Succession Benjy Longworth 42612 Outline Biography Cowles work Plant succession since Cowles r elay floristics vs initial floristic composition Biography 18691939 Born in Kensington Connecticut ID: 1022411
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1. Henry Chandler Cowles andSuccessionBenjy Longworth4/26/12
2. OutlineBiographyCowles’ workPlant succession since Cowlesrelay floristics vs. initial floristic composition
3. Biography1869-1939Born in Kensington, Connecticut1893 – BA from Oberlin College 1898 – PhD in Botany from University of Chicago1899 -1934 – Faculty at U Chicago until retirement 1914 – Helps found Ecological Society of America
4. Main ContributionsPioneered ecology in America“Dynamic” approach to ecologyDescribed in detail the stages of dune successionAutogenic vs. Allogenic
5. A selfless careerFew publicationsInvested much of his time teachingHis largest impact may have been through the work of his students (46/77 influential ecologists between 1900 and 1950)Also spent time advocating conservationResearch was very descriptive, no numbers in his papers
6. Publications1899. The ecological relations of the vegetation on the sand dunes of Lake Michigan. Botanical Gazette 1901. The plant societies of Chicago and vicinity. Botanical Gazette 1901. The influence of underlying rocks on the character of the vegetation. Bulletin of the American Bureau of Geography1908. An ecological aspect on the conception of species. The American Naturalist1909. The Trend of ecological philosophy. The American Naturalist1910. A Textbook of Botany for Colleges and Universities. 1910. The fundamental causes of succession among plant associations.1911. The causes of vegetation cycles. Botanical Gazette1915. The economic trend in botany. Science1926. The succession point of view in floristics.1927. The persistence of praries. Ecology
7. Ecological relations …Dissertation became his most widely known publicationStages of succession = distance from the lakeDescribed abiotic and biotic characteristics of each stage
8.
9. grasses/shrubscottonwood/poplar/basswoodpineoak/mapleNoticed unique vegetation at different stages
10. Embryonic dunesWandering dunesStabilized duneImpact of vegetation on physiography
11. Xeric, sunny, windy, sandyMesic, shaded, less windy,soil Impact of physiography on vegetation
12. View of SuccessionSuccession = mesophication processShallow pond succession
13. Biotic succession (autogenic)Process driven from within Facilitation/InhibitionHumus formationWaterSoil organismsTemperature and aerationShadeTopographic succession (allogenic)Process driven from withoutCreate heterogeneity of successionDisturbance due to erosion and deposition
14. ContemporariesFrederic ClementsClements saw succession as a much more deterministic process than CowlesDriven by facilitation (autogenic)
15. ClementsDirectional change from one plant community to the next until arrival at the climax communityClimax
16. Cowles Made fewer generalizationsFound plant plasticity (presence at several stages)Variable “climax” communityOakMaple
17. Plant succession since CowlesClements 1916 Relay Floristics Odum 1971 Information theoryEgler 1954 Initial CompositionConnell and Slayter 1977Equilibrium HolisticDynamicReductionist“Succession is a variable approaching a variable, not a constant.”- Cowles 1901
18. Relay Floristics ModelOnly one set of species can colonize at a time
19. Initial Floristic CompositionEgler 1954Succession depends on the species that establish initiallyAll species able to establish earlyDifferent growth rates, life spans determine succession
20. Initial Floristics
21. Hibbs 1983
22. Model of succession depends on study systemConnell and Slayter 1977FacilitationInhibitionNeutral
23. Alternative Successional PathwaysImpact of land use early establishmentMesquita 2001
24. Alternative Pathways7 years12 years17 years22 years Blue= Vismia Green = Cecropia