Tundra Ecosystem and Feedback to Global Change

我们在高北极地区进行了3年的主要研究：斯匹茨卑尔根ⅰ号冰川消融区植被的碳循环和演替过程。苔藓光合速率的最适温度为15℃，但即使在3℃也有显著的光合活性。利用温度和光光合曲线，根据PPFD（光合有效光子通量密度）数据和田间苔藓温度估算了该苔藓的净初级产量。这表明该地区的年初级产量远低于海洋南极和低北极地区的报告。通过与斯匹茨卑尔根地区的生态系统对比，对全球环境变化对加拿大北极地区生物多样性的影响进行了初步研究。

We performed mainly the following subjects in the high Arctic during three years : Carbon cycle and successional process on vegetation occurred in the deglaciated area of Spitzbergen I. Photosynthetic rate of the mosses was near to the detectable limit. The optimal temperature of the photosynthetic rate of the mosses was 15℃, but significant photosynthetic activity was detected even at 3℃. Using the temperature and light-photosynthetic curves, the net primary production of the moss was estimated from the date of PPFD (photosynthetically active photon flux density) and moss temperature in the field. It suggested that the annual primary production in this area was much lower than those reported for maritime Antarctic and low arctic. Comparing with the ecosystem in the Spitzbergen area, we also carried out preliminary study for the change of biological diversity in Arctic Canada influenced by global environmental change.