부산대학교 도서관

Climate change is rapidly warming high latitude and high elevation regions influencing plant community composition. Changes in vegetation composition have motivated the coordination of ecological monitoring networks across the Arctic, including the International Tundra Experiment. We have established a long-term passive warming experiment using open-top chambers, which includes five distinct plant communities (Dry Heath; Tussock Tundra; and Dry, Mesic, and Wet Meadow). We measured changes in plant community composition based on relative abundance differences over 26 years. In addition, relative abundance changes in response to fertilization and warming treatments were analyzed based on a seven-year Community-Level Interaction Program experiment. The communities had distinct soil moisture conditions, leading to community-specific responses of the plant growth forms (deciduous shrubs, evergreen shrubs, forbs, and grami-noids). Warming significantly affected growth forms, but the direction of the response was not consistent across the communities. Evidence of shrub expansion was found in nearly all communities, with soil moisture determining whether it was driven by deciduous or evergreen shrubs. Graminoids increased in relative abundance in the Dry Meadow due to warming. Growth form responses to warming are likely mediated by edaphic characteristics of the communities and their interactions with climate. Key words: International Tundra Experiment (ITEX), climate warming, Arctic, vegetation, Latnjajaure. Le changement climatique cause un rechauffement rapide dans les hautes latitudes et en haute altitude, influant sur la composition de la communaute vegetale. Les changements de la composition vegetale ont motive la coordination de reseaux de surveillance ecologique dans l'Arctique, y compris l'Experience internationale sur la toundra (<< International Tundra Experiment >>). Les auteurs ont etabli une experimentation de rechauffement passif a long terme a l'aide de chambres a ciel ouvert, comprenant cinq communautes vegetales distinctes (lande seche, toundra de Tussock, et prairie seche, mesique, et humide). Ils ont mesure les changements dans la composition vegetale en fonction des differences d'abondance relative sur 26 ans. De plus, les changements relatifs d'abondance en reponse aux traitements de fertilisation et de rechauffement ont ete analyses sur la base d'une experience de sept ans du << Community-Level Interaction Program >>. Les communautes presentaient des conditions d'humidite du sol distinctes, ce qui a donne lieu a des reponses propres a la communaute, et ce, aux formes de croissance des plantes (arbustes a feuilles caduques, arbustes a feuilles persistantes, herbes non gramineennes et graminoides). Le rechauffement a eu des repercussions importantes sur les formes de croissance, mais l'orientation de la reponse n'etait pas uniforme dans l'ensemble des communautes. Des signes d'expansion des arbustes ont ete observes dans presque toutes les communautes, et l'humidite du sol a determine si elle etait causee par des arbustes a feuilles caduques ou a feuilles persistantes. L'abondance relative des graminoides a augmente dans la prairie seche en raison du rechauffement. Les reponses de la forme de croissance au rechauffement sont probablement mediees par les caracteristiques edaphiques des communautes et leurs interactions avec le climat. [Traduit par la Redaction] Mots-cles : Experience internationale sur la toundra (<< International Tundra Experiment, ITEX >>), rechauffement du climat, Arctique, vegetation, Latnjajaure.
Introduction Climate change is causing drastic changes to the world's biomes, typically associated with rising global air temperatures. This is especially pronounced in the Arctic and high altitude environments where [...]