Temperature dependence of allelopathy duality and its influence on boreal forest succession-A case analysis of Picea schrenkiana

Abstract

Global warming in conjunction with various biotic or abiotic interferences has been jeopardizing the ecosystem of boreal forests. By integrating field inspection with experimental simulation, this work comprehensively investigated the allelopathic effects of a key allelochemical 3,4-dihydroxyacetophenone (DHAP) in the exudates of P. schrenkiana needles on its seed and seedling growth, endogenous hormone metabolism and antioxidant enzyme activity, identified the existence of DHAP allelopathy duality at a certain temperature with an inflection concentration point (e.g. about 0.25 mM at dark/light temperature of 4/12 °C) as the boundary between promotional and inhibitory effect, and verified that the inflection point of DHAP concentration would inevitably shift to a lower level as temperature increased. Consequently, this paper gives a scientific explanation into the intrinsic mechanism of P. schrenkiana degradation due to allelopathy, but also presents a new approach to explore the relationship between forest evolution and global warming.