A guild is a group of species that use similar resources in a similar way , regardless of their degree of relationship. The term was introduced in 1967 by RB Root in a publication to niche in a mosquito catcher species. The term guild is predominantly used in ecological research in relation to the food resources of animal species, although other resources such as e.g. B. nesting sites can be viewed. The term is hardly used in botany. The conceptual summary of groups of species as guilds is significant in two contexts:
- When studying competition between different species. Types of a guild should compete particularly strongly with each other due to similar niches ( interspecific competition ). Contrary to the original meaning of the word ( guild , German: guild), the species under consideration have a very similar "job" or "livelihood", but the second context, that of a corporation or cooperation, is used as an ecological technical term ignored.
- When comparing different communities in terms of space or time. Types of a guild then in a certain way form interchangeable “building blocks” of complex communities.
The term guild is used in research in a number of slightly different meanings. Deviating from the definition of root, especially those species that use a common resource are very often included in a guild regardless of how they are acquired. This use of the term is at least as widespread as that which corresponds to the original definition. Despite the blurring that this creates, it is no longer considered sensible to coined new, unambiguous names for the various concepts due to the long-standing use of language.
In addition to the concept of the guild, species communities are also divided into “functional groups”. In contrast to the guild, the focus here is on the common reaction to one or more environmental factors. Examples would be the differentiation of species according to their reproductive strategy into r and K species or the division of the macrozoobenthos of rivers into food types such as grazers, shredders, filter feeders, predators, etc. Consideration of functional groups instead of guilds is in botany and limnology more common.
A major problem of the approach is to assign the respective type to a guild. Since all species differ in their resource use in a certain way and the use of the same species can be spatially and temporally different, but on the other hand species with very dissimilar resource use can also interact closely with one another (e.g. a specialist and a generalist in same habitat), the composition of the guild always depends on the classification scheme of the investigator and the question. In addition to an assignment of species based on the (subjective) expert judgment of the investigator, an attempt is made to determine the composition of guilds more objectively using statistical methods. Common methods are, for example, principal component analysis , canonical correlation analysis or Monte Carlo simulation . Usually, depending on the threshold value, a distinction can be made between widely delimited or narrowly delimited guilds. The narrowly defined are usually nested hierarchically in the others.
- After observing the foraging of birds in a mixed forest in the Carpathian Mountains and statistically analyzing the results, Kornan and Adamik distinguish between six guilds: forage seekers on the ground (ring owl, blackbird, song thrush, wren, dunnock, bullfinch, robin), forage seekers on bodies of water (White wagtail, dipper), insect hunters in the trunk and air space (miniature flycatcher, gray flycatcher, collarcatcher, house martin), trunk scavenger (nuthatch, treecreeper), trunk chopper (three-toed woodpecker, white-backed woodpecker), foraging in the foliage of the tree canopy, woodcap Chiffchaff, blackcap, marsh tit, chaffinch, tailed tit)
- ↑ RB Root: The niche exploitation pattern ot the blue-gray gnatcatcher. In: Ecological Monographs 37, 1967; Pages 317-350
- ^ CP Hawkins & JA MacMahon (1989): Guilds: the multiple meanings of a concept. Annual Revue of Entomology 34: 423-451. doi : 10.1146 / annurev.en.34.010189.002231
- ^ Daniel Simberloff & Tamar Dayan (1981): The guild concept and the structure of ecological communities. Annual Review of Ecology and Systematics 22: 115-143.
- ↑ Javier Lopez de Casenave, Víctor R. Cueto, Luis Marone (2008): Seasonal dynamics of guild structure in a bird assemblage of the central Monte desert. Basic and Applied Ecology Volume 9, Issue 1: 78-90. doi : 10.1016 / j.baae.2006.08.006
- ↑ M. Kornan & P. Adamík (2007): Foraging guild structure within a primaeval mixed forest bird assemblage: a comparison of two concepts. Community Ecology 8 (2): 133-149. doi : 10.1556 / ComEc.8.2007.2.1
- ME Begon, JL Harper, CR Townsend: Ecology. Spektrum Akademischer Verlag, Heidelberg 1998, ISBN 3-8274-0226-3 ; Pp. 16 and 539
- Niels Blaum, Eva Mosner, Monika Schwager, Florian Jeltsch (2011): How functional is functional? Ecological groupings in terrestrial animal ecology: towards an animal functional type approach. Biodiversity and Conservation 20: 2333-2345. doi : 10.1007 / s10531-011-9995-1
- Jacques Blondel (2003): Guilds or functional groups: does it matter? Oikos 100: 223-231. doi : 10.1034 / j.1600-0706.2003.12152.x