五大连池火山土壤细菌多样性及其群落结构

火山熔岩生境孕育了独特的土壤微生物群落。为了解火山生态系统土壤细菌群落多样性和群落结构及其关键影响因子,选择五大连池新、老期火山为研究样点,非火山为对照,基于高通量测序方法,分析不同采样点土壤细菌群落结构和多样性,结合土壤理化指标,进一步分析影响火山生态系统土壤细菌群落多样性的环境因子。结果表明：细菌操作分类单元（OTUs）、Ace指数、Chao1指数和Simpson指数变化趋势一致,表现为非火山 > 新期火山 > 老期火山。三个样点土壤的共有OUTs数量为713个,各自特有的OTUs数量不尽相同。三个样点土壤中检测到共有细菌16个类群,其中变形菌门、酸杆菌门、放线菌门和绿弯菌门为优势菌群,老期火山土壤中酸杆菌门、疣微菌门、Rokubacteria相对丰度最大,而Patescibacteria相对丰度最小。三个样点的土壤细菌群落具有明显的空间关系,相似性差异较大,但不符合随地理距离的增加而降低的模型。土壤理化性质测定结果标明：老期火山土壤pH、有机质、全氮、全磷、铵态氮和硝态氮显著高于新期火山和非火山,新期火山土壤含水量和速效磷显著低于老期火山和非火山。喷发时间和火成岩基质等特性会导致不同火山土壤理化性质的差异,进而影响土壤细菌多样性和群落结构。Pearson相关性分析表明：土壤pH显著影响细菌的多样性指数。冗余分析（RDA）结果表明：土壤氮含量、pH和有机质是影响火山森林生态系统土壤细菌群落结构的主要因子。     

Influence of traffic pollution on ecological state of Plantago major L.

The data are presented concerning the amount of mobile compounds of chemical elements (ChE) in soils under various human impact (acetate-ammonium buffer at pH 4.8) and in plants of ripple-seed plantain (Plantago major L.) (extractants such as diluted 1:1 HCl, 10% HCl, distilled H₂O). The content of total ash, mineral impurities of soil origin, water-soluble forms of ChE, polysaccharides and chlorophyll was determined in plants. The obtained data were compared with those for other regions. The ecological state of Plantago major L. was estimated and a conclusion was drawn about its possible use as a medicinal raw material.     

New data on abiogenic synthesis of prebiological compounds in volcanic processes

Volcanoes were deduced to be high-productive generators of complex organic compounds. Ash-gas clouds produced by volcanic eruptions can be considered as many-kilometer chemical reactors with a wide range of temperatures and pressures, powerful electric discharges and a large catalytic surface. In the eruption products investigated, nitrogen-containing components of nucleic acids of uracil type, metal complexes of porphyrins and porphyrins in the metal-free form and polycyclic aromatic hydrocarbons have been found. In all, 54 carbon-containing compounds have been identified in the volcanic juvenile ash and in volcanic bombs and 13 groups of carbon-containing compounds whose composition is yet unidentified have been found.     

长白山和五大连池火山灰土壤电荷零点特性

通过电位滴定曲线探讨了长白山和五大连池火山灰土壤剖面的电荷零点(ZPC)特性。结果表明,两火山灰土壤既有一定量的可变电荷,又有一定量的永久电荷,其土壤胶体是可变电荷胶体和永久电荷胶体的混合体系,两土壤剖面各层ZPC均位于滴定曲线的酸方一侧,并有随深度增加而增大的趋势,但ZPC的位移(σi)则有随剖面深度的增加而减小的趋势,两剖面表层土壤ZPC均较国外的火山灰土壤低,显著高于中国西北地区的黄土质土壤和东北地区的黑土,ZPC和σi值的变化,既受亚洲大陆起源的广域风尘堆积的影响,又与土壤有机质积累有关,二者的综合作用是两地火山灰土壤ZPC降低和σi值增大的主要原因。     

The biogeochemistry of phosphorus after the first century of soil development on Rakata Island, Krakatau, Indonesia

This study examined the accumulation of organic carbon (C) and fractions ofsoil phosphorus (P) in soils developing in volcanic ash deposited in the1883 eruption of Krakatau. Organic C has accumulated at rates of 45 to 127g/m²/yr during 110 years of soil development, resulting inprofiles with as much as 14 kgC/m². Most soil P is found inthe HCl-extractable forms, representing apatite. A loss of HCl-extractableP from the surface horizons is associated with a marked accumulation ofNaOH-extractable organic P bound to Al. A bioassay with hill rice suggeststhat P is limiting to plant growth in these soils, perhaps as a result ofthe rapid accumulation of P in organic forms.     

