Characterization of detritus profiles in some ecosystems of southern Sakhalin

The typology of the detritus profiles for the main forest types in the southern part of Sakhalin is developed for the first time. It is shown that their mean thickness varies from 4 to 8 cm and regularly decreases with increasing proportion of deciduous plants in the ground cover. It is found that this parameter agrees closely with the habitat conditions and the highest diversity of detritus profiles is observed under semihydromorphic conditions typical of alder stands. For the first time, it is proposed to assess the environmental favorability for humus formation using the Shannon index, the coefficient that relates the diversity level of the detritus profiles to the thickness of the humus horizon and enables the composition of ecological series. It is shown that the most favorable conditions for humus accumulation are created in the series birch forest–mixed coniferous forest–mixed deciduous forest. The applicability of the classification developed on the basis of studies in the forests of Primorye and Southern Yakutia to the forest ecosystems of Southern Sakhalin is confirmed.     

Effects of acidic deposition on soil ecosystems under forest in the Chongqing region of China

The effects of acidic deposition on soil ecosystems under temperate coniferous forest in the Chongqing region of China were investigated from 1993 to 1994. Precipitation, throughfall, stemflow, soil solutions, and soil samples were collected to estimate the acidification of soil ecosystems through the changes of their chemical components. The concentrations of ion species in the throughfall and stemflow under masson pine forest in Mt. Zhenwu were higher than those under mixed coniferous forest in Mt. Jinyun and under camphor tree forest in Laojundong, suggesting that Mt. Zhenwu is located in the vicinity of the Chongqing center and that it allowed the canopy of masson pine to intercept air pollutants. However, the level of aluminum dissolution into soil solutions was relatively low under masson pine forest in Mt. Zhenwu in spite of the low pH in the stemflow.     

Long‐term site productivity effects of different Rhododendron control methods in eastern beech (Fagus orientalis Lipsky) ecosystems in the Western Black Sea region of Turkey

The study area is located in an eastern beech stand on a fertile and mesic upland site in the western Black Sea region of Turkey. During natural regeneration of the beech stand, rhododendron was differentially controlled. The experiment used a randomized block design with four replicates and two different site preparation practices. The manual treatment was hand grubbing. The whole plant was uprooted and left on the site. The mechanical treatment scarified the surface soil to 5–10 cm depth with a bulldozer equipped with a brush rake. After 17 years following site preparation, the number of trees on the grubbing site (GS) was 60% more than that of mechanical treatment sites (MTS). Total tree biomass per hectare was 39% greater on GS than that of MTS. Beech trees on the grubbing sites had 18, 115, 29, 17 and 78% more N, P, K, Ca and Mg than MTS, respectively. Forest floor N content on GS was 50% more than that of MTS. On the GS, Ca content also was three times more than that of MTS. At 0–20 cm depth, cation exchange capacity on GS was 48% higher than that of MTS. At the same depth, GS had 50, 100, 78, 23, 8, 10 and 49% more C, N, P, Ca, K, Mg and S concentrations than those of MTS, respectively. Removing of organic layer and upper soil with mechanical site preparation depletes ecosystem nutrient pools compared with manual grubbing. This difference is sustained in the long‐term. Grubbing is both effective and by leaving organic layer on the sites, grubbing preserves the long‐term productivity of the ecosystem.     

The carbonate profile and water regime of migrational-mycelial chernozems in different ecosystems of Kursk oblast

The carbonate profiles of migrational-mycelial (typical) chernozems under regularly mown and absolutely reserved steppes in the V.V. Alekhin Central Chernozemic State Biospheric Reserve and under cropland with cereals (Kursk oblast) were studied in 2007–2009. A comparison of the results of these studies with previous results obtained in the mid-1970s attests to certain changes in the carbonate profiles of the soils. They are conditioned by the activation of the migration of carbonates and the more pronounced manifestation of differently directed processes of the leaching and accumulation of carbonates. The reasons for the observed transformation of the carbonate profiles are related to the increased moistening of the upper 3-m-deep chernozemic layer in different ecosystems because of a general rise in the humidity of the local climate in the recent decades (1973–2006).     

