亚热带区域几种典型人工林生态系统林地土壤质量评价

针对不同经营模式对林地土壤的物理性质、化学性质和生物学性质的影响,采用主成分分析方法直观定量地研究了亚热带区域几种典型人工林生态系统林地的土壤质量指数和土壤退化指数,揭示了土壤质量指数之间的相关性和差异性、以及土壤退化指数之间的相关性和差异性,并很好地识别出了土壤质量指数和土壤退化指数的主要成分。分析结果基本上反映了不同生态类型林地土壤质量状况,主成分分析土壤质量指数得分以常绿阔叶林最高,其次是混交林和阔叶纯林,连栽杉木纯林最低;主成分分析土壤退化指数表明,与次生常绿阔叶林比较,其中连栽杉木纯林退化幅度最大,而混交林和阔叶纯林次之。从而对其林地土壤质量进行了准确评价,为杉木人工林的可持续利用提供直接依据,并为亚热带区域人工林生态系统林地土壤质量评价提供参考。     

The Diversity of Bacterial Communities in Urban Soils

Urbanozems (Urbic Technosols) contaminated by heavy metals and polychlorbiphenyls (Urbic Technosols Toxic) and intruzems (Urbic Technosols Toxic) were studied in Moscow; additionally, we studied recreazems (Urbic Technosols Thaptohumic) and culturozems (Urbic Technosols Pantohumic) on the territory of the Botanical Garden of Moscow State University (Aptekarskii Ogorod, the Apothecaries’ Garden). In the soils contaminated with heavy metals and oil products, the number of viable cells of bacteria decreased, whereas the content of filterable forms of bacteria increased. The taxonomic structure of saprotrophic bacterial complexes in contaminated urban soils was transformed towards an increase in the diversity of bacterial taxa atypical of natural undisturbed soils. Rhodococci (Rhodococcus genus) predominated in the soils contaminated with oil and polychlorbiphenyls, enterobacteria (Escherichia, Enterobacter, and Klebsiella genera) predominated in the soils contaminated with municipal wastes, and Arthrobacter genus was dominant in the soils contaminated with cement dust. Soils of both Botanical Gardens of Moscow State University were characterized by the high population density and specific distribution of bacteria in the profile; the structure of their saprotrophic bacterial complex had some similarity with that in the soils of more southern regions. The obtained data on the bacterial diversity of urban soils attest to considerable transformation of bacterial communities both in the contaminated urban soils and in the soils of botanical gardens.     

大兴安岭北部森林生态系统土壤动物组成与多样性分析

对大兴安岭北部7个代表性森林群落土壤动物进行调查,共捕获湿生土壤动物20216只,大、中小型土壤动物87类,19577只,隶属于4门9纲23目66科。大、中小型土壤动物的优势类群为螨类和节跳虫科,常见类群4类,两者占总捕获量的92.22%。各群落土壤动物的数量和种类组成有一定差异,其中杨落Ⅱ和白桦Ⅲ的数量和种类最多,柳草Ⅶ最少。7个群落共有类群23类,共优类群为螨类中的前气门亚目和中气门亚目,共有的常见类群2类:山跳虫科和线蚓科。7个群落间相似程度均较大,大多为中等相似。各群落土壤动物数量和种类在土壤各层的垂直分布上具有明显表聚性。在多样性分析中,各群落多样性指数H′大小为柳草Ⅶ>白桦Ⅲ>杨落Ⅱ>落沼Ⅳ>樟子松Ⅵ>桦杜Ⅰ>蒙古栎Ⅴ。大部分群落多样性指数的动态变化是8月>6月>10月。     

Forest Pyrogenic Peat Soils and Gleyzems in Swampy Mountain Valleys in the South of Yenisei Siberia

Eurasian Soil Science - The differences between eutrophic peat soils (Hypereutric Sapric Histosols) and peaty gleyzems (Eutric Histic Gleysols) 20 years after a forest-peat fire have been studied...     

