1. Community Ecology BDC321 Pt2 Mark J Gibbons, Room Z108, BCB Department, UWC Tel: 021 959 2475. Email: mgibbons@uwc.ac.za Image acknowledgements – http://www.google.com

2. Some Definitions Environmental Condition Physical environmental variable or factor, that varies in space and time, and to which organisms respond Examples include: Temperature, salinity, moisture, elevation, depth, nitrogen concentration of water, beach grain size etc etc etc Environmental Gradient e.g. Temperature Performance or Abundance Species A Species B Species C Species D Species E Species F Species G Species H Species I Species J

3. Resource Something that is required or used by an organism, the quantities of which can be reduced by the organism Examples include: Dissolved oxygen, sunlight, water, carbon dioxide, mineral nutrients, organisms as food

4. Population A group of individuals of the same species that coexist in space and/or time

5. Population size / density Rate Birth Death K Born Population size / density Numbers Dying Difference = NET Recruitment S-Shaped Growth Curves Characteristic of intra-specific competition N - Shaped K

6. Community? A group of interacting populations of different species that coexist in time/space

7. Outcomes of interactions between two species Inter-specific Interactions -+Predation --Competition 0+Commensalism 0-Amensalism Species BSpecies A ++Mutualism

8. A community as viewed from a predator-prey perspective A group of interacting populations of different species that coexist in time/space

9. A number of other trophic based units also used Community subsets Guild Communities can have very many interacting populations of different species and to study all of them requires a suite of expert taxonomists at the very least. Community ecologists tend to get around this issue by studying subsets of the community

10. Taxocene

11. Morpho-species

12. How big is a community?ANY SCALE Broad patterns in terrestrial vegetation can be recognized at the global scale - BIOMES At this scale, climate is the overwhelming factor that limits vegetation

15. How small is a community?

16. Regional Species Pool Evolutionary Processes Physiological Constraints Historic Events Habitat Selection – Habitat Species Pool Dispersal Ability – Geographic Species Pool Local Community Inter-specific Interactions Rules – a species will only be present if: a)It can disperse there b)Conditions and resources allow it to survive c)Predators and competitors etc don’t preclude it Determinants of Community Composition and Structure

17. Course Aims and Structure Objectives: To train students in the basic theories of community ecology To provide students with the necessary skills to enable them to undertake surveys and identify biological communities To provide students with the necessary skills to enable them to determine those environmental factors contributing to community structure Required Background: Any course on community ecology requires a certain level of background theory and skills - if it is to be successful. For this course, they include a working knowledge of: Measures of central tendency and dispersion MSExcel It is also assumed that students are able to build simple single-species models of population growth and that they have a knowledge of intra-specific competition. As many of you may lack this background, it will be necessary to spend a short period of time completing this work.

18. Approach: The course is a balance between theory, laboratory and field: any person that goes on to work (e.g.) in nature conservation needs to know why data on communities need to be collected, they need to know how to collect the data and then how to analyse the data. They may also need to make informed decisions (often of a management nature) based on the data. As a consequence, any course on community needs to include elements of theory, fieldwork and laboratory simulation, and here the theory and laboratory simulation go very much hand in hand. NB: It is not possible to cover everything in the theory AND develop your field, analytical and report-writing skills. As a consequence, some areas of theory are ignored entirely or are glossed over very superficially. ALL LECTURES AND SUPPLEMENTARY MATERIAL WILL BE PROVIDED ON THE INTERNET AFTER THEY HAVE BEEN PRESENTED

19. Defining a community Summarizing characteristics Examining links Introduction: Definitions Inter-specific Interactions I: Competition Inter-specific Interactions II: Predation Community changes in space and time: Succession Disturbance Effect of Competition in structuring communities Effect of Predation in structuring communities Contents Field & Analytical Theory & Modeling Theory, Modeling and Field

20. Timetable There will be three lectures per week and two practical classes. ALL classes will take place in Z29: it may be necessary to schedule additional classes on Saturday mornings: such classes to start at 08h00. Please note that some official classes will be rescheduled. IT IS EXPECTED THAT YOU WILL ATTEND ALL CLASSES ON TIME

