Response Of The Indicative Plant Communities To Simulated Warming In Forest-tundra Ecotone Of Changbai Mountain

Global warming has become a main trend in climate change. Global mean airtemperature has increased0.6℃in the20th century due to the impact of human activities.Climate change has already shown an important and far-reaching effect on plant communitiesand terrestrial ecosystems. Especially, it is more obvious at high latitudes and high altitudes.This paper is arm to investigate the effects of simulated warming on two plant communities inforest-tundra ecotone of Changbai Mountain, using the open-top chamber (OTC) method.After the short-term experiment, the results show that Rhododendron chrysanthumcommunities showed obvious response to the OTC treatment in the cloudy and fog days, butnot obvious in the sunny and rainy days, due to the shading effect of Ermans birch forest andother environmental factors. Compared with Rhododendron chrysanthum communities, onsunny day, Vaccinium uliginosum Linn. communities showed more obvious response to theOTC treatment because it is not affected by the tree shadow. According to the comparativeanalysis of shade and non-shade, it reveals that the OTC is more useful in the case of externalheat input. The soil depth increases accompanied the decrease of soil temperature rise. Thesoil temperature increments of Rhododendron chrysanthum communities is significant thanthat of Vaccinium uliginosum Linn.According to the OTC warming treatment, Rhododendron chrysanthum and Vacciniumuliginosum Linn. showed different response in terms of the growth form, biomass and thephenophases. The simulated warming increased the plant height, leaf area and totalaboveground biomass of Rhododendron chrysanthum and Vaccinium uliginosum Linn.,whereas the responses of Vaccinium uliginosum Linn. are more obvious. The NDVI valueinverted from the ADC camera is used to compare the phenological differences. The resultsshow that short-term simulated warming experiment has little effect on the Rhododendronchrysanthum community structure and NDVI value, whereas it has obvious influence on theVaccinium uliginosum Linn. community whose coverage has increased by about10%.Meanwhile, the NDVI value in OTC is higher than that of the outside in September, and theend of growing season is postponed.Both Rhododendron chrysanthum and Vaccinium uliginosum Linn. community revealresponse to the short-term simulated warming, whereas the response of Vaccinium uliginosumLinn. community to the warming is more pronounced, due to its life form and habitatconditions. According to the experimental results, it is can be inferred that the plantcommunities and ecosystems of the forest-tundra ecotone of Changbai Mountain will evolvedue to increasing temperature in the context of global warming, and then provide an important reference way for predicting the changes in ecosystems of the forest-tundra ecotone and theevolution trend of plant communities over Changbai Mountain under the context of climatewarming.