共查询到20条相似文献，搜索用时 46 毫秒
1.
土壤微生物多样性的科学内涵及其生态服务功能 总被引：39，自引：2，他引：39
土壤微生物多样性是指土壤生态系统中所有的微生物种类、它们拥有的基因以及这些微生物与环境之间相互作用的多样化程度,当前研究主要集中在物种多样性、遗传多样性、结构多样性及功能多样性等4个方面。土壤微生物多样性作为全球性研究迄今仅有10余年时间,但已呈现对象广、内容多、水平宽、方法新等特点,特别是分子生物学技术在很大程度上决定并体现了其研究水平和发展进程。然而,如何进一步改进土壤微生物的培养技能、加强土壤宏基因组学分析与应用、耦合土壤微生物多样性与生态功能、揭示土壤微域结构的影响机制是土壤微生物多样性研究的4个关键科学问题。当然,土壤微生物多样性的生态系统服务功能是其根本价值所在,主要包括有机物分解、物质循环和生态安全调控等3个方面。今后,土壤微生物多样性研究应紧紧围绕其与土壤生物过程、生态服务功能三者之间的联系,着重建立土壤微生物多样性的研究指标和方法体系,进而阐明人类生产活动影响土壤微生物多样性及其生态服务功能的土壤生物过程。 相似文献
2.
【目的】土壤原生生物是指土壤中除植物、动物和真菌以外的所有真核生物,具有明显的系统发育和功能多样性特征,是地下生态系统的关键组成部分之一。与原核生物(细菌与古菌)和真菌相比,原生生物在土壤食物网中的作用常被忽视。本文系统论述了土壤原生生物的多样性及其生态功能,并综述了土壤养分、水分、pH、温度、重金属、微塑料等因子对土壤原生生物的影响,旨在阐明原生生物对土壤养分转化、土壤食物网和植物健康的生态作用及对主要环境因子的响应。【进展】土壤原生生物的数量、大小与形态各异,且营养级类群多样性丰富,它们可作为光合藻类、微生物捕食者、植物与动物的寄生者,在土壤食物网中扮演重要角色。光合型原生生物除潜在提高土壤氧浓度外,对陆地生态系统的碳储存具有重要贡献。消费型原生生物可通过捕食改变微生物群落,推动土壤微生物环,抑制植物病害,并提高植物性能。寄生型原生生物常被认为对宿主具有负面效应,如改变动物多样性,并引起植物病害。然而,寄生型原生生物对推动养分(如磷)循环也有贡献,且对植物的叶际细菌具有生防功能。总的来看,原生生物推动了陆地生态系统物质循环与能量流动向更高营养级的转移,并在土壤食物网中占据中心位置,... 相似文献
3.
生物多样性与生态系统功能一直是生态学研究的一个热点。近些年来的研究表明,植物多样性除了影响陆地生态系统地上部分的初级生产力等生态系统功能,还会间接影响地下生物多样性及土壤生态系统过程。本文概述了植物多样性对土壤动物的影响及其主要机制,归纳了植物多样性通过改变输入土壤中的资源数量与资源多样性、微生境结构、土壤环境因子等影响土壤动物的途径。目前关于土壤动物群落对植物多样性的响应仍存在很多问题和争议,本文总结了需要进一步深入研究的方向,特别指出了要加强研究影响植物多样性与土壤动物关系的生物与非生物因子、后续的生态效应和反馈、不同机制和途径的贡献定量化等。 相似文献
4.
长白山地丘陵区不同土地利用方式土壤动物群落生态分布特征 总被引：2，自引：1，他引：1
在长白山地丘陵区选择次生落叶阔叶林、灌木林、采伐迹地以及耕地四种土地利用方式,对其土壤动物群落的组成、多样性和分布特征进行研究。结果表明:不同土地利用方式土壤动物群落的水平分布呈现明显的差异。采伐迹地中型土壤动物个体密度和耕地中型土壤动物类群数季节变化明显。次生落叶阔叶林和灌木林土壤动物分布随土层加深急剧减少,采伐迹地和耕地垂直分布递减和缓。同一季节土壤动物的丰富度指数和多样性指数在不同土地利用方式差异显著。土壤动物的多样性表现为灌木林最高,耕地最低。不同土地利用方式影响土壤动物群落的生态分布,其中pH、土壤有机质、有效磷和速效氮是影响长白山地丘陵区不同土地利用方式土壤动物群落分布的主导因子。 相似文献
5.
