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Successful Ecologist Bio’s Groups: Oct 1 – Ecosystem – Lubchenco Oct 8 –Community - Callaway Oct 15 – Population – Ilkka Hanski Oct 22 – Organismal – E. Mayr Nov 3 – Free agents – M. Turner, G. Daily, S. Brown, Mary Power, Martin Wikelski . Journal Review system:
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Successful Ecologist Bio’s Groups: Oct 1 – Ecosystem – Lubchenco Oct 8 –Community - Callaway Oct 15 – Population – Ilkka Hanski Oct 22 – Organismal – E. Mayr Nov 3 – Free agents – M. Turner, G. Daily, S. Brown, Mary Power, Martin Wikelski
Journal Review system: Depends on “impact factor and prestige of journal… (acceptance rate can vary from 10% to 75% - ultimately) Most journals - 2 anonymous reviews and an associate editor to mediate/decide Reviews take from 1 week (bad news if Science/Nature) to 6 months! High profile – initial, very harsh pre-screening prior to full review If the 2 reviews are split, often a revision goes to a 3rd reviewer… Few (no) double blind reviews in Ecological Journals Very few papers are accepted without revision and re-review
There is an appeal system… usually not successful (Unless Hutchinson writes for you!) So, does this mean that if the referees for one of my articles don't like my ideas, in order to get published all I have to do is butter up to one of the bigwigs and they will get my paper in? Does having “Bigwigs” in your corner help? – Yes! But even without them, you can learn a lot from how the editor was dealt with…
The rejection – • Not enough data given the speculation • Sample size of 1!!! (The audacity to generalize!!) • “Desk produced” = Arm chair ecology • Premature… • Hutchinson’s strategy – • Sympathy for the editor – no blame cast… • Some of the ideas are mine, so it partially my fault… • Lindeman is young and needs a job… • Disagreement is not sufficient grounds for rejection…see my earlier reviews • Sample size of 1 is a plus – such detailed information is necessary… • Lack of data is a plus – it will spur others to fill in the gaps… • New and wonderful data will result from this paper – even if the ideas are wrong • Outcome – • Still no strong support for the revision… • Editor: Time is the great sifter in these matters and it alone will judge the question.
I only hope that when I submit my paper in to be published some day that I get a warmer response from the referees. A phenotype all publishing scientists must have: Thick skin…
Today: • Community Ecology • Overview • Brief history • Selective examples • Background for papers
Ecological Hierarchy • • Organismal ecology = autecology: • Evolutionary ecology, Behavior, physiology, morphological • adaptations of individuals. • • Population: group of conspecific individuals: • Population regulation, intraspecific interactions. • • Community: multiple species in same area. • Interplay of multiple species, interspecific interactions. • • Ecosystem: biotic and abiotic factors in a bounded but open system. • Energy flow, recycling. • Landscape, Global, Macroecology… • Class Poll?
Community Ecology is the quintessential study of ecology… It is the proprietary domain of ecologists… (very little sharing or co-option by other sciences or managers) Traditional Ecological Hierarchy • Organismal ecology – strong links to physiology, evolution, systematics… (Endangered Species Act) • Population – strong management implications…Resource management • Community – the how and why of plants, animals and microbes in space and time, and their interactions (biotic and abiotic)…not very “applied” • Ecosystem – Interdisciplinary combining geology, soils, atmospheric studies…also strong management links…Ecosystem services, Ecosystem management…
Within vs. Among Trophic Level Approaches… Focus on the biota….
In Ecological hierarchy, typically mechanistic explanations come from below… Genetics, Ecophysiology, Demography used to explain community patterns… “Hierarchical one-upmanship” = One scientist’s mechanism is another’s pattern…. But – community structure has often been ignored in Ecosystem Studies – the black box approach Only recently, have the consequences of altered community composition on ecosystem structure and function been emphasized…
Community Ecology Roots are: Pattern Mechanism Observation Theory ---------------------------------------------------------------------------------- Focus is on “interactions”….
Ghosts of paradigms past - The degree of interaction among species and populations in communities differentiates the more Holistic perspectives of communities from the more Individualistic perspective (think Clements vs. Gleason). Community: An association of interacting populations, usually defined by the nature of their interaction and the place in which they live. A community is "an assemblage of species populations which occur together in space and time" (Begon, Harper & Townsend). (Community + environment = 'Ecosystem') Most ecologists today are between these two extremes.