Soil-nutrient availability and the nutrient-use efficiencies of forests along an altitudinal gradient on Yakushima Island,Japan

The vegetation on Yakushima Island, Japan, grows on soils derived from Akahoya volcanic ash, released from the Kikai Caldera about 7300 years ago. The eruption was devastating and it is believed that primary succession and soil formation reinitiated across all altitudes at this point. We hypothesize that the concentrations of soil total phosphorus (P) and labile P fractions increase with increasing altitude because the soil formation has progressed less in upslope areas as a result of the cooler temperature and because of the ample P source of the volcanic ash. Conversely, we hypothesize that the concentration of soil inorganic nitrogen (N) decreases with increasing altitude. Available soil P and N would result in increasing P limitation downslope and increasing N limitation upslope, respectively. We studied soil P fractions and soil inorganic N, and P- and N-use efficiencies of the seven forests on Yakushima along an elevation gradient (170–1550 m a.s.l.). Contrary to our hypotheses, soil total P, labile soil P fractions, and inorganic N decreased with increasing altitude. The P- and N-use efficiencies of the forests were negatively correlated with the concentration of soil total active P (total P minus occluded P) and inorganic N, respectively. We suggest that progressive soil acidity and slower decomposition under cooler and wetter environments upslope must have dissolved the P contained in volcanic ash and accelerated P leaching. Forest ecosystems on Yakushima that show a distinct altitudinal zonation are, therefore, characterized by increasing P and N shortage with increasing altitude.     

Volcanic activity signals in tree-rings at the treeline of the Popocatépetl,Mexico

The Popocatépetl volcano resumed its eruptive activity in 1994 and is still active. The largest eruption recorded during this new stage of activity occurred in December 2000. We traced the volcanic activity signal in tree-rings from Pinus hartwegii trees located in the north slope of the volcano, located at ∼3 km from the volcanic cone. Annually resolved tree-ring widths, elemental and stable δ¹³C and δ¹⁸O isotope composition were measured during the period 1989–2014 to study the effects of the volcanic activity on trees. Our results indicate a high increase in the concentration of metal elements (Co, Cr, Cu, Fe, Li, Mo, Ni, Pb, Rb, Sr, Ti, Zn) in tree rings following the major 2000 volcanic eruption, compared to the pre-eruption period from 1989 to 1993. Other chemical elements such as Al, K and S peaked 2 years later, in the 2003 tree ring, that matched with the formation of a very narrow ring that year. This sharp reduction of growth was probably driven by a combination of harsh climatic conditions (drought) with the lagged negative effects of the 2000 eruption. Carbon isotope discrimination (Δ¹³C) and δ¹⁸O increased from 1995 to 2006, suggesting reduced stomatal conductance, photosynthetic activity and water use efficiency due to the large dust veil covering the study zone. The variation of relevant elements (Ca, Mn) showing significant correlations with tree growth, Δ¹³C and δ¹⁸O can be attributed to the selective availability of elements following the soil acidification caused by the volcanic activity. Our findings suggest that the recent activity of the Popocatépetl might have increased tree vulnerability, as reflected in the sharp reduction of growth following the drought recorded 2 years after the large eruption of December 2000. Our results warn about the cumulative negative effects of volcanic activity and harsh climatic conditions on tree growth and functioning.     

