ECOLOGICAL DISTRIBUTION OF SOIL ANIMALS IN BROAD-LEAVED PINE FORESTS IN SOUTHERN SLOPE OF XIAO HINGGAN MOUNTAINS

This paper studied the soil animals of four type forests of broad leaved pine forests in the southern slope of the Xiao Hinggan Mountains. The samples were extracted from four forest types in every first week of June, August, October, and every forest type was chosen out three plots. Since there are different soil animals in different depths, every plot was divided into four partitions with the same vertical distance: litter, 0－ 10 cm, 10－ 20 cm, 20－ 30 cm. Using hand sorting out large soil animals, Tullgren method (to middle and small soil animals) and Baermann method (to moist soil animals) to collect soil animals. Among the four type forests, insecta has the largest amount of groups of 54. Oribatida has the most number of individual, which is 1547, occupying 21.73 percent of total collectings. There are 81 groups of soil animals, totalling 7118 belonging to 8 Class 24 Order 57 Family, in which there are 54 groups of big sized soil animals totalling 2370, 41 groups of middle and small sized soil animals totalling 4808. Among all the soil animals,their dominant group is 3 ones, usual growp is 14 ones, and rare group is 64 ones. The results show that among the four type forests, the groups of soil animal in Tilia pine forest are much more than the others, with the highest variety index, and the individual number of the soil animals is also very large. The numbers of group and individual in Picea Abies Pine forest are both small.Among the four forest types, the soil animals in Tilia pine forest are most similar to Betula costata pine forest. There is so little similarity between the soil animals in Picea Abies pine forest and in the other three forest types.

Effect of organophosphorus pesticide pollution on soil animals

This paper studied the change in soil animal community in contaminated and irrigated area by organophosphorus pesticide waste water and its mechanism was discussed. The results showed that the species and quantities of soil animals decreased with organophosphorus pesticide pollution degree increasing. The species of soil animals decreased with average and rare population mainly decreasing, while the amount change was associated with that of the dominant population of Acarina, Collembola and Nematoda. Toxicity experiment demonstrated that the respiration intensity of soil animal was restrained obviously by pesticide pollution. After observation of SEM, the effect of pesticide pollution on the earthworm (\%Pheretima robusta)\% stomach intestinal mucosa damage has been observed, which showed the pesticide contamination may damage the earthworms bodies. Ulcerous focus and perforation on stomach mucosa were usually seen. The stomach microvilli appeared atrophic and disordered especially in the bodies of these earthworms growing in seriously polluted soil, bad atrophic phenomena were seen not only on the stomach mucosa microvilli but also on the cilia of the intestinal mucosa which appeared swollen as a spheroid. Under TEM, RER and Golgi compound dilatation, chondrisome swell and ridge disappearance were observed on cells of stomach epithelium mucosa of \%P.robusta\% collected from heavy polluted area. By calculation, the safety concentration of earthworm in methamidophos pesticide is 0\^2517 ml/L.

Studies on the diversity of soil animals in Taishan Mountain

Taishan Mountain has diverse habitats and abundant groups of soil animals. Five habitats,Platycladus orientalis forest,Pinus densiflora forest,Robinia pseudoacacia forest,Pinus tablaerormis forest and Grassland, were selected and the diversity of soil animals in different habitats in Mt. Taishan were investigated and studied in 1997–1999. Totally 52 groups of soil animals were found, belonging separately to 7 Phyla, 11 Classes, 25 Orders and 28 suborders or families. There exists remarkable difference in groups, quantity and diversity of soil animals among the five habitats. Grassland habitat was the highest andPinus densiflora forest was the lowest in groups, quantities, Density-group index (DG) and Diversity index of comparing many communities (DIC) of soil animals. Shannon-Wiener’s diversity index (H′) for soil animals of different habitats was in order ofPlatycladus orientalis forest>Pinus densiflora forest>Pinus tablaerormis forest>Grassland>Robinia pseudoacacia forest, Pielou’s equality index (J′) wasPlatycladus orientalis forest>Pinus densiflora forest>Grassland>Pinus tablaerormis forest>Robinia pseudoacacia forest, and Simposn’s dominant index (C) was Grassland>Robinia pseudoacacia forest>Pinus tablaerormis forest>Pinus densiflora forest>Platycladus orientalis forest. The H index and J index of macro-soil animal all were larger than that of mid-small soil animal. Clustering analysis for five soil animal communities and ordination analysis for community structure by multidimensional scaling (MDS) were made and completely identical results were obtained. Soil animal communities of five habitats were divided into 3 groups.

