English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

In polar ecosystems, primary producers have to cope with a veryharsh climate that limits the time available for growth andbiomass production. In this study, diurnal measurement ofphotosynthetic processes in biological soil crust and a lichenwere carried out in Petuniabukta, Spitsbergen. For fieldmeasurements, a method of induced fluorescence of chlorophyllwas used. Measurements of photosynthetic activity were taken asrepetitive measurements of effective quantum yield ofphotosystem II (PhiPSII). The short-term field measurementswere carried out for 10 days in summer 2014. PhiPSII wasrecorded each 5 minutes as well as microclimatic data (airtemperature, air humidity, photosynthetically active radiation- PAR). The microclimatic parameters were recorded by adatalogger. In general, physiological activity of bothbiological soil crust and a lichen showed daily courses. Testedlichen was Cladonia rangiferina and the most dominant speciesin biological soil crust was Nostoc sp. Typically, most ofPhiPSII values ranged 0.6 – 0.7 in both model organisms. Theresults have shown that photosynthetic activity was stronglycorrelated with all observed abiotic factors in both studyobjects. Particularly important was the relation found betweenPAR and PhiPSII in biological soil crust. When the biologicalsoil crust was exposed to high PAR doses of irradiation (about2300 micromol m-2 s-1) photoinhibition of primary processes ofphotosynthesis was observed as PhiPSII decrease, whilephotosynthetic activity of lichen remained at same level.Furthermore, it has been demonstrated increasing that in situphotosynthetic activity increased in both biological soil crustand lichen with a decrease in temperature.

Diurnal changes in photosynthetic activity of the biological soil crust and lichen: Effects of abiotic factors (Petuniabukta, Svalbard)