大庆西城区油田林地绿化和土壤状况分析

植物生长中,土壤属于基础物质,既关乎植物长势,又与植物栽种成活率有直接关联.土壤盐碱化问题的存在,会导致植物产生生理干旱、植物组织受损、营养吸收或转化被抑制等问题.为营造适于绿色植物生长的优良土壤环境,选取大庆西城区油田管辖区内问题突出的60块林地作为研究对象,结合土壤情况,从物理改良、化学改良2个方面分析了土壤改良方...     

基于设施菜地土壤次生盐渍化改良的夏秋蒲公英栽培技术

蒲公英是耐盐植物,经试验证明,蒲公英与设施现有蔬菜进行轮作后的土壤平均含盐量较原始土壤降低31.98％,可有效改善设施土壤的次生盐渍化问题.从产地环境、生产准备、播种、田间管理、病虫害防治、采收等方面系统介绍了夏秋设施菜地蒲公英栽培技术,以供设施蔬菜种植户借鉴,为设施菜地土壤次生盐溃化改良提供参考.     

菌根对植物抗盐碱性的影响机理研究

综合近年来国内外在菌根植物抗盐碱方面研究成果,从植物生理的角度总结和论述了在盐胁迫下菌根提高寄主抗盐碱性的机理,阐述了菌根在提高寄主抗性的同时对盐碱地土壤的改良作用,为用生物方法改良盐碱地提供参考。     

盐碱地改良技术在德州市园林绿化施工中的应用

盐碱地土壤盐度高、地下水位高、植物成活率低,是制约园林事业发展的“瓶颈”,如何做好盐碱地的改良治理成为一项重要议题。基于此,阐述了盐碱地的危害和盐碱地改良技术,并以德州市为例,从渗管排盐、大穴客土、客土抬高地面、合理选择植物、科学栽植植物5个方面,论述了盐碱地改良技术在园林绿化施工中的应用,旨在拓展城市绿色空间,加快国家生态园林城市创建步伐。     

城市园林绿化土壤改良措施

园林绿化是现代城市的重要标志,是改善生态环境的重要途径。土壤是城市生态系统的重要组成部分,在调节城市生态环境中发挥着重要作用。土壤质量直接决定了植物在绿地上的生长和绿地的生态景观效应,土壤质量越来越受到城市化发展的污染,因此,土壤改良势在必行。本文从土壤结构和盐碱地改良2个方面,探讨了改良土壤的技术措施。     

利用热解炭化污水厂污泥对废弃盐池土改良绿化研究

为探寻污泥热解炭后形成生物炭资源的利用,通过对渤海新区废弃盐池土改良后的土壤理化性质及地上植物成活率进行统计研究,分析在改良后3年中土壤含盐量、p H值、有机质等变化规律。结果表明:(1)土壤含盐量、p H值、容重等随着改良时间延长呈显著下降。(2)土壤有机质随着改良时间延长而得到提升。(3)地上植物成活率平均90%以上。     

糠醛渣替代硫磺调节土壤pH值及其对蓝莓生长发育的影响

本试验利用糠醛渣为主要材料对蓝莓栽培的土壤进行改良处理,研究了调节土壤pH值对蓝莓生长发育的影响.结果表明,糠醛渣能很好地降低土壤pH值,使得蓝莓栽培的土壤从pH值6.8降低到4.5.改土处理能使2年生和6年生蓝莓的移栽成活率分别达到95.8％和96.0％；同时使6年生蓝莓的花败育率低于4％的水平,显著提高单产.糠醛渣应用到农业生产中将产生较好环境效益和经济效益.     

四种野生植物对天津盐碱地土壤改良效果的研究

选择天津市蓟县、西青和大港的荒地土壤和耐盐碱的4种野生植物(猪毛菜、草木樨、艾蒿和补血草)进行盆栽试验.植株生长5个月后,测定土壤的各项理化指标.结果显示:4种植物均大大降低土壤总盐量,猪毛菜可以不同程度地降低土壤中CO23-、SO24-和有效磷;补血草对降低土壤SO24-和水溶性钙较有效;草木樨和艾篙可以明显增加土壤有效氮含量.综合分析表明,这4种野生耐盐植物对改良盐碱地土壤效果明显.     

