Year: 2017
Type: article
Abstract: Studies of the impact of climate change on plants are generally based on vascular \nplants. Bryophytes basically differ from tracheophytes in having a smaller size and \na poikilohydric strategy for water and nutrients. Their survival and growth are \nhighly dependent on their external environment. Bryophytes are able to lose most \nof their cell water without dying, and resume normal metabolism after \nrehydration, gaining positive carbon balance over wet-dry cycles. This is sort of \nadaptation is called desiccation tolerance. Desiccation tolerance is a common but \nnot unique phenomenon among bryophytes: cells of bryophytes in exposed sunny \nsites can switch from full turgor to air dryness quickly, while the species of moist \nhabitats dry more slowly, and can suffer stress by even moderate drying. They can \nmaintain efficient photosynthesis under low light conditions, have low chl a/b \nratios, and within a limited temperature range their optimum growth is possible. \nWhen certain bryophytes’ CO2 assimilation is suppressed, photorespiration \nactivity increases and becomes the main electron sink. Bryophytes, as the sensitive \ncomponents of various vegetation types, are capable of effective light absorption \nduring their desiccation, rehydration, freezing and melting, with the help of \ncoexisting alga and vascular plant energy dissipation mechanisms. They have \nrelatively low optimal temperature for growth (with narrow T range for net \nphotosynthetic gain), including only minor differences between the optimum \ntemperatures for net photosynthesis in the same species from polar, temperate \nand tropical populations. Bryophytes have a low acclimatization potential for high \ntemperatures, taking into account that they are generally drought avoiders. \nTemperature acclimatization potential is of high importance for the physiological \nbasis of altitudinal distribution and the likely responses of bryophytes to climate \nchange. Bryophytes with their small and resistant spores are able to disperse over \nlong distances by wind, which might help their survival in the changing \nenvironment. Dominant vascular vegetation might change as temperature will \nincrease; however, suitable microhabitats for bryophytes might still persist. The \nabundance and species composition of bryophytes in plant communities is \npredicted to be altered, as well as the function of the whole ecosystem. Based on \nrecent literature and own data, the author makes an attempt to summarize the \nphysiological mechanisms, morphological features and alternative strategies \nwhich make bryophytes successful in a constantly changing terrestrial \nenvironment. These plants represent a sophisticated solution to the challenges of \nlife at their scale. Further exploration of bryophyte ecophysiology in the changing \nand stressful environment will provide new information that will assist bryophyte \nconservation. The research was supported by the grant EFOP-3.6.1-16-2016- \n00001 (“Complex improvement of research capacities and services at Eszterhazy \nKaroly University”).
Author: Marianna Marschall
Language: English
Domain: Life Sciences
SDG: Climate action
Open Access status: diamond
OpenAlex ID: W2771892469