Adaptive significance of endomycorrhizas for herbaceous plants

It has been shown that endomycorrhizas are found in the majority of herbaceous plants, but their adaptive significance is ambiguous. As a rule, the degree of development of plants and their parts, cenotic status of the species, and species diversity of plant community manifest no definitely positive correlation with the level of mycorrhiza development on root systems. Interactions between the partners in most cases can be classified as indifferent or negative.     

On causes of gigantism in herbaceous plants

Landscape-geochemical features providing for manifestation of gigantism in herbaceous plants have been revealed in natural habitats in the south of Sakhalin and Kunashir islands. Tall herb assemblages have proved to be associated with geochemical landscapes characterized by reducing (gley or hydrogen sulfide) conditions and increased contents of petroleum hydrocarbons and some trace elements (total and movable forms). A hypothesis is put forward that gigantism in herbaceous plants is manifested in zones of active faults, which serve as a kind of conduits supplying endogenous heat, matter, and water to the root systems.     

Free radicals and chromosome aberrations in leaves of woody plants as a test system for the genotoxicity of the urban environment

A new method for estimating the genotoxicity of the urban environment is proposed. The method is based on the analysis of the lipid peroxidation (LPO) rate in leaves of woody plants. The mutagenicity of the urban environment was estimated using standard test systems, including plant root meristem (kidney beans germinated in water with suspended particles collected at different points along the Temernik River) and the Ames test (silt samples were tested). Sensitivities of elm, willow, and poplar leaf meristem cells to unidentified environmental mutagenes were compared. Frequencies of chromosome aberrations (CAs) in leaves of woody plants growing at different points along the Temernik River within the Rostov-on-Don city districts differed from those in the control zone. The frequency of CAs was found to correlate with the concentration of LPO products. This allows a biochemical estimation of the malonic dialdehyde (MDA) concentration in woody plants to be used as an express test for the mutagenicity of environmental factors. An advantage of the proposed test is the possibility of monitoring the level of unidentified environmental mutagens over many years, independently of its sporadic temporal variations.     

Chemical pollution: Transfer of chemical elements to the aboverground phytomass of herbaceous plants

Changes in the species composition and a decrease in species diversity and total plant biomass along the gradient of soil pollution with heavy metals have been shown. Data on the concentrations of chemical elements (Zn, Cu, Cd, Pb, Co, Ni, Mn, Cr, and Fe) in the aboveground organs of herbaceous plants and the biomass of each species make it possible to estimate the role of higher producers in the incorporation of chemical elements into biogenic cycles in background zones and under conditions of chemical pollution. Plants of the composite family (Asteraceae) play the main role in accumulation of chemical elements. The results obtained indicate that natural ecosystems have mechanisms limiting excessive accumulation of chemical elements into the aboveground plant biomass.     

Prevalence and intensity of mycorrhiza formation in herbaceous plants with different types of ecological strategies in the Middle Urals

The prevalence of arbuscular mycorrhizas and abundance of mycorrhizal fungi in the roots of herbaceous plants with different types of Grime-Ramenskii’s ecological strategies (competitors, ruderals, and stress tolerators) have been studied in the Middle Urals. The closest association with arbuscular fungi has been observed in species with a competitive strategy. Compared to them, stress-tolerant species are characterized by lower abundance of mycorrhizal fungal hyphae in the root system, while ruderal plants include a relatively large proportion of nonmycotrophic species showing no interaction with arbuscular fungi.     

Migration and biological effect of natural heavy radionuclides on plants

A complex radioecological study of technogenic landscapes of southern Yakutia showed that the main factor responsible for their contamination with uranium and radium is radionuclide dispersal by air with products of rock weathering. Coefficients of biological absorption by plants decrease with an increase in the contamination level, which is explained by the fact that strongly fixed forms of uranium and radium prevail in the contaminated areas. In addition, the root barrier plays an important role. Radiation load is mainly determined by background gamma-radiation. The contribution of internal irradiation accounted for by incorporated radionuclides does not exceed 16% and decreases with an increase in the level of soil contamination. Manchurian alder seeds produced under conditions of enhanced background radiation are more viable than those from the control area. It is shown that seed generations of plants growing under conditions of chronic irradiation are highly resistant to the radiation factor.     

