大兴安岭冻土区土壤动物功能类群对地温变化的响应

对大兴安岭不同冻土带土壤动物进行的研究,将该区土壤动物划分为植食性、腐食性和捕食性三个功能类群。土壤动物功能类群的水平分布与地温的相关性表明,不同冻土带腐食性土壤动物总的生物量和地温的相关系数为-0.999,呈显著的负相关(P<0.05);不同冻土带捕食性土壤动物总的生物量和地温的相关系数为-0.997,呈显著的负相关(P<0.05)。土壤动物功能类群的垂直分布与地温的相关性表明,岛状融区冻土带土壤动物功能类群的垂直分布与8月份地温值呈显著正相关,岛状融区冻土带的腐食性动物的垂直分布与8月份地温呈显著正相关。各功能类群的个体数量相关分析结果表明,腐食性动物和捕食性动物相关系数为0.8723,呈显著正相关(P<0.05);生物量相关分析结果表明,腐食性动物和捕食性动物相关系数为0.7551,呈著正相关(P<0.01)。     

大兴安岭北部森林生态系统土壤动物的功能类群及其生态分布

对大兴安岭北部塔河县7个森林群落的土壤动物进行研究,将该区土壤动物划分为腐食性、植食性和捕食性动物三个功能类群,无论个体数量还是生物量,腐食性动物所占比例都最大,而植食性和捕食性动物所占比例较小。土壤动物各功能类群在组成、个体数量和生物量等方面均具有相对稳定性,并在一定程度上反映了环境质量。土壤环境条件优越的群落,腐食性动物的个体数量及生物量所占比例相应较大。与小兴安岭森林土壤动物相比,大兴安岭地区腐食性动物所占比例减小,植食性和捕食性动物所占比例相应增加。各地区的共有类群反映了大环境的相似程度,而特有类群则反映出各自局地环境的特殊性,它们对生态系统具有指示作用。     

玉米间作种植对黑土区农田中小型土壤动物群落的影响

中小型土壤动物对环境变化反应敏感,不同种植方式导致农田土壤空间格局改变将影响中小型土壤动物群落多样性和功能。本文通过玉米单作和间作种植,在玉米生长季的不同月份调查取样,研究玉米单作和间作种植对土壤动物的个体数量、类群数、多样性和不同功能群的影响。结果表明:从试验样地共捕获中小型土壤动物1 473只,隶属于40个类群;玉米间作种植显著降低中小型土壤动物的个体数(P 0. 05),玉米间作种植降低中小型土壤动物类群数,未达到显著水平(P 0. 05),这种降低趋势在不同月份和土层中均表现出来;玉米单作和间作种植下中小型土壤动物总体趋势为腐食性杂食性捕食性+植食性的个体数(P 0. 05);玉米间作种植增加了优势度指数,降低了多样性指数、均匀度指数和丰富度指数(P 0. 05);玉米间作种植改变了不同食性中小型土壤动物的个体数和类群数,腐食性、杂食性和捕食性+植食性土壤动物数量降低,杂食性和捕食性+植食性的土壤动物类群数增加,腐食性土壤动物类群数降低,但个体数和类群数的变化未达到显著水平(P 0. 05)。     

土壤原生生物的类群及功能

土壤原生生物是生活在土表凋落物和土壤中最原始、最简单的真核生物。原生生物的演化进程快,种类多样,至今尚没有统一的系统发育分类体系。种类众多的土壤原生生物拥有多样的生态功能,在控制细菌的生长繁殖和群落组成、改变土壤营养物质的循环、调控植物生长发育及土壤污染物的净化等方面发挥着重要作用。本文从形态结构、进化过程及生态功能等几个方面,对土壤原生生物的系统分类及其功能、地理分布和研究方法,及其与土壤微生物、植物之间的生态关系,对土壤环境的潜在影响等领域的研究进展进行了总结,并对土壤原生生物研究中存在的问题进行了展望。旨在深入理解土壤原生生物类群和功能的多样性及其维持机制,为深化土壤原生生物与微生物、植物间的相互关系研究提供依据,为开发新的土壤和植物病害的生物防治技术提供参考。     

