home   research   publications   cv

How will climate-change impact diversity?

     NEON Ants (NEON Blog post about our project HERE). - Funded by an NSF EAGER award, this project will study the activity, abundance and diversity of ants from National Ecological Observatory Network (NEON) sites. This work encompasses multiple spatial (e.g., trap, plot, NEON site, continent) and temporal (bi-weekly, annual) scales. The goal is to create baseline models of how climate impacts seasonal patterns of ant abundance, activity and diversity to parameterize predictive modesl of future abundance and diversity under climate change.

Long-term dynamics of ant abundance and diversity- As part of the NSF EAGER, I will re-sample ant assemblages on transects we sampled in the early 1990s. Using climate data collected at the research sites (many are LTERs and other research stations) as well as interpolated climate data, we will test how recent climate change has impacted activity, abundance and diversity of ants. Collaboration with M. Kaspari (OU).

How are diversity gradients generated and maintained?

The "canonical" Latitudinal Diversity Gradient ("LDG"), where a taxon has highest species richness at the equator which then declines toward higher latitudes, is considered a fundamental pattern of biogeography. There are several standing hypotheses that attempt to explain latitudinal diversity gradients. As these hypotheses were erected to explain the observed pattern (i.e., the observed LDG), they are non-exclusive and typically share predictions. Therefore, progress depends on testing secondary predictions of diversity hypotheses as well as exploring how diversity gradients vary within and amongst taxa. As such, my approach is to test both the primary and secondary predictions of mechanistic hypotheses of the LDG.

Current Projects

     How (and why) diversity gradients differ across taxa- Funded under the NSF Macrosystems Biology Program the Experimental Macroecology project focuses on understanding the relationships between temperature and macroecological pattern and process. My work with this group focuses on diversity patterns across archaea,bacteria, fungi, soil arthropods and trees in collaboration with: J.H. Brown (U. New Mexico), B.J. Enquist (U. Arizona), M. Kaspari (OU), R.B. Waide (U. New Mexico), J. Zhou (OU)

     How (and why) diversity gradients differ within taxa- Diversity hypotheses that invoke mechanisms relating environmental factors such as climate on diversification rates have an implicit assumption that the mechanism is acting on all, or at least most, of the clades within a taxon. To simplify, generality of mechanism should lead to generality of pattern. I study the diversity gradients both across and within taxa to test this assumption and examine how taxonomic scale affects diversity patterns. Importantly, this method allows tests of hypotheses of pattern that allows rejection of specific taxon by gradient diversification hypotheses.


    Spatial patterns of functional trait diversity - I use biodiversity informatics tools to integrate plant species distribution with databases of plant size, morphology and functional traits. In collaboration with plant functional ecologists, I have examined the distribution of plant functional trait diversity across spatial scales from individual plots to comparisons of continents.

I am also part of a nascent collaborative network building a global database on ant life history and functional traits. My database on ant morphometrics (>60,000 linear measures of >3,000 ant species) is the core of the morphology database. Integrating this database with GABI (see below) will allow us to test hypotheses about global patterns of ant functional diversity.


Biodiversity Informatics

Tests of diversity hypotheses at continental to global scales require data that is broad in spatial scope yet fine-grained in resolution. While there is such data for a few vertebrate groups, I use a biodiversity informatics approach where I compile, integrate and analyze large-scale spatially explicit biodiversity databases.

Current Projects

    Global Ant Biodiversity Informatics Project- I co-founded (with Benoit Guénard and Rob Dunn at NCSU) a collaborative biodiversity informatics project collecting distribution data on and producing species level range maps for North American ants. This project has evolved into GABI, the Global Ant Biodiversity Informatics project, which is now producing maps of the known distributions of all ~15,000 ant species via antmaps.org .

    SALVIAS- I co-founded (with Brad Boyle and Brian Enquist) a global plant biodiversity informatics network called SALVIAS ( www.salvias.net). Funded by the Center for Applied Biodiversity Science at Conservation International, SALVIAS merged spatial and taxonomic data from millions of herbarium specimen and thousands of local plant inventories to study plant ecology and biogeography at continental, hemispheric and global scales.

Databases (just ones I can share, let's chat)

Most of the databases I work with are housed in a MySQL database with web accessible PHPMyAdmin front end. They are accessible by r scripting using the libraries DBI and RMySQL.

    FIA- I have a local copy of (parts of) the U.S. Forest Service Forest Inventory and Analysis Database (last updated January of 2015). For more information on the FIA, click here .

    Tundra to Tropics Floristic Data- I have a (taxonomically updated) version of the data that Steve McLaughlin used in his publication "Tundra to Tropics: The Floristic Plant Biogeography of North America" Sida, Botanical Miscellany 30, Botanical Research Institute of Texas. 2007. This consists of the species list for 245 local floras from throughout Canada, the United States and Mexico. There are 138,096 site by species observations with ~19,350 species from 241 families and 65 orders.