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1.
乌拉特荒漠草原群落物种多样性和生物量关系对放牧强度的响应 总被引：1，自引：0，他引：1
以内蒙古乌拉特荒漠草原灌丛和草本植物群落为对象,研究这2种植物群落的物种组成、物种多样性及其与地上生物量关系对不同放牧处理(对照、中牧、重牧)的响应。结果表明:①随着放牧强度的增加,灌丛群落中红砂(Reaumuria songarica)和碱韭(Allium polyrhizum)的优势度增大,沙生针茅(Stipa glareosa)的优势度减小;重牧降低草本群落中沙生针茅的优势度,增加了蒙古韭(Allium mongolicum)和碱韭的优势度。②不同放牧处理显著降低了灌丛和草本群落的盖度、高度以及灌丛群落的密度,消除了灌丛和草本群落之间盖度的差异(P> 0. 05)。中牧降低灌丛群落的Pielou均匀度指数,重牧降低灌丛群落的物种丰富度,灌丛和草本群落的其他多样性指数在放牧处理之间无显著差异(P> 0. 05)。除物种丰富度外,其他多样性指数在灌丛和草本群落之间差异显著(P <0. 05)。③不同放牧处理降低了灌丛和草本群落的地上生物量和凋落物量,导致灌丛和草本群落之间地上生物量的显著差异(P <0. 05)。④地上生物量与Simpson优势度指数负相关,与Shannon-Wienner多样性指数和Pielou均匀度指数正相关;放牧处理下地上生物量与密度、物种丰富度正相关。放牧处理改变了荒漠草原植物群落组成、结构和功能,进而改变了群落结构和功能的重要关系。 相似文献
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针对科尔沁沙地土壤质量退化、花生连作障碍问题,于辽宁省农业科学院章古台试验站进行田间定位实验,设置玉米(Zea mays L)-花生(Arachis hypogaea)-玉米轮作(L1)、花生-玉米-花生轮作(L2)、玉米连作(YL)和花生连作(HL)4种种植模式,采集0-20cm土层土壤样品,采用磷脂脂肪酸法(PLFA)分析土壤微生物群落结构组成及多样性,测定土壤可培养微生物数量及土壤微生物量碳氮磷含量。结果表明：L1和L2模式下土壤微生物群落总丰度、细菌群落丰度、真菌群落丰度、放线菌群落丰度均显著高于YL和HL。主成分分析与冗余分析结果表明,L1和L2与土壤微生物量碳氮磷含量、土壤微生物各菌群丰度呈正相关;土壤可培养微生物总量与土壤总PLFA含量正相关。综上,轮作引起的土壤微生物群落丰度的变化是土壤微生物量碳氮磷累积的驱动因素。花生-玉米轮作种植能有效改善土壤微生态环境、缓解花生连作障碍。 相似文献
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荒漠草原不同植被类型土壤微生物群落功能多样性 总被引：11，自引：0，他引：11
利用Biolog EcoplateTM技术通过对荒漠草原生态系统中沙米、白沙蒿、柠条、沙冬青和人工乔木林5种植被类型土壤微生物群落功能多样性分析,以探讨不同植被类型对土壤微生物群落代谢功能多样性的影响.结果表明,5种植被类型土壤微生物群落代谢活性有显著的差异(P＜0.01),5种植被类型土壤微生物群落利用碳源的种类也存在差异,氨基酸类、羧酸类和糖类是其主要的碳源利用类型.在Biolog ECO板培养基接种培养96 h后,5种植被类型土壤微生物群落多样性显示,物种丰富度指数(R)和均匀度指数(EH)差异显著,Shannon 指数(H′)差异不显著. 相似文献
5.