水蚀风蚀交错带土壤剖面水力学性质变异

土壤剖面水力学性质的确定是土壤水分动态预测的基础。该文在水蚀风蚀交错区六道沟流域分别对居于坡中和坡上两块样地160 cm土层不同深度未扰动土壤的水分特征曲线进行了测定，将Van Genuchtens水分特征曲线模式与Mualem导水模式相结合，确定了两样地土壤剖面的水力学参数，对水力学参数在剖面的变化进行了分析。结果表明，土壤剖面饱和含水率、滞留含水率、进气吸力倒数和孔隙大小分布因子沿剖面变化不大，滞留含水率、进气吸力倒数属于中等程度变异，饱和含水率和孔隙大小分布指标属于弱变异，但经方差检验均不显著，说明该地区160 cm土壤剖面可以处理成均质剖面。     

Modern geochemical evolution of lagoon-marshy landscapes in the western Caspian Sea region

The landscape-geochemical consequences of the full cycle of Caspian Sea fluctuations (regression-transgression-stabilization) that has taken place in the recent decades are analyzed. The regressive and lagoon-transgressive sets of landscape-geochemical processes (LGPs) are characterized. The impact of the regressive stage on the environment is seen in the development of the regressive LGPs in the soils and sediments of the coastal landscapes with a predominance of salinization and weak humus accumulation. The transgression of the sea was accompanied by the formation of specific lagoon-marsh landscapes, in which the accumulation of sulfides, gleyzation, iron oxidation, and humus formation were clearly pronounced. The general scheme of the evolution of the LGPs within the past 30 years is discussed. The rates of the humus accumulation and salinization during the stabilization stage are estimated. The organic matter reserves in the coastal soils increased by 1.5–2 times in a decade. The transformation of the particular forms of chemical elements in the lagoon-marsh landscapes upon fluctuations in the sea level is shown. The rise in the Caspian sea level was accompanied by the enhanced migration of elements with varying valences, such as Fe and Mn (as well as Zn, Cu, Pb, Ni, and Co) due to their mobilization in the slightly alkaline and neutral reducing conditions and their precipitation at the geochemical barriers.     

太湖地区典型水稻土FDA水解酶活性的剖面分布特征

本文主要对太湖地区12个典型水稻土剖面的荧光素二乙酸酯(FDA)水解酶活性及其它相关酶活性进行了分析。耕作层的FDA水解酶活性最高,随土层加深活性明显下降,其中部分土壤在犁底层已经很难检测到其活性。部分样点的酶活性在剖面中呈明显的梯度下降趋势。高产水稻土壤表层FDA水解酶活性差异较大,在50～100g/(g.h)范围内,多数为60～80g/(g.h)。土壤酶活性最高与最低间的差异达到近一倍左右。同时FDA水解酶活性与-葡糖苷酶、脲酶、脱氢酶、酸性磷酸酶和芳基硫酸酯酶活性之间有极显著正相关关系(P0.01),与碱性磷酸酶呈显著相关(P0.05);与土壤养分指标如全氮、全磷、速效氮、有机碳之间有极显著相关性,与土壤pH呈显著负相关(P0.01)关系。     

Biomass and respiration activity of soil microorganisms in anthropogenically transformed ecosystems (Moscow region)

In the forest, meadow, arable, and urban ecosystems (recreational, residential, and industrial zones) of Sergiev Posad, Shatura, Serpukhov, and Serebryanye Prudy districts of Moscow region, spatially separated sites (3–5 points per site) have been randomly selected and soil samples have been taken from the 0–10 (plant litter excluded) and 10- to 150-cm layers (a total of 201 samples have been taken). In the samples, the microbial biomass carbon (C_mic), the rate of the basal (microbial) respiration (BR), and the physical parameters (the particle size distribution (PSD), organic carbon (C_org), pH, heavy metals, and nutrients (NPK)) have been determined. High spatial variability has been revealed for C_mic and BR in all the ecosystems and the functional zones of the studied districts, and a clear tendency of a decrease in these parameters has been shown in the arable soils (by 1.4–3.2 times) and the industrial zone (by 1.7–3.3 times) compared to the natural analogues and other corresponding functional zones. It has been shown that the spatial distribution of the microbiological parameters is significantly (p ≤ 0.05) affected by the physicochemical properties of the soil (C_mic by the PSD and PSD × C_org; BR by the pH and pH × NPK; contributions of 40 and 63%, respectively), as well as by the type of ecosystem and the region of study (the contribution of the sum of these factors to the C_mic and BR was 56 and 67%, respectively). A tendency toward the deterioration of the functioning of the microbial community under the anthropogenic transformation of the soil has been shown. The contribution of the urban soils as a potential source of CO₂ emission to the atmosphere has been calculated and discussed.     

