Ecology Practical II
The ecological exercises are based on the ecology lectures, however, due to the sometimes very complicated nature of ecological phenomena of which study would require considerable time and material resources, only relatively simple problems are investigated. Within this circle, however, the exercises address problems from the simple towards the more complicated, and generally from populations to communities.
The second part contains ecological exercises performed during autumn. As living organisms (especially animals) are not available in sufficient numbers in nature in Hungary at this time of the year, laboratory exercises are performed. The exercises are arranged in „blocks”, meaning several hours per day to allow sufficient time to execute them and summing up to 4-5 days during a given week usually in November. Exercises are performed by groups of 3-5 students.
Autumn plant ecology exercises (The students become familiar with ecological methods through demonstrations, as well as write two essays on the basis of individual literature search: one is review (survey of a scientific problem) and the other is a study plan for a particular research project. In addition they get acquainted with computer data bases and the way to analyse them.
1. Preparing a review. Students have to prepare and clearly present an essay based on the evaluation of 4-7 publications which represent a specific issue of a scientific field so that another fellow student not occupied with the same scientific problem should understand it and gain valuable information.
2. Preparation of a study plan. Concerning a specific scientific problem students have to prepare a project proposal covering three essential elements: work-plan, budget and timely arrangement of research steps.
3. Methods for measuring microclimatic variables. Demonstration of approaches to measure temperature, humidity, light conditions and air movement with hand-tools and automatic appliances.
4. Competition among plant species. Experimenting on interactions between species-pairs in growth-chambers: substitutive and additive tests. Investigations at natural growing sites: subtractive and additive tests.
5. Allelopathy. Experiments for the demonstration of inhibition of germination and growth by chemicals of plant origin. Investigation of volatile inhibitory substances produced through decomposition of plant debris and root exudates.
6. Ecological application of stable isotopes. The students get a knowledge about the process of how naturally occurring two stable isotopes of C, N, O and H are incorporated into living material in various ratios, respectively. The scope of application of the procedure is outlined in cases such as the relative frequency of photosynthetic routes in different soil types; reconstruction of past vegetation; the origin of water taken up by the plant, etc.
7. Remote-sensing of vegetation: an introduction. The spectral properties of incoming radiation from the sun are modified through reflection by plants. It is possible to use and monitor the extent and condition of vegetation on large areas by the help of remote-sensing from satellites (spectral reflectance, NDVI, etc.).
8. Vegetation-mapping. The exercise includes the visualisation of vegetation data, types of maps (from coenological to habitat maps), methods of mapping and technical approaches (high resolution topographic maps, aerial photographs, geographic positioning by satellites, spatial information, etc.). It also gives examples of information obtainable from vegetation mapping.
9. Vegetation dynamics. This exercise investigates timely changes in vegetation. Main approaches are: time-series analysis; substituting space for time; substituting signals (proxies) to reconstruct past vegetation; simulation modelling. Sampling and limits of interpretation.
Autumn animal ecology exercises. (Laboratory exercises, mostly computer simulations.) 10. Calculation of food niche-width from a database. Food-overlap study on frog species applying D. Schluter’s method.
11. Spatial informatics. The methodological application of the geographic information system (Arc View). Concepts and use of databases.
12. Numerical and functional responses in predator-prey interaction. The students obtain the so-called Holling curve of the second type.
13. Island biogeography. Computer simulations of biogeographic events (colonisation of islands of various sizes being at different distances from the mainland) by the use of EcoBeaker program.
14. Preparation of an essay using scientific publications. The exercises will be evaluated on the basis of essays, experimental notes, records, descriptions, explanations and analyses (through proper hypothesis testing and statistical methods) that the students have to submit in written form appended with data analyses, tables and graphs within a given time period.
Southwood, T.R.E. and P.A. Henderson. 2000. Ecologial Methods. 3rd ed. Blackwell Sci., 592.
Eli Meir. 1996. EcoBeaker 1.0. An Ecological Simulation Program. Sinauer Assoc. Inc., Sunderland.