在多元划分的基础上,使用典型对应分析(CCA)对乌鲁木齐地区的灌木物种进行排序,研究影响该地区灌木群落类型的因素,以及与主要环境因子的关系,结果表明:1 CCA排序图较好地显示了灌木群落与主要环境因子的相关性,并指示了灌木物种的生境梯度;2海拔较土壤环境因子对灌木群落分布的影响更显著;3土壤环境因子中,不同土壤层次处土壤全盐含量对灌木群落的分布有重要的作用,全磷含量的影响最小;4研究区灌木群落更易生活在粗质土壤中;5表层土壤性质决定了山地灌丛及灌木荒漠的分布格局,中-浅层和深层土壤的影响较小。 相似文献
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利用Biolog微平板法和高通量测序技术，研究小麦玉米间作条件下，不同长期施肥处理土壤微生物对不同碳源的利用差异以及土壤微生物群落在门、属水平上的变化，探明长期施用绿肥对土壤微生物群落多样性及代谢功能的影响。结果表明：长期施用绿肥可显著提高土壤有机质、速效磷和速效钾含量，降低土壤pH值，增强土壤微生物碳源代谢能力。不同施肥条件下，放线菌门(Actinobacteria)和变形菌门(Proteobacteria)为土壤优势菌群，绿肥处理的放线菌门丰度最高(29.94%),农家肥处理最低(22.95%);秸秆还田处理的变形菌门丰度最高(22.32%),对照处理最低(18.85%);酸杆菌门(Acidobacteriota)、绿弯菌门(Chloroflexi)、厚壁菌门(Firmicutes)在各个处理中的相对丰富度较高，分别为13.39%～19.71%、10.85%～14.56%、3.54%～12.98%。长期施用绿肥有效提高了土壤放线菌门、厚壁菌门、芽孢杆菌属(Bacillus)以及假节杆菌属(Pseudarthrobacter)的丰度，降低了酸杆菌门的丰度，增加了土壤微生物种群数量。综... 相似文献
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不同季节土庄绣线菊根围丛枝菌根真菌群落差异性研究 总被引：1，自引：0，他引：1
土庄绣线菊(Spiraea pubescens)是内蒙古大青山干旱生态系统重要的护土灌木,研究季节变化对土庄绣线菊根围丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)群落的影响,有助于进一步探讨AMF在土庄绣线菊生长发育过程中发挥的作用。采用传统染色检测与Illumina Mi Seq测序相结合的方法,研究季节变化对内蒙古大青山土庄绣线菊AMF侵染率、孢子密度、丰富度、多样性和群落组成的影响。结果显示:在春季、夏季和秋季,AMF侵染率和丛枝丰度不存在显著差异,而孢子密度却存在显著差异。AMF丰富度和多样性在夏季显著低于春季和秋季,但在春季和秋季间差异并不显著;主成分分析(principal coordinate analysis,PCo A)和PERMANOVA分析表明,春季和秋季AMF群落组成与夏季存在显著差异,而在春季和秋季间差异并不显著。 相似文献
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荒漠草原不同植物群落夏季土壤呼吸特征研究 总被引：1，自引：0，他引：1
采用动态密闭气室分析法测定了荒漠草原不同植物群落土壤呼吸速率的日动态并分析了土壤呼吸对温度变化的响应。结果表明:沙蒿(Artemisia desertorum)群落、赖草(Leymus secalinus)群落、甘草(Glycyrrhi-za uralensis)群落和冰草(Agropyron crisatum)群落4种植物群落土壤呼吸速率日变化表现为不对称的单峰曲线形式。冰草群落、赖草群落与沙蒿群落之间土壤呼吸速率存在显著差异,而沙蒿群落和甘草群落则无显著差异。采用指数方程拟合各群落土壤呼吸速率与0-20cm平均土壤温度的关系均显著相关,但不同植物群落间土壤基础呼吸不一样,其值大小依次为:冰草群落>甘草群落>赖草群落>沙蒿群落。Q10值的变化范围为1.22-14.75,且随着土壤深度的增加而增大,其平均值大小依次为:沙蒿群落>赖草群落>甘草群落>冰草群落。 相似文献
9.
