Seasonal shift in factors controlling net ecosystem production in a high Arctic terrestrial ecosystem.
Seasonal shift in factors controlling net ecosystem production in a high Arctic terrestrial ecosystem.
复制标题
控制北极高陆地生态系统净生态系统生产因素的季节性变化。
DOI：
10.1007/s10265-009-0260-6
复制
发表时间：
2010
影响因子：
2.8
通讯作者：
Kanda H. and Koizumi H.
中科院分区：
文献类型：
--
作者：
Uchida M.;Kishimoto A.;Muraoka H.;Nakatsubo T.;Kanda H. and Koizumi H.
我们研究了无雪季节北极高纬度半沙漠生态系统中控制净生态系统生产力（NEP）时间变化的因素。我们研究了NEP和生物和非生物因素之间的关系，在一个占主导地位的植物群落（柳polaris-moss）在挪威高北极。就在7月初融雪后，生态系统向大气中释放了二氧化碳。几天后，融雪，然而，生态系统成为一个CO2汇的叶片S. polaris发展。NEP的日变化反映了夏季光入射（光合光子通量密度，PPFD）的变化。NEP与PPFD显著相关时，S.polarishad充分发育的叶片，即，光合活性高。在秋季，NEP值随着极移藻的衰老而降低。在此期间，二氧化碳有时被释放到大气中。在湿润条件下，苔藓对NEP的贡献较大。事实上，水分含量的苔藓调节NEP在秋季。结果表明，控制夏季NEP的主要因子是北极星的覆盖度和生长量、PPFD和降水。在秋季，控制NEP的主要因子是苔藓含水量。
We examined factors controlling temporal changes in net ecosystem production (NEP) in a high Arctic polar semi-desert ecosystem in the snow-free season. We examined the relationships between NEP and biotic and abiotic factors in a dominant plant community (Salix polaris–moss) in the Norwegian high Arctic. Just after snowmelt in early July, the ecosystem released CO2into the atmosphere. A few days after snowmelt, however, the ecosystem became a CO2sink as the leaves ofS.polarisdeveloped. Diurnal changes in NEP mirrored changes in light incidence (photosynthetic photon flux density, PPFD) in summer. NEP was significantly correlated with PPFD whenS.polarishad fully developed leaves, i.e., high photosynthetic activity. In autumn, NEP values decreased asS.polarisunderwent senescence. During this time, CO2was sometimes released into the atmosphere. In wet conditions, moss made a larger contribution to NEP. In fact, the water content of the moss regulated NEP during autumn. Our results indicate that the main factors controlling NEP in summer are coverage and growth ofS.polaris, PPFD, and precipitation. In autumn, the main factor controlling NEP is moss water content.