[ECOLOG-L] planned contrasts replacing 2-way ANOVA
I am planning a 2x2 factorial experiment whe Dear list members, I am planning a 2x2 factorial experiment where I record several response variables to test several hypotheses. Some of these hypotheses can be tested using the usual 2-way ANOVA. That is, the significance or non significance of the two main effects and their interaction is expected to provide sufficient information to draw conclusions regarding these hypotheses. However, another hypothesis focuses on one of the four treatment combinations, and would be best approached by comparing this focal treatment with the other three. However, if I use the 2-way ANOVA, some possible results may be inconclusive, and require further post hoc analyses with a reduced threshold for significance. Since my a-priori hypothesis calls for 3 specific contrasts, it makes statistical sense to me that I can skip the 2-way ANOVA and only perform these 3 contrasts without reducing the significance threshold. The logic behind this is that these 3 planned contrasts replace the 3 component tests of the 2-way ANOVA procedure (2 for the main effects and one for their interaction) that are each always done without any change to the significance threshold. Though I have found support for this approach on online statistics lectures notes, I have never seen it taken in any published study, and I wonder if it is indeed kosher (and if it can be expected to pass reviewers). I would highly appreciate input on this, and especially references to back this approach in case it is valid. Thank you very much, Asaf
[ECOLOG-L] Ph.D. Assistantship: Spatial Ecology and Epidemiology of White-tailed Deer
The Cooperative Wildlife Research Laboratory, Southern Illinois University at Carbondale is inviting applications for a PhD-level Graduate Research Assistantship beginning January 2011 (or earlier). Assistantships are on a 12 month basis, with competitive stipend plus full tuition waiver and support for research activities. For more information about our graduate program, please see the home pages of the Wildlife Lab ( http://www.siu.edu/~wildlife/) and the Zoology Department ( http://www.science.siu.edu/zoology/index.html) This project will examine short- and long term movement patterns of white-tailed deer in Illinois, especially group cohesion and inter-group interactions, in the context of potential disease spread. The successful candidate have the opportunity to take advantage of extensive existing datasets of movement data as well as initiate new field studies. This project will also provide the successful applicants opportunities to develop and apply mathematical modeling and other quantitative skills. Graduate studies will lead to a Ph.D. in Zoology or Ecology at Southern Illinois University. A completed Master's Degree and competitive GPA and GRE scores are required. Applicants with backgrounds in wildlife biology, ecology, and/or zoology are encouraged to apply. Prior field experience and coursework or experience in mathematics, ecological modeling, statistics, or computer science are desirable. Provide CV, transcripts, and contact information for at least 3 references by July 31, 2010 to: Eric Schauber schau...@siu.edu Wildlife Ecologist -- Coop. Wildlife Research Lab Associate Professor of Zoology Southern Illinois University Carbondale (618) 453-6940 (618) 453-6944 (fax)
[ECOLOG-L] The Year in Ecology and Conservation Biology temporarily open access
Dear Colleagues, Wiley-Blackwell has just provided open access to the 2008 and 2009 volumes of our annual series of reviews, The Year in Ecology and Conservation Biology, published under the Annals of the New York Academy of Sciences. The links are as follows: http://www3.interscience.wiley.com/journal/119880045/issue http://www3.interscience.wiley.com/journal/122343143/issue We're told they'll remain open access for one year. Rick * Richard S. Ostfeld, Ph.D. Senior Scientist Cary Institute of Ecosystem Studies Box AB, 2801 Sharon Turnpike Millbrook, NY 12545 USA 845 677-7600, ext 136 rostf...@caryinstitute.org http://ecostudies.org/people_sci_ostfeld.html FORTHCOMING BOOK: LYME DISEASE: THE ECOLOGY OF A COMPLEX SYSTEM http://www.amazon.com/Lyme-Disease-Ecology-Complex-System/dp/0195388127/ref=sr_1_2?ie=UTF8s=booksqid=1278436447sr=1-2 *
[ECOLOG-L] 5 Phd Assistantships on Socio-ecological Resilience in Hojancha Costa Rica.
