Lawrence R. Walker and his Primary Succession Studies Xuan Chen BIOL Community Ecology Presentation

Contents Introduction of L. R. Walker His primary succession studies His other research His influence on community ecology studies

Character Intro Ph.D., University of Alaska, Fairbanks, 1985 Stanford University University of Hawaii University of Puerto Rico University of Nevada, professor of Department of Biological Science (1) Succession in plant communities (2) Community responses to disturbance (3) Restoration

Contents Introduction of L. R. Walker His primary succession studies His other research His influence on succession studies

Primary Succession Studies Succession – directional change in community composition at a site, initiated by natural or anthropogenic disturbance, or the creation of a new site. Copy from Dr. Kyle Harms’ slides

Primary Succession Studies

Connell and Slatyer, 1977, The American Naturalist Primary Succession Studies

Disturbance (new habitat) Early succession species Later succession species Facilitate Inhibit Neutral Stable ecosystem Primary Succession Studies Primary successionSecondary succession

Primary Succession Studies Primary succession can be defined as directional changes in plant communities after severe disturbances that leave no soil layers intact, or the creation of a new site. Methods (1) Field observations and experiments (such as artificial fertilization, transplanting and sowing of seeds) (2) Growth experiments under more controlled greenhouse conditions (3) Lab analyses of plant and soil nutrients

Primary Succession Studies Primary succession: nitrogen limited Later, P (and/or other elements) but not nitrogen limited Walker & Syers, 1976, Geoderma

Primary Succession Studies River floodplains in Alaska Volcanic substrates in Hawaii Landslides in Puerto Rico Glacial moraines in Alaska science.nature.nps.gov/im/units/swan/vs/repeat_photo

Primary Succession Studies River floodplains in Alaska Volcanic substrates in Hawaii Landslides in Puerto Rico Glacial moraines in Alaska science.nature.nps.gov/im/units/swan/vs/repeat_photo

Walker et al., 1986, Ecology

Stochastic events Fluvial processes, timing, intensity, and scale of riverine disturbance Life history traits Seed rain

Walker et al., 1986, Ecology High seed rain Low seed rain

Stochastic events Fluvial processes, timing, intensity, and scale of riverine disturbance Life history traits Seed rain Growth rate Life span

Walker et al., 1986, Ecology

Nitrogen fixer Dense litter layer Seeding germination and establishment Snowshoe hareSeeding mortality Thick stands Reduced light intensity Root competitionSeeding growth Allelopathy Primary succession: nitrogen limited, need nitrogen fixer Inhibit

Primary Succession Studies River floodplains in Alaska Volcanic substrates in Hawaii Landslides in Puerto Rico Glacial moraines in Alaska science.nature.nps.gov/im/units/swan/vs/repeat_photo Inhibit

Dryas spruce alder

Seed dispersal spruce alder Dryas

spruce alder Shade out Herbivores and pathogens Allelopathy

Chapin et al., 1994, Ecological Monographs

Life history Species interaction Environmental factors their relative importance changes through succession

Primary Succession Studies River floodplains in Alaska Volcanic substrates in Hawaii Landslides in Puerto Rico Glacial moraines in Alaska science.nature.nps.gov/im/units/swan/vs/repeat_photo Inhibit Complex

Upper zone: nearly complete removal of soil and vegetation Lower zone: heterogeneous mixture of broken plants parts, and soil Islands

Elevation Size Land use history Surrounding vegetation Soil development Biotic interaction

Regionally Locally Stochastic Predictable

Primary Succession Studies River floodplains in Alaska Volcanic substrates in Hawaii Landslides in Puerto Rico Glacial moraines in Alaska science.nature.nps.gov/im/units/swan/vs/repeat_photo Inhibit Complex Scale

Myrica faya Myrica faya Metrosideros polymorpha germination Leaf litter canopy seedling root competition nitrogen Metrosideros polymorpha

severe suitable environmental severity facilitate compete facilitate compete Pioneer species Later species

environmental severity / succession stages facilitate inhibit Pioneer species Later species

