Ref ID : 2338
Wilhelm Foissner; [Protozoologische Untersuchungen an Almboden im Gasteiner Tal (Zentralalpen, Osterreich). III. Struktur und Dynamik der Testaceen- und Ciliatentaxozonse] (Studies on the protozoa in alpine soils from the Gastein area (Central Alps, Austria). III. Structure and dynamics of the testacean and ciliate community). Veroff.Osterr.MaB-Programms 9:65-95, 1985
Reprint
In File
Notes
The structure and dynamics of the terrestrial testacean and ciliate community were investigated at 5 sites of the subalpine timberline (~1,800 m above sea-level) of the "Hohe Tauern". Site (A): grazed alpine pasture, site (B): less used alpine pasture, site (C): isolated alder stand, site (D): alder stand mixed with dwarf shrubs and spruces, site (E): heavily eutrophic alpine pasture (Rumicetum alpini). Concerning the vegetation and the degree of utilization the sites (A) to (D) represent a succession from a used to an abandoned alpine pasture. Soil type: alpine pseudogleys with more or less pronounced podzol dynamics. Kind of humus: mull-like moder (A, B, E), moder (C, D), raw humus (D). pH: 4.2-5.4 (A, B, E), 3.2-3.7 (C, D). Abundance and species number were estimated by direct microscopy of freshly collected water-suspended soil samples. For the ciliates also some culture methods were used. The soil parameters are quoted from Peer and Foissner (1984). Active ciliates occur only in 15 of 30 fresh soil samples. Their abundance increases from (A) to (E) and shows a positive correlation (P< /_0.05) with the P2O5 level of the soil. Species number of both communities is highest at sites (C) and (D). Testacea are lowest at site (A) and ciliates at site (E). Diversity and evenness show a similar relationship. These and other results suggest that a site has to be investigated two times a year to gather its content of testacean species, and three times to gather the ciliate species. Species number, abundance, and biomass of the testacea increase from (A) to (D) and show a negative correlation (P< /_0.05) with the catalase activity. Abundance and biomass of the ciliates increase from (E) to (D) and coincides (P< /_0.1) with the soil respiration (CO2). On the whole, many parameters of the protozoan community and of the soil show a trend to increase with the above described succession A < B < C < D, but some of them show an inversed relationship, for instance the pH and dehydrogenase activity. There is no strong soil relationship between the dynamics of the protozoa and the dynamics of the soil enzyme and the soil respiration (CO2). However, the abundance of the testacea is frequently similar to the dehydrogenase activity and the abundance of the ciliates shows a reversed trend to the changes of the CO2-release. Concerning the species identity the testacea assemble into the groups (A, E) and (B, C, D), the ciliates to (A, B, E) and (C, D). These relationships correspond with the expectation that woodland and grassland sites have the most dissimilar species composition. Dominance identity and species-abundance identity produce less pronounced separations of the sites. The structure of both communities is similar to that described by Foissner (1981) and Foissner and Adam (1981) for the Grossglockner area. The testacean species which are common to mild humus occur preferably at sites (A), (B), and (E), species that are common to acid humus predominate at sites (C) and (D). Some ciliate species which could be indicator for mull-like moder and for moder are selected. The zoobiomasses/m2 of the sites (B) and (C) are estimated by means of the data of Meyer (1981) and Gerber (1984). They are compared with those of 4 sites of the Grossglockner area. There is a negative correlation (P=0.1) between zoobiomass and sea-level. The biomass of the protozoa amounts to at least one third of the whole zoobiomass in 2 of the 6 sites. Taking into account the high P/B-quotient of the protozoa, it is apparent that they are one of the most important groups of animals in terrestrial ecosystems.