石漠化区和采石场都是涉及人类活动的经济环境问题的区域,其特征是基岩广泛裸露、水土流失严重、土地贫瘠和植被稀缺,其本质是土地生物潜能的衰减或丧失,其生境保水性和蓄水性差,渗漏性极强,导致机械性缺水频繁,生物多样性下降和缺失,迁入植物群落难以定居,自然恢复需要几十至上百年的时间且很困难。当前其生态恢复主要存在以下问题:普遍追求植被的快速恢复,侧重于植被栽植技术的研究;大量使用外来物种导致的退化现象和潜在威胁乡土生物多样性;缺乏解除贫瘠和干旱等主要限制性因子的土壤微生物及动物添加类的土壤改良产品;极少见石漠化基岩裸露区恢复的研究;生态恢复成本过高、工艺复杂、效果欠佳。 相似文献
6.
陕北枣林土壤动物功能类群及其害虫生态调控 总被引：1，自引：0，他引：1
在陕北枣林研究区域内,以土壤动物为研究对象,采取野外调查取样、定点动态观测与室内鉴定分类的研究方法,选取了延安万花山、延川县、清涧县、佳县枣林4个样点7个样地,于2007年3月、6月、9月、11月,对土壤动物功能类群进行了初步研究。陕北枣林土壤动物可划分为植食性、捕食性、腐食性、枯食性、菌食性土壤、杂食性土壤动物6个功能类群,基于土壤动物功能类群与枣林病虫害生态调控的内在关系,建构陕北枣林害虫生态调控体系,为深入探讨土壤动物与枣林害虫生态调控的关系提供基础资料和理论依据。 相似文献
7.
采用大样地、典型固定样地调查方法,对宁夏香山荒漠草原区生物多样性与环境特征进行了研究。结果表明,研究区所调查151种植物分属39科、95属;植物群落分布体现了山地荒漠草原的特征,多数植物群落类型分布在山地阴坡;群落多样性动态受时间、地形影响较大,在土壤属性中受土壤含水量影响较大;灌丛植被在该山地生态系统中处于重要地位,是生态功能维持的主要因素;昆虫群落符合干旱地区草地植物群落特征,大型动物的稀有也提示对该地区进行生物多样性保护日益紧迫。 相似文献
8.
9.
土壤动物与土壤健康息息相关,土壤动物多样性和功能能够灵敏反映人类活动和气候变化引起的土壤扰动。同时,土壤动物还通过与生物和非生物组分间的相互作用对地上生态系统产生反馈作用。当前土壤动物在土壤健康评价体系中的应用相对较少,主要集中在土壤线虫、节肢动物和蚯蚓等类群,仍缺乏基于土壤动物的系统性评价指标。因此,本文围绕土壤动物在指示土壤健康方面的潜力,系统总结了现有基于土壤动物的土壤健康评价指标,强调未来应建立和完善土壤动物基因组信息数据库,挖掘土壤动物的功能性状,加强土壤食物网结构和生态功能的研究,建立集成土壤动物物种多样性、功能性状和土壤食物网的指标体系,从而促进土壤健康和生态系统的可持续发展。 相似文献
10.
河岸植被缓冲带是河岸生态系统的重要组成部分,对河岸生态系统的生态及水文过程具有重要的影响。世界上许多国家已将河岸植被缓冲带列为河岸生态系统管理的一个重要内容,并在一些国家被作为控制农业流域非点源污染的最佳管理措施。河岸植被缓冲带的生态水文功能体现在控制河岸侵蚀、截留地表径流泥沙和养分、保护河溪水质、调节水温、为水陆动植物提供生境、维护河溪生物多样性和生态系统完整性以及提高河岸景观质量等多个方面。本文综述河岸植被缓冲带生态水文功能方面的研究进展,总结了一些研究中提出的不同河岸植被缓冲带功能发挥所需要的宽度,同时指出由于河岸生态系统保护的目标,侧重的功能,研究区域土壤、地形、植被、排水特征等因素各异,河岸植被缓冲带生态水文功能发挥所要求的实际宽度也有所不同。 相似文献
11.
