Biogeography and comparative ecology of testate amoebae inhabitingSphagnum‐dominated peatlands in the Great Lakes and Rocky Mountain regions of North America

Abstract

Testate amoebae (Protozoa: Rhizopoda) are common inhabitants of peatlands. Strong relationships between community composition and substrate moisture in Sphagnum‐dominated peatlands have made them particularly useful as hydrological proxies in environmental and palaeoenvironmental research. However, stability of these relationships in geographical space is important for widespread applicability. In this study, we compared testate amoeba communities inhabiting Sphagnum‐dominated peatlands of the Great Lakes and Rocky Mountain regions of North America. Our primary objectives were to describe patterns of community composition in the two regions, develop hypotheses to explain differences, and determine if taxa occupy similar ecological niches with respect to substrate moisture in both places. Our results indicated that testate amoeba communities are relatively different in the two regions, and these differences are probably caused by differences in climate and peatland trophic status, although other factors may also play a role. However, many taxa do occur in both regions and these taxa had comparable moisture preferences in each region, suggesting that the ecological niches of taxa with respect to substrate moisture are similar even within communities of relatively different composition.

Ecology of testate amoebae (Protista) in south-central Alaska peatlands: building transfer-function models for palaeoenvironmental studies

“…Direct comparison among studies is difficult because most studies have used one-time DWT measurement, with the notable exception of Woodland et al (1998). To date, only one study has compared two sites using exactly the same methods (Booth and Zygmunt, 2005). But in this study, too, the DWT measurements were not done on the same day, and even had they been given the distance among sites (Rocky Mountains and Great Lakes regions, respectively) the sampling date would be less important than the time since the last significant rain event.…”

“…Given the above-mentioned methodological differences in water-table depth measurements, it is difficult to compare species optima with previous results, as most studies have only measured DWT on a single sampling occasion and therefore do not take account of annual variations in water-table. Booth and Zygmunt (2005) compared the DWT optima for testate amoebae between two distant study sites in North America. They found that although the communities were sometimes quite different, the species' optima were consistent between the two regions.…”

“…Although there is evidence that the hydrological preferences of many testate amoebae taxa are consistent between regions (Booth and Zygmunt, 2005) exceptions may exist for some taxa (Charman and Warner, 1997) and community structure often differs between regions. Therefore the study of testate amoebae ecology in south-central Alaska and the development of new transfer-function models based on these data is a prerequisite to their use in paleoecological studies in this region and will also add to our wider knowledge of testate amoebae ecology and biogeography.…”

Testate amoebae as palaeohydrological proxies in sürmene ağaçbaşi yaylasi peatland (northeast Turkey)

“…The hydrological preferences of many taxa are well known and appear consistent across broad geographic regions (Booth and Zygmunt 2005). However, there are notable differences in community composition between studies, and there are several important taxa whose hydrological preferences are still inadequately understood.…”

Comparing regional and supra-regional transfer functions for palaeohydrological reconstruction from Holocene peatlands

“…Testate amoebaebased hydrological transfer functions have been developed in many parts of the world; Alaska (Markel et al, 2010;Payne et al, 2006), Canada (Charman and Warner, 1997;Warner and Charman, 1994), Europe , Greece (Payne and Mitchell, 2007), New Zealand (Charman, 1997;Wilmshurst et al, 2003), North America (Booth, 2008;Booth and Zygmunt, 2005), Northern Ireland ), Switzerland (Mitchell et al, 1999), Poland (Lamentowicz et al, 2008;Lamentowicz and Mitchell, 2005), and the United Kingdom (Woodland et al, 1998). Due to spatial autocorrelation (Borcard et al, 1992;Lennon, 2000), transfer functions require validation against data sets that are completely independent of the training set (Belyea, 2007;Birks et al, 2010).…”