土壤动物主要生态特征与生态功能研究进展

土壤动物是陆地生态系统重要的组成部分，是物质循环和能量流动正常运行的关键环节。近年来，土壤动物研究越来越受到人们的重视，研究主要包括土壤动物生态特征和生态功能两个方面。本文概括了土壤动物的定义和分类，阐述了土壤动物的数量、种类、分布格局及影响因素等主要生态特征，着重论述了土壤动物的分解、生态指示等功能。认为，目前土壤动物研究发展缓慢，基础研究差，生态特征研究仍处于定性与半定量水平；功能研究单一，缺少土壤动物多样性功能研究。对今后研究提出展望。本文旨在加深对土壤动物的了解，为生物多样性保护、合理开发利用土壤资源、健全生态指标和实现农业、生态可持续发展提供必要的理论支持。     

土壤动物与土壤健康

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。     

贵州喀斯特山区大型土壤动物多样性研究

为了解贵州喀斯特地区土壤动物生物多样性特点,选取贵州4个典型喀斯特山地为研究区进行大型土壤动物多样性和群落特征分析。得出如下结论:（1）4个研究区共获得的大型土壤动物分别隶属于3门8纲21目,共21个类群。优势类群为4类（占总个体数的10%以上）,分别是鞘翅目（占19.7%）、腹足纲（占17.86%）、蚁科（占17.03%）、蜘蛛目（占11.69%）。（2）大型土壤动物的类群数依次是荔波 > 毕节 > 清镇 > 花江;荔波研究区采集到20个类群,该区土壤动物类群组成相对完整,可以作为喀斯特生态系统退化程度的参照标准。土壤动物个体数依次是荔波 > 清镇 > 毕节 > 花江;Shannon-Wiener多样性指数反映出与类群数同样的结果:荔波 > 毕节 > 清镇 > 花江。喀斯特生态环境因子的改变对腹足纲、蜘蛛目、带马陆目等类群的组成结构和数量产生了很大的影响,可以作为喀斯特生态退化程度的指示种。（3）相似性分析表明,毕节研究区大型土壤动物群落与荔波最相似,生态环境较好,清镇次之,花江最差,同时也与其石漠化等级程度相吻合。     

玉米/大豆间作种植对农田大型土壤动物群落动态变化的影响

为调查玉米/大豆间作种植模式对农田大型土壤动物群落结构动态特征的影响,采用手拣法捕获土壤动物,于2016年6～9月玉米生育期内对大型土壤动物群落组成、多样性、垂直分布和功能群特征进行了研究。结果表明:玉米生育期共捕获大型土壤动物818只,隶属于34个类群。大型土壤动物个体数随玉米生长呈现逐渐增加的趋势,在拔节期间作种植显著提高了土壤动物个体数(P<0.05);玉米拔节、抽穗和成熟期10～20 cm土层大型土壤动物个体数显著高于0～10和20～30 cm土层(P<0.05)。Shannon-Weiner指数和Margalef指数随玉米生长呈现先升高后下降的趋势,在拔节期Shannon-Weiner指数和Margalef指数均最大;Simpson指数总体与Shannon-Weiner指数变化趋势相反,随玉米生长呈现先下降后升高的趋势。间作种植在成熟期显著提高了植食性大型土壤动物个体数,在拔节期显著提高了捕食性和腐食性大型土壤动物个体数(P<0.05);植食性和腐食性大型土壤动物个体数随玉米生长呈增加的趋势;捕食性大型土壤动物个体数随玉米生育期基本呈增加的趋势。     

