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1.
荒漠绿洲过渡带人工固沙梭梭（Haloxylon ammodendron）林生长发育过程中,土壤生物多样性的演变研究是认识干旱区植物-土壤相互作用的重要内容。在河西走廊中段临泽绿洲边缘选择不同栽植时间序列（0、3、6、11、19、28、46 a）的固沙梭梭林,取冠层下和冠层外的表层土样（0～10 cm）,研究固沙梭梭林建立后土壤线虫群落组成和多样性变化,探究线虫群落对植被-土壤系统恢复的指示作用。结果表明：在研究区共发现15个属,Eucephalobus和Acrobeloides为优势属,食细菌线虫（BF）为优势营养类群,占线虫总数50.3%～94.1%。梭梭生长显著提高土壤线虫总数、食细菌线虫丰度和线虫多样性。线虫富集指数（EI）和结构指数（SI）均小于50,土壤食物网随梭梭种植年限增加先稳定后逐渐退化。冗余分析表明,土壤化学性质变化（电导率EC、C/N和土壤有机碳SOC）显著影响线虫群落分布,EC对线虫属总变异解释率最高（32.7%）。土壤线虫作为生物指标揭示了植被-土壤生态系统的演变过程。 相似文献
2.
长春市不同土地利用生境土壤甲虫群落结构特征 总被引：6，自引：5，他引：1
在长春市郊区天然次生林、农田、防护林和市区公园绿地等典型土地利用生境共捕获土壤甲虫32科598只,其中幼虫13科312只,成虫25科286只。应用个体密度、类群数量、群落多样性、丰富度和均匀度等指数,研究土壤甲虫的群落生态结构特征,了解土地利用差异对土壤甲虫群落结构的影响。研究结果表明:长春市不同土地利用生境凋落物的移除对土壤甲虫群落结构没有产生显著影响;农田土壤甲虫群落类群数、个体密度和多样性的降低源于生境作物品种单一和周期性的农田生产活动,防护林在空间上起着相邻农田物种交流廊道的作用;提高生境土壤甲虫群落类群数、个体密度和多样性的关键之一是保持生境类型的复杂性。 相似文献
3.
为了研究含油污水对湿地土壤线虫群落的影响,在大庆油田附近,选择受含油污水影响程度不同的4块典型芦苇(Phragmites australis)沼泽样地,分析其土壤线虫群落特征。在4块典型芦苇沼泽样地中,共鉴定出24科34属土壤线虫。其中,有食细菌线虫15属,食真菌线虫、捕食杂食线虫各6属,植物寄生线虫7属。Panagrolaimus和Aphelenchoides为优势类群,个体数占总捕获个体量的26.91%;受到含油污水的影响,土壤线虫的群落结构和多样性都发生改变,受污染样地线虫个体数及类群数显著低于对照样地(p0.01),且与对照样地相比,食细菌线虫相对丰度随着污染程度的增加而增大,重度污染样地中食细菌线虫的相对丰度显著高于对照样地(p0.05),而捕食杂食线虫的相对丰度则与之相反(p0.01)。从土壤线虫的生态指数来看,在不同污染程度条件下,受污染样地丰富度指数显著低于对照样地,而自由生活成熟度指数则相反。 相似文献
4.