黑龙江省东部山地红松人工林生态系统水化学特征

对黑龙江省东部山地红松人工林生态系统的大气降水、穿透水、树干径流、枯透水和地表径流中的pH值、溶解氧、浊度、总溶解固体、K、Na、Ca、Mg、Cu、Zn、Mn和Fe等水质指标进行了检测。结果表明:大气降水经过林冠层后,其水化学特征发生了明显变化,pH和DO降低,TURB和TDS明显增加,化学元素含量均不同程度增加。树干径流除了Cu外其余各化学元素含量均明显增加。穿透水和树干径流中各元素的变异系数较大。枯透水各化学元素的变异系数低于其他水样,只有Mn元素变化较大。穿透水、树干径流和枯透水中的K、Ca淋溶量较大,Cu、Zn淋溶量较少,根据淋溶系数的大小排列穿透水的淋溶序列为Mn>K>Mg>Cu>Fe>Ca>Na>Zn,树干径流的淋溶序列为Mn>Mg>K>Fe>Ca>Cu>Na>Zn,而枯透水的淋溶序列为Mg>Mn>K>Fe>Ca>Cu>Na>Zn。     

喀斯特地区洼地剖面土壤含水率的动态变化规律

本文基于连续2年土壤水分的定位监测数据,分析探讨了喀斯特地区不同地质背景(纯灰岩与白云质灰岩)洼地剖面(0～90 cm)土壤含水率的动态变化规律。结果表明:洼地剖面土壤含水率总体较高,且从表层到深层表现为增长型;2009年和2010年土壤含水率的变化均具有明显的分层现象,从上到下依次为活跃层、次活跃层、相对稳定层,但均无速变层,不同地质背景的具体分层略有差异;活跃层和次活跃层集中分布在浅层土壤层,相对稳定层较厚,对应着较差的水文调蓄功能,洼地土壤的水分调蓄功能可能会因其相对较深厚(80～100 cm)的土层而被高估。受降雨、蒸发及植物蒸腾等因素的影响,土壤储水量具有明显的动态变化特征,一年中可分为相对稳定期、消耗期和补给期3个阶段,而土壤水分亏缺的补偿和恢复,主要依靠强度适中、历时较长且雨量较大的降雨,微雨和暴雨的作用较小。     

Aggregation studied by laser diffraction in relation to plowing and liming in the Cerrado region in Brazil

In the Cerrado savanna region in Brazil, the effects of different land use on Oxisol aggregation were studied using laser diffraction grain size analyses. The topsoil of plowed systems had significantly lower amount of macroaggregates (2000–194 μm) and a significantly higher amount of soil in the microaggregate size and primary particle fraction (<76 μm) compared to pastures and the native Cerrado. In plowed systems low in soil organic carbon (SOC), lime had a negative effect on aggregate stability. Lime addition had no effect on topsoil aggregation in land use systems that were not plowed regularly and generally had a higher SOC content. For all the studied topsoils, pH_KCl was positively correlated with the amount of clay dispersed after 3 h of shaking in water. SOC did not influence clay dispersion in the range of soils studied. In continuous cropping systems in the Cerrado region, with a combination of mechanical stress and low SOC, liming will cause an increase in small aggregates and primary particles and hence contribute to a destabilization of the soil structure.     

