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Assistant Professor Department of Biological Sciences University of Wisconsin - Milwaukee P.O. Box 413 Milwaukee, WI 53201 phone:
(414) 229
- 3146 |
Students Lab Members Courses |
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Assistant Professor Department of Biological Sciences University of Wisconsin - Milwaukee P.O. Box 413 Milwaukee, WI 53201 phone:
(414) 229
- 3146 |
Students Lab Members Courses |
Research Overview
The focus of research in the Schnitzer Lab is that of understanding the forces that structure plant communities and allow species to coexist. We are implementing a variety of studies designed to determine how plant communities regenerate, compete, and interact in forests, grasslands, and old fields. We are also open to new research questions and approaches within this general framework and there are several projects for which we are still seeking incoming graduate students. Interested potential graduate students and undergraduates: Contact me via e-mail (Schnitzer@uwm.edu) to discuss your research interests and how you can become a member of our group. Please include your CV and a brief statement of your research interests.
Forest Regeneration and the Maintenance of Species Diversity
How do forests regenerate and what mechanisms maintain forest diversity? Treefall gaps play a large role in forest regeneration and the maintenance of species diversity (see Schnitzer and Carson 2001, listed below). However, there are many plant-plant interactions occurring in treefall gaps that are ignored by the simplified model of gap-phase regeneration.
We are examining a subset of these interactions to determine what role, if any, they play in gap-phase regeneration and the maintenance of species diversity. Most of this work is currently being conducted at Barro Colorado Island, Panama (BCI), and there are opportunities for graduate research on these projects. There are additional opportunities for related or parallel experiments in temperate forests at the University of Wisconsin - Milwaukee.
Plant Competition
How do plants compete in terrestrial communities? We know that plants compete for resources in most terrestrial ecosystems; however, a less obvious issue is whether plants compete more for above-ground resources (primarily light) or for below-ground resources (water and nutrients)? The answer to this question depends on the most limiting resource in any particular environment. For example, plants in many grasslands, where light is abundant, are probably competing more for below-ground resources than for light. In forests, however, light is very low in the understory, and thus plants in these systems are thought to be light limited.
We are investigating the relative importance of above- versus below-ground competition between plants in tropical forests. Currently, our studies involve liana versus tree competition; I am interested in expanding this work to include liana versus liana and tree versus tree competition.
The Community Ecology of Lianas
How do lianas add to forest dynamics, diversity, and complexity? Lianas (woody vines) are an abundant and diverse group of plants in forests throughout the world, particularly in the tropics. Lianas play a vital role in many aspects of forest dynamics, including contributing substantially to the overall species diversity in tropical forests, suppressing tree regeneration, increasing tree mortality, providing a valuable food source for animals, and physically linking trees together, thereby providing canopy-to-canopy access for arboreal animals (see papers listed below - Schnitzer and Bonger 2002 provides the best general overview).
We are particularly interested in the impact of lianas on forest regeneration and the processes that maintain liana diversity and control their distribution throughout tropical and temperate forests. Currently, we have underway a number of studies in Panama, Costa Rica, and in Wisconsin, including a large study on Barro Colorado Island, Panama, funded by the National Science Foundation (NSF). Lianas are an important component in forests and there are opportunities for graduate and undergraduate research in this area.
Liana sampling methods. Thanks, in part, to grants from the National Science Foundation (NSF) and the National Center for Ecological Analysis and Synthesis (NCEAS), we have written a number of papers designed to standardize liana sampling protocols and to quantify the differences between alternative methods for estimating liana abundance, basal area, and biomass.
Gerwing, J.J., S.A. Schnitzer, R.J. Burnham, F. Bongers, J. Chave, S.J. DeWalt, C.E.N. Ewango, R. Foster, D. Kenfack, M. Martinez-Ramos, M. Parren, N. Parthasarathy, D.R. Perez-Salicrup, F.E. Putz and D.W. Thomas (2006). A standard protocol for liana censuses. Biotropica 38: 256-261. Abstract. PDF.
Schnitzer, S.A., S. Rutishauser, S. Aguilar. Supplemental protocol for liana censuses. Forest Ecology and Management, 2008. PDF.
** See also the Appendix, which is a field-version of the liana sampling protocol that concisely summarizes both Gerwing et al. 2006 and Schnitzer et al. 2008.
Schnitzer, S.A., S.J. DeWalt, and J. Chave (2006). Censusing and measuring lianas: a quantitative comparison of the common methods. Biotropica, 38: 581-591. Abstract. PDF.
Kurzel, B.P., S.A. Schnitzer, and W.P. Carson (2006). Predicting liana crown location from stem diameter in three Panamanian forests. Biotropica 38: 262-266. Abstract. PDF.