以河西走廊典型的荒漠绿洲新垦农田为研究对象,设置9个施肥处理（高量有机肥,M3;高量氮磷肥,NP3;低量氮磷肥+高量有机肥,NP1M3;低量氮磷钾肥,NPK1;中量氮磷钾肥,NPK2;高量氮磷钾肥,NPK3;低量氮磷钾肥+高量有机肥,NPK1M3;中量氮磷钾肥+中量有机肥,NPK2M2;高量氮磷钾肥+低量有机肥,NPK3M1）,于2019—2020年7—8月采用LI-COR 8100对玉米农田土壤呼吸进行观测,分析土壤呼吸的变化、日动态及其主要影响因素。结果表明：（1）不同施肥处理,土壤呼吸速率M3>NP3>NPK1M3>NPK3M1>NPK2M2>NP1M3>NPK2>NPK3>NPK1,单施有机肥能显著提高土壤呼吸速率,较其他处理增长22.1%—41.4%。（2）不同施肥措施土壤呼吸日变化呈单峰曲线,峰值出现在13：00—16：00,土壤呼吸日变化主要受土壤温度变化的影响。（3）土壤温度和土壤湿度分别解释了土壤呼吸变化的24.2%—44.8%和7.7%—36.4%,土壤呼吸与土壤温度显著正相关,而与土壤湿度无显著相关性,不同施肥处理土壤呼吸温度敏感性系数Q10值1.419—1.600。（4）土壤呼吸与有机质、总氮、总碳、碱解氮存在显著正相关关系,施用有机肥使土壤有机质、总氮、总碳、碱解氮分别提升188.9%、80.5%、79.3%、147.0%,进而促进土壤呼吸,土壤呼吸与玉米产量无显著关系。不同的施肥措施会对土壤质量和土壤呼吸产生不同影响,有机肥和氮磷钾化肥的平衡施用,能够在提升土壤质量的同时减少碳排放,可在生产实践中采用。 相似文献
5.
利用2005年安排在临泽边缘绿洲沙地农田的长期施肥定位试验，研究不同用量有机肥、化肥、有机肥和化肥配施对绿洲沙地土壤肥力及有机碳积累的影响。试验包括高量有机肥单施（M3），氮磷化肥单施（NP3），低、中、高量氮磷钾化肥单施（NPK1，NPK2，NPK3），及低、中、高量氮磷钾化肥配施高、中、低量有机肥9个处理（NPK1M3，NPK2M2，NPK3M1），测定分析10年后不同施肥处理耕层（0~20 cm）土壤物理化学性状特征及有机碳动态。结果表明：施有机肥及有机无机配施处理较单施化肥处理容重下降0.13 g·cm-3，田间持水量提高6.7%，单施有机肥、有机无机配施较单施化肥，土壤有机碳（SOC）和全氮含量分别提高64.8%、36.3%和64.9%、49.5%。高量施用氮磷化肥和氮磷钾化肥处理全磷含量最高，有机肥及有机无机配施较单施化肥有效氮含量显著增加，有机无机配施及高量施用磷肥土壤有效磷积累明显，高量施用有机肥能显著提升有效钾含量。连续施肥处理10年后，SOC含量提高了1.68~2.84倍，土壤全氮、全磷、碱解氮及有效磷均有一定程度的提高，但单施化肥及有机肥与氮磷化肥配施有效钾含量下降。SOC的积累速率单施化肥、有机无机配施，单施有机肥处理分别为0.27、0.59，0.87 g·kg-1·a-1。增施有机肥、适量减少化肥投入、氮磷钾化肥的平衡施用是绿洲沙地农田土壤肥力持续提升的施肥管理对策。 相似文献
6.
三江平原典型湿地土壤动物群落结构及季节变化 总被引：6，自引：0，他引：6
土壤动物是湿地生态系统结构的重要组成部分,其群落结构及其变化研究,可为深入揭示湿地生物多样性及其功能提供基础资料。在2005年生长季,对三江平原典型湿地土壤动物进行了野外调查和室内分离、鉴定。结果表明,典型湿地土壤动物隶属5门12纲27目45科,优势类群为真螨目（Acariformes）、鞘翅目成虫（Coleoptera adult）、线虫（Nemata）和柄眼目（Stylommatophora）4类,常见类群9类,。稀有类群19类;优势种群和常见种群都具有明显的季节动态变化。多样性分析表明,整个生长季典型湿地类型土壤动物多样性指数为2．32,丰富度指数为3．85,均匀度指数为0．68,优势度指数为0．15。类群数、多样性指数、均匀度指数和丰富度指数,在温、湿条件优越的8月最大,降水较少的6月最小。优势度指数6月最大,个体数量在类群分布上比较集中。土壤动物功能类群可划分为腐食性、捕食性和植食性土壤动物,其数量比例关系整体上表现为腐食性土壤动物最多,其次为捕食性土壤动物和植食性土壤动物。土壤动物垂直分布格局研究表明,除了10月外,其他各月都表现为明显的表聚性;10月的逆向分布格局是由于表层土壤温度低造成的。 相似文献
7.
