| Research
in the Bowman lab focuses on
multiple areas of plant ecology,
particularly on the
interaction between plants and their resources, ranging from
plant adaptations to low resource availability, to how plants influence
soils and subsequently ecosystem function and biodiversity. Over
the past decade
my work has concentrated on the interaction between alpine plants and
nutrients, examining the response of plants to low nutrient supply,
as well as the influence that plants have on their nutrient
environment. Because of the tremendous variation in soil resource availability associated with landscape topographic and microclimatic diversity, and the accompanying variation in biotic diversity, the alpine is an excellent model system to address questions of plant-soil interactions. Research projects have addressed specific resource limitations to primary production in alpine communities, the role of competition in community composition, the role of symbiotic N2-fixation in the alpine N cycle and its influence on species diversity, and plant species influences on N cycling. |
 |
Current Projects
| Plant control over nutrient
cycling and implications for species interactions: Plants
affect the availability of critical resources, such as water and
nutrients, simply by consuming them. However, plants can also
directly
influence the supply of nutrients through influences on soil biology,
by varying the amount and chemistry of organic matter. We've been
investigating the role of plant chemistry on nitrogen cycling in alpine
plants, from the perspective of its influence on spatial variation in
ecosystem function, as well as a biotic influence on community
dynamics. By influencing resource supply, plants can also
influence the outcome of competitive interactions. We've used a
model system in the alpine, consisting of a slow-growing forb (alpine
avens- Geum rossii) and a
fast growing grass (tufted hair grass or Deschampsia caespitosa). Geum effectively competes with Deschampsia through chemical
modification of nitrogen cycling- exuding phenolic compounds into the
soil that either bind to inorganic nitrogen, or by providing an energy
substrate to soil microbes which then immobilize the nitrogen. exemplary publications: Meier, C.L. and W.D. Bowman. 2008. Links between plant litter chemistry, species diversity, and below-ground ecosystem function. Proceedings of the Bardgett, R.D., W.D. Bowman, R. Kaufmann, and S.K. Schmidt. 2005. Linking aboveground and belowground ecology: a temporal approach. Trends in Ecology and Evolution 20: 634-641. pdf Bowman, W.D., H. Steltzer, T.N. Rosenstiel, C.C. Cleveland, and C.L. Meier. 2004. Litter effects of two co-occurring alpine species on plant growth, microbial activity and immobilization of nitrogen. Oikos 104: 336-344. pdf |
 Geum rossii
|
 Niwot Ridge, Colorado
|
Plant resource partitioning: Use
of different chemical forms of nitrogen- All plants
need essentially the same resources in the same chemical structure, and
thus partitioning by form, like animals can do for prey species, has
not been considered for plants until recently. Plants are capable
of taking up several forms of nitrogen (ammonium, nitrate, and small
amino acids), and thus the potential exists that plants could
specialize in the form of nitrogen they take up. This might
alleviate competition with neighbors for a resource that is often
limiting to plant growth and community diversity. My lab, in
combination with my former student Amy Miller and Katie Suding's lab,
have described patterns of uptake of different nitrogen forms by alpine
plants that indicate differing degrees of specialization in
uptake. Some plants appear to have narrow preferences for the
form of nitrogen they take up, while others appear to be more
versatile. The implications of these patterns for the outcome of
competition and alpine diversity is being explored. exemplary publications: Ashton, Miller, A.E., W.D. Bowman and K.N. Suding. 2007. Plant uptake of inorganic and organic nitrogen: Neighbor identity matters. Ecology 88: 1832-1840. pdf |
| Nitrogen deposition and alpine
ecosystem function- Nitrogen deposition, a form of acid
rain, remains one of the most serious regional environmental
problems. Alpine areas are particularly susceptible to
detrimental effects, due to their thin, poorly weathered soils,
low rates of biological activity, and strong seasonality, all of which
lower the
buffering capacity of alpine systems to neutralize the ecological
effects of N deposition. We have been examining the influence of
N deposition on plant species composition, soil chemistry (base cations
and acidity), and ecosystem function in alpine ecosystems.
Research sites include Niwot Ridge, Rocky Mountain and Glacier National
Parks, and the Western Tatra Mountains of Slovakia. exemplary publications: Bowman, W.D., C.C. Cleveland, L. Halada, J. Hreško, and J.S. Baron. 2008. Negative impact of nitrogen deposition on soil buffering capacity. Nature Geoscience 1: 767-770. pdf Nemergut, D., A. R. Townsend, S. R. Sattin, K. R. Freeman, N. Fierer, J. C. Neff, W. D. Bowman, C. W. Schadt, M. N. Weintraub, and S. K. Schmidt. 2008. The effects of chronic nitrogen fertilization on alpine tundra soil microbial communities: implications for carbon and nitrogen cycling. Environmental Microbiology 10: 3093-3105. pdf Bowman, W.D., J.L. Gartner, K. Holland, and M. Wiedermann. 2006. Nitrogen critical loads for alpine vegetation and terrestrial ecosystem response – Are we there yet? Ecological Applications 16: 1183-1193 pdf |
 Mount Gould, Glacier National Park |
A complete CV can be viewed by clicking here