Title: Responses of plant biomass allocation and carbon storage characteristics to altitude gradient in alpine peat bogs
Abstract: Abstract The change in hydrothermal conditions caused by altitude gradient will affect plant growth. The study of plant biomass and carbon storage in peat bogs at different elevations is of great significance for further understanding plant tolerance to habitat stress and the uncertainty of plant carbon sinks. According to the distribution characteristics of peat bogs in Zoige Plateau, 3400–3800 m peat bogs in the Shouqu Nature Reserve of the Yellow River were selected as experimental samples. The characteristics of plant biomass allocation, carbon storage, and their main influencing factors were studied by single-factor analysis and path analtysis. The results showed that (1) The biomass distribution ratio of plants in peat bogs was root > leaf > stem, and the subsurface biomass of vegetation was higher than that of above-ground biomass. With the increase in altitude, the aboveground biomass decreased, the total biomass and underground biomass increased first and then decreased, and the root-shoot ratio increased. (2) The organic carbon content of plants in peat bogs was higher in stem > leave > root. The underground carbon storage of plants was higher than that of above-ground carbon storage, and the total carbon storage decreased with the increase in altitude. (3) Path analysis showed that AD, SWC, and TS had direct positive effects on plant biomass and carbon storage, while DEP and pH had direct negative effects on plant biomass and carbon storage. The biomass allocation patterns and carbon storage characteristics of plants in peat bogs reflect the adaptation rules of plants in heterogeneous habitats. It is of great theoretical and practical value to understand the environmental response mechanism of plants in peat bogs under the global climate background and to evaluate wetland plants carbon sink.