,

We are writing to you in search of datasets that could be used by an upcoming LTER Working Group.  We are specifically seeking the following types of plant datasets:

1)     Trait and/or fitness data collected on individuals growing within experiments or across natural environmental gradients. Trait data might include things like: SLA, LDMC, flowering time, height. Fitness data might include: seed production, survival, biomass, size metrics. We have no restrictions with respect to the types of traits or fitness measures.

2)     Plant community data on species (e.g., percent cover, relative biomass, etc.) collected from the same experiments or natural environmental gradients on which individual trait/fitness data have been collected (see 1).

We are most in need of individual plant trait/fitness datasets for our analyses, but welcome all datasets, from either the same or different studies, that fit these criteria (see Full project description below for more details). If you know of any such datasets, or if you have questions about the data we are trying to obtain, please contact José Waterton at jwaterto@iu.edu.

Many thanks for your help in our dataset search!

José Waterton, on behalf of the LTER Selection Synthesis Group

Full project description

We are members of a synthesis working group funded by an LTER Network Office Scientific Peers Advancing Research Collaborations (SPARC) grant entitled Selection across scales—merging evolutionary biology and community ecology to understand trait shifts in response to environmental change, for which we kindly seek your assistance in obtaining relevant data. We believe that this synthesis project is an exciting opportunity to leverage work carried out in LTER sites to address important questions in evolutionary ecology that spans scales of biological organization.

The ultimate goal of the synthesis working group is to evaluate the extent to which selection acting among individuals within populations under given environmental conditions (i.e., how trait values of individuals are associated with their fitness) is concordant with selection acting among species within communities in those same conditions (i.e., how trait values of species are associated with their relative abundance). Such parallel selective processes at different scales of biological organization, along with phenotypic plasticity, will determine the functional composition of communities; specifically, when plasticity and selection in a given environment are concordant (i.e., they shift trait values in the same direction at each level), then that environment will shift community functional composition to a greater extent than if selection and/or plasticity are discordant.

To carry out our analysis, we are compiling a database of datasets with which we aim to 1) carry out formal analysis evaluating the concordance of selection and plasticity, and 2) characterize the data that has been collected to date in LTER sites (and others) and identify what additional data would need to be collected to allow such analyses to be carried out in future. We would appreciate your assistance in identifying and acquiring relevant datasets from your sites which will further working group’s progress towards these two aims. 

Dataset criteria

The “ideal” dataset (if it exists!) to evaluate concordance of selection at the community- and population-scale would contain the following:

1. Population scale components – individual traits and fitness

  1. A measure of the “performance” (i.e., fitness) of a set individuals or genotypes for one or more given species in each different environmental condition (e.g., grazed and ungrazed, fertilized and unfertilized),), such as seed count or biomass.
  2. Functional trait values for a set of individuals/genotypes for one or more given species in each different environmental condition.
  • Note that the traits MUST be measured on the same individuals/genotypes for which fitness was measured in order to evaluate natural selection.

Selection at the population scale would be evaluated by regressing individual performance on individual traits. Plasticity can be evaluated by evaluating changes in trait values between environments.

2. Community scale components – species traits and abundance

  1. A measure of the “performance” of each species (or a subset of species, e.g., common species) in multiple different manipulated environmental conditions (e.g., grazed and ungrazed) such as total biomass or percent cover in a plot.
  2. Functional trait values for each species in each environmental condition.
    • Note that data for trait values could be: 1) averages for each species in each environment or 2) traits measured on a set of individuals in each environment, from which species averages could be calculated.

Selection at the community scale would be evaluated by regressing species performance on species traits. Plasticity can be evaluated by evaluating changes in trait values between environments.

In the “ideal” dataset, the population and community scale data would be collected for the same species in the same community in each environment. However, because required community and population scale data address questions at different scales of organization, we expect that such comprehensive datasets will be rare, if they exist at all. We therefore expect that analyzing the concordance of selection at each scale of organizing will only be possible by combining different datasets from the same or different sites, 

Therefore, we are interested in compiling a database of datasets that contain one or more components at the population and community scale (e.g., 1A, 1B, 2A, 2B from the list above). We have no restrictions with respect to site, experimental treatments, or experiment duration as we are currently in the data exploration and gathering phase of the working groups aims.