Estimating the amount and distribution of radon flux density from the soil surface in China

Based on an idealized model, both the annual and the seasonal radon ((222)Rn) flux densities from the soil surface at 1099 sites in China were estimated by linking a database of soil (226)Ra content and a global ecosystems database. Digital maps of the (222)Rn flux density in China were constructed in a spatial resolution of 25 km x 25 km by interpolation among the estimated data. An area-weighted annual average (222)Rn flux density from the soil surface across China was estimated to be 29.7+/-9.4 mBq m(-2)s(-1). Both regional and seasonal variations in the (222)Rn flux densities are significant in China. Annual average flux densities in the southeastern and northwestern China are generally higher than those in other regions of China, because of high soil (226)Ra content in the southeastern area and high soil aridity in the northwestern one. The seasonal average flux density is generally higher in summer/spring than winter, since relatively higher soil temperature and lower soil water saturation in summer/spring than other seasons are common in China.     

Soil-dwelling Collembola in coniferous forests along the gradient of pollution with emissions from the Middle Ural Copper Smelter

The results of three-year studies on Collembola communities in spruce-fir forests along the gradient of pollution with emissions from the Middle Ural Copper Smelter (Revda, Sverdlovsk oblast) are presented. They show that the species and ecological structure of these communities change abruptly in the impact zone (1 km from the source of emissions), compared to the background zone (30 km from the source), which involves a decrease in the abundance and diversity of Collembola. Their total abundance and species richness in the zone of intermediate disturbance (7 and 4 km) are considerably higher than in the background zone, and the species structure of communities is characterized by superdominance. Four species groups differing in sensitivity to pollution are distinguished. Preference for zones with different pollution levels in closely related species is regarded as a case of ecological vicariation.     

Condition of the Soil Fauna near the Epicenter of an Underground Nuclear Explosion in the Northern Urals

Radioactive contamination affects soil organisms and causes profound structural rearrangements in soil zoocenoses, which are manifested in the decreased species diversity of invertebrate communities and low relative abundance of large soil invertebrates. However, these communities gradually recover their initial structure. The soil biota near the epicenter of an underground nuclear explosion performed 30 years ago in Perm oblast has been studied to reveal specific structural features of the soil macro- and microfauna. Its structural diversity is considered with regard to such components as species (taxonomic) composition, the structure of dominance, and the ratio of ecological and trophic groups.__________Translated from Ekologiya, No. 3, 2005, pp. 171–179.Original Russian Text Copyright © 2005 by Kolesnikova, Taskaeva, Krivolutskii, Taskaev.     

Accumulation of (137)Cs in Brazilian soils and its transfer to plants under different climatic conditions

The spatial distribution and behaviour of the global fallout (137)Cs in the tropical, subtropical and equatorial soil-plant systems were investigated at several upland sites in Brazil selected according to their climate characteristics, and to the agricultural importance. To determine the (137)Cs deposition density, undisturbed soil profiles were taken from 23 environments situated between the latitudes of 02 degrees N and 30 degrees S. Sampling sites located along to the equator exhibited (137)Cs deposition densities with an average value of 219Bqm(-2). Extremely low deposition densities of 1.3Bqm(-2) were found in the Amazon region. In contrast, the southern part of Brazil, located between latitudes of 20 degrees S and 34 degrees S, exhibited considerably higher deposition densities ranging from 140Bqm(-2) to 1620Bqm(-2). To examine the (137)Cs soil-to-plant transfer in the Brazilian agricultural products, 29 mainly tropical plant species, and corresponding soil samples were collected at 43 sampling locations in nine federal states of Brazil. Values of the (137)Cs concentration factor plant/soil exhibited a large range from 0.020 (beans) to 6.2 (cassava). Samples of some plant species originated from different collecting areas showed different concentration factors. The (137)Cs content of some plants collected was not measurable due to a very low (137)Cs concentration level found in the upper layers of the incremental soils. Globally, the soil-to-plant transfer of (137)Cs can be described by a logarithmic normal distribution with a geometric mean of 0.3 and a geometric standard deviation of 3.9.     