不同玉米秸秆还田量的土壤大型动物夏季群落动态特征

摘 要 调查不同玉米秸秆还田量下农田大型土壤动物群落动态特征,于2016年6—9月玉米生育期内进行,采用手拣法捕获土壤动物。结果表明：共捕获大型土壤动物2 681只,隶属于41个类群。方差分析显示,13 500 kg?hm-2还田处理(SR4)显著提高了大型土壤动物个体数,12 000 kg?hm-2还田处理(SR3)显著提高了大型土壤动物类群数。多样性表明：多样性指数和丰富度指数随玉米生长季总体呈现出先增加后下降的趋势;均匀度指数随玉米生长季总体呈现出下降的趋势;优势度指数总体与多样性指数变化趋势相反,随玉米生长季呈现出先下降后增加的趋势。垂直分布表明：随玉米的生长时期的推移,表层0~10 cm土层的大型土壤动物有向10~20 cm土层下移的趋势。功能群特征表明：捕食性大型土壤动物个体数随玉米生长季呈现先增加后下降的趋势;植食性和腐食性大型土壤动物个体数随玉米生长季呈现增加的趋势;杂食性大型土壤动物个体数在玉米生长季无明显变化。RDA分析表明：受农田土壤环境因子影响较大的大型土壤动物类群主要是研究区的优势类群,大型土壤动物的个体数与土壤有机质含量和土壤含水量关系紧密。总体上,玉米秸秆还田影响地表土壤的微环境,进而影响了大型土壤动物群落的组成、分布特征和功能群,玉米秸秆还田有益于农田大型土壤动物功能群的发展。     

沿海区土壤线虫对海水入侵土壤盐渍化的响应

在2013年对大连市大魏家镇海水入侵污染区域进行了土壤理化性质和线虫群落调查,在此基础上,应用线虫多样性指数和功能类群指数研究海水入侵土壤盐渍化以及不同土地利用方式对土壤线虫群落结构的影响。研究期间共鉴定出土壤线虫30科48个属。其中食细菌类群的比例最高,共17属,占总数42.81%;其次为杂食/捕食类群,共9个属,占总数25.26%。优势属为Plectus。结果显示:海水入侵已造成该地区土壤盐渍化;土壤盐分与线虫生态指数SR、f/b、NCR、PPI、MI、PPI/MI、PP%、FF%、BF%和OP%存在显著的相关关系;土地利用方式、土壤盐分对线虫群落的生态指数影响显著,是影响该地区土壤线虫群落结构的主要因素。通过开展土壤线虫对海水入侵土壤盐渍化响应的研究,为促进沿海受海水污染区土壤生态系统的健康发展提供科学依据。     

海拔对表居土壤动物不同取食功能群多度分布的影响

物种多度分布格局是群落生态学研究的前沿领域之一。海拔梯度下开展土壤动物多度分布研究有利于认识分解者群落的构建过程如何响应环境变化。选用5种常见的生态位分配模型(断棍模型、生态位优先占领模型、生态位重叠模型、随机分配模型和优势优先模型),分别采用个体数量与生物量作为多度表征指标,对分布于北京东灵山辽东栎林下不同海拔范围的表居土壤动物群落整体与不同取食功能群(杂食者、植食者、捕食者、腐食者)的相对多度分布进行研究。结果表明,拟合表居土壤动物群落整体的最优生态位分配模型不受海拔影响,均为断棍模型。但表居土壤动物各功能群多度分布受海拔影响,杂食者随海拔升高,最优模型由断棍模型转变为生态位优先占领模型,而植食者与之相反。多度表征指标选择影响拟合表居土壤动物不同功能群(捕食者和腐食者)多度分布的最优模型。总体而言,海拔和多度指标选择并未影响表居土壤动物整体的多度分布,但对表居土壤动物中不同取食功能群的多度分布有影响。     

Interactions between soil development,vegetation and soil fauna during spontaneous succession in post mining sites

