TROPHIC STATUS OF THE MIRES IN CHANGBAI MOUNTAINS, NORTHEAST CHINA

摘要

Trophic status of mires is a significant indicator of the processes and trends of mires development, which help guide rational use of peat resources and reconstruct the past environmental changes during the formation of mires. Changbai Mountains in Northeast China is one of areas in which mires are widely distributed. However, little attention has been paid to the trophic status of the mires in it. We investigated 130 plant quadrats of 75 mires in Changbai Mountains in 2014, and collected the peat samples from the depth of 15cm beneath each plant quadrat. Total organic carbon (TOC), total nitrogen (TN) and pH (KC1) were measured for all peat samples. The types of plants are mainly the herbs (Carex spp, reed, sedge) and the shrubs (Salix spp, Betula spp, Spiraea spp, Ledum palustre and Vaccinium uliginosum). In addition, Sphagnum spp and Polytrichum spp have been found in some peatlands. TOC/TN ratio is 9.8-50.0, and pH (KC1) is 3.53-5.54. Hence, we conclude the majority of the mires are still in eutrophic condition although they originated at least 2000 years ago. Some mires developed at the early-middle Holocene at the foot of Changbai Mountains and some ones developed at the late Holocene in the ridge appear to be in a transition from the eutrophic status to the mesotrophic one. The trophic status of the mires in Changbai Mountains may be attributed to abundant nutrition sources, especially atmospheric deposition derived from the East Asia monsoon.