An annotated checklist of Tasmanian mosses

An annotated checklist of the Tasmanian mosses is presented to clarify the occurrence of taxa within the state. Some recently collected species, for which there are no published records, have been included. Doubtful records and excluded species are listed separately. The Tasmanian moss flora as recognised here includes 361 species

Terrace types and vegetation dynamics on Macquarie Island

Feldmark vegetation occurs extensively on the plateau of Macquarie Island above about 200 m. Alternating stripes of vegetation and gravel are frequently associated with terraced terrain. Detailed study of 38 terraced sites with non-windward aspects shows vegetation-terrace interaction to be active under present climatic conditions. Wind, moisture, hillslope, slope stability and vegetation all affect terrace form

Hypolithic Microbial Community of Quartz Pavement in the High-Altitude Tundra of Central Tibet

The hypolithic microbial community associated with quartz pavement at a high-altitude tundra location in central Tibet is described. A small-scale ecological survey indicated that 36% of quartz rocks were colonized. Community profiling using terminal restriction fragment length polymorphism revealed no significant difference in community structure among a number of colonized rocks. Real-time quantitative PCR and phylogenetic analysis of environmental phylotypes obtained from clone libraries were used to elucidate community structure across all domains. The hypolithon was dominated by cyanobacterial phylotypes (73%) with relatively low frequencies of other bacterial phylotypes, largely represented by the chloroflexi, actinobacteria, and bacteriodetes. Unidentified crenarchaeal phylotypes accounted for 4% of recoverable phylotypes, while algae, fungi, and mosses were indicated by a small fraction of recoverable phylotypes

Photoinhibition in the Antarctic moss Grimmia antarctici Card when exposed to cycles of freezing and thawing

Freezing and thawing of the endemic moss species Grimmia antarctici Card, caused photoinhibition. When snow cover was removed from moss in the field, resulting in exposure to fluctuating temperatures and light conditions, photoinhibition, measured as a reduction in the ratio of variable to maximum chlorophyll a fluorescence (F-v/F-m), was observed. The extent of photoinhibition was highly variable and appeared to be reversible during periods of warmer temperatures, A series of controlled laboratory studies found that the light conditions that prevail between freezing and thawing events influenced the recovery from photoinhibition observed during freezing and thawing, with low light conditions facilitating the greatest rates of recovery, After four cycles of freezing and thawing, recovery from photoinhibition in hydrated moss was achieved within 12 h of transfer to 5 degrees C and 15 mu mol quanta m(-2) s(-1). These results favour the hypothesis that photoinhibition observed during freezing represents a protective process involving the down-regulation of photosystem II when photosynthetic carbon assimilation is limited by low temperatures