Structure of the communities of small mammals (micromammalia) in forests on western slopes of the Northern Urals

Long-term data on the species composition and ratio of insectivores and rodents in forest ecosystems of the western macroslope of the Northern Urals are considered. It is shown that the micromammalian communities of mountain forests are characterized by higher total abundance and polydominance and comprise greater numbers of common species than the communities of taiga forests in neighboring regions of the Russian Plain. Hence, the mountain-forest communities of small mammals have high indices of species diversity and uniformity.Translated from Ekologiya, No. 2, 2005, pp. 138–145.Original Russian Text Copyright © 2005 by Bobretsov, Lukyanova, Poroshin.     

Vegetation of Northeast China during the late seventeenth to early twentieth century as revealed by historical documents

Historical vegetation antedates current anthropogenic land use. It can therefore be used to reveal land use/cover changes due to human activities. We collected 197 records from Chinese historical documents, including gazettes, government files, private literature, and travel notes, to reveal vegetation status during the late seventeenth century to early twentieth century across Northeast China. The results indicate that woodland and grassland were the dominant landscapes, whereas swamps accounted for a small area. Woodland was composed of needleleaf deciduous forest, broadleaf deciduous forest, and mixed needleleaf and broadleaf forest. Mixed forest occupied the largest area. This forest type covered most of the Greater Khingan Range, Lesser Khingan Range, and Changbai Mountains. Grassland occupied the Songnen Plain, Liao River Plain, and Inner Mongolia Plateau, whereas swamps covered nearly the entire Sanjiang Plain. In addition, the data revealed that most current cropland was converted from grassland in the Northeast Plain, whereas a small area of cropland was converted from woodland and swamp.     

Cs uptake by four plant species and Cs-K relations in the soil-plant system as affected by Ca(OH)2 application to an acid soil

Three rates of Ca(OH)₂ were applied to an acid soil and the ¹³⁴Cs uptake by radish, cucumber, soybean and sunflower plants was studied. The ¹³⁴Cs concentration in all plant species was reduced from 1.6-fold in the sunflower seeds to 6-fold in the soybean vegetative parts at the higher Ca(OH)₂ rate. Potassium (K) concentration in plants was also reduced, but less effectively. The significantly decreased ¹³⁴Cs-K soil to plant distribution factors (D.F.) clearly suggest a stronger effect of soil liming on ¹³⁴Cs than on K plant uptake. This observation was discussed in terms of ionic interactions in the soil matrix and within the plants. The results also indicated that the increased Ca²⁺ concentration in the exchange phase and in the soil solution along with the improved root activity, due to the soil liming, enhanced the immobilization of ¹³⁴Cs in the soil matrix and consequently lowered the ¹³⁴Cs availability for plant uptake.     

Genetic Diversity in Annual Xerohalophytes of the Family Chenopodiaceae along Soil Moisture and Salinity Gradients

Genetic polymorphism has been studied in populations of two annual xerohalophyte species of the family Chenopodiaceae, Atriplex tatarica and Sedobassia sedoides, growing on soils with different levels of soil moisture and sodium and potassium ion contents. A tendency toward decrease in the percentage of polymorphic loci in A. tatarica at higher soil salinity and increase in the observed heterozygosity of S. sedoides populations at higher levels of soil potassium has been revealed, with parameters of genetic variation in either species showing no dependence on soil moisture. Soil potassium deficiency is a stress factor for S. sedoides at both physiological and population-genetic levels. Mechanisms controlling sodium absorption and maintaining ion homeostasis and also a high level of homozygosity in S. sedoides indicate the improvement of stress tolerance in this annual species.