土壤动物在土壤有机质形成中的作用 总被引：2，自引：1，他引：2
作为土壤生态系统重要组成部分的土壤动物,在土壤元素循环转化和迁移过程中发挥着重要的作用。土壤动物是凋落物分解的"微型粉碎机",通过体内"特殊转换器",影响土壤有机质的转化、腐殖质的形成。本文从土壤动物对地表枯落物分解入手,分析了影响土壤动物对凋落物分解的因素,土壤动物通过刺激土壤酶活性,与土壤微生物群落一起,加快土壤有机物的分解,促进土壤腐殖质的转化。旨在拓宽土壤动物生态功能,丰富土壤腐殖质形成机理学说,对保护土壤生物多样性、提高土壤地力、保障粮食安全具有重要的科学意义。 相似文献
12.
The aim of this field experiment was to quantify the contribution of soil fauna to plant litter decomposition in three forest sites differing in C/N ratio under natural conditions in Xishuangbanna, southwestern China. We conducted a survey of soil fauna communities, the forest floor litter and investigated mass loss of mixed tree species leaf litter for two years in a tropical secondary forest, an evergreen broad-leaf forest and a tropical rain forest. Exclusion treatments of different sized soil fauna from the leaf litter by using varying mesh size litter bags (2 mm and 0.15 mm) were also performed. Mass loss and C and N concentrations in litter bag leaf materials were determined at monthly intervals. We found that: (1) the three forests differed in floor litter biomass and nutrient contents but not in soil fauna richness and abundance; (2) litter mass loss and decomposition rate were slower when soil macrofauna and most of mesofauna were excluded; and (3) greatest soil fauna contribution to plant litter decomposition occurred in the rain forest, where leaf litter C/N ratio was also highest (41.5% contribution: 54.8 C/N ratio), in comparison to 8.69% in the broad-leaf forest and 19.52% in the secondary forest, both with low leaf litter C/N ratios (<32). Our results suggested that, soil fauna played a more pronounced role in the decomposition of mixed leaf litter in tropical rain forest, and significantly bigger effects from fauna were ascribed to the enhancement of N concentration and decrease of C concentration of the initially high C/N ratio litter in this forest site. 相似文献
13.
Soil fauna has been postulated as one of the paramount determinants of decomposition in the humid tropics. However, its effect on litter decomposition has only been demonstrated in few forest sites in Central America. In addition, landslide is a common disturbance associated with heavy rainfall brought by tropical cyclones in the tropics and can potentially alter abundance and structure of soil animals and thus affect litter decomposition. In this study, we examined the effect of soil animals on litter decomposition in an Asian subtropical monsoon forest and compared the animal effects in landslide-disturbed (2 years old) and undisturbed sites. Animal exclusion by naphthalene treatment significantly reduced the density and diversity of litterbag animals and slowed down the rate of decomposition in both landslide-disturbed and undisturbed sites. However, density (per unit area) and diversity of the litter animals and litter decomposition rate did not differ between the landslide-disturbed and undisturbed sites for both control and animal-excluded treatments. Our data suggest that the abundance of soil animals is not limited by litter mass. Furthermore, soil fauna recover quickly from landslides, and fauna's facilitative effect on litter decomposition is not altered after their recovery. 相似文献
14.
Extensive studies have been conducted to evaluate the effect of soil fauna on plant litter decomposition in terrestrial ecosystems. However, scholars have reported inconsistent results on the direction and magnitude of the soil fauna effect. We present a global synthesis of 75 papers that cover 197 plant species with 543 cases of plant litter decomposition experiments and soil fauna effects on plant litter decomposition. By using a boosted regression tree model (BRT), we aim to provide a synthesis of existing data that comprehensively and quantitatively evaluates how climate, plant litter quality, and study methods interact with soil fauna in affecting plant litter decomposition. Global average effect size (ES) is −0.426, which indicates a 35% lower decomposition rate when soil fauna is excluded by physical or chemical exclusion techniques. The final model explains 32.3% of the variation in ES. The predictors that substantially account for the explained variation include mean annual temperature (MAT, 37.1%), mean annual precipitation (MAP, 9.7%), phosphorus (12.4%), nitrogen (5.6%), and lignin content (5.5%). By contrast, the heterogeneity of the study duration and soil fauna exclusion technique have negligible contributions (each <5%). Log effect size strongly decreases with both MAT and MAP. Plant litters with high quality have stronger soil fauna effect because the log effect size is negatively related to nitrogen and phosphorus content and positively related to lignin content. Our analysis demonstrates the critical role of climate and plant litter quality in determining the soil fauna effect on plant litter decomposition in terrestrial ecosystems. However, the large unexplained variation (67.7%) in ES in the BRT model indicates undiscovered mechanisms underlying the soil fauna effect in our analysis. We call for further studies on this topic in the future. 相似文献
15.
