摘要
在北极附近存在的两大类淡水生态系统,即:激流(流水;如:河流、溪流、三角洲及河口)和死水(静水;如湖泊、池塘及湿地)生态系统,它们在大小、丰度及生物群方面存在着巨大的差异。北极的气候,其许多的组分沿纬度梯度呈现出强烈的变化,直接影响这些水生系统中的各种物理、化学及生物学过程。此外,北极气候通过控制陆地水文系统和过程,特别是那些与诸如永久冻土、淡水冰和雪聚积/融化等低温层组分有关的,而产生其它间接的生态影响。北极淡水系统的生态结构和功能也受外部过程和条件的控制,特别是在主要北极河流源头和毗邻海洋环境中的那些。物理、化学及生物组分穿过互连的死水和激流淡水生态系统的运动是北极淡水生态的主要决定因素。
Large variations exist in the size, abundance and biota of the two principal categories of freshwater ecosystems, lotic (flowing water; e.g., rivers, streams, deltas and estuaries) and lentic (standing water; lakes, ponds and wetlands) found across the circumpolar Arctic. Arctic climate, many components of which exhibit strong variations along latitudinal gradients, directly affects a range of physical, chemical and biological processes in these aquatic systems. Furthermore, arctic climate creates additional indirect ecological effects through the control of terrestrial hydrologic systems and processes, particularly those associated with cryospheric components such as permafrost, freshwater ice and snow accumulation/ablation. The ecological structure and function of arctic freshwater systems are also controlled by external processes and conditions, particularly those in the headwaters of the major arctic rivers and in the adjacent marine environment. The movement of physical, chemical and biotic components through the interlinked lentic and lotic freshwater systems are major determinants of arctic freshwater ecology.