不同施肥对黑河中游边缘绿洲沙地农田玉米产量及土壤硝态氮积累影响的初步研究 总被引：8，自引：3，他引：5
在黑河中游边缘绿洲的沙地农田进行不同施肥对玉米产量及土壤硝态氮积累的试验研究表明,有机肥与化肥配合施用增加作物产量。不同肥料处理,玉米籽粒产量由高到低的顺序依次为NPK3M1（高量氮磷钾肥低量有机肥配施:N-P2O5-K2O-M,300-225-225-15 000 kg·hm-2）>NPK2M2（中量氮磷钾肥中量有机肥配施:N-P2O5-K2O-M,225-135-135-22 500 kg·hm-2）>NPK3（高量氮磷钾肥配施:N-P2O5-K2O-M,300-225-225-0 kg·hm-2）>NP1M3（低量氮磷肥高量有机肥配施:N-P2O5-K2O-M,150-90-0-30 000 kg·hm-2）>NP3（高量氮磷肥配施:N-P2O5-K2O-M,300-225-0-0 kg·hm-2)>NPK1M3（低量氮磷钾肥高量有机肥配施:N-P2O5-K2O-M,150-90-90-30 000 kg·hm-2）>NPK2（中量氮磷钾肥配施:N-P2O5-K2O-M,225-135-135-0 kg·hm-2）>NPK1（低量氮磷钾肥配施:N-P2O5-K2O-M,150-90-90-0 kg·hm-2）>M3（单施有机肥:N-P2O5-K2O-M,0-0-0-30 000 kg·hm-2）。高量氮磷钾肥配合低量有机肥处理玉米产量最高,单施有机肥处理产量最低。与只施有机肥处理相比,各处理产量分别增加37.68%、33.43%、28.32%、25.10%、24.60%、23.84%、21.46%、11.30%。在不施有机肥的3个氮磷钾施肥处理中,玉米产量和氮肥农学利用效率（AE）随施肥量的增加而增加,但当施肥量超过225-135-135 kg·hm-2（N-P2O5-K2O）时,玉米产量和AE不再随施肥量的增加而增加。与不施有机肥处理不同,在氮磷钾配施有机肥的3个处理中,AE随化肥施用量的增加而减少,有机肥的施用使得化肥利用效率增加。不同施肥处理对土壤硝态氮的积累与分布有显著的影响,土壤硝态氮受土壤质地影响主要分布于0~40 cm土壤层次内,与化肥单施相比,有机肥导致土壤中硝态氮的积累。因此,从持续农业发展及保护生态环境等方面考虑,有机无机肥配合施用是增加绿洲农田土壤生产力,维持和提高土壤质量的有效途径,与当地农户普遍采用的施肥量相比,有机无机配施的情况下,适度减少化肥投入33%是合理的施肥对策。 相似文献
8.