     

Plant uptake of radiocaesium from artificially contaminated soil monoliths covering major European soil types

Uptake of ¹³⁷Cs was measured in different agricultural plant species (beans, lettuce, barley and ryegrass) grown in 5 undisturbed soil monoliths covering major European soil types. The first cultivation was made three years after soil contamination and plants were grown during 3 successive years. The plant–soil ¹³⁷Cs transfer factors varied maximally 12-fold among soils and 35-fold among species when grown on the same soil. Single correlations between transfer factors and soil properties were found, but they varied widely with plant type and can hardly be used as a predictive tool because of the few soils used. The variation of ¹³⁷Cs concentrations in plants among soils was related to differences in soil solution ¹³⁷Cs and K concentrations, consistent with previous observations in hydroponics and pot trials. Absolute values of transfer factors could not be predicted based on a model validated for pot trials. The ¹³⁷Cs activity concentration in soil solution decreased significantly (11- to 250-fold) for most soils in the 1997–1999 period and is partly explained by decreasing K in soil solution. Transfer factors of lettuce showed both increasing and decreasing trends between 2 consecutive years depending on soil type. The trends could be explained by the variation in ¹³⁷Cs and K concentrations in soil solution. It is concluded that differences in ¹³⁷Cs transfer factors among soils and trends in transfer factors as a function of time can be explained from soil solution composition, as shown previously for pot trials, although absolute values of transfer factors could not be predicted.     

Initial Stages of Recovery of Soil Macrofauna Communities after Reduction of Emissions from a Copper Smelter

Analysis of natural recovery of communities after reduction of industrial emissions is important for gaining an insight into their stability. However, there is obvious deficit in observations on the course of this recovery; in particular, no data on direct comparisons of the state of communities before and after reduction of emissions are available for soil macroinvertebrates. We have studied the structure of soil macrofauna communities at the level of supraspecific taxa in southern taiga spruce-fir forests in the region exposed to emissions from the Middle Ural Copper Smelter (MUCS; Revda, Sverdlovsk oblast). The data over three periods—high, reduced, and almost terminated emissions (1990–1991, 2004, and 2014–2016, respectively)—have been compared to test the hypothesis that the communities do not recover rapidly. The results partly confirm this hypothesis. On the one hand, the response of pedobionts to pollution at a qualitative level has remained basically unchanged: in each of the three periods, their total abundance (and that of the majority of groups) decreased abruptly as the MUCS was approached, with dominance shifting from saprophages to phyto- and zoophages. On the other hand, signs of recovery have appeared during the last period: the abundance of pedobionts has increased, and pollution-sensitive groups (earthworms, enchytraeids, and mollusks) have approached closer to the MUCS. This is most likely explained by decrease in the toxicity of metals due to normalization of soil pH. Rapid recolonization of defaunated territory may be accounted for by the presence in it of microsites with more favorable conditions, compared to the surrounding area, which allow low-mobile forms to survive beyond the boundaries of their main distribution area.

     

铜绿山矿冶废弃地优势植物重金属的积累与迁移

通过野外调查和取样分析,研究了大冶铜绿山矿冶废弃地鸭跖草等5种优势植物对重金属的吸收累积与迁移特性,以期为矿区退化生态系统的植被恢复、重金属污染土壤的治理等提供依据。结果表明,鸭跖草等5种植物对重金属Cu、Pb、Zn、Cd、Cr都有程度不等的高量积累,尤其是铜元素,其最高积累量出现在海洲香薷根部,达到844.65 mg/kg,是一般植物Cu含量（5~25 mg/kg）的33.8~1689倍;而在同样条件下,As在5种植物体内的含量为018~098 mg/kg,远远低于As在一般植物中的含量（＜10 mg/kg）,这说明这些植物对As可能具有某种规避机制。从植物对重金属的吸收、富集和转运能力综合考虑,鸭跖草等5种植物都不太可能是重金属Cu等6种重金属的超累积植物。但是,它们对重金属所表现出的耐性无疑对矿冶废弃地的植被恢复过程有重要意义。     

Factors of variation in the number of adventive species in herbaceous communities of the Western Caucasus

The saturation of herbaceous communities with adventive species in the Northern Caucasus has been estimated using as an indicator the number of such species in 0.5-m² plots. Among factors accounting for variation in the test parameter, consideration has been given to the coverage of the herbaceous layer, the species richness of communities (in 0.5-m² plots), and the numbers of adventive and indigenous species (in 15-m² plots). The field data have been processes by methods of ordinary and multivariate regression analysis. The results show that variation in saturation with adventive species between small areas of herbaceous communities largely depends on the number of such species in larger areas, their species-holding capacity, and the level of completeness of communities.     