岷江源区植物群落复杂性研究 总被引：3，自引：0，他引：3
采用通讯理论中的霍夫曼编码方法研究了岷江源区植物群落复杂性及其与环境因子之间的一般关系,并揭示了群落复杂性与多样性、物种丰富度和均匀度之间的关系。结果表明:2900-3100m和3500-3700m两个海拔段的植物群落有较高的总复杂性。不同群系的总复杂性,表现为森林群系>灌丛群系>草甸群系;云杉林的总复杂性最高,蒿草草甸的总复杂性最低;灌丛群系中,锦鸡儿灌丛的总复杂性最高,沙棘灌丛的总复杂性最低;草甸群系中,苔草草甸和白茅草甸群系总复杂性较高。群落总复杂性与土壤水分和养分之间呈现显著的二次曲线关系。总复杂性与多样性及物种丰富度呈现出极显著的正相关关系;均匀度与结构复杂性有极显著的负相关关系,均匀度较高的群落,其总复杂性和多样性差别较小,结构复杂性较低;结构复杂性对群落内物种数的变化较为敏感,均匀度和物种数共同影响着群落的结构复杂性。 相似文献
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通过田间试验,研究了陕西关中塿土区地膜覆盖和秸秆覆盖对表层土壤有机碳、全氮和微生物量碳氮,以及0~200 cm土壤剖面水分及硝态氮分布的影响。结果表明:与不覆盖(NM)相比,白色全膜覆盖(WF)、黑色全膜覆盖(BF)和秸秆覆盖(SM)的表层土壤有机碳分别降低了19.8%、26.3%和20.9%,土壤全氮也分别降低了4.8%、9.6%和10.6%。与NM相比,覆盖处理(WF、BF和SM)可以提高表层(0~20 cm)土壤硝态氮的含量,增加0~40 cm土层的硝态氮累积量(BF的差异不显著),降低40~120 cm土层的硝态氮累积量,但120~200 cm土层的硝态氮累积量差异不显著。SM和BF显著降低0~200 cm土层的硝态氮总累积量,而WF没有显著差异。与NM相比,地膜覆盖(WF和BF)和秸秆覆盖(SM)均可以提高表层0~40 cm土壤水分含量和储水量,但SM的效果低于地膜覆盖;WF可以降低深层土壤水分含量和储水量,而SM和BF与NM无显著差异。0~200 cm土层的总储水量,SM显著高于NM,而地膜覆盖则与NM无显著差异。各覆盖处理均显著降低了表层土壤微生物碳(MBC)和微生物氮(MBN)的含量,与NM相比,MBC分别降低了27.4%、55.4%和66.5%,MBN分别降低了4.6%、4.8%和6.8%。地膜覆盖(WF和BF)和秸秆覆盖(SM)均能够加速土壤有机碳的矿化分解,降低土壤微生物,减少土壤硝态氮的深层淋溶,其对塿土碳氮和水分的长期影响值得进一步研究关注。 相似文献
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为了解荒漠化土地植被恢复对土壤微生物量的影响,以地处毛乌素沙地南缘的榆林市沙生植物园植被恢复30年的乔木、灌木和草地3种植被群落下土壤为研究对象,分析了植被恢复对土壤微生物量碳、氮、磷含量及比值的影响及其与土壤理化性质的相关性。结果表明,农牧交错带荒漠化土地植被恢复可以明显提高表层土壤微生物碳、氮、磷的含量。土壤微生物量碳以灌木林地为最高,含量为288.35 mg·kg-1,显著高于草地和乔木,分别是乔木林地和草地的3.99和2.10倍;土壤微生物磷在三种植被群落间差异不明显;三种植被群落下土壤微生物碳氮比的高低为乔木林地草地灌木林地,土壤微生物碳磷比表现为草地略高于乔木林地和灌木林地。相关性分析结果显示微生物量碳、氮、磷与土壤理化性质相关性极为密切,其中与土壤养分各指标大多呈现极显著相关,与土壤容重多为极显著负相关。说明土壤微生物量可以作为评价土壤质量的生物学指标。 相似文献
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乌兰布和沙漠东北部几种白刺群落植物多样性研究 总被引：2，自引：0，他引：2
根据对乌兰布和沙漠东北部4种白刺植物群落的样地调查数据,采用物种丰富度指数S、Shannon-Wiener指数H'、Simpson指数D、Pielou均匀度指数J、Alatalo均匀度指数Ea、Whittaker指数βw、相异性系数CD、群落共有度Jaccard指数CP、Bray-Curtis指数CN等指标研究了该地区4种白刺群落分层的α多样性和β多样性。结果表明:这些α多样性和β多样性测度指标有效表征了干旱沙漠区同属不同植物群落内部在物种组成方面的差异、生境差异、群落间物种组成差异。四种白刺群落的草本层的物种丰富度指数都明显大于灌木层;唐古特白刺群落的物种丰富度指数最小,泡泡刺群落的物种多样性Shannon-Wiener指数H'和Simpson指数D最大,而且其群落均匀度也最大。唐古特白刺植物群落的Whittaker指数βw要比其它三种白刺群落要大,若仅考虑群落间共有物种数目多少,大白刺与泡泡刺在群落、灌木层与草本层间的相异性系数CD都最小,共有度Jaccard指数CP都最大;而西伯利亚白刺群落、灌木层和草本层与其余三种白刺的相异性系数CD都较大,Jaccard指数CP都较小。而数量数据指标Bray-Curtis指数CN变化与上述有所不同。采用植物盖度和相对盖度进行α多样性和β多样性对比分析,能够合理地说明不同白刺植物多样性特征。 相似文献
13.