Chorotega Biological Corridor-Hojancha Team PhD Assistantship Announcements Interdisciplinary PhD Research Assistantships in Landscape Ecology and Ecosystem Service Science, Entomology, Regional Planning and Sustainable Communities, Social Systems and Resilient Livelihoods, and Environmental and Natural Resource Economics of the Chorotega Biological Corridor, a crucially important Mesoamerican landscape. Up to five Ph.D. research assistantships will be available to join a collaborative team working on ecological, socio-economic, and institutional aspects of sustainable production, conservation, and sustainable rural livelihoods within the Hojancha region of Costa Rica. The linked dissertation projects will work in a region that faces a variety of natural resource management problems and where landuse changes affect, positively or negatively, the provision of ecosystem services for which increasing demand exists. With funding from the National Science Foundation’s Integrative Graduate Education and Research Traineeship program (IGERT), fellows will pursue disciplinary research important for the overall theme, and work together to identify and address interdisciplinary issues critical for effective policy development, institution building, management planning, and implementation. The team will interact with members of five other IGERT-funded student/faculty teams pursuing similar objectives in other ecosystems in Costa Rica and Idaho in which sustainability and conservation in the face of changing conditions and pressures are desired. PhD Assistantship in Landscape Ecology and Ecosystem Service Science. Seeking a highly motivated and qualified student to study the integration of landscape ecology in landuse planning, with a special focus on spatially explicit ecosystem services. Conservation in Latin America is increasingly being driven by social-ecological drivers. Forest restoration and conservation in the Chorotega Biological Corridor has largely been driven by a strong desire by local stakeholders to reduce system vulnerability to annual droughts and severe storm events. However, a concurrent objective of the corridor is to ensure functional biological connectivity between reserves and protected areas in the region. For example, recent studies suggest that pollination and pest control services at the local scale are spatially dependent on broader scales. With a landscape ecology and ecosystem services approach, the successful candidate will work with local communities, as well as other team members, to prioritize ecosystem services are in the region. The project will include GIS analyses to determine how landuse, including conservation units, can be spatially arranged to maximize the provisioning of bundled ecosystem services. The successful candidate will have a strong background in landscape ecology, GIS and modeling. The candidate must also demonstrate the ability to work in a team setting, integrating both the human and ecological dimensions of ecosystem services. In addition, the student will conduct collaborative research to examine interdisciplinary aspects of ecological and social resilience in the dynamic, human-dominated landscape that constitutes the Hojancha region with team members in fields such as entomology, landscape ecology, regional planning, rural sociology, and environmental and natural resource economics. Contact Alex Fremier (afrem...@uidaho.edu) and Fabrice De Clerck (fdecle...@catie.ac.cr). PhD Assistantship in Entomology and Landscape Ecology. Seeking a highly motivated and qualified student to pursue studies on communities of arthropods in diverse landuses, including forest and pastures within the Chorotega Biological Corridor. Arthropods are excellent indicators of ecosystem health, but have been studied minimally following conservation efforts in the region. Research will focus on a combination of the following or related topics: 1) assessment of ecosystem services provided by arthropods, 2) examination of the impact of diverse landuses including pastures and forest lands on arthropod abundance and dispersal, and 3) determination of the effect of land management practices and landscape factors including spatial scales, on arthropod biodiversity. In addition, the student will conduct collaborative research to examine interdisciplinary aspects of ecological and social resilience in the dynamic, human-dominated landscape that constitutes the Hojancha region with team members in fields such as ecosystem service science, landscape ecology, regional planning, rural sociology, and environmental and natural resource economics. Contact Nilsa Bosque-Pérez (nbos...@uidaho.edu), Steve Cook (steph...@uidaho.edu), and Fabrice De Clerck (fdecle...@catie.ac.cr). PhD Assistantship in Regional Planning and Sustainable Communities. Seeking a highly motivated and qualified student with a background in urban and
[ECOLOG-L] Two Postdoctoral research positions