Yolima Carrillo Becky A. Ball Mark A. Bradford Marirosa Molina 《Soil biology & biochemistry》2011,43(7):1440-1449
Plant chemical composition and the soil community are known to influence litter and soil organic matter decomposition. Although these two factors are likely to interact, their mechanisms and outcomes of interaction are not well understood. Studies of their interactive effects are rare and usually focus on carbon dynamics of litter, while nutrient dynamics in the underlying soil have been ignored. A potential mechanism of interaction stems from the role fauna plays in regulating availability of litter-derived materials in the mineral soil. We investigated the role of soil fauna (meso, macro) in determining the effect of surface-litter chemical composition on nitrogen mineralization and on the micro-food web in mineral soils. In a field setting we exposed mineral soil to six types of surface-applied litter spanning wide ranges of multiple quality parameters and restricted the access of larger soil animals to the soils underlying these litters. Over six months we assessed litter mass and nitrogen loss, nitrogen mineralization rates in the mineral soils, and soil microbes and microfauna. We found evidence that the structure of the soil community can alter the effect of surface-litter chemical composition on nitrogen dynamics in the mineral soil. In particular, we found that the presence of members of the meso- and macrofauna can magnify the control of nitrogen mineralization by litter quality and that this effect is time dependent. While fauna were able to affect the size of the micro-food web they did not impact the effect of litter composition on the abundance of the members of the micro-food web. By enhancing the strength of the impact of litter quality on nitrogen dynamics, the larger fauna can alter nitrogen availability and its temporal dynamics which, in turn, can have important implications for ecosystem productivity. These findings contribute to evidence demonstrating that soil fauna shape plant litter effects on ecosystem function. 相似文献
16.
陕西秦岭山区典型人工林地腐殖质层土壤客土混合效应研究 总被引：1，自引：0，他引：1
引进更新树种形成混交林是解决人工纯林连栽障碍问题的根本途径,为了了解陕西秦岭山区日本落叶松、油松、灰楸和锐齿栎4种典型人工林树种混交的可行性,本项研究尝试通过不同针阔树种林地腐殖质层土壤的原位混合培养来模拟混交造林试验,从土壤生物化学和枯落叶分解的角度探讨了4种树种种间关系的协词性。结果表明:(1)在针叶林地引入阔叶林树种后可以促进土壤微生物量、酶活性和原林地枯落叶年分解速率的提高,而且随着引入阔叶树种比例的增加促进作用增强,引入树种灰楸的作用大于锐齿栎;(2)在阔叶林地适量引入针叶树种后虽然也可以促进土壤微生物量、酶活性和原林地枯落叶年分解速率的提高。但是随着引入针叶树种比例的增加促进作用减弱,引入树种油松的作用大于落叶松;(3)从土壤生物化学性质和枯落叶分解的角度综合表明,4种典型人工林树种的针阔种间关系均表现为协调,而且油松与灰楸的种间协调性最好,其次为落叶松与灰楸、油松与锐齿栎,而落叶松与锐齿栎的种间协调性较差。 相似文献
17.
Leaf decomposition in two semi-evergreen tropical forests: influence of litter quality 总被引：10，自引：0，他引：10
Gladys Loranger Jean-François Ponge Daniel Imbert Patrick Lavelle 《Biology and Fertility of Soils》2002,35(4):247-252
Decomposition processes in tropical semi-evergreen forests are still poorly understood. The influence of soil properties and litter quality on decomposition rate was studied in two semi-evergreen forests of Guadeloupe, a forest plantation and a secondary forest, located on different soils. Leaf litter of four tree species was enclosed in litterbags for a 14-month period. Non-linear correlations were calculated between mass loss and the concentration of major leaf components (soluble C, N, lignin, cellulose, tannins, total soluble phenols) in order to determine the best predictor of leaf litter decomposition. Soil physico-chemical properties and ratios between some of the above-mentioned litter quality parameters were also examined as mass loss predictors. In addition, non-linear correlations were calculated between mass loss and litter quality parameters, at successive periods. Litter quality was the main determinant of litter decomposition in the studied forests. Several litter quality parameters were correlated with leaf disappearance, varying according to stages of decomposition. Between 1 month and 2.5 months, the mass loss was correlated negatively with the initial phenol content and with initial lignin:N and (lignin+phenol):N ratios. From 2.5 to 5.5 months, the mass loss was correlated negatively with the initial phenol content and positively with the initial cellulose content. At later stages of decomposition (9-14 months), the mass loss was correlated negatively with the initial tannin content. Differences in soil characteristics and fauna did not seem to be enough to affect decomposition. 相似文献
18.