Effect of volcanic ash deposition on length and radial growths of a deciduous montane tree (Nothofagus pumilio)

Extreme environmental events such as volcanic eruptions can trigger plant responses that largely exceed those recorded for moderate‐intensity disturbances. We assessed the effects of the June 2011 eruption of the Puyehue – Cordón Caulle volcano on the length and radial growths of juvenile Nothofagus pumilio trees at two sites located 20 (with >40 cm ash accretion) and 75 (without ash) km from the volcano. Variations in length and radial growth were evaluated for the periods 1999–2013 and 1993–2013 respectively; pre‐ and post‐eruption growth rates were computed. The length growth of the N. pumilio trees located close to the volcano increased significantly after the eruption: shoot extensions during the growing season after the eruption were, on average, two to three times longer than average according to ontogenetic growth trends. Variations in radial growth after the eruption were comparatively less noticeable than those in length growth. No significant effects of the eruption were observed in those trees located 75 km from the volcano. In order to explain the exceptionally positive response of N. pumilio's length growth to the volcanic eruption, three non‐exclusive explanations were proposed: (i) thick ash layers increase water retention in the soil; (ii) volcanic ash facilitates the access of plants to nutrients; and (iii) volcanic ashes decrease herbivory and competition. The comparatively lower sensitivity of radial growth to this extreme volcanic event is also noteworthy. These findings highlight the need to further examine how large‐scale volcanic events influence structure and/or functioning of ecosystem in the Patagonian forest.     

Stabilization of recent soil carbon in the humid tropics following land use changes: evidence from aggregate fractionation and stable isotope analyses

Quantitative knowledge of stabilization- and decomposition processes is necessary to understand, assess and predict effects of land use changes on storage and stability of soil organic carbon (soil C) in the tropics. Although it is well documented that different soil types have different soil C stocks, it is presently unknown how different soil types affect the stability of recently formed soil C. Here, we analyze the main controls of soil C storage in the top 0.1 m of soils developed on Tertiary sediments and soils developed on volcanic ashes. Using a combination of fractionation techniques with ¹³C isotopes analyses we had the opportunity to trace origin and stability of soil carbon in different aggregate fractions under pasture and secondary forest. Soil C contents were higher in volcanic ash soils (47–130 g kg⁻¹) than in sedimentary soils (19–50 g kg⁻¹). Mean residence time (MRT) of forest-derived carbon in pastures increased from 37 to 57 years with increasing silt + clay content in sedimentary soils, but was independent from soil properties in volcanic ash soils. MRTs of pasture-derived carbon in secondary forests were considerably shorter, especially in volcanic ash soils, where no pasture-derived carbon could be detected in any of the four studied secondary forests. The implications of these results are that the MRT of recently incorporated organic carbon depends on clay mineralogy and is longer in soils dominated by smectite than non-crystalline minerals. Our results show that the presence of soil C stabilization processes, does not necessarily mean that recent incorporated soil C will also be effectively stabilized.     

Dissolved organic sulphur in soil water under <Emphasis Type="Italic">Pinus sylvestris</Emphasis> L. and <Emphasis Type="Italic">Fagus sylvatica</Emphasis> L. stands in northeastern Bavaria,Germany variations with seasons and soil depth

Organically bound species have been identified as prominent and mobile forms of nitrogen and phosphorus in soils. Since a large portion of sulphur (S) in soil is bonded to carbon (C) also dissolved organic S likely is a significant constituent in soil water. To investigate the role of dissolved organic forms in leaching and cycling of S in forest soils, we examined concentrations, fluxes, and chemical composition of organic S in forest floor leachates and in soil solutions of Rendzic Leptosols under 90-year-old European beech (Fagus sylvatica L.) and Haplic Arenosols under 160-year-old Scots pine (Pinus sylvestris L.) for 27 months. These soils are low in adsorbed SO₄^2- and receive little atmospheric S depositions at present. The chemical composition of organic S was estimated by fractionation with XAD-8 and wet-chemical characterisation (HI reduction) of binding forms. Although not as prominent as the organic forms of other nutrient elements, organic S proved to be an important contributor to S dissolved in forest floor leachates and in mineral soil solutions. Dissolved organic matter contained on average 29% of total S in forest floor leachates at the pine site and 34% at the beech site. The largest portion of organic S occurred in the subsoil solutions under beech in summer and autumn (up to 53%). Mean concentrations of organic S peaked (up to 1.1 mg l^-1) in summer after rainstorms that followed dry periods. Fluxes with forest floor leachates and at 90 cm soil depth were largest in autumn because of huge amounts of rainfall. Organic S contributed significantly to the fluxes of S in the subsoils under beech comprising on average 39% of total dissolved S at 90 cm depth. Organic S produced in the forest floor layers was mainly in the hydrophilic fraction of dissolved organic matter (62 ± 6% at the pine site, 85 ± 4% at the beech site). The major binding form of organic S in the hydrophobic fraction was C-bonded S while in the hydrophilic fraction ester sulphate S, possibly associated with carbohydrates, was more prominent. Since the hydrophobic fraction increased in summer and autumn, C-bonded S was of greater importance during that time of the year than in winter and spring. With depth, concentrations and composition of organic S (and also of C) hardly changed at the pine site because of little retention of dissolved organic matter, presumably because of the small sorption capability of that soil. At the beech where organic C showed a marked decrease with depth, only a slight decrease in organic S, exclusively from the hydrophobic fraction, was found indicating that organic S was mobile compared with organic C. This was probably due to the concentration of S in the hydrophilic fraction of dissolved organic matter. Because of being concentrated in the mobile hydrophilic fraction, ester sulphate S was more mobile in the soil under beech than C-bonded S.     