认识沙地植物群落物种多样性及其与环境的关系,对维护沙地生态系统的结构与功能具有重要意义。本研究基于浑善达克沙地83个样地的群落数据及环境数据,通过数量生态学方法对群落物种多样性及其影响因子进行分析,探讨浑善达克沙地物种多样性特征及其环境解释。结果表明：（1）主要群落有榆树（Ulmus pumila）群落、小叶锦鸡儿（Caragana microphylla）群落、黄柳（Salixgordejevii）群落及长梗扁桃（Prunus pedunculata）群落等,其中榆树群落分布在降水和土壤养分都比较高的区域,小叶锦鸡儿群落适生生境为降水较少且土壤贫瘠的区域;影响该区群落分布的主要环境因子依次为生长季降水量、生长季温度、土壤全氮和全钾含量,降水量的差异显著影响群落分布格局。（2）浑善达克沙地植物多样性的分布呈现出一定的规律性变化。物种多样性指数均随经度和海拔的增加而增加;Patrick指数与Shannon-wiener指数随纬度的增加呈现减少的趋势;Simpson指数与Pielou指数随纬度增加而增加;Patrick指数、Simpson指数和Shannon-wiener指数与生长季降水量、土壤有机碳和有效氮含量呈显著正相关,与生长季均温、≥0 ℃积温、生长季风速呈显著负相关,所有环境变量与Pielou指数均无显著相关性。研究结果阐明了浑善达克沙地物种多样性及植物群落分布的规律以及与关键环境因子之间的关系,有利于提高沙地植物多样性和稳定性,增强沙地植被的生态功能。 相似文献
9.
干旱、半干旱区几种典型生境大型土壤动物群落多样性比较研究 总被引：23，自引：10，他引：13
对中国北方干旱、半干旱地区3种大型土壤动物群落的组成、多样性和相似性进行了比较研究。调查共得123类大型土壤动物,优势类群为蚁科成虫和鳃金龟科幼虫。其中,有15个广布类群,31个中布类群,而狭布群在沙地生态系统和草原生态系统分布较多,荒漠生态系统分布较少。3 个大型土壤动物群落在类群数、个体数优势类群组成和相似性等方面,沙地生态系统和草原生态系统是较为接近的,且它们的群落类群多样性明显高荒漠生态系统。在对研究区大型土壤动物群落多样性的测度中,含有样方大小的物种丰富度指数(dGL)、密度群指数(DG)、群落复杂性指数(Cj)能较好地反映实际情况。 相似文献
10.
保护性耕作改善东北农田黑土土壤生物多样性及其生态功能 总被引：2，自引：0，他引：2
保护性耕作是攻克黑土地保护和利用的核心技术之一。研究立足中国科学院黑土区农业生态重点试验室保护性耕作长期定位试验基地,系统梳理总结了农田黑土土壤生物多样性对保护性耕作的响应特征。与传统耕作相比,保护性耕作显著增加各生物类群（微生物、线虫、跳虫、螨类及蚯蚓）的物种丰富度（1%~8%）、数量（25%~57%）和生物量（30%~50%）,提高食物网网状结构的复杂性及各营养级间的连通性（14%~32%）,促进土壤生物在固土蓄水、土壤碳固存、氮素高效利用以及稳定作物产量四方面生态功能的可持续性发挥。研究结果表明,实施保护性耕作可有效利用土壤生物的功能潜力,实现东北黑土区农田生态系统的健康发展、服务国家粮食安全产业带建设和现代农业发展。 相似文献
11.
The effects of salinity on soil organic carbon(SOC) and its labile fractions including microbial biomass carbon(MBC) and easily oxidation organic carbon(EOC),basal soil respiration,and soil nematode community in the Fluvents,an oasis in an arid region of northwestern China were investigated.Five sites were selected which had a salinity gradient with different groundwater table from 1.0 m to 4.0 m.Soils were sampled at the 0–20 cm plough layer from 25 irrigated fields of five sites and electrical conductivity was measured in the saturation paste extracts(ECe).Soils were categorized into five salinity levels:(1) non-saline,(2) very slightly saline,(3) slightly saline,(4) moderately saline,and(5) strongly saline according to the values of ECe.The results show that SOC and total nitrogen concentration,cation exchange capacity(CEC),and the concentrations of labile organic fractions(MBC,EOC),and basal soil respiration decreased significantly with increasing ECe.The relationships between ECe and MBC,EOC and basal soil respiration were best described by power functions.Slight and moderate salinity had no significant impact on soil nematode abundance,but excessive salt accumulation led to a marked decline in soil nematode community diversity and abundance.Soil salinity changed soil nematode trophic groups and bacterivores were the most abundant trophic groups in salt-affected soils.Further study is necessary to identify the response of soil microbial processes and nematode community dynamics to soil salinity. 相似文献
12.
