Ecophysiology of Antarctic vascular plants

Abstract

Most of the ice and snow-free land in the Antarctic summer is found along the Antarctic Peninsula and adjacent islands and coastal areas of the continent. This is the area where most of the Antarctic vegetation is found. Mean air temperature tends to be above zero during the summer in parts of the Maritime Antarctic. The most commonly found photosynthetic organisms in the Maritime Antarctic and continental edge are lichens (around 380 species) and bryophytes (130 species). Only two vascular plants, Deschampsia antarctica Desv. and Colobanthus quitensis (Kunth) Bartl., have been able to colonize some of the coastal areas. This low species diversity, compared with the Arctic, may be due to permanent low temperature and isolation from continental sources of propagules. The existence of these plants in such a permanent harsh environment makes them of particular interest for the study of adaptations to cold environments and mechanisms of cold resistance in plants. Among these adaptations are high freezing resistance, high resistance to light stress and high photosynthetic capacity at low temperature. In this paper, the ecophysiology of the two vascular plants is reviewed, including habitat characteristics, photosynthetic properties, cold resistance, and biochemical adaptations to cold.

Carbohydrates in Colobanthus quitensis and Deschampsia antarctica

“…The studies by Zúñiga et al (1994Zúñiga et al ( , 1996 that of other grasses while the soluble carbohydrates level is higher than in cereals. Alberdi et al (2002) suggested that carbohydrate accumulation could be related to enhanced freezing tolerance of this species. Our observations support this hypothesis and it seems even more true for Colobanthus quitensis.…”

“…Plants have to be able to cope with severe abiotic stresses, caused by low temperature, repeated freezing and thawing, repeated desiccation, high irradiance and salinity (Alberdi et al 2002). The acquisition of abiotic stress resistance by plants and seeds depends on chemical substances preventing adverse effects stress.…”

Evidence of morphometric differentiation among Antarctic moss populations as a response to local microenvironment

“…In Antarctica, snow cover is an important microclimatic factor in protecting plants from windblown ice and sand particles (Alberdi et al 2002). During the growing season, without the snow cover in ice-free areas, the moss populations are suitable to windblown ice and sand particles, causing damages in the leaves and consequently, reducing the photosynthesis area.…”

“…Microclimate, including factors such as ground-level wind speed, water availability, and low temperature, has a major influence on Antarctic plants growth (Alberdi et al 2002).…”

The influence of some environmental factors on cytological and biometric parameters and chlorophyll content of Deschampsia antarctica Desv. in the maritime Antarctic

“…Bartl.) that are probably most sensitive to warming, as well as of different mosses and macroalgae [4][5][6]. For using plant communities as indicators of cli matic changes it is essential to study the variability of their composition, as well as the parameters of plant edificators in relation to the ecological con ditions of their habitats.…”