Environmental Implication of Intensive Farming Practices on North China Plain

Abstract

The current pressure on production resources of North China Plain, such as land and water to feed the growing population, necessitates the assessment of the sustainability of farming practices. This study focuses on the sustainability of farming practices related to groundwater and soil fertility management. The assessment is based on selected site-specific key indicators and their established threshold limits. The current farming practices in the study area are clearly unsustainable. Only about 6% of the surveyed farm households practice sustainable farming. The study stresses that farming practice, which is economically sustainable, should not be promoted at the cost of environment. Holistic strategies need to be developed and implemented that aim at balanced use of inputs, which satisfy both productivity and environmental concerns.     

“5·12”汶川地震极重灾区生态服务功能恢复总体评估

2008年"5·12"汶川特大地震,对生态系统造成巨大威胁。为了解汶川地震灾区生态恢复总体状况,以期为灾区中长期生态恢复跟踪监测、生态恢复措施的制定和调整提供决策支持,分别以2007年、2009年、2013年代表地震前、地震后以及恢复期3个时期,采用土壤侵蚀敏感性、林冠截留量、生境适宜性等指标,分别评估了汶川地震极重灾区10个县市水土保持功能、水源涵养功能、生物多样性保护功能的状况及变化动态。结果表明:研究区的水土保持功能、水源涵养功能,以及生物多样性保护功能在震后遭到了严重破坏。总体来说5a后,区域生态服务功能得到了一定程度的恢复,但未达到震前水平。在极重灾区10个县市中,地理上位于中南部的6个县市(汶川、都江堰、什邡、彭州、绵竹、安县)在地震中总体受损程度较大。6个县市处于中国西部泥石流、滑坡的活跃区,震后因降雨诱发滑坡泥石流,导致了龙门山、茶坪山局部区域的水土保持功能、水源涵养功能、生物多样性保护功能在恢复期进一步下降,甚至低于震后。其中汶川县草坡乡、银杏乡、耿达乡、卧龙镇、三江乡有较大范围的功能下降,另外,都江堰市、彭州市、什邡市、绵竹市、安县等也分别有较大面积的功能下降区。区域生态服务功能在未来10a内,有可能进一步恶化。灾后重建一定程度上改善了区域生态功能状况,加快了生态功能恢复进程。但是,也存在对生态服务功能的恢复与维持重视不足等问题。部分灾后重建项目的实施,甚至又导致局部地区出现生态服务功能的退化。建议(1)加强汶川地震极重灾区中长期生态恢复遥感及地面监测、评估,进行生态服务功能恢复效应评估;(2)加强干旱河谷、龙门山及茶坪山等重点区域的生态修复。     

Dynamics of the Mite Communities (Acari: Parasitiformes) in Nests of the Parus major

The dynamics of nest-dwelling mites from the nests of the great tit in the protected area of Kamchia Mountain in Northeastern Bulgaria was investigated. The mite fauna inhabiting the nests of great tit differs significantly in terms of the degree of infestation, species richness, abundance and structure of communities in study years. There are statistically significant differences in the specimens’ number between 2014 and the other years 2012, 2013 and 2015. The mite species such as Dermanyssus gallinae, Androlaelaps casalis and Ornithonyssus sylviarum demonstrated significant changes in the abundance over the study years. A relation between the abundance of a species and the species diversity in the nests was not registered. Comparison of the annual dynamics of mites in the nests of great tit and the nests of semi-collared flycatcher for the same period of time and for the same environment, showed similarities—a significant fluctuation in the abundance of mites over the years and differences—in the species richness. Regarding the structure of the communities, both similarities and differences were recorded.

     

Is there a density compensation effect in plant communities of anthropogenic habitats?