选择半干旱(宁夏盐池)、干旱(内蒙古乌拉特后旗)荒漠草原区为研究样地,以牛枝子枯落物为研究对象,采用网孔分解袋法研究土壤动物分解功能对枯落物C、N、P、K分布的影响,结合枯落物分解过程中土壤有机碳(SOC)、全氮(TN)、全磷(TP)、全钾(TK)含量分布特征,阐明土壤动物分解作用对土壤营养元素含量分布的影响规律。结果表明：(1)共捕获土壤动物226只,隶属14科(属)。土壤动物个体数表现为盐池地区均高于乌拉特地区,而类群数差异较小,仅在乌拉特地区灌丛高于裸地。土壤动物Simpson指数、Shannon指数和Margalef指数在不同生境下均无显著差异,Pielou指数在裸地生境下表现为乌拉特地区显著高于盐池地区。(2)不同网孔分解袋中枯落物养分元素均处于不同程度的释放状态。其中枯落物C、N元素累积系数在盐池地区表现为2 mm网孔显著低于0.01 mm网孔,在乌拉特地区表现为2 mm网孔显著高于0.01 mm网孔;枯落物P、K元素累积系数分别在乌拉特地区和盐池地区表现为2 mm网孔显著高于0.01 mm网孔,且土壤动物对盐池枯落物C、N、P、K元素释放均表现为正效应;对乌拉特枯落物C、... 相似文献
19.
Climate and litter quality have been identified as major drivers of litter decomposition, but our knowledge of how soil characteristics (e.g. microbial community and chemical properties) determine carbon (C) and nitrogen (N) availability derived from the decomposition of litter of different qualities is still scarce. We conducted a microcosm experiment to evaluate how soils with contrasting microbial communities and soil properties (denoted Soils A and B hereafter, where Soil B has higher bacterial and fungal abundance, fungal:bacterial ratio, and organic C than Soil A) determine the availability of soil C (carbohydrates, proteins, amino acids and phenols) and N (dissolved organic and inorganic N, microbial biomass N and available N) during the decomposition of litter of contrasting quality (C:N ratios ranging from 20 to 102). We also evaluated the relative importance of soil characteristics and litter quality as drivers of C and N inputs to the soil during this process. Overall, higher soil C and N availability after litter decomposition was found in Soil B than in Soil A. Soil characteristics had a higher positive effect on soil C and N contents than litter quality during litter decomposition. We also found that changes in N availability and organic matter quality registered after litter decomposition, linked to different soil characteristics, were able to promote dissimilarities in the potential mineralization rates. In conclusion, our study provides evidence that soil characteristics (e.g. microbial communities and chemical properties) can be more important than litter quality in determining soil C and equally important for N availability during the decomposition of leaf litter. 相似文献
20.
气候变化对土壤有机碳库分子结构特征与稳定性影响研究进展 总被引：5，自引：0，他引：5
气候变化与土壤碳库之间的相互作用及耦合机制一直是学术界研究的热点与难点。虽然目前在群落—生态系统、区域—全球等不同尺度上开展了大量研究,然而在分子尺度上探究气候因子波动对土壤有机碳库化学结构特征影响机制方面却鲜有研究。本文综述了近年来气候因子变化及其导致的环境、生态因子变化与土壤有机碳库分子结构特征的关系。气温升高不仅将改变土壤中源自植物部分的有机碳来源特征,同时也会将加速土壤木质素等碳组分分解,排水或者旱化引起有机质分解加速,土壤中C=O键增加。植被演替、土壤动物及微生物等与气候变化密的切相关的生态因子则会影响输入土壤植被残体性质,加速糖类、脂类及木质素分解、并改变有机碳结构的生物分子标志物;土壤中有机碳稳定性与分子结构特征密切相关,土壤中具有高的苯环结构(芳香族化合物)及O-烷基碳通常表明土壤碳库具有更高的稳定性,而之前认为较为稳定的木质素等结构在气候变暖背景下可能并不稳定。未来研究中应着重关注与土壤有机碳分子标志物的识别与生态意义判读、生物对土壤有机碳分子结构转换过程的调控作用及机制、大尺度环境/生态过程与碳库分子结构转变的耦合机制及新的土壤有机碳分子结构辨识技术及判读等方面的研究。 相似文献