More than 50 parameters of vegetation, soil and soil fauna were studied in 27 non-reclaimed post mining sites of various age (1–41 years old) located near the town of Sokolov (Czech Republic). A clay alkaline substrate (pH 8.5) was dumped in heaps; its pH and contents of available calcium and sodium decreased during succession. Total carbon and nitrogen, available potassium and water-soluble phosphorus increased with increasing successional age. In early stages, i.e. before the establishment of a shrub layer, the topsoil was formed mainly from the dumped spoil material. In shrub-dominated sites (14–22 years old), the litter reserve on the soil surface was higher than annual litter production, and a thick fermentation layer developed below the litter layer indicating slow litter decomposition and soil mixing. In older plots (24 year old or older), a humus layer was formed and the thickness of the fermentation layer decreased. Microstructure analysis indicated that earthworm activity, namely the mixing of organic and mineral layers, played a principal role in humus layer formation. No group of soil fauna preferred early successional stages, but tardigrades, bacteriophagous and fungivorous nematodes, and microsaprophagous dipterans, were tolerant to these stages. The density of most fauna guilds increased in intermediate stages with thick fermentation layer. Pauropods and testate amoebae reached highest densities on these sites. Macrosaprophagous guilds of soil fauna, most important for litter decomposition and soil mixing, attained their highest density in the oldest sites. Two clearly separated clusters of sites were distinguished based on TWINSPAN classification of vegetation. The first cluster included sites 1–23 years old, dominated by ruderal plants. Sites 24–41 years old were grouped in the second cluster; forest and grassland species were more frequent here. The presence of humus layer was selected by a discriminant analysis as the strongest predictor to discriminate between these two clusters. All considered ecosystem components, i.e. soil, soil fauna, and vegetation, passed through substantial changes in about the 25th year of succession and their changes were mutually correlated.     

Rehabilitation of the nematode fauna in a phytostabilized,heavily zinc-contaminated,sandy soil

Background Aim and Scope  The Maatheide in Lommel, Belgium, is an extremely metal contaminated, sandy area where vegetation has disappeared over ca. 130 hectares due to the activities of a former pyrometallurgical zinc smelter. To reduce the environmental impact of this area a rehabilitation strategy had to be developed. Therefore, in the centre of this area, an experimental phytostabilization (grass) field of three hectares had been installed in 1990. After a grass cover had been established, the development of the nematode fauna in the phyto-stabilized soil was studied. Nematodes act at various levels in soil ecosystems: herbivorous species extract their food from plant roots, bacterivorous and fungivorous species feed on microbes, predatory species consume other nematodes, and omnivorous species have mixed diets. In a mature soil ecosystem that normally exercises its manifold functions, a diverse nematode fauna occurs, reflecting the intactness of the ecosystem. As such, this fauna is indicative of crop growth, vegetative diversity, organic matter decomposition, microbial activity and diversity, and the maturity of the soil ecosystem. Methods  A metal immobilizing soil amendment (beringite) and municipal waste compost (to improve the nutrient status and water-retaining capacity) were incorporated in the soil and metal tolerant ecotypes of grasses were sown. Soil samples for nematode analyses were taken four times. Results  As a result of the treatment, pH of the soil increased and the water extractable amount of Zn was strongly reduced. Grass growth revitalized the impoverished soil ecosystem, organisms as well as metabolic processes. The nematode fauna of the experimental field in the Maatheide has been studied since 1997 and the recovery of the various feeding guilds and taxa was checked again in 2002. Nematode densities and feeding guilds have normalized, with omnivores and predators as the last guilds to reappear. Up to 27 species with a current diversity were observed in the grass-covered experimental plot, but a number of ubiquitous species, present at a comparable site at some distance, remained absent. Conclusion  It can thus be concluded that rehabilitation of an impoverished soil ecosystem is possible in heavily contaminated soils by means of phytostabilization, but there are some limitations on rehabilitation, since a number of common nematode species remained absent. Further research should indicate if this absence is indicative of a loss of essential processes in the soil. Recommendation and Perspective. Phytostabilization of heavily zinc-contaminated, sandy soil also remediates impoverished soil ecosystems. In particular, the recovery of nematode feeding categories is indicative for the normalization of soil life. The absence/presence of a number of ubiquitous taxa should be checked again after some time to verify if recovery is completed.     