The occurrence of density compensation effect (DCE) has been estimated in areas occupied by synanthropic communities in the Western Caucasus. The density of dominant plant species has been estimated from their coverage, and that of subordinate species, from their frequency in 0.5-m² squares within 15 (16)-m² plots, using natural and seminatural communities as a reference standard. The factual material has been analyzed by the method of numerical experiments. The results show that the transformation of natural habitats into anthropogenic ones has led to a decrease in the species diversity of plant communities, but without causing a widespread occurrence of DCE. It is hypothesized that relatively high average values of species frequency in low-diversity synanthropic communities are more likely accounted for by random rather than compensatory processes.     

南京方山生态公园不同人工植被土壤动物群落结构时空变化

2009年3月~2010年4月采用干漏斗法和手捡法对南京方山生态公园针阔混交林、茶园、农田等3种典型人工植被生境的土壤动物群落结构及其季节变化进行初步调查。共采得土壤动物样本3 164个，27个类群隶属于5门12纲23目。结果表明：近孔寡毛目（Plesiopora）、弹尾纲（Collembola）和蜱螨目（Acarina）为常年优势类群；双翅目（Diptera）、同翅目（Homoptera）、膜翅目（Hymenoptera）、等足目（Isopoda）、后孔寡毛目（Opisthopora）和鞘翅目（Coleoptera）则为常年常见类群。土壤动物群落类群数和个体数量的季节消长规律分别是夏季>冬季>秋季>春季和夏季>秋季>冬季>春季。不同植被生境的土壤动物个体数量总数依次为茶园>混交林>农田；不同季节、不同人工植被类型以及不同季节和不同人工植被类型之间土壤动物群落的组成具有较大变化，不同类群之间个体数量差异显著。多样性分析表明，土壤动物类群多样性和均匀性指数在夏季时最高；茶园和混交林多样性指数和丰富度指数均高于农田。不同植被类型土壤动物垂直分布特征均表现为具有明显的表聚性，土壤动物的类群垂直分布差异明显，类群数随土层向下逐步减少     

水稻流入施肥法及流入肥料效果研究

进行了流入施肥法可行性，流入肥肥效及替代进口肥料试验。结果表明：流入施肥法与人工撒施，均能使肥料在田间分布均匀，流入施肥法比人工撒施增产3．4％，流入施肥法是可行的，日本流入肥和国产复合肥流入施肥田间3－4d后，在田间分布都较均匀，水稻追施分蘖肥和穗肥时水的温度都在30℃左右，两种肥料的溶解度比较大，易配成溶液，适合作流以施用，日本流入肥和中国复合肥对水稻的增产效果相差不大，可用国产复合肥料替代进口肥料；吸附试验表明，施肥5d后，流入肥料和其它氮素肥料中氮素的吸附率达82．5％－89．3％，流入施肥后5d内不要排水。流入施肥法适合土地平整，田块较大，灌溉条件好，人多地少或农业人口老龄化和血吸虫疫区等平原湖区稻田。     

金华市高山与平原无公害蔬菜生产的环境质量比较

对金华市高山、低山和平原无公害蔬菜基地的水、大气和土壤等环境质量的系统监测及对蔬菜生产现状的调查分析结果表明：三地环境优良，均适宜发展无公害蔬菜生产、高山区气候独特，昼夜温差大，蔬菜产量高，品质好，是发展经济途径之一，但山地环境脆弱，应加强环境保护。     

Analysis of trends in the formation of species richness of plant communities using syntaxonomy and ecological scales

On the basis of syntaxonomy of primary forests in the Southern Ural region, an analysis of trends in the formation of their species diversity has been performed in regard to heat supply, soil moisture, and general soil richness. The roles of environmental factors have been estimated using Landolt’s scales. The results have shown that communities of forest classes Querco-Fagetea, Brachypodio-Betuletea, and Vaccinio-Piceetea differ in the trends of changes in species richness along gradients of the above factors. In communities of all these classes, species richness depends primarily on heat supply, with soil richness being the second most important factor.