Wood ash applications to temperate forest ecosystems—potential benefits and drawbacks

The objectives of the present work were (a) to quantify the effects of wood ash on forest ecosystems through a meta-analysis approach associated with a detailed review of the literature (mainly composed of work carried out in Nordic countries) and (b) to extrapolate the effects on forest growth to other contexts (i.e. warm temperate countries) by identifying the cases for which wood ash applications can be beneficial to forest production. Three databases were built regarding the effects of wood ash on soil (151 observations; 33 experimental field trials), on nutrient concentrations of tree foliage (68 observations; 28 trials) and on annual stem biomass growth rate (70 observations; 27 trials). We obtained information on the wide variability of ash properties due to differences in burnt compounds, combustion processes and ash conditioning. Two important properties of wood ash are its high pH value and neutralizing capacity. These properties result in biochemical modifications of forest soils limed with ash. In the short term, soil solution composition was dramatically modified. Intense peaks of the K, Na or SO₄ concentrations were observed, resulting from the dissolution of salts contained in ash. At the same time, Ca and Mg concentrations increased as the carbonate pool of wood ash started to dissolve. The consequence of this dissolution process was an increase in the pH in all the soil phases. These modifications increased the activity of the soil microflora and some isolated peaks in the mineralization of soil organic matter may be observed in mineral soils. In the longer term, that is to say after the first year following ash application, only the effect on the acidity status of the soil remained significant. The effects of ash addition on forest ecosystems usually increased with the dose and were more pronounced with loose ash compared to aggregated ash. The addition of wood ash into forest ecosystems increased the foliar Ca status of trees. Some modifications of other nutrients, like P or K, were also observed but only for a few years after treatment. For most stands growing on mineral soils of Nordic countries, this treatment did not result in an increase in tree growth, probably because of the absence of N in the ash. For stands growing on organic soils of the same area, this input, associated with a long-lasting increase of soil organic matter mineralization, was sufficient to improve tree growth significantly (median = +59% compared to the control). For soils located in warm temperate regions, similar responses are expected for organic soils. For mineral soils, the wood ash application is expected to be suitable for stands showing deficiencies in K, Ca or Mg. Ash may contain high amounts of toxic heavy metals such as Cd. The bioavailability of most of these elements appeared to be very low in a forest context. No contamination of food chains has been observed, except possibly via some species of fungi, and heavy metals remain in the forest litter or in the topsoil. Based on all the reviewed results, several guidelines for wood ash application into forest ecosystems are proposed. Wood ash application should be restricted to acidic soils. Applications should consist of low doses of a stabilized ash form. Wood ash should be applied to adult stands rather than onto seedlings.     

Perturbation pathways affecting the avian lotic predator, blue duck, following a volcanic eruption