Parren, M.P.E., F. Bongers, G. Caballé, J. Nabe-Nielsen, and S.A. Schnitzer (2005). On censusing lianas: a review of the issues. Pages 41-58 in: Forest Climbing Plants of West Africa: Diversity, Ecology, and Management. Bongers, F., M.P.E. Parren, and D. Traore, editors. CABI Publishing, Wallingford.
2008
Schnitzer, S.A., R.A. Londré, J. Klironomos, and P.B. Reich (2008). Biomass and toxicity responses of poison ivy (Toxicodendron radicans) to elevated atmospheric CO2: Comment. Ecology, 89: 581-585. PDF.
Schnitzer, S.A., S. Rutishauser, S. Aguilar (2008). Supplemental protocol for liana censuses. Forest Ecology and Management, 255: 1044-1049. PDF.
Paine, C.E.T., K.E. Harms, S.A. Schnitzer, W.P. Carson (2008). Weak competition among tropical tree seedlings: implications for species coexistence. Biotropica, in press.
Mascaro J., K. Becklund, F. Hughes, S.A. Schnitzer (2008). Limited native plant recruitment in exotic-dominated forests in Hawai’i. Forest Ecology & Management, in press.
Garrido-Pérez, E.I., J.M. Dupuy, R. Durán-García, G. Gerold, S.A. Schnitzer, M. Ucan-May (in press). Structural effects of lianas and hurricane wilma on trees in Yucatan Peninsula, Mexico. Journal of Tropical Ecology.
Carson, W.P. and S.A. Schnitzer, Editors (2008). Tropical Forest Community Ecology. Blackwell Publishing, Oxford. In press. 517 pp.
Schnitzer, S.A. and W.P Carson (2008). Tropical forest community ecology: scope of the book and key contributions. Pages: 3-8 in: Tropical Forest Community Ecology, Carson, W.P. and Schnitzer, S.A., eds. Blackwell Publishing, Oxford.
Schnitzer, S.A., J. Mascaro, W.P Carson (2008). Treefall gaps and the maintenance of species diversity in tropical forests. Pages: 196-209 in: Tropical Forest Community Ecology, Carson, W.P. and Schnitzer, S.A., eds. Blackwell Publishing, Oxford.
Carson, W.P., J. Anderson, E. Leigh, S.A. Schnitzer (2008). Challenges Associated with Testing and Falsifying the Janzen-Connell Hypothesis: A Review and Critique. Pages: 210-241 in: Tropical Forest Community Ecology, Carson, W.P. and Schnitzer, S.A., eds. Blackwell Publishing, Oxford.
HilleRisLambers, J., W.S. Harpole, S.A. Schnitzer, D. Tilman, P.B. Reich (resubmitted after minor revision). The effects of elevated CO2, nitrogen deposition and declining diversity on seed production of prairie grasses and forbs. Ecology.
2007
Mascaro, J. and S.A. Schnitzer (2007). Rhamnus cathartica (common buckthorn) as an ecosystem dominant in southern Wisconsin forests. Northeastern Naturalist, 14: 387-402.
Dickie, I.A., S.A. Schnitzer, P.B. Reich, and S.E. Hobbie (2007). Is oak establishment in old fields and savannas context dependent? Journal of Ecology, 95: 309-320.
Dickie, I.A., R.A. Montgomery, P.B. Reich, and S.A. Schnitzer (2007). Physiological and phenological responses of oak seedlings to oak forest soil in the absence of trees. Tree Physiology, 27: 133-140.
2006
Schnitzer, S.A., S.J. DeWalt, and J. Chave (2006). Censusing and measuring lianas: a quantitative comparison of the common methods. Biotropica, 38: 581-591. Abstract. PDF.
Kurzel, B.P., S.A. Schnitzer, and W.P. Carson (2006). Predicting liana crown location from stem diameter in three Panamanian forests. Biotropica 38: 262-266. Abstract. PDF.
Gerwing, J.J., S.A. Schnitzer, R.J. Burnham, F. Bongers, J. Chave, S.J. DeWalt, C.E.N. Ewango, R. Foster, D. Kenfack, M. Martinez-Ramos, M. Parren, N. Parthasarathy, D.R. Perez-Salicrup, F.E. Putz and D.W. Thomas (2006). A standard protocol for liana censuses. Biotropica 38: 256-261. Abstract. PDF.
Mascaro, J. and S.A. Schnitzer (2006). Structuring of forest plant communities through variable disturbance severity. Invited chapter in Ecological Research. Pages 1-27 in: New Developments in Ecological Research, A.R. Burke, editor. NOVA Science Publishers, New York.
