摘要
黑土滩草地退化不仅体现在植被群落特征的退化,同时也体现在土壤微生物群落结构和功能的退化。为明确不同地区黑土滩退化草地土壤微生物群落的空间异质性,探究植被与土壤微生物对黑土滩草地退化的响应规律,利用样方调查法和Biolog-ECO微平板法,分析了青海省海北州野牛沟乡、果洛州大武镇及玉树州巴塘乡3个地区黑土滩退化草地的植被群落特征及土壤微生物群落多样性特征。结果表明,(1)黑土滩退化草地毒杂草化,优良牧草成为群落偶见种。3个地区植被群落组成存在差异:大武地区植物物种丰富度最大,为16.25,野牛沟次之,巴塘最小;植被优势度指数、多样性指数和均匀度指数均为野牛沟>大武>巴塘;地上生物量和0-10 cm土层地下生物量均为大武地区最大,巴塘次之,野牛沟最小,三者间均存在显著差异(P<0.05);大武和巴塘地区10-20 cm土层地下生物量显著大于野牛沟地区(P<0.05)。(2)黑土滩退化草地土壤微生物在0-10 cm土层主要利用氨基酸类、酯类和胺类碳源,碳源相对利用率均在19%以上;在10-20 cm土层主要利用氨基酸类和酯类碳源,碳源相对利用率均在22%以上。不同地区黑土滩退化草地土壤微生物对单一碳源的利用存在差异,差异主要来源于酸类、氨基酸类和酯类。(3)土壤微生物AWCD(平均每孔颜色变化率)和H指数(Shannon-Wiener多样性指数)与植物多样性和生物量相关性较高;物种重要值、多样性及生物量对土壤微生物AWCD变化的共同解释率为88.42%。综上,黑土滩退化草地植被物种组成及群落结构存在地域差异,不同地区黑土滩退化草地土壤微生物群落结构不同;黑土滩退化草地利用D-半乳糖酸γ内酯、L-精氨酸、D-半乳糖醛酸、L-天冬酰胺酸、D-甘露醇、L-丝氨酸、N-乙酰基-D-葡萄胺等的功能微生物显著富集,利用i-赤藻糖醇、2-羟苯甲酸、L-苏氨酸、α-丁酮酸、α-D-乳糖等的功能微生物显著分异。
The degradation of black soil beach grassland is not only reflected in the degradation of vegetation community characteristics,but also in the degradation of soil microbial community structures and functions.In order to clarify the spatial heterogeneity of soil microbial community,and to explore the response regulations of vegetation and soil microorganism to the degradation of the black soil beach in different regions,the community characteristics of vegetation and soil microbes in the black soil beach degraded grassland were studied by quadrate survey procedure and Biolog-Eco method at Yeniugou of Haibei prefecture,Dawu of Guoluo prefecture and Batang of Yushu prefecture,Qinghai province.The results showed that,(1)The proportion of poisonous grass in black soil beach degraded grassland is high,and the good quality forage occasionally appeared in this vegetable communities.Significant differences were shown in vegetation community composition among the three various regions.The plant richness index in Dawu is the largest,followed by Yeniugou,and the smallest is in Batang.The plant Simpson index,Shannon-Weiner index and Pielou index of grassland were shown in turns as Yeniugou>Dawu>Batang.The aboveground biomass and belowground biomass at 0-10 cm soil layer in Dawu is the largest,followed by Batang,and Yeniugou is the smallest and the difference between them were significant(P<0.05).The belowground biomass at the soil depth of 10-20 cm in Dawu and Batang was significantly higher than that in Yeniugou(P<0.05).(2)At the soil depth of 0-10 cm in black soil beach degraded grassland,soil microorganisms mainly use carbon sources of amino acids,esters and amines,and the relative utilization rate of carbon sources is over 19%.While at the depth of 10-20 cm,amino acid and ester carbon sources were mostly used,and the relative utilization rate was above 22%.The differences for the single carbon source utilization by soil microorganisms in the black soil beach degraded grassland were significant at three different regions,and the discrepancy mainly come from acids,amino acids and esters.And(3)the AWCD(average well color development)and H index(Shannon-Wiener index)of microorganisms were highly correlated with plant species diversity and biomass.For the variation of soil microbial AWCD index,the interactions of plant species important value,vegetable community diversity and plant biomass can interpret 88.42%.In summary,there are regional differences in plant species composition,vegetable and soil microbial community structures in black soil beach degraded grassland.In the black soil beach degraded grassland,the functional microorganisms such as D-galactonic acid lactone,L-arginine,D-galacturonic acid,L-asparagine,D-mannitol,L-serine and N-acetyl-D-glucosamine are significantly enriched.While the microorganisms related to i-erythritol,2-hydroxybenzoic acid,L-threonine,alpha-ketobutyric acid and alpha-D-lactose are dramatically discrepant.
作者
刘燕
李世雄
尹亚丽
赵文
王玉琴
LIU Yan;LI Shixiong;YIN Yali;ZHAO Wen;WANG Yuqin(Qinghai Academy of Animal and Veterinary Science,Xining 810016,China;State Key Laboratory of Plateau Ecology and Agriculture,Xining 810016,China)
出处
《生态环境学报》
CSCD
北大核心
2019年第7期1394-1403,共10页
Ecology and Environmental Sciences
基金
国家自然科学基金项目(31560660)
青海省科技项目(2019-ZJ-7070)
青海省重大科技专项(2019-SF-A3)
关键词
黑土滩退化草地
植被群落特征
土壤微生物群落结构
碳源利用
black soil beach degraded grassland
the community characteristics of vegetation
soil microbial community structure
carbon source utilization