典型黑土区不同生态系统下土壤团聚体中胡敏酸的结构特征

为了揭示生态系统类型对土壤团聚体中腐殖质分子结构的影响,本研究以黑土区24 a长期定位试验处理下的自然草地(GL)、耕地(CL)和裸地(BL)土壤为研究对象,采用湿筛法将土壤团聚体分为2 mm、2～0.25 mm、0.25～0.053 mm和0.053 mm 4个粒级,运用元素分析、红外光谱和差热分析技术,对团聚体中胡敏酸(HA)的结构性质进行了研究。结果表明,生态系统类型对团聚体中HA的分子结构产生了影响。耕地各级团聚体中HA的O+S含量以及(O+S)/C比值(摩尔比)普遍高于草地相应粒级团聚体,反映了耕地土壤团聚体中HA的氧化程度高于草地;差热分析中,耕地和裸地土壤团聚体中HA的中温放热量低于草地相应粒级团聚体,且二者的热量高/中比值均高于草地,说明耕地和裸地土壤团聚体中HA的芳香性/脂族性高于草地;草地和耕地土壤团聚体中HA在2 920和2 850 cm-1处代表脂族聚亚甲基和末端甲基中C-H伸缩振动的吸收峰明显强于裸地,脂族碳/羧基碳(2 920/1 720)以及脂族碳/芳香碳(2 920/1 620)比值高于后者。与自然草地相比,耕地和裸地生态系统会增强土壤团聚体中HA的缩合度、氧化度和芳香性,提高其分子结构的稳定性。     

Assessment of the effect of aerial transport of salts on solonetzic process in the Black Sea region

The aerial deposition of salts is often considered as one of the sources of soil salinity; the amount and composition of the salts deposited from the air are studied. In this paper, the potential contribution of aerial salts to the development of the solonetzic process in the soils of the Black Sea region is analyzed. The wet and dry (with dust) depositions are considered separately. To reveal their influence on the potential development of the solonetzic process, special calculations with the use of cation exchange equations have been performed. It is shown that solutions of salts deposited from the air can lead to a very weak development of the solonetzic process. Their amount is only sufficient to ensure the exchangeable sodium percentage in soils from 0. ⁿ to 2–4% of the exchange capacity.     

基于电磁感应仪的河口地区底聚型盐分剖面特征的解译

针对长江河口地区存在的盐渍化问题,以该地区分布较广泛的底聚型盐分剖面类型为研究对象,通过电磁感应仪EM38测量与田间采样,建立了磁感式表观电导率和土壤电导率之间的多元回归模型。在分析土壤盐分剖面分布特征的基础上提出了Logistic模型,并运用该模型对盐分剖面进行了参数拟合和验证。结果表明：磁感式表观电导率水平读数和垂直读数呈极显著线性相关,回归模型和Logistic模型均具有很好的预测效果。通过模型精度检验,二者的预测精度差异不显著,但Logistic模型所需参数少,表明该文提出的Logistic模型不仅能降低待估参数数量,同时还具有较高的预测精度。该研究结果为利用电磁感应仪快速、精确地进行土壤盐分预测及土壤次生盐渍化的防控提供了一定的理论参考。     

太湖地区不同土壤-森林生态系统中林木生长对微量元素的反应及反馈效应

Vector analysis technique and ecological sequential comparison methods were adopted to study tree growth response to the micronutrients,B,Mo,Cu,Zn,Fe,and Mn,in soils derived from various parent materials in the forest area of Tailhu Lake region in southeast China,The results showed that the dry weight of individual current-year needle of Chinese fir(Cunninghamia lanceolata) grown on the soil derived from granite parent rock was increased by 8% and 13% in comparison with that grown on the soils derived from sandstone and ash-tuff parent rock,respectively.And such dry weight of loblolly pine (Pinus taeda) grown on the soil derived from sandstone parent rock was increased by 21% in comparison with that on the soil derived from ash-tuff parent rock.One of the reasons for those results was that micronutrients content in the soil derived from ash-tuff parent rock were not sufficient to meet the requirement of the growth of Chinese fir and loblolly pine ,i.e.,micronutrients in soil were deficient and/or induced defiient.The amounts of Cu,Zn,Fe,and Mn uptake by Chinses fir and loblolly pine were in agreement with the contents of available micronutrients in soil respectively,except for B and Mo.Meanwhile,there might exist and “antagonism“ between the uptake of B versus Mo by trees,although more studies are needed to confirm it .Regression analysis indicated that amount of a soil available micronutrient was correlated to the type of parent material and its total amount in the forest floor, except for B.The F test identified that the correlation of each equation reached the significant level to different extents,respectively,The t test confirmed that amount of available forms was mainly depended on the type of parent material for Mo,Cu,Zn and Mn but on the forest floor for ,Fe,There was a feedback effect of forest stand on the amount of soil available micronutrients.The ability of accumulating available micronutrients in soil was better by the sawtooth oak(Quercus acutissima) stand than by the Chinese fir stand (except for B).The ability of accumulating available Zn,Fe,Mn and Mo in soil was better by the Chinese fir stand than by the loblolly pine stand ,while as for available B and Cu,by the latter was better than by the former,When discussing the efect of forest stand on the amount of soil available micronutrients,not only the amount of micronutrient in the forest floor and the parent materials but also the amount of micronutrient taken up by current-year needles have to be considered.     

