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Protistology ■ 39
LAND USE AND LITTER CHEMISTRY IMPACT MICROBIAL DECOMPOSER COMMUNITIES AND LITTER DECOMPOSITION IN TROPICAL LOWLANDS OF SUMATRA, INDONESIA
Krashevska V.1, Malysheva E.2, Klarner B.1, Mazei Y.32, Maraun M.1, Widyastuti R.4, Scheu S.1
1 - J.F. Blumenbach Institute of Zoology and Anthropology, Georg August University Göttingen, Berliner Straße 28, 37073 Göttingen, Germany
2 - Penza State University, Russia
3 - Lomonosov Moscow State University, Russia
4 - Institut Pertanian Bogor - IPB, Department ofSoil Sciences and Land Resources, Damarga Campus, Bogor 16680, Indonesia
We investigated how the conversion of rainforest into jungle rubber, intensive rubber and oil palm plantations affects the decomposer community and decomposition processes. Further, we investigated the role of litter chemistry in structuring the decomposer system. In total 192 litterbags were placed into the field: 3 litter types (forest, rubber, oil palm) in 4 land use systems, with 2 harvest times and 8 replicates, each. After 6 and 12 months litterbags were collected and litter mass loss was measured, testate amoebae and microbial communities were studied, and litter element concentrations were measured. The decomposition in converted systems was slower as compared to rainforest; and litter of oil palms and rubber decomposed faster than that of forest. A total of 58 species oftestate amoebae (TA) colonized the litter. Species number and density of TA, as well as microbial biomass (MB) were high in rainforest and jungle rubber and decreased significantly in rubber and oil palm plantations. Further, TA density and MB was highest in rubber litter, whereas TA species number was at a similar levels in rubber and forest litter. Overall, our data indicate negative effects of rainforest conversion on the structure and functioning of decomposer community and, thereby litter decomposition. Further, testate amoebae and microorganisms were interactively affected by litter element concentrations. The data suggest that element ratios of litter material as basal resource of the decomposer food web exhibit strong bottom-up control on the structure of decomposer communities and decomposition processes
RHIZOPOD ANALYSIS IN THE PEAT-LAKE SEDIMENTS OF THE MOUNTAIN MIRE "BEZRYBNOE" IN THE SOUTH OF MIDDLE SIBERIA
Kurina I.V., Blyakharchuk T.A.
Institute of Monitoring of Climatic and Ecological Systems of SB RAS, Tomsk [email protected]
The research is devoted to rhizopod analysis (analysis of the testate amoebae complexes) in peat-lake sediments. The aim is the reconstruction of hydrological conditions in the mire during its development in the late Holocene. The study site Bezrybnoe Mire lies in Yergaki Natural Park in the Western Sayan Mts, southern Middle Siberia (52°51' N, 93°21' E, 1300 m a.s.l.). The thickness of sediments is 6 m, ofwhich the lower 2 m — gyttja, the upper 4 m - peat composed mainly of remnants of sphagnum moss. Age ofpeat at a depth of 4 m is 2,420 cal yr BP. Total 80 testate amoeba taxa was revealed. The dominant species were: Amphitrema wrightianum, Centropyxis aculeata, C. gibba, Difflugia globulus, Euglypha rotunda, Schoenbornia smithi, Trinema lineare, T. enchelys. There are both oligotrophic and minerotrophic species. 22 species were met only in gyttja. Water table depth (WTD) reconstruction is made on the basis of species optima obtained in our study of modern oligotrophic and minerotrophic mire habitats in the south of Western Siberia using the transfer function (training set includes 115 samples). Decrease of WTD in the mire are observed 2350-2300, 1850-1800, 1650, 1450, 1350 1100-900, 400-0 cal yr BP and increase - in 2400, 2000, 1900, 1800-1700, 1600-1500, 1400, 1300, 800-500 cal yr BP. Minerotrophic testate amoebae species were prevailed in the studied sediments. However, there were also oligotrophic species. For the reconstruction of WTD during development of such mires the information is needed about optima of both oligotrophic and minerotrophic species. The work was supported by RFBR grant (16-3460057).
BENTHIC CILIATES ON HERON ISLAND REEF, AUSTRALIA Langlois G.A.
Bryant University, Smithfield, RI USA [email protected]
Field studies conducted at the Heron Island Research Station, located in the Capricorn region of the Great Barrier Reef, revealed complex protistan communities. Heron Reef, home to about two-thirds of the coral species found on the GBR, has experienced repeated bleaching episodes in the past decade. This study, with comparisons to similar observations in 2006, emphasizes the diversity of ciliates and diatoms found in reef sediments. Observations included the interactive role of the protistan component of a coral reef, in particular the dynamics of opportunistic and/or potentially