ECOLOGICAL SERIES OF SOIL ANIMALS IN DARLIDAI MOUNTAIN

The ecological series of soil animals under the broad-leaved and pine mix ed forest in Darlidai Mountain was studied.Seven sample plots were selected according to different altitude gradients,which belong to dif ferent vegeta-tion types.By investigating and analyzing soil animals in every sample p lot it is found that there are 45group s and 1956individuals,which are involved in 3phylums,7classes,16orders,respectively.The altitude is a key factor which af-fects ecological series of soil anim als.Both the groups and individuals of soil animals increase with altitu de increasing under certain conditions,which con trastes with ordinary cases,resulting from special micro-climate in studied area.The groups and individuls of soil animals are the most under the broad-leaved and pine forest on the top of the mount ain,and the least under Picea-Abies forest in the foot of the mountain.

Soil animals and nitrogen mineralization under sand-fixation plantations in Zhanggutai region,China

The effects of soil animals on soil nitrogen (N) mineralization and its availability were studied by investigating soil animal groups and their amounts of macro-faunas sorted by hand, and middle and microfaunas distinguished with Tullgren and Baermann methods under three Pinus sylvestris var. mongolica Litv. plantations in Zhanggutai sandy land, China. In addition, soil N mineralization rate was also measured with PVC closed-top tube in situ incubation method. The soil animals collected during growing season belonged to 13 orders, 5 groups, 4 phyla, whose average density was 86 249.17 individuals·m^(-2). There were significant differences in soil animal species, densities, diversities and evenness among three plantations. Permanent grazing resulted in decrease of soil animal species and diversity. The average ammonification, nitrification and mineralization rates were 0.48 g·m^(-2)·a^(-1), 3.68 g·m^(-2)·a^(-1) and 4.16 g·m^(-2)·a^(-1), respectively. The ammonification rate in near-mature forest was higher than that in middle-age forests, while the order of nitrification and net mineralization rates was: middle-age forest without grazing < middle-age forest with grazing < near-mature forest with grazing (P<0.05). Soil N mineralization rate increased with soil animal amounts, but no significant relationship with diversity. The contribution of soil animals to N mineralization was different for different ecosystems due to influences of complex factors including grazing, soil characteristics, the quality and amount of litter on N mineralization.

Composition and ecological distribution of forest soil animalin Confucian graveyard of Qufu

Soil animal communities of Secondary forest,Platycladus forest andQuercus acutissima forest in Confucian graveyard of Qufu were investigated. 3583 specimens were collected, belonging separately to 5 Phylums, 11 Classes and 23 Orders. Two dominant groups and 9 common groups account for 94.45% of the total numbers. The soil animals in these three forest habitats differ in composition, ecological distribution and important indices. The dominant groups of soil animals in the three forests were the same, but other groups differ more greatly. Diversity index (H′) and evenness index (E) of soil animal in Secondary forest are the highest, and yet dominance index (C) inQuercus acutissima forest is the highest. Most soil animals in each forest habitats congregate to the surface soil layer. Their sorts and individual numbers are all layer I>II>III. It is very similar for composition of soil animals in the three forests.

Optimization of Specific Draft Requirement and Hitch Length for an Animal Drawn Sub-Soiler: A Case of Sandy Clay Loam Soils