Largest subdiscipline of Ecology at ESA is community ecology (data source: me!) Interests and domain: Historically: Succession, Niche and niche partitioning, community and diversity patterns, Island biogeography…temporal & spatial aspects of community dynamics… Today: Community assembly rules/restoration ecology Trophic interactions Invasive species Biodiversity and ecosystem stability and function Mechanisms of species coexistence in communities Impacts of species loss….conservation issues
Interesting & long history… 1898 - Frederick Clements publishes "The Phytogeography of Nebraska", first American "ecology" book 1899 - Henry Chandler Cowles - studies dune succession and develops “dynamic ecology”, U. of Chicago School 1900-1930 - Clements, with support of the Carnegie Institute publishes numerous volumes on succession, research methods in ecology, phytogeography Early 1900s William Skinner Cooper - a student of Cowles at Chicago, Ph.D. thesis on forests of Isle Royal; studied succession in Glacier Bay; joined University of Minnesota; Rexford Daubenmire was student 1913 - Victor Shelford publishes book on Animal Communities of the Chicago area, Shelford is first president of Ecological Society of America (1915) “Shelford’s law of tolerance” 1926 Henry Allan Gleason - publishes on individualistic hypothesis in ecology
1927 Charles Elton, famous British animal ecologist - refines concepts of ecological niche, proposes negative relationship between diversity and invasion… 1940-78 G.E. Hutchinson - limnologist and zoologist, publishes many influential books and papers, wrote on niche, Ph.D. advisor for Robert MacArthur (Yale School) 1940s-50s John Curtis - developed concept of importance values, strong inductive approaches to vegetation analysis (Wisconsin school) 1956 R.H. Whittaker publishes ordination study of Great Smoky Mountains; becomes major influence in ordination, gradient analysis and succession 1950s- 1960s Robert MacArthur, mathematical/theoretical ecologist, developed island biogeography theory, Ph.D. student of Hutchinson.
Thus, major scientists in this subdiscipline of ecology: Historically-- F. Clements H. Gleason G.E. Hutchinson E. Lucy Braun (1st female ESA president and award named after her) R. MacArthur R. Whittaker More contemporary--- Connell (Intermediate Disturbance Hypothesis) Paine (Food webs and Keystone Species concept) Grime (Species trade-offs and coexistence) Tilman (Resource ratio hypothesis for species coexistence and Biodiversity-Ecosystem function studies) Hubble – Neutral Theory
Historically: Strong interest in describing and categorizing communities GRADIENT ANALYSIS (Wisconsin School and Whittaker) Gradient analysis - the portrayal and interpretation of the abundances of species along environmental gradients of physical conditions. • Examples of environmental gradients: • plants: • soil nitrogen • soil temperature • soil moisture • soil depth • annual precipitation • animals: • prey availability • soil texture (for burrowing animals) • height above low tide (for intertidal organisms).
Classification and Ordination: Objective ways to seek trends and patterns in community data. Classification is the allocation of species to groups so that members of the same group share many species in common, and members of different groups share relatively few species. This assumes species can be grouped into relatively distinct groups (communities have abrupt boundaries).
Ordination is an alternative approach to analysis and is based on the idea that the environment, and therefore species composition, changes gradually, rather than abruptly. Ordination describe gradients in species composition and often relate these to known or suspected environmental gradients.
The purpose of ordination is to assist one in uncovering pattern in data sets that are otherwise too complicated to interpret. Ordination should identify the most important dimensions in a data set, and minimize the "noise", in order to show these patterns. However, ordination techniques are meant primarily as exploratory tools,not for testing hypotheses. Ordination of plant communities of the Jackson Purchase Region of Kentucky: A. Bottomland Hardwoods; B. Swamps; C1. Flatwoods-Wet Phase; C2. Flatwoods-Dry Phase; D. Oak-Hickory (Open or Savanna-Like); E. Oak-Hickory (White Oak and/or Black Oak); F. Mixed Mesophytic; G. Transitional (disturbed or successional); H. Former Barrens.
Concepts of Community Ecologists: CENTRAL CONCEPT - Niche: An organism’s place in the community and what environmental factors limit it to that space (Grinnell) – environmental emphasis An organism's role in its community (Elton) – species emphasis An organism's "ecological position in the world" (Vandermeer 1972). Today: environmental requirements for species as well as the impact of a species on other organisms in the community (Leibold 1995 Ecology)
As always seems to be the case… Despite its strong synthetic role and its crucial importance in community theory, the niche concept remains unclear: "most [ecologists] would agree that niche is a central concept of ecology, even though we do not know exactly what it means" (Real and Levin 1991). The word niche is a pseudocognate. A "pseudocognate" is a term in which each individual who uses it feels that all readers share his/her own intuitive definition, but in reality each individual has their own distinct definition.
A long running major interest: explaining why so many species co-exist and patterns of species diversity • Many concepts based on the Equilibrium paradigm… • Gause – competitive exclusion principle - two species cannot coexist if they share the same resource (Gause 1934) • resource partitioning… • Hutchinson – niche (multi-dimensional) can be defined and quantified • Principle of limiting similarity -how different do the niches of two species have to be in order for them to coexist? (1.3 ratio?) • niche partitioning…
Equilibrium paradigm • MacArthur & Wilson – Species area and island biogeography • Paine – Keystone species • Tilman – Resource ratio hypothesis • Non-equilibrium components creep in… • Connell – Disturbance regimes • Ricklefs – Regional vs. local processes and history
Keystone species concept Keystone species is one whose impacts on its community or ecosystem are large and greater than would be expected from its relative abundance or total biomass In contrast, dominant species (foundational species)- trees, giant kelp, prairie grasses, and reef-building corals all have impacts that are large but not disproportionate to their total biomass, and therefore they are not keystone species Keystone species can reduce or increase diversity
Problem with concept: Difficult to quantify Few actual comparative studies Concept important because it convinced managers and conservationists alike that the ecological impact of single species matters. To manage, understand, and restore ecological assemblages, the roles of individual species have to be understood and considered