2005
Schnitzer, S.A., M. Kuzee, and F. Bongers (2005). Disentangling above- and below-ground competition between lianas and trees in a tropical forest. Journal of Ecology, 93: 1115-1125. Abstract. PDF.
Dickie, I.A., S.A. Schnitzer, P.B. Reich, and S.E. Hobbie (2005). Spatially disjunct effects of co-occurring competition and facilitation. Ecology Letters, 8: 1191-1200. Abstract.
Andrade, J.L., F.C. Meinzer, G. Goldstein, and S.A. Schnitzer (2005). Water uptake and transport in lianas and co-occurring trees of a seasonally dry tropical forest. Trees: Structure & Function, 19: 282-289. Abstract.
Schnitzer, S.A. and F. Bongers (2005). Lianas and gap-phase regeneration: implications for forest dynamics and species diversity. Invited chapter in : Forest Climbing Plants of West Africa: Diversity, Ecology, and Management. Bongers, F., M.P.E. Parren, and D. Traore, eds. CABI Publishing, Wallingford.
Parren, M.P.E., F. Bongers, G. Caballé, J. Nabe-Nielsen, and S.A. Schnitzer (2005). On censusing lianas: a review of the issues. Pages 41-58 in: Forest Climbing Plants of West Africa: Diversity, Ecology, and Management. Bongers, F., M.P.E. Parren, and D. Traore, editors. CABI Publishing, Wallingford.
Schnitzer,
S.A. (2005). Determining the factors controlling liana
abundance in tropical forests: disturbance versus edaphic
factors. Inside CTFS, Summer 2005.
2004
Schnitzer, S.A., M.P.E. Parren, and F. Bongers (2004). Recruitment of lianas into logging gaps and the effects of pre-harvest liana cutting in a lowland forest in Cameroon. Forest Ecology and Management 190: 87 - 98. Abstract. PDF.
Mascaro, J., S.A. Schnitzer, and W.P. Carson (2004). Liana diversity, abundance, and mortality in a tropical wet forest in Costa Rica. Forest Ecology and Management 190: 3 - 14. Abstract. PDF.
Holmgren, M. and S.A. Schnitzer (2004). Science on the rise in developing countries. PLoS Biology 2: 10-13. Abstract. PDF.
Pérez-Salicrup, D.R., S.A. Schnitzer and F.E. Putz (2004). Community ecology and management of lianas. Forest Ecology and Management, 190: 1-2.
Stevens, M.H.H., D. Bunker, S. A. Schnitzer and W.P. Carson (2004). Declining plant species richness along a nutrient gradient is not due to seed limitation. Journal of Ecology 92: 339 - 347.
2003
Carson, W.P. and S.A. Schnitzer (2003). Nouragues: Deep forest ecology. Book review: Nouragues: Dynamics and Plant-animal Interactions in a Neotropical Rainforest. Ecology 84: 1340-1341.
2001
2000
Schnitzer, S.A., J.W. Dalling and W.P. Carson (2000). The impact of lianas on tree regeneration in tropical forest canopy gaps: Evidence for an alternative pathway of gap-phase regeneration. Journal of Ecology 88: 655 - 666. Abstract. PDF.
Schnitzer, S.A. and W.P. Carson (2000). Have we missed the forest because of the trees? Trends in Ecology and Evolution 15: 376 - 377. PDF.
DeWalt, S.J., S.A. Schnitzer and J.S. Denslow (2000). Density and diversity of lianas along a seasonal tropical forest chronosequence in central Panama. Journal of Tropical Ecology 16: 1 - 19. Abstract.
Schnitzer, S.A. and R.K. Neely (2000). Criticism of the litterbag technique for the study of aquatic plant decay: Suppression of epiphytic algal biomass. Archiv fur Hydrobiologie 148: 433 - 440.
1999
Schnitzer, S.A. and W.P. Carson (1999). Tropical environments. Invited chapter in The Encyclopedia of Environmental Sciences, Alexander, D.E. and R. Fairbridge. (editors). McGraw-Hill Publishing, pp. 605 - 609.
Books and Journals
Carson, W.P. and S.A. Schnitzer, editors (2008). Tropical Forest Community Ecology. Blackwell Publishing, Oxford. 517 pp.
Pérez-Salicrup, D.R., S.A. Schnitzer, and F.E. Putz, guest editors (2004). Community Ecology and Management of Lianas in Tropical Forests. Special Issue of Forest Ecology and Management 190.
Stevens, M.H.H., Z.T. Long, S.A. Schnitzer, D.E. Bunker, R. Collins, A. Bledsoe, and W.P. Carson (2003). Testing Ecological Theory. University of Pittsburgh. Online ecology laboratory manual: http://www.pitt.edu/~ecology/manual.html.
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