Opportunities for studies of succession We can imagine a study that investigates succession after invasion of a non-native as a result of climate change that might be used to suggest restoration measures to protect local biodiversity

Contents Introduction of L. R. Walker His primary succession studies His other research His influence on succession studies

(1) Chronosequences study successionLong term without disturbance

successionLong term without disturbanceDecline phase significant reduction in ecosystem productivity and standing plant biomass

Wardle et al., 2004, Science Later, P (and/or other elements) but not nitrogen limited

biomass richness tree herbaceous

Restoration Succession Site amelioration Development of community structure Nutrient dynamics Species life history traits Species interactions Modeling the transitions between successional stages and how those stages fit together into trajectories (2) Restoration

RestorationSuccession Clarify successional processes Improve the predictability of succession

(3) Invasive ecology (4) Hurricane ecology ……

Contents Introduction of L. R. Walker His primary succession studies His other research His influence on succession studies

Primary succession is complex Study methods Restoration

Thank you

References Bellingham, P.J., Peltzer, D.A., Lawrence R. Walker, L. R Contrasting impacts of a native and an invasive exotic shrub on flood-plain succession. Journal of Vegetation Science 16 (1): Callaway, R.M. and L.R. Walker Competition and facilitation: A synthetic approach to interactions in plant communities. Ecology 78: Chapin, F.S., Walker, L.R., Fastie, C.L., Sharman, L.C Mechanisms of Primary Succession Following Deglaciation at Glacier Bay, Alaska. Ecological Monographs 64:149–175. Myster, R.W., Walker, L R Plant successional pathways on Puerto Rican landslides. Journal of Tropical Ecology 13 (2): Prach, K., Walker, L R Four opportunities for studies of ecological succession. Trends in Ecological and Evolution 26 (3): Shiels, A.B., Walker, L.R Bird perches increase forest seeds on Puerto Rican landslides. Restoration Ecology 11: 1-9. Vitousek, P.M., Walker, L.R Biological invasion by Myrica faya in Hawaii: Plant demography, nitrogen fixation, and ecosystem effects. Ecological Monographs 59: Vitousek, P.M., Walker, L.R., Whiteaker, L.D Nutrient Limitations to plant-growth during primary succession in Hawaii-volcanos National Park. Biogeochemistry 23 (3): Vitousek, P.M., Walker, L.R., Whiteaker, L.D., Muellerdombois, D., Matson P.A Biological invasion by Myrica faya alters ecosystem development in Hawaii. Science 238 (4282): Walker, L. R., Chapin, III. F. S Physiological controls over seedling growth in primary succession on an Alaskan floodplain. Ecology 67: Walker, L.R., del Moral, R Lessons from primary succession for restoration of severely damaged habitats. Applied Vegetation Science 12: Walker, L.R., Bellingham, P.B., Peltzer, D.A Plant characteristics are poor predictors of microsite colonization during the first two years of primary succession. Journal of Vegetation Science 17: Walker, L.R., Clarkson, B.D., Silvester, W., Clarkson, B.R Colonization dynamics and facilitative impacts of a nitrogen-fixing shrub in post-volcanic primary succession. Journal of Vegetation Science 14: Walker, L. R., Zasada, J. C., Chapin, III. F. S The role of life history processes in primary succession on an Alaskan floodplain. Ecology 67: Walker, L.R., Zimmerman, J.K., Lodge, D.J., Guzmán-Grajales, S An altitudinal comparison of growth and species composition in hurricane-damaged forests in Puerto Rico. Journal of Ecology 84: Walker, L.R., Voltzow, J., Ackerman, J.D., Fernandez, D.S., Fetcher, N Immediate impact of Hurricane Hugo on a Puerto Rican rain forest. Ecology 73: Walker, L.R., Zarin, D., Fetcher, N., Myster, R., Johnson, A Ecosystem development and plant succession on landslides in the Caribbean. Biotropica 28: Wardle, D., Walker, L.R., Bardgett, R.D Ecosystem properties and forest decline in contrasting long term chronosequences. Science 305: