Morphology of Chrysophycean stomatocysts in three peatlands in central China

Abstract

Chrysophytes are sensitive to environmental changes in alpine peatlands, within which acidic and oligotrophic conditions favour the proliferation of chrysophytes. Previous investigations of chrysophyte stomatocysts in temperate and boreal regions provide basic knowledge on their morphology and distribution; however, subtropical areas have been less thoroughly explored. Twelve Sphagnum samples collected from three subtropical montane peatlands (central China) were analysed to reveal the morphotypes of stomatocysts in this less investigated region. Twenty-three morphotypes of chrysophyte stomatocysts were identified in these samples following the International Statospore Working Group (ISWG) guidelines, and illustrated by SEM and LM micrographs. They include nineteen previously described cysts and four newly described stomatocysts. The results of canonical correspondence analysis (CCA) indicated that the cyst assemblage was related to depth to water table (DWT), pH, oxidation reduction potential (ORP) and electrical conductivity (EC). These results improve our knowledge of the taxonomy and autecology of stomatocysts, highlighting the potential of stomatocysts as bioindicators in peatlands.

Keywords

• chrysophyte
• environmental gradient
• stomatocyst morphotype
• subtropical peatland