Effect of interspecific competition on functional properties of plants in mountain-steppe communities of the Gobi

The isotope ratios δ¹³C and δ¹⁵N and the contents of nitrogen, carbon, and mineral substances have been studied in the leaves of Ephedra sinica, Allium polyrhizum, and Stipa glareosa plants growing separately or together under arid conditions of the Gobi (Mongolia). The contents of nitrogen, mineral substances, and δ¹⁵N have proved to decrease when these species grow together, providing evidence that they compete for environmental resources. The nitrogen content decreases to the greatest extent in E. sinica due to the low competitiveness of this species. The direction of change in δ¹³C in E. sinica is opposite to that in A. polyrhizum and S. glareosa. Differences in physiological mechanisms of adaptation to stress between these species provides a basis for attributing them to different functional groups and for predicting the result of their competition upon changes in climatic conditions.     

Monitoring of species diversity in the herbaceous layer of mixed forests on the central Russian plain

The diversity and structure of the herbaceous layer were monitored on a transect through mixed forests in the Malinskaya Biogeocenotic Station (Moscow oblast, Russia). The data obtained in 1987 and 1997 were compared. The parameters of species rank distribution, number of species, and entropy estimate of specie diversity only slightly changed during that period. The total coverage and abundance changed substantially; statistically significant changes in the contributions of species to the community were revealed. Estimates of changes in the community status of species belonging to different ecological groups on the Ellenberg scale served as the basis to demonstrate that soils were eutrophicated and the climate became more continental during the period of the study. Transformations of the vegetation structure were found to be equilibrium; and the community, to exhibit elements of self-organization.     

Effect of boric acid on the ability of plants to accumulate heavy metals

The effect of boric acid on the ability of herbaceous plants to absorb heavy metals has been studied. The results show that at a low content of boron in sandy loam soil (0.0007 mg/kg dry matter), boric acid at doses of 0.1–3.0 kg/ha stimulates the accumulation of certain heavy metals in the aboveground part of plants from the families Asteraceae (Taraxacum officinale Wigg.), Poaceae (Phleum pratense L.), and Fabaceae (Trifolium pratense L.). The most active accumulation is characteristic of dandelion (T. officinale) plants, which allows this species to be considered promising for phytoremediation of soils with a low boron content given that boron is applied at specified doses.     

Emergency management of reservoirs and water treatment plants in typhoon season: a case study of Ningbo

ABSTRACT

Coastal cities represented by Ningbo are directly or indirectly affected by typhoons each year. By analyzing the past three typical typhoons landing in Ningbo from 2013 to 2016, it was found that before and after the typhoon transit, reservoir and water treatment plant would be made by the destructive impact, including the increasing water level, water volume in a short time, and the deteriorating water quality. Among those, the water quality caused by typhoons increased the water treatment process load, the amount of water purification agents increased significantly, and the emergency response put a great pressure on the inventory of water plants. Based on the statistics and analysis of the basic parameters of the reservoir and water treatment plant during the typhoon season, the emergency management of the typhoon was divided into three situations, namely, pre-typhoon, typhoon period and post-typhoon. Thus, it is effective for the relevant practitioners of the reservoir and water plant to ensure the safe water supply during typhoon season.     