艾比湖湿地自然保护区典型群落物种多样性分析 总被引：6，自引：2，他引：4
采用Shannon-Wiener和Simpson物种多样性指数,Margalef和Gleason丰富度指数,均匀度指数和生态优势度指数对艾比湖湿地自然保护区典型群落物种多样性进行分析研究。结果表明:植物群落在垂直结构上的多样性分布是灌木和乔木的物种均匀度、多样性和丰富度指数的变化趋势均大于草本,而生态优势度指数则与其相反,表现出单一的植物群落结构,说明艾比湖自然保护区典型群落在多个层次上物种的数量和分布与该地环境条件成正相关,即该区植物种类少、盖度低,生物资源丰富度十分匮乏。 相似文献
14.
XU Wenxuan 《干旱区科学》2015,7(6):852-859
Great gerbil(Rhombomys opimus) colonies, with bare soil and herbaceous plants, are conspicuous to the background environment throughout their range area. In order to quantify the engineer role of great gerbils, we investigated the plant communities of 20 active colonies in the Junggar Basin, Xinjiang, China. In areas without disturbance, desert plant communities were dominated by the shrubs with low level species richness. In burrow areas and surrounding intermediate areas, which were disturbed by great gerbils, the shrubs were suppressed with the decrease of vegetation cover and aboveground biomass. As a result, "niche gaps" were created in disturbed areas and worked as a refuge for herbaceous annuals and perennials. So the existence of great gerbils increased the overall species richness of the desert. Furthermore, herbaceous annuals and perennials are the major food source for great gerbils in spring, indicating that great gerbils have a mutually beneficial relationship with herbaceous plants. 相似文献
15.
Effects of exotic and endogenous shrubs on understory vegetation and soil nutrients in the south of Tunisia 总被引：1，自引：0，他引：1
Zouhaier NOUMI 《干旱区科学》2015,7(4):481-487
This study was conducted in southern Tunisia in the growing seasons of 2013 and 2014, and aimed to compare the effects of exotic and endogenous shrub species(Haloxylon persicum and Retama raetam, respectively) on understory vegetation and soil nutrients. For each shrub species, the canopied sub-habitat(under the shrub crown) and un-canopied sub-habitat(in open grassland area) were distinguished. The concentrations of soil nutrients(organic matter, total nitrogen and extractable phosphorus) were found to be significantly higher(P<0.05) under R. raetam canopy than under H. persicum canopy and in open area. The result also showed that the presence of shrubs improved all the values of understory vegetation parameters(floristic composition, density, total plant cover and dry matter) and all these values were significantly higher under endogenous species canopy than under exotic species canopy. These results highlighted the positive effect of endogenous shrubs on understory vegetation and soil nutrients compared to the exotic ones in the Saharan areas of Tunisia. 相似文献
16.
Rentao Liu 《Arid Land Research and Management》2018,32(1):91-110
We examined the ground-active arthropods using pitfall trapping beneath Hammada scoparia and Zygophyllum dumosum shrubs and in adjacent open spaces in wet winter, short spring, dry and hot summer, and autumn in the Negev Desert, Israel. The activity abundance of ground-active arthropods was 244, 424, and 506 individuals trap?1 in open spaces and beneath H. scoparia and Z. dumosum shrubs, and was 134, 448, 414, and 178 individuals trap?1 in winter, spring, summer, and autumn, respectively. The activity abundance and richness of predators and phytophages were found to exhibit an inconsistent pattern between shrub microhabitats throughout seasonality. In contrast, the activity abundance and richness of omnivores indicated contrasting pattern between summer and other seasons. Likewise, total abundance was found to exhibit a similar pattern to taxa richness and Shannon index between shrub microhabitats only in summer. There was a consistent pattern of diversity indices between shrub microhabitats observed in both winter and autumn. However, no significant (P?>?0.05) differences in activity abundance and diversity indices were found between shrub microhabitats in spring. The Sørensen index between open spaces and H. scoparia and Z. dumosum canopy microhabitats, and that between the latter two microhabitats were found to be 0.26, 0.29, and 0.19 in winter, 0.53, 0.48, and 0.48 in spring, 0.47, 0.45, and 0.52 in summer, and 0.57, 0.56, and 0.78 in autumn, respectively. It was suggested that seasonality could mediate the activity abundance and diversity distribution of ground-active arthropods between shrub microhabitats in the Negev Desert. 相似文献
17.