This review summarizes main research findings in soil fauna eco-geography in China in the past 30 years. The subject areas and main results were overviewed including biodiversity and eco-geological distribution of soil fauna communities. Studies of ecological distributions of soil fauna and dynamic ranges in space from tropical, subtropical to temperate regions, and in categories from forest, grassland, desert, wetland, farmland to urban ecosystems, the responses and indications of soil fauna to soil environments. Effects of intensive disturbance such as fire, grazing, farming, fertilization on soil fauna include sensitive (e.g. nematode) and rare groups and community indexes. The functions of soil fauna were discussed including environmental construction, environmental purification, litter decomposition and elements cycling. Interactions between soil fauna and other biota in soil ecosystems and linking between aboveground and belowground diversity and the effects of global change on soil fauna community in China were also included. Finally, the authors pointed out common interests in soil fauna eco-geographical studies, which include application of molecule biology into soil fauna taxa; function and mechanism of soil fauna community diversity; interaction between aboveground and belowground ecosystems; effects of disturbance, pollution, biological invasion, and global change on soil fauna community and function. The review is to provide a scientific basis for promoting soil fauna eco-geographical studies in China. 相似文献
13.
Soil respiration is one of the primary fluxes of carbon between soils and the atmosphere.It is produced by rhizosphere respiration and soil microbial respiration.Soil respiration is not only affected by environmental factors,but also changes with the hu-man-induced disturbances of ecosystems.Land-use,the measures of land management,the pollution of soil,and so on can affect soil respiration and change the soil efflux.According to some research,the authors summed up their impacts on soil respiration by human activities through land-use changes and land-management measures among agroecosystem,grassland ecosystem,and for-est ecosystem.The results showed that (1) when adding fertilization to farmland,the soil respiration will increase;(2) fenced land can decrease soil respiration,while soil respiration in the grazed land at a grassland ecosystem will decline with the increasing of grazing intensity;(3) with grassland fertilization;farmland cultivation;fire,fertilization,and cutting of forest,conflicting results were found in the changes of soil respiration.Perhaps plant species,site condition,and measurement season can lead to different results on soil respiration. 相似文献
14.
The priming effect is well acknowledged in soil systems but the effect of nitrogen (N) fertilization remains elusive. To explore how N modifies the priming effect in soil organic matter (SOM), one in situ experiment with 13C labeled glucose addition (0.4 mg C g-1 soil, 3.4 atom % 13C) was conducted on soil plots fertilized with three gradients of urea (0, 4 and 16 g N m-2 yr-1). After glucose addition, the soil CO2 concentration and phospholipid fatty acid (PLFA) were measured on day 3, 7, 21 and 35. The study found that N fertilization decreased soil CO2, PLFA and the fungi to bacteria ratio. Glucose triggered the strongest positive priming in soil at 0 g N m-2 yr-2, meanwhile N fertilization decreased SOM-derived CO2. Soil at 4 g N m-2 yr-2 released the largest amount of glucose-derived carbon (C), likely due to favorable nutrient stoichiometry between C and N. Stable microbial community biomass and composition during early sampling suggests “apparent priming” in this grassland. This study concludes that N fertilization inhibited soil priming in semi-arid grassland, and shifted microbial utilization of C substrate from SOM to added labile C. Diverse microbial functions might be playing a crucial role in soil priming and requires attention in future N fertilization studies. 相似文献
15.
