OCR
114 ÍVI. Methods of a zoocoenological analysis There are two conseguences: a zoocoenologist must collect most of the animals from the field, and the material identified in the laboratory must be analysed by methods that allow delimitation of the individual associative categories. Ihese are also warnings that, in the place of phytocoenological characteristics, or in addition to their use, we need other characteristics that will help to achieve our goals. Therefore, all zoocoenological research has two methodological stages: censusing the association, and analysing it. The aim of the census is to collect information about the totality of the animal assemblages of a given area, the entirety of its constituent population. This definition indicates that this phase is nearly identical with the task of faunistical research. Indeed, the difference is only that the aim of faunistics is only to identify all species living in the study area, while the coenologist also wants to know about their roles. In practice, a zoocoenological collection phase is different from the faunistical one, because it has to be performed so that the collected material is suitable for a subsequent coenological analysis. The first criterion is that the overall picture would not only reflect the constituent species, but also of their density and relative abundance. It is impossible to use the same survey method for all groups, yet it is a necessary condition that the methods used for a given group be identical in all cases. Thus, for example, on a wheat field we should take the same number of soil samples (this would be an error - as the size of the field needs to be taken into account, otherwise the sampling intensity will be different); on the soil surface, we ought to examine the same number of quadrats; from the plants (in order to study endophytes) we should take the same number of samples, and; from the plants, we collect animals by sweep netting, using the same number ofsweeps taken at the same time ofthe day. An exhaustive sampling, due to the complicated life patterns of animals, needs a set of different methods, thus the sampling methods can be grouped into three: a) collecting methods can be used when full compilation of the studied assemblage can be attained by methods used in faunistical studies b) incubating methods need to be used when a population cannot be properly sampled by any methods, because of its hidden way of life, or because it is “hidden” within another population, thus its presence is impossible to detect using traditional collecting methods. Such methods need to be employed when censusing animals living in stems, seeds of galls. Also, incubation is necessary to assess the degree of infestation by endoparasites, i.e. to what degree a given parasite population is present in the zoocoenosis. c) observational methods are to be used when neither collecting nor incubation methods are usable, either because of the high vagility of animals, or the strong dispersion of semaphoronts. In such cases, only observations can enlighten us as to how these animals live in the community, how they spend their time, and what role they fulfil. Thus, observation — be that under field conditions if possible, or in the laboratory, if necessary - firmly belongs to the