This study aimed at optimizing tillage depth and hitching length for optimal draft requirement in sandy clay loam soils for animal drawn subsoiler. Field experiments were conducted to collect draft datasets using the MSI 7300 digital dynamometer communicating remotely with MSI-8000 RF data logger connected to a laptop through the serial port. To determine the numeric values of soil parameters pertinent to subsoiling, field experiments, laboratory tests and numerical analysis techniques were employed. For a specified speed, a combination of three hitch lengths of 2.5 m, 3.0 m and 3.5 m and three depths from 0 cm to 30 cm with a range of 10 cm interval was used. Soil bulk density was found to vary between 1.52 to 1.37 g/cm3 and 1.44 to 1.67 g/cm3 for Machakos and Kitui experimental plots respectively. Soil moisture content increased with an increase in depth ranging from 3.53% to 9.94% for Machakos site and from 4.15% to 9.61% for Kitui site. Soil shear strength parameters ranged between 21.71 and 29.6 kPa between depths of 0 - 20 cm and decreased to 28.07 kPa for depths beyond 20 cm at Machakos experimental plot;while for Kitui experimental plot, it ranged between 30.02 and 39.29 kPa between depths of 0 - 30 cm. A second-order quadratic expression of the form y = ax2 + bx + c was obtained for the relationship between specific draft and depth at given hitching length as well as specific draft against hitching length at a given depth. The optimal hitching length and tillage depth for Machakos experimental plot were obtained as 2.9 m (~3 m) and 16.5 cm respectively. In Kitui experimental site, the optimal hitching length was obtained as 2.9 m (~3 m) and the optimal tillage depth was 15.4 cm.

民勤县石羊河湿地公园春季土壤动物群落特征

2023年3-5月,对甘肃民勤石羊河公园4个功能区5个植被型组7个不同植物群系的土壤动物群落特征进行了调查。结果表明:共收集到土壤动物46个类群1488头,隶属于3门5纲13目25科。中小型土壤动物和大型土壤动物分别占97.38%和2.62%,线虫在群落结构中占绝对优势。中小型土壤动物中的优势类群为头叶属、真头叶属、臭蚁属;占总捕获量的48.58%;常见类群为丽突属、拟丽突属、短体属、鞘属、半懒甲螨属等16个类群,占总捕获量的47.13%;稀有类群有椎实螺属、耳萝卜螺属、两坑螺属、虹蛹螺属、逍遥蛛属等14个类群,占总捕获量的4.29%。大型土壤动物主要为拟步甲科和叩甲科,其中优势类群为琵琶甲属、蒙小鳖甲和尖尾东鳌甲,均为荒漠草原沙地种类。沙枣群系和油蒿群系土壤动物的个体数、类群数、丰富度指数和Shannon-Wiener多样性指数均高于其他植物群系,优势度指数则较低。7个植物群系的土壤动物群落结构的相似性为中等不相似和极不相似。沙枣群系、白刺群系、多枝柽柳群系的土壤动物具有明显的表聚性,而油蒿群系、芨芨草群系和芦苇群系中的土壤动物垂直分布具有异质性。

微塑料对土壤生态系统的影响及其修复技术

由于农膜破碎、污水灌溉等活动,土壤中的微塑料含量与丰度正逐渐超越海洋,并成为土壤的主要污染源之一。土壤生物能吸收土壤微塑料,其中粮食作物中的微塑料能通过食物链进入人体,造成人体微塑料暴露风险,此外,土壤微塑料也会直接对土壤产生毒性。概述了微塑料在土壤生态系统中的来源、迁移等环境行为,重点综述了微塑料对土壤生态系统的影响。结果表明:1)微塑料能通过土壤颗粒间的空隙、植物侧根裂缝及动物运动等在土壤环境系统中迁移转运;2)微塑料能影响土壤物理化学性质、植物生长发育、动物行为和微生物多样性;3)微生物和酶能降解土壤环境中的微塑料,并直接减少土壤系统中的微塑料,而生物炭可以减轻微塑料对土壤生态系统的毒性,三者均为土壤微塑料修复技术的潜在选择。最后,提出了土壤微塑料未来可能的研究方向,以期为土壤微塑料的污染防治提供指导。