Harvard Forest – Harvard University Two Postdoctoral research positions Theoretical Ecology / Conservation Biology Two-year positions, based in Petersham, MA Position 1: Animal movement in heterogeneous environments: Understanding animal movement in relation to environmental features is central to predicting consequences of habitat loss and alteration on wildlife populations. Nonetheless, understanding how animals move in heterogeneous environments is one of the most challenging problems in ecology. Responsibilities: The successful candidate for this position will help develop a new model system for investigating how animals move through mixed use (natural- and human-dominated) landscapes. The focal system for this study will be selected in collaboration with the successful candidate but must be: (1) well-suited to analysis with mechanistic movement models (random walk and diffusion models, extended to include responses to landscape features); (2) relevant to conservation of the New England landscape; (3) complementary to past and ongoing research in the Crone lab, which has focused mostly on ecology of wildflowers, butterflies, and bees, but includes research on spatial population dynamics of diverse taxa (trees, amphibians, songbirds, small mammals). Required Experience and Skills: The successful candidate for this position will be a biologist or ecologist with basic quantitative skills (familiarity with principles of algebra, calculus and probability) and strong interest in developing expertise at the interface of empirical and mathematical ecology. I am open to applications from candidates trained in the mathematical sciences with strong interest in ecology and some experience in field biology. Position 2: “Colored” stochasticity and plant population dynamics: Environmental stochasticity plays a central role in population and evolutionary dynamics, but stochastic processes are difficult to quantify from typical short (3-10 year) demographic studies. Variation in vital rates is usually modeled as “white noise”, meaning that rates in one year are not correlated with rates in the recent past or recent future. However, there are good reasons to believe that variation may be “red”, meaning good years tend to follow good years (due to trends in environmental conditions or carry-over through physiological condition), and there is evidence that some species experience “blue” noise, meaning bad years tend to follow good years (for example, if reproduction depletes stored resources). Responsibilities: The successful candidate for this position will explore statistical approaches for estimating correlations and serial correlations among vital rates from demographic studies for perennial plants, explore consequences of empirical patterns for population dynamics, and assist with field research. Required Experience and Skills: (1) knowledge of statistical computing (e.g., graduate degree in statistics or applied mathematics), including familiarity with generalized linear mixed models and hierarchical Bayesian models; (2) interest in ecology, botany and conservation biology; (3) ability to participate in demographic studies in Montana and Finland (6-10 weeks travel/year). Coding for this position will be in R, but I am open to candidates with strong computational skills whose primary experience to date is in other languages/platforms. Both positions are open until filled. The successful candidates could begin as soon as September 2010, and preference will be given to candidates who can participate in field work during spring/summer 2011. Both positions are funded for two years, and based at Harvard Forest (http://harvardforest.fas.harvard.edu/). To apply, send CV (pdf format) and names of 3 references to Elizabeth Crone: Through December 2010: Associate Professor, Wildlife Biology Program University of Montana Missoula MT 59812 US elizabeth.cr...@cfc.umt.edu Effective January 2011: Senior Ecologist, Harvard Forest Harvard University Petersham MA 01366 USA Applicants who will be attending the 2010 ESA meetings in Pittsburgh can arrange to discuss the position during the meeting. Harvard University is an Equal Opportunity/Affirmative Action employer. Applicants from groups traditionally underrepresented in science including minority and women candidates are encouraged to apply. More information about post doctoral benefits are available at: http://www.postdoc.harvard.edu/index.html
[ECOLOG-L] Announcing ClimatePrep.org a new adaptation focused blog
Dear Colleagues, It is my pleasure to announce the official launch of a new climate change adaptation focused blog, ClimatePrep.orghttp://www.ClimatePrep.org. Through first-hand accounts and expert interviews, the site aims to illustrate climate change adaptation through on the ground adaptation projects, explorations of adaptation concepts, and tracking firsthand the progress of adaptation in the international policy arena. At this time we would also like to invite the submission of new material. If you have an adaptation related project, event, or concept that you would be interested in writing about please feel free to get in touch with me at eliot.lev...@wwfus.orgmailto:eliot.lev...@wwfus.org. The main page: www.climateprep.orghttp://www.climateprep.org Some recent posts: Community Solutions for Sea Turtle and Coastal Protection http://www.climateprep.org/2010/06/09/community-solutions-for-sea-turtle-and-coastal-protection/ http://www.climateprep.org/2010/07/02/modeling-future-coastlines/ Building Mangrove Resiliencehttp://www.climateprep.org/2009/12/04/building-mangrove-resilience-to-climate-change/ http://www.climateprep.org/2009/12/04/building-mangrove-resilience-to-climate-change/ From Analogy to Chronologyhttp://www.climateprep.org/2009/11/30/from-analogy-to-chronology/ http://www.climateprep.org/2009/11/30/from-analogy-to-chronology/ Best, Eliot Levine World Wildlife Fund | 1250 24th Street, NW Washington, DC 20037 | 202.495.4596 | eliot.lev...@wwfus.org |skype: Eliot.Levine| www.worldwildlife.orghttp://www.worldwildlife.org/ |www.ClimatePrep.org