21. Assessments and Deadlines Evaluation will take the form of continuous assessment. This continuous assessment is broken up as follows: Class test (33%) + Practical work (67%) = Course Mark Class Tests The Class test will be held on Thursday 15 April 2010 during periods 2-4: Z29. Students will be tested on ALL material covered up to and including that of Tuesday 13 April 2010. If a re-test is necessary (i.e. more than 35% of the class failed the first test), this will be held on Saturday 8 May 2010 at 08h00 in Z29. ONLY those students that failed the first test will be eligible to sit the re-test, and the better of the two marks will be taken into consideration. Students will be tested on ALL material covered up to and including that of Friday 7 May 2010. Course Mark (60%) + Exam (40%) = Final Mark Prac Exam (30%) + Theory Exam (70%) = Exam Mark

22. Practical Work In this course, the practical component will comprise two evaluations. These are listed below: PLEASE BE ADVISED THAT FACULTY RULES REGARDING PLAGIARISM AND THE SUBMISSION OF LATE ASSIGNMENTS WILL BE UPHELD You will be expected to use Turnitin Poster – 40% towards Practical Mark Preliminary Deadline – Friday 23 April 2010 Final Deadline – Friday 30 April 2010 Report - 60% towards Practical Mark Preliminary Deadline – Monday 12 April 2010 Final Deadline – Friday 7 May 2010

23. Create a poster (size A0) in MS PowerPoint to illustrate one of the following topics: POSTER 1.Mutualism 2.Commensalism 3.Amensalism 4.Parasitism The audience is undergraduate students – Teaching Tool The poster should be based on a published, peer-reviewed scientific paper that CLEARLY illustrates the concept behind the topic OR that CLEARLY shows how the concept can influence biological community structure The poster MUST be professional in appearance The poster will be assessed using a rubric and ALL TEXT must be submitted to Turnitin and the report attached

24. TITLE CONCEPT NOTE & DEFINITION Article Details METHODS RESULTS & DISCUSSION Legend * Acknowledgements

25. REPORT Rocky shore communities along the NW coast of False Bay, South Africa Prepare a 2 000 word paper on the above topic for submission to the African Journal of Marine Science. The instructions for authors and an exemplar manuscript have been provided to assist you prepare your paper. READ them thoroughly! Reports MUST make reference to at least three journal articles, and CAN refer to a maximum of three text book articles and a maximum of one internet article. Copies of ALL the cited journal articles, appropriate sections of text books and internet sources should be attached to the submitted essay, and the relevant sections (i.e. those pieces of information referred to in the report) MUST be highlighted. Failure to attach supporting documentation will result in the report being returned to the student, with concomitant penalties for late submission being then enforced.

26. The data set that you will use for this exercise was collected from the shore at Dalebrook. ALL the data, in a raw state, can be accessed from the www site. Tide data You must prepare the data for analysis yourselves but in so doing, beware of possible species misidentifications. ONE other issues are worth mentioning. How will you deal with replicates from each station samples along the shore? Your report should include (at the very least), a description of changes in animal and plant abundance or cover and diversity across the shore as well as a description of changes in communities across the shore. Credit will be given to those students, whose reports investigate some of the links between community members in a quantitative way. YOU MUST SUBMIT YOUR REPORTS TO TURNITIN BEFORE FINAL SUBMISSION (report from Turnitin must be attached) – AND YOU ARE ADVISED TO USE THE WRITING CENTRE IN ADVANCE!

27. Suitable references could include: Branch, GM and Branch, M (1983) The living shores of southern Africa. Struik Lewis, JR (1964) The ecology of rocky shores. English Universities Press Little, C and Kitching, JA (1998) The biology of rocky shores. Oxford McQuaid, CD and Branch, GM (1984). Influence of sea temperature, substratum and wave exposure on rocky intertidal communities: an analysis of faunal and floral biomass. Marine Ecology Progress Series, 19: 145-151 McQuaid, CD and Branch, GM (1985). Trophic structure of rocky intertidal communities: response to wave action and implications for energy flow. Marine Ecology Progress Series, 22: 153-161 Stephenson, TA and Stephenson, A (1972) Life between tidemarks on rocky shores. Freeman.

29. Pass or Fail? A student is deemed to have passed the course if her/his Final mark (i.e. Coursework + Exam) is ≥50% AND the Exam mark is ≥40% AND the Practical mark is ≥50% Should a student obtain a Final mark of ≥50% AND have a Practical mark of ≥50% BUT have an Exam mark <40%, then that student will get an opportunity to write a Supplementary Exam* Should a student obtain a Final mark of 45-49%, AND the Practical mark is ≥50%, then that student will have an opportunity to write a Supplementary Exam* Should a student obtain a Coursework mark (i.e. Class tests + Practical) of ≥50% AND have a Practical mark of ≥50% AND have an Exam mark of ≥30% then that student will get an opportunity to write a Supplementary Exam* A student who does not meet the above grades fails and is not eligible to sit the Supplementary Exam. A student who fails to get a mark of 50% in the Practical work automatically fails, regardless of the Coursework or Exam mark – such a student not being eligible to sit the final exam. Similarly, a student that fails to obtain a course-work mark of less than 40% is not eligible to sit the final exam. * - Supplementary exams will be held at the end of the examination period. This exam will test the student on ALL the work undertaken in the module.

