Current Projects

1. What controls the floristic diversity of a National Park? Species turnover as a common currency for quantifying diversity patterns within the Great Smoky Mountains and among 23 National Parks [National Parks Ecological Research Fellowship with Peter White, UNC].

SUMMARY: This project is an examination of the environmental and historical controls over regional plant species diversity in Great Smoky Mountains National Park.  It has several components, including: 1) two field seasons of surveying underrepresented Park vegetation; 2) deploying a network of microclimate data loggers in several major watersheds for a landscape modeling study of critical environmental variables such as ground-level air temperature and soil moisture balance; 3) assimilating the first vegetation database (currently over 1500 vegetation plots) for the Smokies; and 4) deriving new approaches to gradient analysis that incorporate advances in null modeling techniques to quantify the nature of plant species turnover along environmental gradients.  Floristic patterns from the Smokies will then be compared to those from other National Parks using sources of Park vegetation and environment data.       Photo update: Field season 2004

Looking south from Forney's Ridge over Noland Creek watershed.

2. Connecting genes to ecosystems: how does genetic diversity maintain species diversity in a species-rich pastureland? [National Science Foundation International Research Fellowship with Phil Grime, University of Sheffield, UK].

SUMMARY: In 1997, Rosemary Booth, Phil Grime and colleagues used their extensive knowledge of an ancient, species-rich pasture ecosystem in northern England to create the first long-term experimental investigation of the effects of genetic impoverishment on plant species diversity and ecosystem processes. Results of the first five years of this study (Booth & Grime 2003) suggest that 1) species diversity declines as component populations lose genetic variation, and 2) communities of genetically diverse populations maintain a more consistent and predictable species composition than those more genetically impoverished.  However, the processes responsible for these patterns remain unclear, and although local genetically-controlled polymorphisms appear significant to community- and ecosystem-level processes, their importance relative to species-level effects has never been explored.        Phil Grime and I are taking this work in two directions, both experimental. The first explores how such levels of genetically-controlled polymorphisms are maintained in such a small local area (all genotypes are from a 10 x 10 m quadrat in Cressbrookdale).  This experiment involves growing selected genotypes from three species (the tussock grass Koeleria macrantha, the clonal sedge Carex caryophyllea, and the precise-foraging forb Campanula rotundifolia) in five different environments thought to significantly vary in space and time at Cressbrookdale (nutrient and water availability, grazing and pathogen pressure).  Because genetic identity may mediate species interactions, our design includes species mixtures of different genotypes.  A second experiment simultaneously manipulates species diversity and genetic diversity within populations to examine the relative controls of local species and genetic diversity in maintaining ecosystem functioning (yield).  Environmental heterogeneity is also incorporated by using a patch design of basic (rendzina) and acidic (podsol) local soil types in each box, along with localized regions of extremely shallow (< 5cm) and deep (45 cm crevices) soils.         Experimental Details and Reference

Cressbrookdale limestone grassland, Derbyshire, UK. Grassland species manipulations, Tapton Garden, Sheffield.

3. A characterization of plant communities surrounding North Carolina agroecosystems [postdoctoral work with Robert Peet, UNC].

SUMMARY: North Carolina farmers have extensively used crop protection products such as herbicides for many decades. Although the effects of these chemicals on target plants are well researched, their effects on plant communities in proximity to agricultural fields are virtually unknown because no baseline data on the structure and composition of these communities are available. To fill this gap, we are providing a detailed characterization of the plant communities neighboring selected fields from North Carolina agricultural landscapes in the piedmont and coastal plain. Our study is focusing on the rate of community change with proximity to crop fields and the distribution of exotic plant species.     Field team included, from left to right: Alenna Clements (NCSU), Joel Gramling (UNC), Todd Jobe (UNC), Annika Dollander (NCSU), Matt Kudla (NCSU), Jenny Mayer (NCSU), Eric Fridley (freelance adventurer), Christina Zakas (UNC), Jessica Long (UNC), and at bottom Amanda Senft (UNC).

4. Ecoinfomatics Working Group [with plant ecology faculty and graduate students from UNC, NCSU].

SUMMARY: This group of vegetation ecologists is exploring the unique 5000-plot vegetation and environment database of the Carolina Vegetation Survey. Our many projects include:  How do environmental controls over species richness change with scale?  What traits characterize co-occurring species at different spatial and temporal scales?  With international collaborators, Robert Peet and I are also exploring the interdependence of spatial and temporal variation in local plant diversity in multi-spatial time-series datasets from three countries.

[HOME]    Jason D. Fridley, updated January 2005