Practical Field Ecology. C. Philip Wheater. Читать онлайн. Newlib. NEWLIB.NET

Автор: C. Philip Wheater
Издательство: John Wiley & Sons Limited
Серия:
Жанр произведения: Биология
Год издания: 0
isbn: 9781119413240
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circumstances – it could have been much worse than a frozen shoe! When transporting frozen samples, invest in a good cooler with proper insulation, pack it well (i.e. leave no air spaces and put the most important samples at the bottom), and make your own ice blocks that have a large volume to surface area ratio. Finally, do not rely on luck on the day as Gareth did, but instead organise any additional supplies you may need for your sample journey to be a success well ahead of time.

      Equipment and technical support

      Ensure the availability of equipment before starting and obtain essential items well in advance of beginning your research project. You may need to allow adequate time to order specialist equipment or materials. If your project requires technical support, arrange this as far in advance as possible.

      You need to be as familiar with your equipment as possible before commencing your fieldwork. This includes knowing how reliable it is likely to be under the conditions in which you are working and whether you need to have access to spare components or extra full items of equipment. For example, small mammals will eventually chew through the sides of an aluminium trap and, and they rather more quickly get through the sides of an equivalent plastic trap. Whilst it is possible to patch these up, this is tricky in the field, and therefore spares should be taken. Anything that runs on batteries (e.g. data loggers or light traps) need to be recharged on a regular basis and spare batteries, bulbs, etc. should be available whilst in the field. If you are using multiple pieces of equipment, then you should ensure they are comparable (e.g. different makes of bulb may provide different wavelengths and illumination in light traps, and monitoring equipment from different companies may have different levels of accuracy and resolution). Wherever possible, ensure that identical equipment is used for an individual project. Instrumentation errors may occur if users are unaware of the limits of the equipment (e.g. where attempts are made to estimate between gradations on an analogue scale). Some equipment may require regular calibration against standards of approximately similar values to the variables being measured (e.g. calibrating pH meters at pH 7 for neutral soil and water pH measurements). It is also important to take care of equipment, including protecting it against vandalism, theft, and animal damage (many a moth trap has been trampled by inquisitive cattle when placed in their pasture, and crows and magpies seem to very much enjoy pulling white pitfall cups out of the ground).

      Field/laboratory notebook

      Box 1.3 Keeping a field notebook

      Use a field notebook to write down data, ideas, observations, tentative conclusions, and hypotheses as you do your fieldwork to create an immediate and faithful history of your research. Produce comprehensive, clearly organised notes as a reference and so that you can reconstruct the research timeline and follow the development of your thoughts and ideas. Although you may use other collection sheets (e.g. pre‐printed data collection forms to ensure data are collected consistently in different locations and at different times), your field notebook should provide the context for data collection and help resolve ambiguities or inconsistencies when preparing for analysis. After data analysis, reference to your notebook may generate further hypotheses and suggest further lines of enquiry.

      Select an A5 or A6 hardback notebook with a spiral binding and wide‐ruled lines, ideally on waterproof paper. Use a clutch‐type propelling pencil with a moderately soft lead (HB or B). If you do not use waterproof paper, then encase your notebook in a plastic bag large enough to cover your hand and the notebook when writing. In very wet conditions, write on an A4 sheet of white plastic with a thick soft pencil (use kitchen cleaner to erase your notes after transcription).

      What should be recorded?

      Before starting work each day, write down the date, weather, general location, nature of the habitat, and purpose of the day's work. Write down any changes in weather or habitat that occur during the day, e.g. ‘At 15.00 hours snow began to fall and visibility was reduced to 20 m’. When observing behaviour, note the sampling method, how animals were chosen for observation, and the recording method (e.g. whether you noted all occurrences or used a time‐sampled method). If animals or start times are chosen at random, note how this was done.

      Note the type and model number of any equipment (e.g. GPS receiver type Garmin 12). Some instruments need calibrating at intervals, so record the time of calibration and any raw data and subsequent calculations so that any arithmetic errors can be identified and corrected later. Use your notebook to create rough species accumulation curves, etc. so you can tell when you should stop collecting data (see p. 31). Although notes should be made at the time observations are made, it can be difficult to observe and write at the same time, but if you do rely on memory, you should note this. Write exactly what you see or hear, e.g. when describing behaviour do not ascribe a function to it in the guise of a description (i.e. do not write that a goose was ‘vigilant’ when you mean that the bird was in a standing posture with an elongated neck and raised head).

      Sketches enhance any photographs you take of your study sites and you will have a sketch available in your notebook the next time you visit the area. Sketches can be added to subsequently (annotating any changes with the date of the amendment). The value of sketches can be increased by explanatory labels. A careful sketch can aid species identification and will help to jog your memory when you encounter a species in the future; such sketches are more valuable if labelled with the diagnostic feature(s) you