Jin Zhen-jiang, Zeng Hong-hu, Li Qiang, Cheng Ya-ping, Tang Hua-feng, Li Min, Huang Bing-fu
Huan Jing Ke Xue. 2016 Jan 15;37(1):335-41.
The purpose of this study is to compare microbial number, microbial biomass as well as soil enzyme activity between paddy field and dryland originated karst wetland ecosystems. The soil samples (0-20 cm) of uncultivated wetland, paddy field and dryland were collected in Huixian karst cave wetland, Guilin, China. Microbial numbers and biomass were detected using dilute plate incubation counting and chloroform fumigation-extraction, respectively. Microbial DNA was extracted according to the manufacturer's instructions of the kit. Microbial activity was examined using soil enzyme assays as well. The result showed that the bacteria number in paddy filed was (4.36 +/- 2.25) x 10(7) CFU x g(-1), which was significantly higher than those in wetland and dryland. Fungi numbers were (6.41 +/- 2.16) x 10(4) CFU x g(-1) in rice paddy and (6.52 +/- 1.55) x 10(4) CFU x g(-1) in wetland, which were higher than that in dryland. Actinomycetes number was (2.65 +/- 0.72) x 10(6) CFU x g(-1) in dryland, which was higher than that in wetland. Microbial DNA concentration in rice paddy was (11.92 +/- 3.69) microg x g(-1), which was higher than that in dryland. Invertase activity was (66.87 +/- 18.61) mg x (g x 24 h)(-1) in rice paddy and alkaline phosphatase activity was (2.07 +/- 0.99) mg x (g x 2 h)(-1) in wetland, both of which were higher than those in dryland. Statistical analysis showed there was a significant positive correlation of microbial DNA content, alkaline phosphatase activity and microbial carbon with soil pH, soil organic carbon (SOC), total nitrogen, alkali-hydrolyzable nitrogen, soil moisture, exchangeable Ca2+ and exchangeable Mg2+, as well as a significant positive correlation of intervase activity with the former three microbial factors. The above results indicated that microbial biomass and function responded much more sensitively to land-use change than microbial number in karst cave wetland system. Soil moisture, SOC and some factors induced by land-use change could affect mainly microbiological characteristics. We suggest that rice paddy, a kind of constructed wetland, should be kept and protected in experimental area or buffer area of Huixian karst cave wetland in the light of its similar property with the natural wetland.
本研究旨在比较稻田和旱地起源的喀斯特湿地生态系统之间的微生物数量、微生物生物量以及土壤酶活性。在中国桂林会仙喀斯特洞穴湿地采集了未开垦湿地、稻田和旱地的土壤样本（0 - 20厘米）。分别采用稀释平板培养计数法和氯仿熏蒸 - 提取法检测微生物数量和生物量。按照试剂盒制造商的说明提取微生物DNA。还通过土壤酶测定来检测微生物活性。结果表明，稻田中的细菌数量为(4.36 ± 2.25)×10(7) CFU×g(-1)，显著高于湿地和旱地中的细菌数量。稻田中的真菌数量为(6.41 ± 2.16)×10(4) CFU×g(-1)，湿地中的真菌数量为(6.52 ± 1.55)×10(4) CFU×g(-1)，均高于旱地中的真菌数量。旱地中的放线菌数量为(2.65 ± 0.72)×10(6) CFU×g(-1)，高于湿地中的放线菌数量。稻田中的微生物DNA浓度为(11.92 ± 3.69) μg×g(-1)，高于旱地中的微生物DNA浓度。稻田中的蔗糖酶活性为(66.87 ± 18.61) mg×(g×24 h)(-1)，湿地中的碱性磷酸酶活性为(2.07 ± 0.99) mg×(g×2 h)(-1)，均高于旱地中的相应酶活性。统计分析表明，微生物DNA含量、碱性磷酸酶活性和微生物碳与土壤pH、土壤有机碳（SOC）、总氮、碱解氮、土壤湿度、交换性Ca2+和交换性Mg2+之间存在显著正相关，蔗糖酶活性与前三个微生物因子之间也存在显著正相关。上述结果表明，在喀斯特洞穴湿地系统中，微生物生物量和功能对土地利用变化的响应比微生物数量更为敏感。土壤湿度、SOC以及土地利用变化引起的一些因素主要会影响微生物学特征。我们建议，鉴于稻田作为一种人工湿地与天然湿地具有相似的特性，应在会仙喀斯特洞穴湿地的试验区或缓冲区保留并保护稻田。