Relationship between Oil Palm Yield and Soil Fertility as Affected by Topography in an Indonesian Plantation

Abstract

Typically, Indonesian oil palm plantations rest on rolling topography. There is limited information on how topography affects soil fertility and oil palm yields. A study was conducted to evaluate these relationships in a commercial oil palm plantation located in South Sumatra, Indonesia. Two sites with differing past management history and fertility regimes were each partitioned into three topographic positions. At each topographic position, yields were recorded at 10‐day intervals over a period of 2 years. Leaf and soil samples were collected from corresponding points spaced at 36.4 m (x direction) and 8.7 m (y direction) using a systematic scheme. Leaf analysis was performed to quantify nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg), and calcium (Ca), and soil analysis was carried out to determine pH, organic carbon (C), extractable P, exchangeable K, Mg, and Ca, effective cation exchange capacity (ECEC), and texture. The collected data were subjected to exploratory, univariate, and bivariate analyses, as well as analysis of variance. Empirical production functions based on measured variables were defined for each topographic position. Results showed that average yields at both study sites varied with topographic position. At site 1 (Sungai Pelepah Estate), the sideslope and the summit consistently gave higher yields than the toeslope. At site 2 (Sri Gunung Estate), a yield gradient was observed with the highest yield occurring at the toeslope and the lowest yield from the summit. Soil fertility varied across topographic positions at both sites. The measured leaf/soil variables showed varying levels of optimality/sufficiency across topographic positions. In most cases, leaf and soil variables showed comparable performance as yield predictors. Validation of the calibrated models showed reasonable accuracy for the toeslope of site 1 and all three positions at site 2.     

不同石油污染程度土壤细菌群落多样性及优势菌群分析

  目的  探究辽河油田不同石油污染程度土壤中理化性质及细菌群落多样性和组成的变化规律,并对石油污染土壤中的石油降解菌进行分离培养和鉴定。  方法  采集了辽河油田不同石油污染程度土壤,采用高通量测序技术和化学分析法对土壤细菌群落组成和土壤理化性质进行测定,并进一步筛选出石油降解菌株。  结果  在出油口（A）、距离出油口50 m（B）和距离出油口150 m（C）采集的三个土壤样品,其土壤总石油烃含量分别为2467.44 mg kg?1、884.99 mg kg?1和141.63 mg kg?1,三个土壤样品具有不同的石油污染程度。石油污染显著提高了土壤总有机碳含量,土壤总石油烃含量与总有机碳含量呈现正相关（P < 0.001）。土壤细菌群落多样性和丰富度指数与土壤石油烃的浓度呈显著负相关（P < 0.01）。不同石油污染程度土壤具有不同的细菌群落组成和结构,土壤石油烃含量是影响细菌群落变化的主要因素。出油口石油污染土壤样品（A）中,变形菌门（Proteobacteria）为优势菌门,假单胞菌属（Pseudomonas）、假黄单胞菌属（Pseudoxanthomonas）、博代氏杆菌属（Bordetella）和伯克氏菌属（Burkholderia）为优势菌属。从出油口石油污染土壤（A）中分离出3株石油降解菌株,通过16S rRNA基因测序分别被鉴定为Pseudomonas baetica、黄褐假单胞菌（Pseudomonas fulva）和施氏假单胞菌（Pseudomonas stutzeri）,其石油降解率分别为37.2%、46.9%和57.8%。此结果与A样品高通量测序属水平组成分析相吻合,表明石油污染能够选择性富集土壤中具有石油降解能力的假单胞菌属。  结论  石油污染提高了土壤总有机碳含量,降低了土壤细菌群落多样性,富集了具有烃类降解能力的优势菌属,是造成土壤细菌群落组成和结构改变的主要因素,并筛选出具有潜在开发应用价值的石油降解假单胞菌株。     

Humus Horizons of Soils in Urban Ecosystems

The origin, structure, composition, and properties of soil humus horizons in functional zones of St. Petersburg have been studied. The radiocarbon age of organic matter in the humus horizons varies from 500 to 2700 years, which attests to the natural origin of humus. The structure of microbiomes in the humus horizons of soils under different plant communities has its specific features. The taxonomic structure of microbial communities at the phylum level reflects both genetic features of natural soils and the impact of anthropogenic factors, including alkalization typical of the studied urban soils. Tomographic studies have shown that the transporting system of humus horizons is less developed in the anthropogenically transformed soils in comparison with the natural soils. It can be supposed that the intensity of water and gas exchange in the anthropogenic soils is much lower than that in the natural soils. The fractional and group composition of humus in the urban soils is specified by the long-term pedogenesis, on one hand, and by the impact of metabolic products of the city and the factors of soil formation in the megalopolis, on the other hand. Bulk density of the humus horizon in the urban soils is higher than that in the natural soils; the portion of overcompacted humus horizons in the urban soils reaches 44%. Humus horizons of the lawns along highways are most contaminated with heavy metals: Pb, Zn, and Cu. There are no definite regularities in the distribution of major nutrients (NPK) in the humus horizons of anthropogenic soils.     

