The aim of our work was to assess photosynthetic plasticity of two hairgrass species with different ecological origins （a temperate zone species, Deschampsia caespitosa （L.） Beauv. and an Antarctic species, D. anta...The aim of our work was to assess photosynthetic plasticity of two hairgrass species with different ecological origins （a temperate zone species, Deschampsia caespitosa （L.） Beauv. and an Antarctic species, D. antarctica） and to consider how the anticipated climate change may affect vitality of these plants. Measurements of chlorophyll fluorescence showed that the photosystem Ⅱ （PSⅡ） quantum efficiency of D. caespitosa decreased during 4 d of incubation at 4℃ but it remained stable in D. antarctica. The fluorescence half-rise times were almost always lower in D. caespitosa than in D. antarctica, irrespective of the incubation temperature. These results indicate that the photosynthetic apparatus of D. caespitosa has poorer performance in these conditions. D. caespitosa reached the maximum photosynthesis rate at a higher temperature than D. antarctica although the values obtained at 8 ℃ were similar in both species. The photosynthetic water-use efficiency （photosynthesis-to-transpiration ratio, PIE） emerges as an important factor demonstrating presence of mechanisms which facilitate functioning of a plant in non-optimal conditions. Comparison of the PiE values, which were higher in D. antarctica than in D. caespitosa at low and medium temperatures, confirms a high degree of adjustability of the photosynthetic apparatus in D. antarctica and unveils the lack of such a feature in D. caespitosa.展开更多
Climate warming has become evident in the maritime Antarctic over the past decades, and has already influenced the growing season and the population size of two native vascular plants in Antarctica, Deschampsia antarc...Climate warming has become evident in the maritime Antarctic over the past decades, and has already influenced the growing season and the population size of two native vascular plants in Antarctica, Deschampsia antarctica and Colobanthus quitensis. Both vascular plant species are therefore regarded as good bioindicators of regional warming in west Antarctica. To carry out long-term monitoring of vegetation （mainly using D. antarctica） and build a comprehensive research platform for multi-disciplinary study （including botany, microbiology, ecology, and environmental science） for Chinese scientists, 13 permanent plots were established in January and February of 2013-2015 in the area of Fildes Peninsula （King George Island）. Here we present the benchmark data of the first observations from these plots, including site characteristics, and the population and associates of D. antarctica in each plot. The basic data are important to understand the vegetation change, distribution range, and expansion of D. antarctica in Antarctica under future climate change scenarios.展开更多
The question of why only two species of vascular plant have colonized Antarctica has not been fully answered. This review is based on a series of parallel analyses of distribution, ecology, and adaptation on the morph...The question of why only two species of vascular plant have colonized Antarctica has not been fully answered. This review is based on a series of parallel analyses of distribution, ecology, and adaptation on the morphological, cellular, and molecular genetic levels, and addresses the causes of the exclusive adaptation of Deschampsia antarctica Desv. (Poaceae) and Colobanthus quitensis (Kunth) Bartl. The authors conclude that the unique distribution of these species, including the Antarctic Peninsula, is not related to the presence of any specific mechanisms of adaptation to the ex-treme environment, but rather is a result of a gradual adaptation of these taxa to the extreme conditions during the de-velopment of glacial events and wide distribution and a substantial seed bank which could ensure mosaic survival in some ice-free areas, as well as survival through several years of snow and ice cover. Glaciological, molecular, popula-tion and reproduction biology studies are still necessary to deepen our understanding of the timing of the colonization of the region by vascular plants. However, keeping in mind that molecular methods alone are unlikely to give exhaus-tive evidence, application of other adequate methods in the context of the history of Pleistocenic glaciation in the region is also necessary to answer the question.展开更多
基金Supported by the Foundation for Polish Science (FNP) for the DomesticStipend for Young Scholars ("START",awarded in 2008)
文摘The aim of our work was to assess photosynthetic plasticity of two hairgrass species with different ecological origins （a temperate zone species, Deschampsia caespitosa （L.） Beauv. and an Antarctic species, D. antarctica） and to consider how the anticipated climate change may affect vitality of these plants. Measurements of chlorophyll fluorescence showed that the photosystem Ⅱ （PSⅡ） quantum efficiency of D. caespitosa decreased during 4 d of incubation at 4℃ but it remained stable in D. antarctica. The fluorescence half-rise times were almost always lower in D. caespitosa than in D. antarctica, irrespective of the incubation temperature. These results indicate that the photosynthetic apparatus of D. caespitosa has poorer performance in these conditions. D. caespitosa reached the maximum photosynthesis rate at a higher temperature than D. antarctica although the values obtained at 8 ℃ were similar in both species. The photosynthetic water-use efficiency （photosynthesis-to-transpiration ratio, PIE） emerges as an important factor demonstrating presence of mechanisms which facilitate functioning of a plant in non-optimal conditions. Comparison of the PiE values, which were higher in D. antarctica than in D. caespitosa at low and medium temperatures, confirms a high degree of adjustability of the photosynthetic apparatus in D. antarctica and unveils the lack of such a feature in D. caespitosa.
基金financially supported by the National Natural Science Foundation of China (Grant no.41271222)Main Direction Program of Knowledge Innovation of Chinese Academy of Sciences (Grant no.KSCX2-EW-J-1)SKLSEB-IBCAS (Grant no.56176G1048)
文摘Climate warming has become evident in the maritime Antarctic over the past decades, and has already influenced the growing season and the population size of two native vascular plants in Antarctica, Deschampsia antarctica and Colobanthus quitensis. Both vascular plant species are therefore regarded as good bioindicators of regional warming in west Antarctica. To carry out long-term monitoring of vegetation （mainly using D. antarctica） and build a comprehensive research platform for multi-disciplinary study （including botany, microbiology, ecology, and environmental science） for Chinese scientists, 13 permanent plots were established in January and February of 2013-2015 in the area of Fildes Peninsula （King George Island）. Here we present the benchmark data of the first observations from these plots, including site characteristics, and the population and associates of D. antarctica in each plot. The basic data are important to understand the vegetation change, distribution range, and expansion of D. antarctica in Antarctica under future climate change scenarios.
文摘The question of why only two species of vascular plant have colonized Antarctica has not been fully answered. This review is based on a series of parallel analyses of distribution, ecology, and adaptation on the morphological, cellular, and molecular genetic levels, and addresses the causes of the exclusive adaptation of Deschampsia antarctica Desv. (Poaceae) and Colobanthus quitensis (Kunth) Bartl. The authors conclude that the unique distribution of these species, including the Antarctic Peninsula, is not related to the presence of any specific mechanisms of adaptation to the ex-treme environment, but rather is a result of a gradual adaptation of these taxa to the extreme conditions during the de-velopment of glacial events and wide distribution and a substantial seed bank which could ensure mosaic survival in some ice-free areas, as well as survival through several years of snow and ice cover. Glaciological, molecular, popula-tion and reproduction biology studies are still necessary to deepen our understanding of the timing of the colonization of the region by vascular plants. However, keeping in mind that molecular methods alone are unlikely to give exhaus-tive evidence, application of other adequate methods in the context of the history of Pleistocenic glaciation in the region is also necessary to answer the question.