1. Perturbation pathways affecting interactions between feeding habitat, food supplies and diet of a lotic avian predator, blue duck (Hymenolaimus malacorhynchos Gemlin), were tracked in a New Zealand river following substantial inputs of sediment from a volcanic eruption. Sediment impacts were separated temporally into two distinct phases: (i) deposition of fine ash from volcanic fall‐out, and (ii) pulsed releases of volcanic sand and gravel retained by an upstream dam. 2. Levels of interstitial suspendable inorganic sediments increased by several orders of magnitude following ash inputs to the river, but returned to low levels within 3 months. Flushing of volcanic sand and gravel retained by the dam resulted in sediment deposition upstream of a large island where coarse material lodged firmly between larger benthic substratum elements in blue duck feeding habitat. 3. Changes in algal biomass appeared to largely reflect seasonal and hydrological influences, but the percentage inorganic content of periphyton increased significantly during both posteruption phases. 4. Diversity and abundance of blue duck food supplies on boulders and on the riverbed declined following the eruption, whereas significant impacts on biomass were only detected in benthic habitats which were more susceptible to sediment deposition. However, percent composition of the benthic and boulder invertebrate food resources appeared largely unaffected by the eruption. 5. There was no apparent association between the eruption and the composition or electivity (E*) of blue duck diet, but there was a significant increase in the percent inorganic content of faeces, suggesting a reduction in the quality of food rations. 6. Changes in food quantity and quality associated with deposition of volcanic sediments were linked to an observed decline in blue duck population density and fecundity following the eruption. An interacting continuum of adaptive responses to perturbation intensity and impact duration is proposed for blue duck, and potentially other long‐lived, riverine birds, that enable them to cope with disturbances in highly variable and heterogenous lotic environments.     

The reserve of weatherable primary silicates impacts the accumulation of biogenic silicon in volcanic ash soils

Banana plantlets (Musa acuminata cv Grande Naine) cultivated in hydroponics take up silicon proportionally to the concentration of Si in the nutrient solution (0–1.66 mM Si). Here we study the Si status of banana plantlets grown under controlled greenhouse conditions on five soils developed from andesitic volcanic ash, but differing in weathering stage. The mineralogical composition of soils was inferred from X-ray diffraction, elemental analysis and selective chemical/mineralogical extractions. With increasing weathering, the content of weatherable primary minerals decreased. Conversely, clay content increased and stable secondary minerals were increasingly dominant: gibbsite, Fe oxides, allophane, halloysite and kaolinite. The contents of biogenic Si in plant and soil were governed by the reserve of weatherable primary minerals. The largest concentrations of biogenic Si in plant (6.9–7 g kg⁻¹) and soil (50–58 g kg⁻¹) occurred in the least weathered soils, where total Si content was above 225 g kg⁻¹. The lowest contents of biogenic Si in plant (2.8–4.3 g kg⁻¹) and soil (8–31 g kg⁻¹) occurred in the most weathered desilicated soils enriched with secondary oxides and clay minerals. Our data imply that soil weathering stage directly impacted the soil-to-plant transfer of silicon, and thereby the stock of biogenic Si in a soil–plant system involving a Si-accumulating plant. They further imply that soil type can influence the silicon soil–plant cycle and its hydrological output.     

The influence of mobile forms of heavy metals on the microbiological activity of soil at gold placers (Exemplified by the Dzhalinda River Valley,Amur Region)

The soil was sampled in the zone of long-term mining of a gold placer. The total contents of heavy metals, mobile forms of these elements, and the quantitative characteristics of the ecological trophic groups of the soil microbial community have been determined. The soil samples are characterized by stable enrichment with such elements as Co, Ni, Cr, Cu, Pb, Zn, As, and Mo. The amount of mobile forms (relative to total content) varies from 0.5 to 54% for different elements. It has been shown that the abundance of the main ecological-trophic groups of microorganisms depends on degree of pollution. The correlations between increased concentrations of the mobile forms of some heavy metals and microbiological indices are established and illustrated.     

Trace elements in soils and crops.

To demonstrate the total amounts to be expected in soils, the ranges of contents of some 60 trace elements in ten representative Scottish arable surface soils are compared with ranges in soil-forming rocks and with crustal averages. It is, however, the amounts potentially available to plants rather than the total contents that are biologically significant. In temperate climates, trace element mobilization is greatest when weathering takes place under conditions of impeded pedological drainage, leading to the formation of gleyed soils. Mobilized trace elements occur in arable surface soils largely in adsorbed and chelated forms, which are available to plants to a greater or smaller extent depending on the prevailing soil parameters and on the element in question. Different species take up different amounts of trace elements: the proportions in the various plant parts vary with the element and the stage of growth. Information is required about the mobilization and uptake of many elements about which little is at present known but which may affect the functions of essential elements through inter-element interactions. Systematic soil surveys in which soils are mapped by associations related to parent material, with their series related to genetic soil types, provide a useful countrywide guide to trace element status.     