Gas Diffusion Coefficient of Undisturbed Peat Soils

Determination of the gas diffusion coefficient D _s of peat soils is essential to understand the mechanisms of soil gas transport in peatlands, which have been one of major potential sources of gaseous carbons. In the present study, we aimed at determining the D _s of peat soils for various values of the air-filled porosity a and we tested the validity of the Three-Porosity Model (Moldrup et al. 2004) and the Millington-Quirk model (1961) for predicting the relative gas diffusivity, the ratio of D _s to D ₀, the gas diffusion coefficient in free air. Undisturbed peat soil cores were sampled from aerobic layers in the Bibai mire, Hokkaido, Japan. The MQ model reproduced the measured D _s/ D ₀ curves better than the TPM. The TPM, a predictive model for undisturbed mineral soils, overestimated the D _s/ D ₀ values for peat soils, implying that in the peat soils the pore pathways were more tortuous than those in the mineral soils. Since the changes in the D _s/ D ₀ ratios with the a values of a well-decomposed black peat soil tended to be more remarkable than those of other high-moor peat soils, the existence of a positive feedback mechanism was assumed, such that peat soil decomposition itself would increase the soil gas diffusivity and promote soil respiration.     

亚热带杉木人工林下植物多样性对氮沉降的响应

基于野外长期控制试验,研究了氮沉降7 a后人工杉木林下植物多样性的响应。试验处理分为N₀[(Control),0 kg/(hm²·a)];N₁[60 kg/(hm²·a)];N₂[120 kg/(hm²·a)];N₃[240 kg/(hm²·a)]。林下植物中共发现51种植物,隶属34科,45属。随着氮沉降的增加,呈现出植物α多样性指数减少,而β_ws多样性指数增加的趋势,群落相似性指数明显降低。去趋势对应分析排序(detrended correspondence analysis, DCA)结果表明,氮沉降改变了植物群落结构。其中,菝葜和沿海紫金牛在4个处理中均有发现,为广适种。毛冬青、粗叶榕、毛花连蕊茶、毛枝连蕊茶、香附子这几种植物在N₀-N₂处理中有发现,属于较耐受种。茅莓、羊乳、羊角藤、琴叶榕、紫麻、杜虹花、乌蔹莓、海金莎均为一般耐受种,在N₀和N₁处理中有发现。另外,黄瑞木、黄樟等16种植物可能为敏感种,仅可在N₀处理中发现。总之,亚热带森林植物多样性受到了氮沉降增加的不利影响,应针对某些濒危植物种类实施合理的保育措施。     

不同栽培环境下有机与常规蔬菜土壤的细菌群落多样性差异

土壤细菌群落在蔬菜栽培中发挥着重要作用。基于DNA和RNA水平,利用PCR-DGGE技术研究了不同栽培环境下有机与常规蔬菜土壤细菌群落多样性差异,以及土壤理化性质与细菌群落多样性的关系。结果表明：不同栽培方式下土壤细菌多样性存在明显差异,土壤微生物的优势种群和数量受有机、常规栽培和季节影响,有机栽培较之常规栽培能够显著增加土壤细菌群落多样性;聚类分析表明,16S rDNA细菌群落多样性与季节相关,而16S rRNA细菌群落多样性与栽培方式相关;差异条带测序显示,大多细菌与不可培养细菌种属有较高同源性,其余9种推测属于假单胞菌属;CCA分析说明pH是影响土壤细菌群落多样性的主要因素,有机栽培土壤中微生物生物量C、N以及有机质含量显著高于常规栽培土壤。综上,有机栽培能够丰富活性细菌群落多样性,具有土壤优化效应。     

