Details

Autor(en) / Beteiligte

• Hasanuzzaman, Mirza

Titel

Adaptation of Halophytes to the Gradient Conditions on the Northern Seas Coast

Ist Teil von

• Plant Ecophysiology and Adaptation under Climate Change: Mechanisms and Perspectives II, 2020, p.821-856

Ort / Verlag

Singapore: Springer

Erscheinungsjahr

2020

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Nowadays, it is relevant to study the mechanisms of rhythmic processes that are the basis of the vital activity of all organisms. From this point of view, it is necessary to study the functioning of organisms living in tidal conditions on the coastal zone of the northern seas. Twice a day, plants are flooded with water on the intertidal zone, and then they go out for drying—there is a change in the water and air environment, which is accompanied by changes in light, temperature, oxygen and CO2  concentrations, pressure, and other parameters. These conditions have led to the formation of a unique halophyte complex of higher terrestrial plants, which have formed various adaptive mechanisms that provide the possibilities for normal existence. Three zones are distinguished on the coastal zone of the White Sea: supratidal, intertidal, and subtidal zones. For each zone, the following species was investigated: for supratidal—Alopecurus arundinaceus, Atriplex glabriuscula, Carex subspathacea; for intertidal—Tripolium vulgare, Triglochin maritima, Salicornia europaea, and three species of Plantago genus; for subtidal—Zostera marina. Species growing on intertidal and subtidal zones are resistant to flooding and have various structural and functional adaptations. The photosynthetic characteristics (CO2 rate of gas exchange, transpiration, stomatal conductivity, and CO2 concentration in the intercellular spaces of the leaves) were studied using the LCPro + portable gas analyzer at natural light intensity and air temperature. Analysis of CO2 exchange curves by the model of Farquhar et al. showed a difference in the values of the maximum carboxylation rate (Vcmax), the electron transport rate at light saturation (Jmax), the utilization rate of triose phosphate, and a number of other parameters in plants of different zones. A comparative study of physiological parameters showed the highest functional activity in plants in the intertidal zone, which undergo daily tidal dynamics. The influence of environmental factors on the content of chlorophylls a and b and the amount of carotenoids was estimated. Evaluation of the implementation of photosynthetic activity in natural habitats in relation to the maximum values at saturating concentration of CO2 showed that the species of higher vascular plants realize their potential in the range of 6–20% on the supratidal zone, from 10 to 70% on the intertidal zone, and from 30 to 60% on the subtidal zone. In the case of a global increase of CO2 concentration, we can expect a significant increase in CO2 absorption by the following halophytes: T. vulgare, Plantago maritima, Z. marina, Al. arundinaceus, and At. glabriuscula, as well as an increase in productivity of P. maritima and Z. marina among the studied halophytes of the coastal zones of the northern Holarctic seas.