Effect of nitrogen amendments on microbial biomass, above-ground biomass and nematode population in the Negev Desert soil 总被引：1，自引：0，他引：1
Nitrogen amendments (0, 25, 50 and 100 kg NH4NO3/ha) were used to study the responses of primary production, microbial biomass and nematode population in desert soil. The study was conducted in the Israeli Negev Desert, a region characterized by low and randomly distributed rainfall. Over a 1-year study period, nitrogen amendments resulted in a significant (p<0·01) increase in soil microbial biomass. Soil microbial biomass also increased concomitantly with the increase in soil organic matter. The number of free-living nematodes in the soil increased with the increase in soil moisture, ranging from 43,000 individuals per square metre at the end of the summer to 351,000 individuals per square metre during the rainy season. No significant correlation was found between the nitrogen treatments and the nematode population, whereas a significant positive correlation was found between the nitrogen amendments and the above-ground biomass (r2=0·94, p<0·03). The nitrate proportion of the total soluble nitrogen in the soil also increased with the increase in soil moisture. This study provides baseline data for nitrogen amendments on soil microbial status, as well as insights into the importance of nitrogen in fertility in arid environments. 相似文献
16.
The island of Surtsey, Iceland, was formed in 1963 by a volcanic eruption. Since then, it has served as a unique natural laboratory for scientists interested in primary succession. In this study we investigated the state of the soil microfauna succession in 1995. We examined locations on the island with different vegetation types (unvegetated soil, soil with one or two plant species, and bird colony soil with a diverse vegetation). We recorded at least 16 nematode taxa and 13 flagellate taxa. Most of these were not reported in previous surveys from Surtsey. On the location with unvegetated soil, ciliates and nematodes were absent and only amoebae and heterotrophic flagellates were found. Most of the protozoan populations we examined were unable to survive salinity levels corresponding to seawater. We therefore conclude that many of soil protozoa populations on Surtsey arrived to the island as airborne cysts brought there from nearby land. However, in the bird colony soil with a high input of salts from the bird droppings, several flagellate species survived and multiplied at seawater salinity. This indicates that the bird colony soil harbours microhabitats where marine flagellate populations have been established. 相似文献
17.
以黑河中游人工绿洲边缘天然草地及其转变的人工梭梭灌木林（21 a）、人工杨树林（28 a）、人工樟子松林（33 a）和农田（开垦27 a和100 a）为研究对象,基于6种研究样地中小型土壤动物群落的调查数据,采用多变量排序和通径分析等方法,研究了土地利用/覆被变化与管理措施对中小型土壤动物群落及其主要类群演变的耦合效应。主要结果是:①将天然草地转变为未实施管理措施的人工梭梭灌木林后并未引起土壤动物群落组成、数量和物种多样性的显著变化,而转变为实施管理措施的杨树和樟子松人工林及农田后,导致了土壤动物群落组成、数量和物种多样性的变异,证实了土地覆被变化对中小型土壤动物群落的作用及其效应受管理措施的强烈调控。②土壤动物群落的演变过程受土地覆被变化与灌溉和施肥管理的共同影响,其中灌溉的贡献率最大,是关键驱动因子。③不同土壤动物类群对土地覆被变化和管理耦合作用的响应不同。灌溉对跳虫、甲螨和革螨的个体数量和物种丰富度的直接影响和总效应最大;施肥对辐螨的个体数量和物种丰富度的直接影响和总效应最大;灌溉和施肥对稀有类群的个体数量和物种丰富度的直接影响和总效应均较大,具同等重要的作用。结论是,土地覆被变化与管理耦合作用通过改变土壤水文和生态环境条件驱动了中小型土壤动物群落的演变过程。 相似文献
18.
太湖流域典型地区土壤全氮的空间变异特征 总被引：37，自引：5，他引：32
在地理信息系统的支持下 ,运用地统计学方法分析了太湖流域典型地区耕层土壤全氮的空间变异特征 ,并在此基础上利用BlockKriging法绘制了土壤全氮的空间分布图。结果表明 ,研究区域土壤全氮具有明显的空间自相关性 ,自相关距离在 16km左右。在 4 0km步长变化范围内 ,土壤全氮的空间变异表现为明显的各向同性特征 ,超出此范围 ,各向异性趋向明显。Kriging插值结果表明 ,土壤全氮含量在江阴和宜兴境内要高于锡山和武进境内 ,且高值斑块区主要分布在地势低洼的圩田区。 相似文献