雅鲁藏布江中游不同生境大型土壤动物群落特征

为了解雅鲁藏布江中游地区不同生境的大型土壤动物群落特征,于2022年6月和9月进行了2次调查。选择农田、灌木丛、草地、人工林和天然林5种生境,并在每个生境中选择3个采样点作为重复。使用梅花五点法采集土样;采用手捡法和吸虫管法收集土壤表层的大型土壤动物样本,共捕获1 716只大型土壤动物,隶属于3门7纲22目48科。其中,蚁科(Formicidae)是优势类群,占总捕获量的15.97%。非参数检验(Kruskal-Wallis检验)结果显示,5个生境之间的多样性指数差异不显著(P>0.05)。Jaccard相似性系数(J)在0.35~0.73,表示5种不同生境的大型土壤动物群落在相似性程度上介于中等不相似到中等相似之间。置换多元方差分析(PERMANOVA)显示,5个生境群落结构之间存在显著差异(P<0.05)。在雅鲁藏布江中游地区的大型土壤动物功能类群中,以捕食性大型土壤动物为主,占总捕获量的43.13%。相关性分析显示,土壤pH值和全氮(TN)、有效磷(AP)及速效钾(RAK)含量是影响雅鲁藏布江中游大型土壤动物群落分布和多样性的重要因素(P<0.05)。

减氮配施有机粪肥对土壤理化性质及玉米产量的影响

为提高畜禽粪便等农业废弃物在农业生产过程中循环利用效率,改善土壤肥力,促进作物增产增收,于2022年春季在宝泉岭农场开展有机粪肥还田减施氮肥试验,设置生育期不施化肥(CK)、当地常规施肥(FFP)、优化施肥(OPT)、有机粪肥替代15%N(OPT-1)、有机粪肥替代30%N(OPT-2)5个处理,研究有机粪肥和减施氮肥对土壤理化性质和玉米产量的影响。结果表明,在拔节期,与常规施肥(FFP)相比,有机粪肥替代30%氮肥处理(OPT-2)土壤有机质和速效钾含量分别显著提高14.28%和6.71%,有机粪肥替代15%氮肥处理(OPT-1)土壤有机质和速效钾含量分别显著提高10.20%和11.32%;与优化施肥处理(OPT)相比,OPT-2处理土壤有机质含量显著提高7.63%,OPT-1处理土壤速效钾含量显著提高7.01%。在成熟期,与FFP处理相比,OPT-2处理土壤有机质、碱解氮和速效钾含量分别提高15.60%、9.64%和6.83%,玉米产量显著提高8.46%,OPT-1处理土壤有机质、碱解氮和速效钾含量分别显著提高10.33%、5.26%和10.62%,玉米产量显著提高5.14%;与OPT处理相比,OPT-2处理土壤有机质、碱解氮含量分别显著提高11.09%和8.93%,OPT-1处理土壤有机质、碱解氮和速效钾含量分别显著提高6.03%、4.57%和5.80%。综合分析,施用有机粪肥可以改善土壤理化性质,提高玉米产量,改善籽粒品质,其中,30%有机粪肥替代氮肥(OPT-2)施用效果最优。

啮齿类实验动物健康监测用脏垫料哨兵动物法和排风粉尘PCR法比较

实验动物微生物质量对科学研究数据的有效性和重复性以及人类健康和动物福利至关重要。目前,独立通风笼具(individualventilationcage,IVC)已成为主流的啮齿类实验动物饲养系统。针对这种饲养方式的病原体监测方法最常用的是脏垫料哨兵动物法(soiledbeddingsentinels,SBS),该方法是以间接接触和延迟反馈的方式监测鼠群的微生物携带状况,能有效监测通过粪-口途径传播的病原体如小鼠肝炎病毒、呼肠孤病毒等。但这种方法难以监测到主要通过气溶胶、直接接触等途径传播的病原体,例如仙台病毒、嗜肺巴斯德杆菌等。排风粉尘(exhaustairdust,EAD)-PCR监测方法分为在IVC笼架排风管道中拭子采样,用以监测管道相对应的笼架;主机初效过滤前拭子采样,用以监测整个IVC笼架;EAD收集装置采样,用以监测同一个主机连接的所有笼架。不同IVC厂商针对各自的IVC系统开发了相应的EAD收集装置,使操作便捷,容易实现标准化。目前,与SBS方法相比,EAD-PCR方法的检出率和时效性都有显著提升,最快暴露一周就可检出,可作为SBS方法的补充或替代,有利于维护实验动物福利。本文对上述两种病原体监测方法的应用进展进行综述,同时结合本实验室和送检单位EAD-PCR监测的实施情况,对该方法存在的局限性进行分析并提出解决方案。EAD-PCR方法有助于减少活体哨兵动物的使用量,可以更好地维护实验动物福利的“3Rs”原则。