A comparison of the wet and dry season DNA-based soil invertebrate community characteristics in large patches of the bromeliad Bromelia pinguin in a primary forest in Costa Rica

In Costa Rica, the Maquenque National Wildlife Refuge (MNWLR) contains a unique habitat gradient ranging from primary old growth forests, grasslands, pastures, to various ages of secondary forests. Within these primary old growth forests are extremely dense naturally occurring Bromelia pinguin (Bromeliaceae) patches that often grow with densities up to 2 plants per square meter. A previous study found that anti-fungal activity of this particular plant appears to be altering the fungal community in soils adjacent to these plants. No work has been previously conducted on the possible effects of this plant community on soil faunal communities and if seasonality contributes to changes in soil invertebrate populations along a moisture gradient. Thus, a study was conducted to assess the effects of this specialized plant community on soil invertebrates with respect to season, and if these changes in soil fauna guild structure could prove to be valid candidates as indicators of ecosystem condition with changes in precipitation. In addition, a meta-analysis was done to determine how the bromeliad-associated soil invertebrate communities differ from those in adjacent primary forest soils. Therefore, comparisons were determined from previous primary forest soil invertebrate environmental DNA (eDNA) to the current wet season bromeliad soil invertebrate eDNA. Roche 454 pyro-sequencing was conducted on the 650 bp fragment of the cytochrome oxidase subunit I (COI) gene of invertebrates to obtain and characterize soil invertebrate sequence composition. To determine relationships among soil fauna guilds across seasons, relative abundance of the sequences were calculated, and used in conjunction with EcoSim niche overlap and co-occurrence values. From the bromeliad seasonal soil fauna eDNA study, it appears certain invertebrate guilds are driven by moisture as indicated by fluctuations in relative abundance of each invertebrate guild across seasons in bromeliad patch soils, as well as indicated by EcoSim niche overlap values. In particular, Guilds 1, 4, and 5, should warrant further investigation as indicators of habitat condition. The meta-analysis showed that a naturally occurring modified environment (the bromeliad patches), can result in differences in relative abundance and partitioning of a limited resource between invertebrate guild structure. Those guilds associated with microbivorous and complex decomposition activities (i.e. Guilds 3 and 4), are more abundant in primary forest soils than bromeliad patch soils and could potentially used for bioindicators of habitat perturbations.     

Disturbance–diversity relationships for soil fauna are explained by faunal community biomass in a salt marsh

Disturbance–diversity relationships have long been studied in ecology with a unimodal relationship as the key prediction. Although this relationship has been widely contested, it is rarely tested for soil invertebrate fauna, an important component of terrestrial biodiversity. We tested disturbance–diversity relationships for soil meso- and macrofauna in a salt marsh where periodic sea water inundation and cattle grazing occur as stressors. We hypothesized a unimodal inundation frequency–diversity relationship, whereas we expected grazing to overrule the effects of inundation frequency due to its large effects on the habitat of soil fauna. We found a negative relationship between inundation frequency and diversity at the ungrazed sites and no relationship at the grazed sites. Moreover, we found a negative relationship between community biomass and diversity for soil fauna that may have caused this negative disturbance–diversity relationship. Community biomass at the intermediate inundation frequency increased due to the dominance of Orchestia gammarellus (a macro-detritivore species), which could exploit low quality litters at the ungrazed sites. We highlight that the negative relationship between faunal community biomass and faunal diversity may influence disturbance–diversity relationships and illustrate that total biomass distribution of feeding guilds of soil fauna can improve our understanding of the soil fauna response to stressors in salt marshes.     

