Fluorescence procedures to assess the photosynthetic resilience in Scots pines after a surface fire

Abstract

Abstract. Forest fire represents one of the most serious abiotic stress factors that influence the function and productivity of ecosystems globally. Siberian pine forests are often exposed to forest fires but they are not always harmful to them. We have analyzed the effects of repeated heat stress on the photosynthetic apparatus of Scotch pines before and after surface fire exposure that occurred in the growing season in 2014. The survey area was the forest steppe zone of Krasnoyarsk region (South Siberia). First, we investigated the changes in the temperature-dependent responses of photosynthesis in the needles by means of fast and delayed chlorophyll fluorescence. Our results are indicative of some acclimation of Scotch pines after fire to the repeated high temperature stress. Also, this paper discusses the possibility of using chlorophyll fluorescence parameters for evaluating the presence of physiological changes after the fire affects. The time after fire effect and growth season were found to be important to assess the repair of photosynthesis and pigment content.