Enzymatic activity and stabilization of organic matter in soil with different detritus inputs

ABSTRACT

The aim of the study was to assess the effects of different forest stands (Silver fir (Abies alba) and sycamore maple (Acer pseudoplatanus) with common hornbeam (Carpinus betulus)) on the enzymes activities and microbial biomass. The objective was to explore how changes in the detritus inputs affect soil organic matter (SOM) composition. The content of SOM fraction has been compared with soil enzyme activities. The investigation was carried out in the ?wi?tokrzyskie Mountains of central Poland. Twenty investigation plots were selected, including fir stands (10 plots) and maple with hornbeam stands (10 plots). Contents of organic C, N and base cations, pH, hydrolytic acidity, and soil texture were investigated. The content of C and N in the physically separated SOM fractions was distinguished. The study indicated only small changes in soil properties and stabilization of organic matter as a result of different detritus inputs. The maple-hornbeam and fir stands have a similar influence on microbiological processes and the SOM. Acidity of soil is a major factor affecting microbial activity and therefore pH affects enzyme dynamics. Differences in soil pH confirmed the stronger acidifying effects of fir stands compared to maple-hornbeam stands. Additionally, fir stands stimulate β-glucosidase activity, probably through a simultaneous interaction of mycorrhizal fungi in the roots of fir stands.     

Nitrogen balances in forest ecosystems of the Pacific Northwest

In order to understand the role of nitrogen in the forests of the Pacific Northwest, especially Douglas-fir, a great number of studies have been initiated to evaluate both static and dynamic aspects of the nitrogen balance. This paper presents a summary of many of these past results covering 20 yr research with the specific intent of defining the nitrogen economy of these systems and the long- and short-term changes that are occurring. Variations of nitrogen in both soils and vegetation are discussed with some sampling techniques applicable to coniferous forests given. It appears that the soil total nitrogen, in different soils, varies several fold more than the nitrogen in the forest crops of these soils. The dynamics of nitrogen transfer within the ecosystem, together with gains and losses from the system, are presented.     

环渤海盐碱地区农业资源分布特征与农业持续发展模式初探

综合分析了河北省沧州市运河以东环渤海盐碱地区农业资源分布特征及经济发展状况,提出该区应依据资源与经济的梯级分布布局及开展盐碱地梯级开发治理的战略,利用与保护并举,实施生物措施与工程措施相结合,发展特色、优质和高产高效农业,促进该区农业的持续高效发展。     

Functioning of cyanobacteria in soil ecosystems

The data of long-term studies pertinent to functioning of cyanobacteria and their effects on soil fertility during periods of soil “blossoming” over more than 50% of the soil surface are presented. Parameters of and participants in this process and its features typical for the temperate zone are discussed. Using modern methods of investigations (field ¹⁵N₂ and ¹³CO₂ chambers, spectral-isotope and gas chromatographic analyses), cyanobacteria were revealed to produce 725 kg/ha. They are characterized by intense photosynthesis inherent to mosses and lichens. The conditions of cyanobacteria functioning in plowed soils are discussed. Their contribution to the nitrogen pool of soils reaches 30 kg/ha. Based on the model experiments, a concept of transforming the organic matter of cyanobacteria in soil and its movement along trophic chains of the biological cycle has been developed.     

Parameters of the productivity of soil algae in terrestrial ecosystems

A review is presented of the recent state of the problem of soil algae productivity in terrestrial ecosystems on the basis of literature data and our own research. It is shown that the organic matter accumulated by soil algae is highly mobile. The following parameters were analyzed: the biological production, the time of the biomass turnover, and the rate of the algal organic matter renewal in the soil. The average monthly production of algae ranged from 0.9 to 765 g/m², the rate of the organic matter renewal ranged from 0.03 to 25.5 g/m² per day, and the time of the algal biomass renewal ranged from 0.1 to 7 days.