吉林黑土区不同施肥条件下农田土壤动物组成及多样性变化

采用手捡法和改良干漏斗法(Modified.Tullgren)对吉林黑土区长期定位施肥农田土壤动物群落组成及多样性进行研究。12个施肥小区内共采集108个土壤样品,获得农田土壤动物标本17265只(未鉴定标本187只),隶属3门9纲19目3亚目48科。统计分析结果表明,所采集标本中,营养功能群以植食性(35.53%)为主。其中,大型农田土壤动物捕获的个体数和类群数以撂荒和施氮肥区最多;中小型农田土壤动物则以撂荒和轮作区最多;大型农田土壤动物群落的多样性指数(H′)依次是NP>N>1.5MNPK>PK>M2NPK>CK>NK>NPK>M1NPK>轮作>SNPK>撂荒,中小型农田土壤动物多样性指数依次是M1NPK>M2NPK>SNPK>1.5MNPK>NP>CK>轮作>NK>NPK>PK>N>撂荒。群落相似性指数分析表明,不同施肥之间相似性系数一般较低。农田土壤动物群落组成异质性较高,SNPK与M1NPK、撂荒地处理之间的相似性明显高于其他群落,N与SNPK、M2NPK和轮作之间、CK与1.5MNPK和NPK之间的相似性明显低于其它施肥之间的相似性。反映出不同施肥处理对土壤生态系统内部环境,进而对土壤动物群落产生的影响。     

陕西农田土壤动物群落与长期施肥环境的灰色关联度分析

2001年7月至2002年10月,对陕西黄土区6种长期定位施肥农田土壤动物群落进行调查,采集72个定点土壤样品,通过手捡法和Cobb过筛法,共获得农田土壤动物标本5495只,隶属6门11纲22目;分析测定了土壤环境中的3类土壤微生物(细菌、真菌和放线菌)和土壤因子的5项指标(耕层全N、有机质含量、有效P、pH、土壤含水率)。以长期定位施肥农田土壤动物5种优势类群、弱势类群以及农田土壤动物个体数为研究对象,应用灰色理论对长期定位施肥农田土壤动物群落与土壤环境之间的灰色关联系数和灰色关联度进行了分析。结果表明,本研究选取的环境因子与农田土壤动物因子的关联表现出一定的规律性,土壤pH和含水量对土壤动物个体总数的影响最大。对农田土壤动物的影响的大小顺序为:全N有机质含水量pH细菌真菌放线菌有效P。优势分析显示,土壤有机质对土壤动物的影响最大,土壤全N的影响次之,其灰色综合关联系数分别为0.6555和0.6444;细菌的影响最小,其灰色综合关联系数为0.5429。土壤因子对农田土壤动物的影响大于土壤微生物。     

华北潮土区不同耕作方式下土壤动物丰富度与多样性

在黄淮海平原小麦-玉米一年两熟地区,试验设置了5个处理,分别为玉米小麦每年均翻耕(CTWT)、玉米免耕+小麦每年翻耕(CNTWT)、玉米免耕+小麦每2年翻耕(CNTW2T)、玉米免耕+小麦每4年翻耕(CNTW4T)、玉米小麦每年均免耕(CNTWNT),所有处理的农作物地上秸秆全部移出。调查结果显示,中小型土壤动物在数量上占总数的比例为83%～91%,土壤动物主要分布在表层,占有其总量的71.9%～73.2%。土壤动物存在显著的季节性动态,其丰富度在玉米季高于小麦季。土壤动物Shannon多样性指数在整体上表现为翻耕高于免耕处理,玉米季翻耕处理下有更高的均匀度指数,但小麦季均匀度指数差异不显著。多元典范冗余分析表明,耕作方式主要是对土壤动物的时间动态和垂直分布产生影响,从而间接地影响了土壤动物的数量和组成。     

土壤动物在土壤有机质形成中的作用

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。