Huang Ke-Chao, Shen Yu-Yi, Xu Guang-Ping, Huang Yu-Qing, Zhang De-Nan, Sun Ying-Jie, Li Yan-Qiong, He Wen, Zhou Long-Wu
Guangxi Key Laboratory of Plant Conservation and Restoration Ecology in Karst Terrain, Guangxi Institute of Botany, Guangxi Zhuang Autonomous Region and Chinese Academy of Sciences, Guilin 541006, China.
Guangxi Key Laboratory of Functional Phytochemicals Research and Utilization, Guangxi Institute of Botany, Guangxi Zhuang Autonomous Region and Chinese Academy of Sciences, Guilin 541006, China.
Huan Jing Ke Xue. 2018 Apr 8;39(4):1813-1823. doi: 10.13227/j.hjkx.201707196.
To investigate the effect of reclamation on soil quality in the Huixian Karst Wetland, samples from different soil levels were collected from marsh wetland, reclaimed paddy field, and reclaimed dry farmland, for analyzing soil nutrient (carbon, nitrogen, phosphorous, and potassium) contents, microbial biomass carbon/nitrogen (MBC/MBN), and microbial activity indicators[i.e. basal respiration (BR), potential respiration (PR), microbial quotient (qMB), and metabolic quotient (qCO)]. The correlations between the soil nutrient contents and soil microbial activity indictors were examined. The results showed that:①Artificial reclamation led to the trend of slight acidity in the soil and a marked loss in soil nutrients, while, the pH value, soil water content (SWC), and the contents of soil organic carbon (SOC), total nitrogen (TN), available nitrogen (AN), total phosphorus (TP), available phosphorus (AP), total potassium (TK), and available potassium (AK) decreased with reclamation. ②Among all the microbes, bacteria were the most numerous, followed by actinomycetes, and fungi were the least numerous. The microbial quantity decreased with the increase in the soil depth on the whole. The proportion of bacteria and actinomycetes were much higher in the paddy field, and that of fungi was the highest in the dry farmland. ③ In total, protease, sucrase, urease, catalase, and polyphenol oxidase activities decreased with the increasing of soil depths. Soil reclamation reduced the soil enzyme activities. ④qCO decreased after an initial increase in the marsh wetland, while it rose gradually in the reclaimed paddy field and reclaimed dry farmland. The contents of MBC, MBN, BR, PR, and qMB were the highest in the marsh wetland, followed by those in the reclaimed paddy field, with the lowest contents occurring in the reclaimed dry farmland. The trend of qCO contents in the 0-10 cm and 10-20 cm soil layers followed the order of marsh wetland > paddy field > dry farmland, but in the 20-30 cm and 30-40 cm soil layers, it showed the order dry farmland > paddy field > marsh wetland. The continuation of reclamation resulted in the decrease in soil microbial activity, and soil quality as well, especially in the dry farmland. Meanwhile, we should reduce the areas of paddy fields and dry farmlands under reclamation during the process of wetland ecological restoration in future. Conversion of farmlands to wetlands or lakes, to improve and increase the size of wetland ecosystems of nearby lands, should be done gradually.
为研究土地开垦对辉县喀斯特湿地土壤质量的影响，采集了沼泽湿地、开垦水田和开垦旱地不同土层的样本，用于分析土壤养分（碳、氮、磷和钾）含量、微生物生物量碳/氮（MBC/MBN）以及微生物活性指标[即基础呼吸（BR）、潜在呼吸（PR）、微生物商（qMB）和代谢商（qCO₂）]。研究了土壤养分含量与土壤微生物活性指标之间的相关性。结果表明：①人工开垦导致土壤呈微酸性趋势，土壤养分显著流失，开垦后土壤pH值、土壤含水量（SWC）、土壤有机碳（SOC）、全氮（TN）、有效氮（AN）、全磷（TP）、有效磷（AP）、全钾（TK）和有效钾（AK）含量均下降。②在所有微生物中，细菌数量最多，其次是放线菌，真菌数量最少。总体上微生物数量随土壤深度增加而减少。水田中细菌和放线菌的比例较高，旱地中真菌的比例最高。③总体而言，蛋白酶、蔗糖酶、脲酶、过氧化氢酶和多酚氧化酶活性随土壤深度增加而降低。土壤开垦降低了土壤酶活性。④沼泽湿地中qCO₂先升高后降低，而在开垦水田和开垦旱地中则逐渐升高。MBC、MBN,、BR、PR和qMB含量在沼泽湿地中最高，其次是开垦水田，开垦旱地中含量最低。0-10cm和10-20cm土层中qCO₂含量的变化趋势为沼泽湿地>水田>旱地，但在20-30cm和30-40cm土层中，呈现旱地>水田>沼泽湿地的顺序。持续开垦导致土壤微生物活性降低，土壤质量也随之下降，尤其是旱地。同时，在未来湿地生态恢复过程中，应减少开垦水田和旱地的面积。应逐步将农田转变为湿地或湖泊，以改善和扩大附近土地的湿地生态系统面积。
