MODELING HYDROLOGICAL RELATIONSHIPS OF TESTATE AMEBAS (PROTOZOA, RHIZOPODA) ON NEW-ZEALAND PEATLANDS

Research in the Northern Hemisphere shows the principal control on spe cies distribution and abundance of testate amoebae to be local hydrolo gy, which in ombrotrophic mires is linked directly to climate. Fossil faunas can therefore be used to infer past hydrological and climatic c onditions. This study investigates whether a similar relationship can be found for New Zealand peatlands, as a first step towards developing a method for palaeomoisture reconstructions. Fifty-seven samples from 13 peatlands were analysed for testate amoebae and related to site hy drology, pH and conductivity of mire waters, climate, and vegetation t ype using canonical correspondence analysis (CCA). Water table and soi l moisture were the dominant factors, and their relationship with spec ies assemblage was modelled using four transfer functions: weighted av eraging (WA), tolerance downweighted weighted averaging (WA-Tol), part ial least squares (PLS), and weighted average partial least squares (W A-PLS). PLS and WA-PLS performed best, and suggest that palaeohydrolog y could be accurately inferred from fossil faunas. Results are contras ted with those found in the northern peatlands.