The distribution of Cs, K, Rb and Cs in plants in a Sphagnum-dominated peatland in eastern central Sweden

We record the distribution of ¹³⁷Cs, K, Rb and Cs within individual Sphagnum plants (down to 20 cm depth) as well as ¹³⁷Cs in vascular plants growing on a peatland in eastern central Sweden. In Calluna vulgaris¹³⁷Cs was mainly located within the green parts, whereas Andromeda polifolia, Eriophorum vaginatum and Vaccinium oxycoccos showed higher ¹³⁷Cs activity in roots. Carex rostrata and Menyanthes trifoliata showed variable distribution of ¹³⁷Cs within the plants. The patterns of ¹³⁷Cs activity concentration distribution as well as K, Rb and Cs concentrations within individual Sphagnum plants were rather similar and were usually highest in the capitula and/or in the subapical segments and lowest in the lower dead segments, which suggests continuous relocation of those elements to the actively growing apical part. The ¹³⁷Cs and K showed relatively weak correlations, especially in capitula and living green segments (0-10 cm) of the plant (r = 0.50). The strongest correlations were revealed between ¹³⁷Cs and Rb (r = 0.89), and between ¹³⁷Cs and stable Cs (r = 0.84). This suggests similarities between ¹³⁷Cs and Rb in uptake and relocation within the Sphagnum, but that ¹³⁷Cs differs from K.     

Development of a dynamic transfer model of (14)C from the atmosphere to rice plants

A dynamic compartment model was investigated to describe ¹⁴C accumulation in rice plants exposed to atmospheric ¹⁴C with temporally changing concentrations. In the model, rice plants were regarded to consist of three compartments: the ear and the mobile and immobile carbon pools of the shoot. Photosynthetically fixed carbon moves into the ear and the mobile carbon pool, and these two compartments release a part of this carbon into the atmosphere by respiration. Carbon accumulated in the mobile carbon pool is redistributed to the ear, while carbon transferred into the immobile carbon pool from the mobile one is accumulated there until harvest. The model was examined by cultivation experiments using the stable isotope, ¹³C, in which the ratios of carbon photosynthetically fixed at nine times during plant growth to the total carbon at the time of harvest were determined. The model estimates of the ratios were in relatively good agreement with the experimental observations, which implies that the newly developed compartment model is applicable to estimate properly the radiation dose to the neighboring population due to an accidental release of ¹⁴C from nuclear facilities.     

Concentration of caesium-137, cobalt-60 and potassium-40 in some wild and edible plants around the nuclear power plant in Bulgaria

The activities of 137Cs, 60Co and 40K were determined in samples of wild (Taraxacum officinale, Plantago lanceolata and Populus nigra 'Italica') and edible (vegetable, corn, fruit) plants as well as soil collected from the 30 km safety zone of the Bulgarian NPP "Kozloduy" and comparisons with earlier measurements and analyses of samples from other regions and with literature values were performed. The derived transfer factors for 137Cs and 40K from soil to plants ranged between 0.002 and 0.009 for 137Cs, and between 0.09 and 0.35 for 40K. The individual effective dose (calculated from the present results and data on the activity of other foodstuffs and from information about dietary habits) comprises 4.5% of the annual dose limit.     

Iodine-129 in the environment of a nuclear fuel reprocessing plant: II. Iodine-129 and iodine-127 contents of soils,forage plants and deer thyroids

Concentrations of ¹²⁹I and ¹²⁷I in soils, forage plants and deer thyroids collected in the environment of the small Karlsruhe nuclear fuel reprocessing plant (WAK) were determined by neutron activation analysis. Levels of ¹²⁹I in all samples were found to be elevated by several orders of magnitude above current average biospheric background values. In particular, deer thyroids were found to have very high ¹²⁹I levels and corresponding high ¹²⁹I/¹²⁷I ratios.Using all the analytical data for ¹²⁹I and ¹²⁷I concentrations in plants it seems probable that there is a correlation between the ¹²⁹I and the natural ¹²⁷I concentrations in plants.     