In order to investigate the spatio-temporal variability of soil water content to rainfall under Caragana microphylla shrub in Horqin Sandy Land,a plot of 25 m × 25 m,where there were 6 shrub canopies of C. microphylla,was sited for measuring soil water content at two soil layers of 0-20 cm (top layer) and 20-40 cm (lower layer). Soil water content was measured on the 1st,5th,10th and 15th day after a 42 mm rainfall in Naiman of Inner Mongolia. The results showed that soil water contents at both layers under C. microphylla shrub were gradually decreased after the rain. Soil water content at the top layer outside the shrub canopy was higher than that inside the shrub canopy within 5 days,and became similar inside and outside the shrub canopy on the 10th day after the 42 mm rainfall,and it was lower outside than that inside the shrub canopy on the 15th day. The soil water content at lower layer in the area without shrubs was higher than that under shrub canopy all along. All the measured values of soil water content can be fitted to a variogram model. There was significant autocorrelation of the values of soil water content between top layer and lower layer,except for the fourth measured values of soil water content at top layer. The range and spatial dependence of soil water content at top layer were lower than that at lower layer. 相似文献
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为明确日晒高温覆膜对韭菜生长及根际土壤微生物群落的影响,本研究在河北省韭菜主产区基于日晒高温覆膜措施对韭菜迟眼蕈蚊进行田间防治试验,就覆膜前后土壤的理化性质进行了比较,并采用Biolog-ECO技术分析了覆膜对土壤微生物群落功能多样性的影响。结果表明,日晒高温覆膜技术对韭蛆各龄期幼虫的防治效果达到100%,覆膜12 d后韭菜株高、茎粗、叶宽、色泽、百株鲜重及根长等生长发育指标与未覆膜的对照相比均无显著影响;覆膜后土壤中全磷量显著增加;根据Biolog-ECO培养第144 h的AWCD值计算土壤微生物群落的Shannon-Wiener指数、Simpson指数、McIntosh指数和丰富度指数均无显著变化。可见日晒高温覆膜对韭菜迟眼蕈蚊具有明显的防治效果,对韭菜生长及韭菜根际土壤微生物多样性无显著影响。 相似文献
20.
ZhengJun GUAN Qian LUO Xi CHEN XianWei FENG ZhiXi TANG Wei WEI YuanRun ZHENG 《干旱区科学》2014,(2):164-173
Soil enzyme activity plays an important role in the conversion of soil organic carbon into inorganic carbon,which is significant for the global carbon cycle.In this study,we investigated the soil enzyme activities of two ligninolytic enzymes(peroxidase and polyphenol oxidase)and five non-ligninolytic enzymes(α-1,4-glucosidase(AG);β-1,4-glucosidase(BG);N-acetyl-β-glucosaminidase(NAG);β-D-cellobiosidase(CBH);andβ-xylosidase(BXYL))in four plant communities of the Sangong River basin in Fukang,North Xinjiang,China.The four typical plant communities were dominated by Haloxylon ammodendron,Reaumuria soongonica,Salsola passerina,and Tamarix rarmosissima,respectively,with saline soils of varied alkalinity.The results showed that the soil peroxidase activity decreased seasonally.The activities of the five non-ligninolytic enzymes decreased with increasing soil depths,while those of the two ligninolytic enzymes did not show such a trend.In the four plant communities,BG had the highest activity among the five non-ligninolytic enzymes,and the activities of the two ligninolytic enzymes were higher than those of the four non-ligninolytic ones(AG,NAG,CBH,and BXYL).The community of H.ammodendron displayed the highest activity with respect to the two ligninolytic enzymes in most cases,but no significant differences were found among the four plant communities.The geometric mean of soil enzyme activities of the four plant communities was validated through an independently performed principal component analysis(PCA),which indicated that different plant communities had different soil enzyme activities.The correlation analysis showed that soil polyphenol oxidase activity was significantly positively correlated with the activities of the five non-ligninolytic enzymes.The soil pH value was positively correlated with the activities of all soil enzymes except peroxidase.Soil microbial carbon content also showed a significant positive correlation(P0.01)with the activities of all soil enzymes except polyphenol oxidase.The results suggested that the H.ammodendron community has the highest ability to utilize soil organic carbon,and glucoside could be the most extensively utilized non-ligninolytic carbon source in the saline soil of arid areas in Xinjiang. 相似文献