 |
Research in the Fridley Lab at Syracuse University concerns the ecology of plant communities, including their organization, their distribution with respect to the environment, and their control over ecosystem processes. Current topics of active research include:
Vegetation response to climate change
North-temperate ecosystems are expected to warm by several degrees C or more over the coming century, which may force large shifts in the composition and functioning of terrestrial vegetation. The Fridley lab, in collaboration with Phil Grime and colleagues at the University of Sheffield (UK), directs one of the longest running manipulations of temperature and precipitation on a steep daleside in calcareous grassland in northern England. Established in 1992, the Buxton Climate Change Experiment has demonstrated that some ecosystems may be relatively resistant to climate forcing. With support from the National Science Foundation, current studies are focused on whether such resistance stems from 1) high fine-scale substrate heterogeneity, 2) dispersal limitation of potential invasive species, or 3) the capacity of existing populations to evolve quickly in response to new climate regimes.
|
|
 The Buxton Climate Change Experiment, a long-term manipulation of temperature and rainfall in species-rich grassland in Derbyshire, UK. |
Related publications:
Moser, B., Fridley, J.D., Grime, J.P., and Askew, A.P. 2011. Simulated migration in a long-term climate change experiment: invasions impeded by dispersal limitation, not biotic resistance. Journal of Ecology 99: 1229-1236.
Fridley, J.D., Grime, J.P., Askew, A.P., Moser, B., and Stevens, C.J. 2011. Soil heterogeneity buffers community response to climate change in species-rich grassland. Global Change Biology 17: 2002-2011.
Grime, J.P., Fridley, J.D., Askew, A.P., Thompson, K., Hodgson, J.G., and Bennett, C.R. 2008. Long-term resistance to simulated climate change in an infertile grassland. Proceedings of the National Academy of Sciences USA 105: 10028-10032.
Plant invasions in a global floristic context
 The shrub garden at Syracuse University contains over 100 shade-tolerant species of native, naturalized, and invasive shrubs and vines of the Eastern U.S. |
|
The introduction and spread of plant species to areas distant from their native ranges is a complex biological process that gets to the heart of how plant communities are assembled. It is also a phenomenon of great public importance, given the economic and environmental ramifications of wholesale changes to ecosystems caused by aggressive invader species. We seek to understand properties of ecosystems that make them susceptible to invasion and properties of species that make them invasive. This is an area of research that is highly evolving, and by necessity we address invasion questions on scales ranging from small experimental studies to biogeographic surveys. |
One of our latest projects is an evaluation of the ecological mechanisms of invasion of a large group of shade-tolerant, forest understory shrubs spreading throughout the Eastern Deciduous Forest of North America. Most of these species are native to East and Central Asia or Europe but have close relatives in the Eastern U.S. flora, and relatives that are introduced as ornamentals but are not (yet) invasive. Our approach is to compare the behavior and morphology of congeneric groups that include native, exotic but non-invasive (naturalized), and exotic-invasive species. We have established a common garden at Syracuse that includes species in several focal genera, as well as other common native forest shrubs. For each species, we are quantifying key physiological and morphological traits that may confer high competitive ability in understory environments, including leaf demography, photosynthetic capacity, and shoot architecture. A list of focal taxa is available here.
Related publications:
Fridley, J.D. 2012. Extended leaf phenology and the autumn niche in deciduous forest invasions. Nature 485: 359-362.
Fridley, J.D. 2011. Biodiversity as a bulwark against invasion: conceptual threads since Elton. In: Richardson, D.M. ed. Fifty years of invasion ecology: the legacy of Charles Elton. Blackwell, pp. 121-130.
Fridley, J.D. 2008. Of Asian forests and European fields: Eastern U.S. plant invasions in a global floristic context. PLoS ONE 3: e3630.
Fridley, J.D., Stachowicz, J.J., Naeem, S., Sax, D.F., Seabloom, E.W., Smith, M.D., Stohlgren, T.J., Tilman, D., Von Holle, B. 2007. The invasion paradox: reconciling pattern and process in species invasions. Ecology 88: 3-17.