我国西北地区土壤动物生态学研究进展

土壤动物在生态系统物质循环和能量流动中扮演着重要角色,对生态环境状况具有重要的指示作用.我国西北地区由于深居内陆,生态环境相对脆弱,为了全面了解该地区土壤动物生态相关研究进展,明确当前研究重点与薄弱环节,重点介绍了我国西北地区土壤动物生态学研究进程、西北地区土壤动物群落生态状况以及土壤动物与环境因子响应,论述了不同土地利用方式、环境污染、枯落物分解等环境因子会影响土壤动物的生态群落.在总结与归纳的基础上,明确了今后我国西北地区土壤动物生态学研究应注重长期固定样地的建立、环境变化对土壤动物的影响、地上与地下生态系统的相互作用等方面,为我国西北地区土壤生态系统恢复和重建以及土地利用等提供新思路.

基于放射性污染的土壤生物修复技术研究

随着核能、核工业和核武器的不断发展及应用,核污染近年来逐渐成为人们关注的热点问题。放射性核素可通过多种途径进入土壤并累积,严重威胁了人体健康和生态系统安全。本文总结了放射性污染土壤的植物修复、动物修复、微生物修复及联合修复技术,并分析了各种修复技术的优缺点,展望了生物治理技术的未来发展方向,以期为土壤放射性污染生物修复技术的进一步发展提供科学依据和理论参考。

Impact of agricultural intensification on soil organic carbon＂ A study using DNDC in Huantai County, Shandong Province, China

Using the biogeochemical model den itrification/decomposition （DN DC）, the dynamic changes of soil organic carbon （SOC） of farmland from the 1980s to 2030s were investigated in Huantai County, a typical intensive agricultural region in the Huang- Huai-Hai Plain of China. Prior to modelling, validation of the DNDC model against field data sets of SOC from Quzhou Experimental Station in the Huang-Huai-Hai Plain was conducted at the site scale. We compared the simulated results with the observed SOC in Huantai County during 1982-2011 under two different classification methods of simulation unit （the first method integrated soil type and land use of Huantai County to form the overlapped modeling units; the second selected the 11 administrative towns as the modeling units）, and achieved a high accuracy in the model simulation with the improvement of the model parameters. Regional SOC （0-20 cm） density and stocks for Huantai County in the years 2012-2031 were predicted under different scenarios of farming management. Compared with current management practices, optimized fertilization （20% decrease of mineral N）, crop straw incorporation （90%） and appropriate animal manure input （40 kg N ha-1 yr-1） could achieve the highest level of SOC density （56.8% higher than 2011） in the period of 2012-2031. The research highlighted the importance of crop straw incorporation, optimized N fertilization and integration of crop production with ani- mal husbandry on the farmland carbon sequestration for maintaining a high land productivity in the Huang-Huai-Hai Plain.

Dynamics of Soil Fauna in Da Hinggan Mountains, Northeast China

The dynamics of soil animals was studied in seven representative forest communities in the north of the Da Hinggan Mountains, Northeast China. The results indicate that it was distinctive in the changes of the numbers of soil animals and groups and diversity in relationship with seasons for macrofauna and meso-micro fauna in the study area. The numbers of the observed soil animals in different months were: October>August>June. Group number was larger in August and October, but smaller in June. The change of diversity index in different months was: August>June>Oc- tober. The biomass for macrofauna in different months was: October>June>August. The composition and number of each functional group was relatively stable. In the community of the predominant soil environment, the percentage of saprophagous animals was higher than carnivorous animals and herbivorous animals. The dynamics changes of sapro- phagous and carnivorous animals were distinctive, increasing from June to October, while the change of herbivorous animals was unremarkable.

