| 李林蔚,吴攀,曹星星,杨诗笛,刘闪,廖家豪.贵州威宁草海湿地表层沉积物有机质时空分布及其来源辨析[J].农业环境科学学报,2022,41(1):153-161. |
| 贵州威宁草海湿地表层沉积物有机质时空分布及其来源辨析 |
| Spatial-temporal distribution of organic matter in surface sediments of Caohai wetland in Weining, Guizhou Province, China |
| 投稿时间：2021-05-27 |
| DOI：10.11654/jaes.2021-0617 |
| 中文关键词: 草海湿地 有机质 碳同位素(δ13C) 氮同位素(δ15N) 来源 |
| 英文关键词: Caohai Lake wetland organic matter carbon isotope(δ13C) nitrogen isotope(δ15N) source |
| 基金项目:国家自然科学基金项目(41807376); 贵州大学人才引进项目[贵大人基合字(2019)24号]; 贵州省人才基地项目(RCJD2018-21); 喀斯特地质资源与环境教育部重点实验室开放课题(KST2017K06) |
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| 中文摘要: |
为探究岩溶湿地生态环境的营养状况及污染物来源，以贵州威宁草海岩溶湿地为例，通过对其不同水文期表层沉积物中总有机碳（TOC）和总氮（TN）的含量分布及其稳定碳同位素（δ13C）、稳定氮同位素（δ15N）和C/N的分析，探讨了沉积物有机质的分布特征及来源。结果表明：草海湿地表层沉积物丰水期TOC、TN含量变化范围分别为3.75%~32.71% 和0.39%~2.90%，平均值分别为14.34% 和1.52%；枯水期TOC、TN含量变化范围分别为1.26%~34.11%和0.18%~2.49%，平均值分别为12.46%和1.12%；丰水期TOC、TN含量略高于枯水期，这与丰水期大量降雨带来的陆源输入有关，同时在空间分布上二者在两个水文期均表现为西南和湖心区域大于东部和西北区域。草海湿地表层沉积物丰水期δ13C、δ15N分布范围分别在-2.55%~-1.97% 和0.03%~0.37%，平均值分别为-2.23% 和0.24%；枯水期δ13C、δ15N分布范围分别在-2.75%~-1.96%和0.10%~0.46%，平均值分别为-2.35% 和0.30%；其中δ13C的空间分布特征表现为东区较西区明显偏负，说明东区污染严重，这是由于东区毗邻县城，污染物来源复杂，沉水植物遭到破坏，使得湖泊自身生产力降低。通过端元混合模型对沉积物来源进行定性和半定量分析，结果表明：草海湿地表层沉积物有机质的主要来源为土壤有机质、浮游藻类及淡水水生植物，同时由于草海岩溶湿地具有较高的初级生产力，沉积物中有机质来自内源的贡献大于来自外源的输入。 ![]() |
| 英文摘要: |
| To explore the nutritional status and pollutant sources of the ecological environment of karst wetlands, the distribution of total organic carbon(TOC)with total nitrogen(TN), including stable carbon isotopes(δ13C), nitrogen isotopes(δ15N), and C / N ratios, were studied in the surface sediments of the Caohai Lake karst wetland in Weining, Guizhou Province; then, the distribution characteristics and sources of organic matter in sediments were discussed. The results showed that the TOC and TN contents varied from 3.75% to 32.71% and 0.39% to 2.90% in the wet season, with average values of 14.34% and 1.52%, respectively. The TOC and TN contents ranged from 1.26% to 34.11% and 0.18% to 2.49% in the dry season, with average values of 12.46% and 1.12%, respectively. The TOC and TN contents in the high water period were slightly higher than those in the dry season, which was related to the land source input caused by increased rainfall during the high water period. Meanwhile, regarding the spatial distribution, the concentrations of TOC and TN in the southwest and the lake center region were greater than those in the east and northwest regions in both seasons. Regarding surface sediments in the Caohai Lake wetland, the distribution of δ13C, δ15N ranged from -2.55% to -1.97% and from 0.03% to 0.37% in the wet season, with average values of -2.23% and 0.24%, respectively. The distribution of δ13C and δ15N ranged from -2.75% to -1.96% and 0.10% to 0.46% in the dry season, with average values of -2.35% and 0.30%, respectively. The spatial distribution of δ13C in the eastern area was significantly lower as compared to the western area, which indicated that the eastern area was seriously polluted. This was because the eastern area was adjacent to the county, the source of pollutants was complex, the submerged plants were destroyed, and the productivity of the lake itself was reduced. The end member mixed model was used to qualitatively and semi-quantitatively analyze the sediment sources. The results showed that the main sources of organic matter in the surface sediments of the Caohai Lake wetland were soil organic matter, planktonic algae, and freshwater aquatic plants. At the same time, due to the high primary productivity of the Caohai Lake karst wetland, the contribution of organic matter in the sediments from internal sources was greater than that from exogenous inputs. |
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