Re: [ECOLOG-L] planned contrasts replacing 2-way ANOVA
Orthogonal sets of a priori contrasts do not require adjustment of p-values because they ARE simply components of the ANOVA. That is why they are so powerful for hypothesis testing. They are also greatly under utilized. William J. Resetarits Program Director Population and Community Ecology Cluster Division of Environmental Biology National Science Foundation 4201 Wilson Blvd., Suite 635 wrese...@nsf.gov Voice (703) 292-7184 Fax (703) 292-9064 -Original Message- From: Ecological Society of America: grants, jobs, news on behalf of Asaf Sadeh Sent: Wed 7/7/2010 11:20 AM To: ECOLOG-L@LISTSERV.UMD.EDU Subject: [ECOLOG-L] planned contrasts replacing 2-way ANOVA I am planning a 2x2 factorial experiment whe Dear list members, I am planning a 2x2 factorial experiment where I record several response variables to test several hypotheses. Some of these hypotheses can be tested using the usual 2-way ANOVA. That is, the significance or non significance of the two main effects and their interaction is expected to provide sufficient information to draw conclusions regarding these hypotheses. However, another hypothesis focuses on one of the four treatment combinations, and would be best approached by comparing this focal treatment with the other three. However, if I use the 2-way ANOVA, some possible results may be inconclusive, and require further post hoc analyses with a reduced threshold for significance. Since my a-priori hypothesis calls for 3 specific contrasts, it makes statistical sense to me that I can skip the 2-way ANOVA and only perform these 3 contrasts without reducing the significance threshold. The logic behind this is that these 3 planned contrasts replace the 3 component tests of the 2-way ANOVA procedure (2 for the main effects and one for their interaction) that are each always done without any change to the significance threshold. Though I have found support for this approach on online statistics lectures notes, I have never seen it taken in any published study, and I wonder if it is indeed kosher (and if it can be expected to pass reviewers). I would highly appreciate input on this, and especially references to back this approach in case it is valid. Thank you very much, Asaf
Re: [ECOLOG-L] planned contrasts replacing 2-way ANOVA
There should be no problem with using a priori contrasts. No adjustment of the p-value is required, UNLESS the contrasts are non-orthogonal, which is often the case when more than two hypothesis tests. If the contrasts are not orthogonal, some type of adjustment (e.g. Bonferroni) is required, which will lower the power you would otherwise gain with a planned contrast. Casey - Casey terHorst Ecology Evolution Program Department of Biological Science Florida State University 319 Stadium Drive King Life Science Building Tallahassee, FL 32306-4295 terho...@bio.fsu.edu Quoting Asaf Sadeh asaffi...@yahoo.com: I am planning a 2x2 factorial experiment whe Dear list members, I am planning a 2x2 factorial experiment where I record several response variables to test several hypotheses. Some of these hypotheses can be tested using the usual 2-way ANOVA. That is, the significance or non significance of the two main effects and their interaction is expected to provide sufficient information to draw conclusions regarding these hypotheses. However, another hypothesis focuses on one of the four treatment combinations, and would be best approached by comparing this focal treatment with the other three. However, if I use the 2-way ANOVA, some possible results may be inconclusive, and require further post hoc analyses with a reduced threshold for significance. Since my a-priori hypothesis calls for 3 specific contrasts, it makes statistical sense to me that I can skip the 2-way ANOVA and only perform these 3 contrasts without reducing the significance threshold. The logic behind this is that these 3 planned contrasts replace the 3 component tests of the 2-way ANOVA procedure (2 for the main effects and one for their interaction) that are each always done without any change to the significance threshold. Though I have found support for this approach on online statistics lectures notes, I have never seen it taken in any published study, and I wonder if it is indeed kosher (and if it can be expected to pass reviewers). I would highly appreciate input on this, and especially references to back this approach in case it is valid. Thank you very much, Asaf
