Peatlands In China Research Articles

Recent atmospheric lead deposition recorded in an ombrotrophic peat bog of Great Hinggan Mountains, Northeast China, from 210Pb and 137Cs dating

Radioactive markers are useful in dating lead deposition patterns from industrialization in peat archive. Peat cores were collected in an ombrotrophic peat bog in the Great Hinggan Mountains in Northeast China in September 2008 and dated using 210Pb and 137Cs radiometric techniques. The mosses in both cores were examined systematically for dry bulk density, water and ash content. Lead also was measured using atomic emission spectroscopy with inductively coupled plasma (ICP-AES). Both patterned peat profiles were preserved well without evident anthropogenic disturbance. Unsupported 210Pb and 137Cs decreased with the depth in both of the two sample cores. The 210Pb chronologies were established using the constant rate of supply model (CRS) and are in good agreement with the 137Cs time marker. Recent atmospheric 210Pb flux in Great Hinggan Mountains peat bog was estimated to be 337 Bq m −2 y −1, which is consistent with published data for the region. Lead deposition rate in this region was also derived from these two peat cores and ranged from 24.6 to 55.8 mg m −2 y −1 with a range of Pb concentration of 14–262 μg g −1. The Pb deposition patterns were consistent with increasing industrialization over the last 135–170 y, with a peak of production and coal burning in the last 50 y in Northeast China. This work presents a first estimation of atmospheric Pb deposition rate in peatlands in China and suggests an increasing trend of environmental pollution due to anthropogenic contaminants in the atmosphere. More attention should be paid to current local pollution problems, and society should take actions to seek a balance between economic development and environmental protection.

Recent Carbon Accumulation in Changbai Mountain Peatlands, Northeast China

The Changbai Mountain range is a well-known and important mountain chain in northeast China, bordering the Korean Peninsula in the south. It is also one of the areas most sensitive to global change. Massive peatlands that play a key role in the global carbon (C) cycle are found in this region. Estimating and assessing C dynamics in Changbai Mountain peatlands is of great importance to local sustainable development. Dry bulk density and C content analyses based on 8 selected peat cores dated by 210Pb were used to estimate recent rates of carbon accumulation (RERCA, g C m−2 yr−1) in Changbai Mountain peatlands. RERCA ranged from 124.2 to 292.8 g C m−2 yr−1 (average 199.6 ± 60.9 g C m−2 yr−1). Obvious increasing trends in RERCA were observed in all peat cores. The C pool for 200 years was 38.5–52.1 kg C m−2, which can supplement the database of C pools for Changbai Mountain ecosystems. The 210Pb radiometric technique was tested and found to be a useful study method for recent terrestrial carbon sequestration. This study could contribute to a better understanding of rarely studied mountain peatlands in China and may be useful to global mountain and climate change research.

Assessment of volatile organic compound emissions from ecosystems of China

Isoprene, monoterpene, and other volatile organic compound (VOC) emissions from grasslands, shrublands, forests, and peatlands in China were characterized to estimate their regional magnitudes and to compare these emissions with those from landscapes of North America, Europe, and Africa. Ecological and VOC emission sampling was conducted at 52 sites centered in and around major research stations located in seven different regions of China: Inner Mongolia (temperate), Changbai Mountain (boreal‐temperate), Beijing Mountain (temperate), Dinghu Mountain (subtropical), Ailao Mountain (subtropical), Kunming (subtropical), and Xishuangbanna (tropical). Transects were used to sample plant species and growth form composition, leafy (green) biomass, and leaf area in forests representing nearly all the major forest types of China. Leafy biomass was determined using generic algorithms based on tree diameter, canopy structure, and absolute cover. Measurements of VOC emissions were made on 386 of the 541 recorded species using a portable photo‐ionization detector method. For 105 species, VOC emissions were also measured using a flow‐through leaf cuvette sampling/gas chromatography analysis method. Results indicate that isoprene and monoterpene emissions, as well as leafy biomass, vary systematically along gradients of ecological succession in the same manner found in previous studies in the United States, Canada, and Africa. Applying these results to a regional VOC emissions model, we arrive at a value of 21 Tg C for total annual biogenic VOC emissions from China, compared to 5 Tg C of VOCs released annually from anthropogenic sources there. The isoprene and monoterpene emissions are nearly the same as those reported for Europe, which is comparable in size to China.

Vegetation of alpine marshland and its neighboring areas, northern part of Sichuan Province, China

To obtain the characteristics of Chinese alpine grassy marshland, the vegetation of Ruoergai marshland, which is the largest peatland in China, and of neighboring areas was surveyed along mountain slopes in three areas, Ouhailao, Waqie and Kaharqiao. Based on the clustering of 122 1 m × 1 m quadrats surveyed, the vegetation was grouped into 8 types. From bottom to top of mountain slopes, the dominant species, zonally established, were: 1) Carex enervis and Equisetum limosum; 2) Carex meyeriana; 3) Deschampsia caespitosa, Caltha scaposa and Anemone obtusiloba; 4) Koeleria cristata; 5) Kobresia tibetica and Caltha scaposa; 6) Blysmus sinocompressus; 7) Polygonum sphaerostachyum and Trollius ranuncloides; and 8) Ranunculus pedicularis. In this order, species richness increased gradually along the slopes. A principal component analysis demonstrated that water depth partly regulated the establishment of vegetation. The geographical difference of vegetation was also observed, in particular, in Waqie. Likewise, grazing is considered to modify this vegetation.