EFFECTS OF SOIL FAUNA ON LITTER DECOMPOSITION

Forest l itter is the physical makeu p part of forest ecosystem．The rate o f decompositi on of forest litter is low in temperate and cool temperate zones．There is impor tant signific ance to search and utilize the functi on of soil animals，in order to probe the material circulation and energy flow in forest ecosystem．We selec ted three kin ds of mesh bag with different mesh size，in which，large pore mesh bag is large enough to permit the activities of all kinds of soil animals，medi um mesh bag is designed to exclude the function of soil macrofauna，while small mesh bag is small enough to exclude the effects o f any kind of soil animals as far as possible．The decomposition time is thr ee years．The studying results sh ow that：the decomposing speed of the bags with big meshes，under functions of a ll kinds of soil animals，faster than the bags with medium meshes，under functio ns of medium and small soil animals，as well as the bags with small meshes that exc luding all possibility of functions of soil animals；in the process of dec o mposition of litter，relationship of the litte r lost weight with number of soil anim als is not obvious clearly；the degre e of functions of soil animals to so ft litter higher than hard litter；according to the an alysis of diversity index ，no regula r changes will happen to the diversity of soil anima ls as the time of decomposing samples lengthen．

Deforestation effects on biological and other important soil properties in an upland watershed of Bangladesh

Deforestation occurs at an alarming rate in upland watersheds of Bangladesh and has many detrimental effects on the environment. This study reports the effects of deforestation on soil biological proper- ties along with some important physicochemical parameters of a southern upland watershed in.Bangladesh. Soils were sampled at 4 paired sites, each pair representing a deforested site and a forested site, and having similar topographical characteristics. Significantly fewer （p〈0.001） fungi and bacteria, and lower microbial respiration, active microbial biomass, metabolic and microbial quotients were found in soils of the deforested sites. Soil physical properties such as moisture content, water holding capacity, and chemical properties such as organic matter, total N, avail- able P and EC were also lower in deforested soils. Bulk density and pH were significantly higher in deforested soils. Available Ca and Mg were inconsistent between the two land uses at all the paired sites. Re- duced abundance and＇biomass of soil mesofauna were recorded in defor- ested soils. However, soil anecic species were more abundant in defor- ested soils than epigeic and endogeic species, which were more abundant in forested soils than on deforested sites.

Selenium Concentrations in Southeastern Missouri Soils and Its Impact on Livestock Nutrition

Selenium is a trace element in animal nutrition provided through forage. Vegetation should accumulate adequate levels to meet this livestock requirement. This study assessed southeastern Missouri soils for their selenium concentrations. Multiple sites across southeastern Missouri were sampled, from which a total of twenty-six soils were collected. Parent materials ranged from coarse to fine-textured alluvium and terrace deposits, colluvium, loess, limestone residuum and rhyolite residuum from poor to well-drained soils. The mean whole soil selenium contents ranged from less than 0.1 mg Se kg-1 for the Kaintuck pedons to 1.0, 2.2, and 2.4 mg Se kg-1 for the Irondale, Killarney, and Frenchmill pedons. For individual soils, Menfro pedons were deep, well-drained soils developed in loess. Paired Menfro pedons having similar soil morphology and having A-E-BE-Bt-C horizon sequences were selected and the greatest selenium concentrations were in the argillic horizons. Soils having fine textures (clayey) had moderate selenium concentrations, whereas soils having coarse textures (sandy) revealed minimal selenium concentrations. A wide soil selenium concentration variation was shown;however, no toxic selenium levels were measured. Therefore, soil selenium toxicity is not a regional issue. Noting that soil selenium concentrations in medium to fine-textured soils are appropriate for providing selenium to livestock, the need to artificially soil incorporate selenium or add selenium into the livestock ration remains critical for coarse-textured soils.

土壤起源与宜居地球的形成

在各种成土因素交互作用下,地球土壤起源和演变历经变化的环境和多种成土过程。研究表明最早的古风化壳出现在太古宙;而随着地球生物演进,生物因素加入风化成土作用与成土过程,土壤学家眼中的土壤形成、发育于寒武纪。漫长的地质历史时期不同的成土环境发育有各种类型土壤,这些土壤发育与演化过程又反作用于景观、地形、生态系统、气候系统,改变大气成分组成和地球化学循环,影响、反馈、调节全球或地区的表层系统,土壤圈的形成是宜居地球形成的重要标志。