Ecosystem consequences of biodiversity
Modern ecology has seen the study of biodiversity broadened from investigations of its causes (how ecosystem properties and local biota drive diversity) to consideration of biodiversity's consequences — e.g., are more diverse ecosystems more productive or more stable than similar but less diverse systems? The question has important implications for the management of both natural and managed plant communities, which in some circumstances are seeing rapid declines in biodiversity (due to eutrophication, for example) and in others at least temporary increases due to species invasions.
| Experimental studies in our lab in collaboration with Phil Grime from the University of Sheffield (UK) are establishing links between the local genotypic diversity of eight species of limestone grassland and the long-term productivity of this pasture ecosystem. Two long-term experiments established in Sheffield in 2004 seek to understand how such levels of genetically-controlled polymorphisms are maintained in a small local area, and the relative importance of species and genetic diversity in maintaining productivity in the face of spatial and temporal environmental heterogeneity. |
|
 Limestone grassland of Cressbrookdale, Derbyshire, UK. |
Related publications:
Fridley, J.D. and Grime, J.P. 2010. Community- and ecosystem-level consequences of intraspecific genetic diversity in grassland microcosms of varying species diversity. Ecology 91: 2272-2283.
Fridley, J.D., Grime, J.P., and Bilton, M. 2007. Genetic identity of interspecific neighbours mediates plant responses to competition and environmental variation in a species-rich grassland. Journal of Ecology 95: 908-915.
Biogeographic patterns of secondary succession
 Establishing an experimental plot at the Cary Institute, Millbrook, NY.
|
|
Across the Eastern U.S., old fields of former crop and pasture lands revert to forests in a pattern of plant succession that has been well described for over a century. In a research collaboration with Justin Wright's lab at Duke University, we're exploring a novel biogeographic perspective in succession research that suggests the rate at which woody species colonize and dominate old fields decreases with latitude. With funding from the National Science Foundation, we've established an experimental network of six research sites from Syracuse to northern Florida to identify whether faster rates of succession in the South are linked to a warmer climate, poorer soils, or differences in the competitive abilities of old-field herbaceous and pioneer woody species across latitudes. |
Related publications:
Fridley, J.D. and Wright, J.P. Drivers of secondary succession rates across temperate latitudes of the Eastern U.S.: climate, soils, and species pools. Oecologia, in press.
Wright, J.P. and Fridley, J.D. 2010. Biogeographic synthesis of secondary succession rates in Eastern North America. Journal of Biogeography 37: 1584-1596.
Landscape modeling of montane microclimate and vegetation
 Ground-level temperature model output for Great Smoky Mountains NP during July, showing large effects of local topography on microclimate. |
|
The Fridley lab has been involved in an ongoing study of vegetation-environment relationships of Great Smoky Mountains National Park (GSMNP). Building on decades of past vegetation research in the Smokies, we've assembled vegetation and environment databases for GSMNP, for the purposes of linking plant species distributions to environmental and historical factors (such as logging and settlement). A major part of this project has been the establishment of the Smokies Temperature Network, a 175+ datalogger array of ground-level temperature loggers deployed to construct high resolution (30-m) maps of daily temperature for the >2000 sq. km park. Temperature maps will allow new analyses of species distributions with respect to current and potential future climates. |
Related publication:
Fridley, J.D. 2009. Downscaling climate over complex terrain: high fine-scale spatial variation of near-ground temperatures in a montane forested landscape (Great Smoky Mountains, USA). Journal of Applied Meteorology and Climatology 48: 1033-1049.
Geographical ecology and multi-scale diversity patterns
| Patterns of biodiversity—such the number of species in a given area—are scale-dependent, meaning that their shape depends on the spatial grain and extent examined. As a consequence, many of the most well-studied patterns in ecology—such as species-area and species-time curves, species-abundance distributions, measures of beta diversity, diversity-environment relationships—all take on different functional forms when examined in small vs. large areas (or over small vs. long durations), and will thus defy generalization until researchers can account for scale sensitivity. We are particularly interested in how the distribution of plant diversity at ‘fine' scales (e.g., vegetation plots) reflects the distribution of diversity at much broader scales (such as a state or continent). Current research centers on constructing a general theory of species-area curves based on statistical constraints, environmental variance, and dispersal processes. |
|
 Hyperdiverse longleaf pine savanna from the NC coastal plain. |
Related publication:
Fridley, J.D., Peet, R.K., van der Maarel, E., and Willems, J.H. 2006. Integration of local and regional species-area relationships from space-time species accumulation. The American Naturalist 168:133-143.
|
 |
 |