30. Readings Although there are no prescribed books for this course, the following texts are recommended (especially those in bold- typeface): all are currently placed on short-loan at the UWC library. Begon, M., Harper, J.L. and Townsend, C.R. (1990). Ecology: Individuals, Populations and Communities. Blackwell Scientific Publications, 945pp. Begon, M. and Mortimer, M. (1986). Population Ecology: A Unified Study of Animals and Plants. Blackwell Scientific Publications, 220pp. Krebs, C.J. (1999). Ecological Methodology. Benjamin Cummings, 620pp. Morin. P.J. (1999). Community Ecology. Blackwell Science, 424pp Zar, J.H. (1984) Biostatistical Analysis. Prentice-Hall

31. N t+1 / N t = R = R / {1 + [N t.(R-1)/K]} For a population of organisms showing discrete breeding and a fundamental reproductive rate (R) of 1.41 (per year), determine when the population will reach its carrying capacity of 643 215 individuals if the initial population size in 2007 is 12 individuals. N t+1 = N t R / {1 + [N t.(R-1)/K]} REFRESHER…… 10 minutes…..

33. Assuming that you can ALL project populations growing under the influence of intra-specific competition into the future…….. Length (mm) Frequency Table of cephalothorax of Euphausia superba collected during February 2008 from the Weddell Sea, Antarctica. Calculate the mean cephalothorax length of E. superba in the Weddell Sea during February 2008 and determine the standard deviation, variance, standard error and 95% Confidence limits around your estimate. ALL CALCULATIONS TO BE CONDUCTED “LONG-HAND” 20 MINUTES……..

36. Basic Model Building…… 1)– How many tennis balls could fill this room? You have 60 seconds to come up with an answer How did you arrive at your answer? Real world vs model world Resolution Assumptions and trade-offs 2) – in groups of two, and using your PC, tell me how many tennis balls could fill this room? You have 5 minutes to come up with an answer How did you arrive at your answer?

37. A gas storage tank has a Vol of 3000 cubic m. It currently contains methane. The tank must be emptied & then cleaned before being modified for use as a milk storage vessel. Safety regulations require that it should contain no more than 1 part in 100 of methane before it can be cleaned. Nitrogen is available and can be pumped into an opening near one end of the tank. Another opening near the other end will let gases escape. How much nitrogen will you need to dilute the methane effectively? Working in groups of two, think about the problem for about 30 mins and prepare a plan, before explaning it to the rest of the class. DO NOT solve the problem at this stage. Solve the problem

38. Identifying or Delineating Communities 1 – physically defined communities Assemblages of species found in a particular place or habitat ARTIFICIAL?

39. 2 – taxonomically defined communities Identified by presence of one or more conspicuous species that dominate biomass and/or numbers, or which contribute importantly to the physical attributes of the community Topographic distributions of the characteristic dominant tree species of the Great Smokey Mountains, Tennessee, on an idealized west-facing mountain and valley BG, beech gap; CF, cove forest; F, Fraser fir forest; GB, grassy bald; H, hemlock forest; HB, heath bald; OCF, chestnut oak-chestnut forest; OCH, chestnut oak- chestnut heath; OH, oak-hickory; P, pine forest & heath; ROC, red-oak-chestnut forest; S, spruce forest; SF, spruce-fir forest; WOC, white oak-chestnut forest. Great Smoky Mountains Tennessee SUBJECTIVE?

40. 3 – statistically defined communities Sets of species whose abundances are significantly correlated, positively or negatively, over space and/or time. Look at numerical and specific composition of samples Determine similarities between samples Look for a pattern in the similarities between samples And so identify communities OBJECTIVELY

41. 4 – interactively defined communities Subsets of species in a particular place or habitat, whose interactions influence their abundance. Only some, and perhaps none, of the species in a physically defined community may constitute an interactively defined community. Hairston (1981: Ecology, 62: 65-72) noted that of the seven species of plethodontid salamander in his study (North Carolina, USA), only the two most common influenced each others abundances: the balance, while ecologically similar, remained unaffected by each others abundance.

42. THE END Image acknowledgements – http://www.google.com