六六六对红壤和紫色土中细菌群落多样性及结构的影响

尽管六六六已被禁用多年,但由于难降解、易持留的特性,其在土壤中检出率仍较高。残存的六六六对土壤细菌群落多样性和组成结构的影响一直备受关注,相关认识仍待深化。采用小麦盆栽试验,借助高通量测序技术,模拟研究了不同施药浓度(0、600、1 500 g·hm^–2)下六六六对旱地红壤和紫色土中细菌群落多样性和结构的影响。α指数分析结果表明,在培养初期,施用六六六显著提高红壤细菌群落多样性,而对紫色土无显著影响;但随培养时间延长,在第42天时细菌群落多样性均恢复至对照组(CK)水平。细菌群落组成分析显示,红壤中优势菌门为变形菌门(Proteobacteria)和放线菌门(Actinobacteria)。分析OTUs(可执行分类操作单元)丰度发现,六六六提高了红壤放线菌门和酸杆菌门(Acidobacteria)的多样性和丰度,从而导致红壤细菌群落多样性指数上升;紫色土中优势菌门为变形菌门和酸杆菌门。六六六增加了红壤中固氮菌Bradyrhizbium(慢生根瘤菌)丰度,600和1 500 g·hm^–2六六六处理组较对照分别增长了150%和180%;紫色土中,...     

Hydrophysical Properties of the High-Ash Lowmoor Peat Soils

The water retention curve (WRC), density, botanical composition, and ash contents were determined for high-ash lowmoor peat soils (Rheic Sapric Histosols) developing on the floodplain of the Yakhroma River (Moscow oblast) from the herb–hypnum and hypnum peat enriched in carbonates, agromineral peat soils (Rheic Drainic Sapric Histosols (Mineralic)), and peat soils developed from woody peat underlain by herb, sedge, and woody peat layers (Rheic Sapric Histosols (Lignic)). The WRC was determined by capillarimetric method in the range of water pressure from 0 to 80–90 кPa. For the studied peat soils, the WRC represents a close to linear dependence of the water content on the water pressure in semilogarithmic scale. In contrast to mineral soils, a characteristic point of the air-entry pressure is virtually absent on the WRC of peat soils. The WRC of peat largely depended on their density: denser peat samples were characterized by a higher water content at the same water pressure, which attests to the increased water retention capacity. An increase in the degree of decomposition of peat and its ash content also leads to the rise in the water retention capacity, but the effect of these factors is considerably smaller than the effect of peat density.     

木本泥炭对红黄壤性水田土壤有机质提升和细菌群落组成的影响

通过工程措施开发新垦耕地是增加耕地面积的重要方法,这些新垦耕地的主要问题为土壤有机质(SOM)低下,而农田SOM培育是一个漫长的过程。本研究以新垦红黄壤性水田为研究对象,通过施用腐熟秸秆及与土壤腐殖质结构类似的木本泥炭,明确其快速提升SOM效应。此外,为了促进秸秆养分的快速转化,本研究进一步比较分析了3种商用激发剂的激发秸秆分解潜力,并采用16s高通量测序技术阐明其微生物机制。试验包含6个处理:对照(CK)、施用腐熟秸秆(S)、施用腐熟秸秆+木本泥炭(SP)、以及在SP基础上添加激发剂Ⅰ、Ⅱ、Ⅲ(SPJ1、SPJ2、SPJ3)。结果表明,SP、SPJ1、SPJ2、SPJ3中的土壤有机质(SOM)、易氧化碳(EOC)、可溶性有机碳(DOC)分别比S或CK处理高12.1%～20.6%、29.9%～48.9%、50.8%～75.5%,微生物生物量碳(MBC)则为它们的10.5倍～16.1倍,导致MBC/MBN增加了5.1倍～12.4倍;土壤有效磷(Ava P)和团聚度在SPJ1、SPJ2、SPJ3间类似,并比SP、S、CK处理显著提高44.7%～63.6%、26.4%～43.6%,表明木本泥...     