DEATH OF STEPPE CRYPTOGAMS UNDER THE ASH FROM MOUNT ST. HELENS

Terrestrial mosses and lichens in the steppe of Washington were buried under volcanic ash from the 18 May 1980 eruption of Mount St. Helens. Unlike adult vascular plants in these communities, these cryptogams died following the deposition of silt-size ash. Death within as little as four months was demonstrated by anatomical deterioration and these organisms' inability to fix CO₂, to fluoresce in IR radiation, and to absorb vital stains. Although cryptogams in the steppe have probably been destroyed repeatedly by ash falls during the Holocene, this recent destruction is the first since the arrival of alien plants in the nineteenth century. Death of cryptogams may allow the initiation of further colonization by alien plants because a cryptogamic crust forms a barrier to seedling establishment.     

Long‐term carbon storage through retention of dissolved aromatic acids by reactive particles in soil

Soils retain large quantities of carbon, thereby slowing its return to the atmosphere. The mechanisms governing organic carbon sequestration in soil remain poorly understood, yet are integral to understanding soil‐climate feedbacks. We evaluated the biochemistry of dissolved and solid organic carbon in potential source and sink horizons across a chronosequence of volcanic soils in Hawai'i. The soils are derived from similar basaltic parent material on gently sloping volcanic shield surfaces, support the same vegetation assemblage, and yet exhibit strong shifts in soil mineralogy and soil carbon content as a function of volcanic substrate age. Solid‐state¹³carbon nuclear magnetic resonance spectra indicate that the most persistent mineral‐bound carbon is comprised of partially oxidized aromatic compounds with strong chemical resemblance to dissolved organic matter derived from plant litter. A molecular mixing model indicates that protein, lipid, carbohydrate, and char content decreased whereas oxidized lignin and carboxyl/carbonyl content increased with increasing short‐range order mineral content. When solutions rich in dissolved organic matter were passed through Bw‐horizon mineral cores, aromatic compounds were preferentially sorbed with the greatest retention occurring in horizons containing the greatest amount of short‐range ordered minerals. These minerals are reactive metastable nanocrystals that are most common in volcanic soils, but exist in smaller amounts in nearly all major soil classes. Our results indicate that long‐term carbon storage in short‐range ordered minerals occurs via chemical retention with dissolved aromatic acids derived from plant litter and carried along preferential flow‐paths to deeper B horizons.     

Characteristics of wood ash and influence on soil properties and nutrient uptake: an overview

Wood industries and power plants generate enormous quantities of wood ash. Disposal in landfills has been for long a common method for removal. New regulations for conserving the environment have raised the costs of landfill disposal and added to the difficulties for acquiring new sites for disposal. Over a few decades a number of studies have been carried out on the utilization of wood ashes in agriculture and forestry as an alternative method for disposal. Because of their properties and their influence on soil chemistry the utilization of wood ashes is particularly suited for the fertility management of tropical acid soils and forest soils. This review principally focuses on ash from the wood industry and power plants and considers its physical, chemical and mineralogical characteristics, its effect on soil properties, on the availability of nutrient elements and on the growth and chemical composition of crops and trees, as well as its impact on the environment.     

On available forms of chemical compounds in soils

Different methods are used to study available forms of chemical compounds in soils. The sequential extraction method is described in detail. Also, a comparative overview is given of the most frequently extracted fractions of chemical elements (water-soluble, exchangeable, specifically sorbed, carbonate, bonded to organics, Fe and Mn oxides/hydroxides, and aluminosilicates), as well as of relevant extractants. Advantages and disadvantages of various extractants are discussed, and ways to improve their selectivity are proposed. It is also shown that the content of available forms of chemical compounds in soil can be used for estimating the extent of industrial soil pollution.     

Distribution of total mercury in peat soil profiles in West Siberia

Total mercury content in peat soils of different botanical composition has been determined. Mercury content in peat depends on principal properties of peat soil such as botanical composition, ash content, degree of peat decomposition, as well as nitrogen, carbon, and humic acid content in peat. A model based on the mercury/biomass concept is proposed to determine the distribution of total mercury in peat soil profiles in West Siberia from the content of the main biogenic elements C and N.