Cs,Co and K uptake by lettuce plants in two distributions of soil contamination

¹³⁷Cs and ⁶⁰Co, two of the radionuclides more representative of discharges from nuclear facilities, are of interest for radiological protections because of their great mobility in biosphere and affinity with biological systems. The aim of the present work is the investigation of the possible influence of the vertical distribution of ¹³⁷Cs and ⁶⁰Co in soil upon their uptake by lettuce as function of plant's growth. An experiment ad hoc has been carried out in field conditions. The results show that (i) the transfer of ¹³⁷Cs and ⁶⁰Co from soil to lettuce is independent by their distribution in soil, (ii) the soil–plant transfer factors of ¹³⁷Cs and ⁶⁰Co show a similar trend vs. growth stage, (iii) the ⁴⁰K transfer factor trend is different from those of anthropogenic radionuclides, and (iv) ¹³⁷Cs and ⁶⁰Co specific activities are about 1 Bq/kg, in the mature vegetable with soil activity from 9 to 21 kBq/m².     

中国适应气候变化技术分类研究

近百年来,全球气候变化呈现出变暖的主要特征,气候变化所带来的影响日趋严重,其所造成的经济损失在全球范围内显著上升。适应气候变化是现阶段应对气候变化行动的重要方面,适应气候变化的技术分类研究是清晰认识适应气候变化的基础,是实现适应技术集成并构建合理有效的适应技术体系的手段。本文通过对适应气候变化技术分类问题的分析,提出了不同的适应气候变化技术分类方式,气候变化影响过程、区域、领域、适应目的、适应机制、适应时效、适应程度、适应层面等,针对气候变化及其影响梳理了中国不同区域与不同领域的适应气候变化技术清单。从气候变化影响过程来看,可以将适应气候变化技术分为气候变化影响发生前、发生过程中、发生后三类;从区域与领域气候变化影响来看,可以将适应气候变化技术分为八大区域与七大领域;本研究重点针对八大区域与农业、水资源、生态环境三大领域进行了分析。通过研究发现,现阶段适应气候变化技术分类研究尚存在一些问题,适应气候变化技术分类的导向不明确,造成对适应技术认识的不清晰;适应气候变化技术的分类往往与分层混淆在一起,导致人们对适应气候变化技术的认识和理解出现偏差;适应气候变化技术分类对适应行动的指导作用存在不足。综合来看,对适应气候变化技术进行精细分类,可以为适应气候变化技术的筛选、集成、效益评估奠定基础,推进适应气候变化行动高效有序开展,为适应气候变化技术体系构建提供支撑。     

减排与适应协同发展研究:以广东为例

减排和适应是全球应对气候变化的两大任务.发展中国家对气候变化不利影响的承受能力特别脆弱,同时面临着减排和发展任务,在资金有限的情况下,促使适应和减排联合行动能发挥协同效应,降低减排和适应成本,取得增量社会效益.适应分为增量型和发展型活动.在国家规定的减排和适应重点活动领域中,挑选出能源领域减排与增量型适应活动进行协同效应分析,至少有4个强协同效应和10个弱协同效应发生.以广东省为例,增量型适应活动和能源领域减排措施的协同效应主要体现在以下3个方面:工程性适应项目建设与低碳能源生产、消费的关联效应,提高能效有利于工程性适应项目的建设;海岸带适应措施增加碳汇和节约减排成本;城市绿化建设通过有目的的公共设施建设,缓解气候灾害对人们生活的直接影响,节约适应成本,同时增加碳汇和节约减排成本.减排和适应行动的联动机制是未来发展中国家研究的重点.     

Sex Structure of Scotch Pine Populations in the Dry Steppe

it has been determined that the sex structure of the population is of great importance for pine adaptation to extreme environmental conditions. As environmental conditions deteriorate, differentiation of populations with respect to sex becomes more apparent, the proportion of trees of mixed type decreases, and the number of male trees increases. A tendency toward correlation between tree habitus, needle and shoot sizes, and the sex structure of population is noted. The prevalence of male trees in populations exposed to increasing stress reflects the rearrangement of such populations aimed at the more efficient use of natural resources.