Retention and Uptake by Plants of Added Selenium in Peat Soils

In soil, adsorption of selenium (Se) onto mineral surfaces is accompanied by poorly known retention via organic matter. The effects of these components on the availability of Se were examined in two pot experiments. Spring wheat was grown with increasing amounts of selenate (SeO₄ ^2–) in one sand and three peat soils, and ryegrass with selenate and selenite (SeO₃ ^2–) in sphagnum peat manipulated by iron (Fe) hydroxide. Selenate persisted in soluble form, whereas selenite was fixed in the soil. In wheat, 5–50% of the selenate addition was recovered in the plant, the proportion increasing with increasing Se. In ryegrass, 30–40% of the added selenate but less than 2% of the selenite was found within the leaves. The Fe hydroxide enrichment enhanced the selenite uptake. Phosphate buffer desorbed a minor proportion of the added selenite, except in peat amply enriched with Fe hydroxide. The results suggest that the retention mechanism of selenite was changed due to the hydroxide amendment.     

不同起源云杉林土壤有机碳密度及与物种多样性关系

对甘南地区云杉人工林和天然林的不同林龄(包括幼龄林、中龄林、近熟林和成熟林)土壤有机碳密度及其群落物种多样性的关系进行研究。结果表明:不同起源云杉林在各林龄中均以表层土壤(0—10cm)土壤有机碳含量最高,随土壤深度的增加逐渐减少;土壤有机碳密度除天然云杉成熟林在表层最高外,其他均以深层土壤(50—100cm)最高,且土壤有机碳含量和有机碳密度随林龄的变化不显著(p0.05)。冗余分析表明,人工林0—10,10—20,20—30,30—50cm的土壤有机碳密度除与Ea指数呈负相关关系外,与丰富度(S)、Shannon-Wiener指数(H′)、Simpson指数(D)、Pielou指数(Jsw)均呈正相关关系;天然林0—10,10—20,20—30cm的土壤有机碳密度与这5个指数均呈正相关关系。     

Nitrification in Eutrophic Peat Soils under Different Land-Use Management Practices

Eurasian Soil Science - We have analyzed the distribution of soil properties and the intensity of net nitrification in the profiles of eutrophic peatlands on the Yakhroma River floodplain (Moscow...     

Microbial Community and Rate of Cellulose Decomposition in Peat Soils in a Mire

A field survey was carried out from April to October, 1992 in the Miyatoko Mire in Fukushima Prefecture, Japan, to determine the characteristics of the microbial community and cellulose decomposition rates in the peat soil. A total of 14 study sites were selected, including three types; hummocks (type I), hollows covered with Sphagnum (type II), hollows and streams without Sphagnum (type III). The numbers of fungi (2-1,000×10⁴ CFU g^-1) and bacteria (8.5-9,000 ×10⁵ CFU g^-1) varied with the sites and sampling dates: seasonal fluctuations were especially high in hummocks. The numbers of cellulolytic fungi (4.7-300×;10⁴ CFU g^-1) and cellulolytic bacteria (1.5-9.2×10⁵ CFU g^-1) also differed between sites. Cellulolytic fungi were predominant in the Sphagnum peat of type I, while cellulolytic bacteria were predominant in the peat soil of type III. Decomposition rates of cellulose filter paper for the 6 month period ranged from 0.01 to 0.83, and tended to be higher in the peat of type II than type I.     

民勤地区梭梭人工林密度与林下植物多样性的关系

[目的]开展梭梭人工林不同密度对林下植物多样性的影响研究,为合理经营梭梭人工林,充分发挥其生态功能提供技术支持。[方法]以甘肃省民勤县5种不同密度(1 250,1 111,1 000,1 333,1 667株/hm2)10~15年生梭梭人工林林下植物的重要值、丰富度指数、多样性指数、均匀度指数为指标,对林下植物多样性随林分密度的变化规律进行分析。[结果](1)梭梭人工林林下共有植物16种,隶属于9科15属,其中灌木层6科6属6种,草本层4科7属10种。(2)灌木层优势种随着密度变化明显,草本层优势物种受密度影响较小。(3)林下植被多样性对密度响应具有非同步性。随着密度的增加,呈现先增大后减少的变化规律。(4)综合评分表明,民勤县梭梭人工林密度为1 250株/hm2时林下植被多样性水平较好,比较适合林下植被生长。[结论]林下植被多样性指数对密度响应具有非同步性,比较适合林下植被生长的密度为1 250株/hm2。