江苏滨海地区盐碱地现状及改良措施

根据江苏滨海地区盐碱地土壤生态现状,分析并阐述用于盐碱地改良的物理、化学、生物等技术,按生态位引种耐盐植物,综合治理改良滨海盐碱土,旨为建设江苏滨海地区可持续的盐碱地综合治理规划。     

城市园林绿化工程施工中盐碱地的土壤改良

盐碱地是指土壤中的盐碱成分含量过高,高浓度的盐碱大大降低了园林植物的存活率,对上海地区而言,重点是要对土壤盐碱化进行改良。本文就这一问题展开了重要探讨,认为通过化学、生物、物理3种方法能有效改良盐碱地土壤,使其对植物的危害力度降低。     

Agricultural soil redistribution and landscape complexity

A number of hypotheses and conceptual models, particularly those emphasizing nonlinear dynamics and self-organization, postulate increases or decreases in complexity in the evolution of drainage basins, topography, soils, ecosystems, and other earth surface systems. Accordingly, it is important to determine under what circumstances and at what scales either trend might occur. This paper is concerned with changes in soil landscape complexity due to redistribution of sediment by fluvial, aeolian, and tillage processes at historical time scales in an agricultural field system near Grifton, North Carolina. Soil mapping and soil stratigraphic investigations were used to identify and map soil changes associated with erosion and deposition by water, wind, and tillage; reconstruct the pre-agricultural soil pattern; and identify transformations between soil types. The Kolmogorov entropy of the pre- and post- agricultural landscapes was then compared. The soil transformations associated with erosion and deposition created four distinct new soils and made possible new transformations among soil series, increasing the number of soil types from seven to 11 and the number of possible transformations from 14 to 22. However, the entropy and complexity of the soil landscape decreased, with associated increases in information and redundancy. The mass redistributions created a lower-entropy landscape by concentrating particular soils and soil transformations in specific landscape settings. This result is contrary to studies showing a trend toward increasing pedological complexity at comparable spatial scales, but over much longer time scales. These results point to the importance of temporal scale, and to the fact that environmental complexity is influenced by factors other than the number of different landscape units present.     

Hierarchical relationships between landscape structure and temperature in a managed forest landscape

Management may influence abiotic environments differently across time and spatial scale, greatly influencing perceptions of fragmentation of the landscape. It is vital to consider a priori the spatial scales that are most relevant to an investigation, and to reflect on the influence that scale may have on conclusions. While the importance of scale in understanding ecological patterns and processes has been widely recognized, few researchers have investigated how the relationships between pattern and process change across spatial and temporal scales. We used wavelet analysis to examine the multiscale structure of surface and soil temperature, measured every 5 m across a 3820 m transect within a national forest in northern Wisconsin. Temperature functioned as an indicator – or end product – of processes associated with energy budget dynamics, such as radiative inputs, evapotranspiration and convective losses across the landscape. We hoped to determine whether functional relationships between landscape structure and temperature could be generalized, by examining patterns and relationships at multiple spatial scales and time periods during the day. The pattern of temperature varied between surface and soil temperature and among daily time periods. Wavelet variances indicated that no single scale dominated the pattern in temperature at any time, though values were highest at finest scales and at midday. Using general linear models, we explained 38% to 60% of the variation in temperature along the transect. Broad categorical variables describing the vegetation patch in which a point was located and the closest vegetation patch of a different type (landscape context) were important in models of both surface and soil temperature across time periods. Variables associated with slope and microtopography were more commonly incorporated into models explaining variation in soil temperature, whereas variables associated with vegetation or ground cover explained more variation in surface temperature. We examined correlations between wavelet transforms of temperature and vegetation (i.e., structural) pattern to determine whether these associations occurred at predictable scales or were consistent across time. Correlations between transforms characteristically had two peaks; one at finer scales of 100 to 150 m and one at broader scales of ^>300 m. These scales differed among times of day and between surface and soil temperatures. Our results indicate that temperature structure is distinct from vegetation structure and is spatially and temporally dynamic. There did not appear to be any single scale at which it was more relevant to study temperature or this pattern-process relationship, although the strongest relationships between vegetation structure and temperature occurred within a predictable range of scales. Forest managers and conservation biologists must recognize the dynamic relationship between temperature and structure across landscapes and incorporate the landscape elements created by temperature-structure interactions into management decisions.     

Spatial variability in soil nitrogen dynamics after prescribed burning in Ohio mixed-oak forests

This study describes the results of the application of a single dormant season prescribed fire to two southern Ohio forest sites for the purposes of restoring the ecosystem functional properties that existed in these sites prior to major human intervention (clearcutting, fire suppression, and atmospheric deposition). Each forest site was composed of three contiguous watershed units, two of which were burned in April of 1996. The forest sites differed in soil pH and available litter mass prior to the fires, and in both sites pH and available inorganic N varied among landscape positions such that inorganic C increased with increasing longterm soil moisture potential (measured as the GIS-derived Integrated Moisture Index [IMI] developed for this region). The fire temperatures at 10 cm above the litter surface were generally 150–300°C, and 29–80% of the litter was consumed, depending on site and landscape position. Soil solution total inorganic N (TIN) present one month after the fires did not differ significantly from that present prior to the fires in either burned or unburned watersheds, but was consistently greater in mesic landscape positions than in more xeric ones. N mineralization potential and organic C content varied both among fires and landscape positions. At the site which burned at higher intensity, soil N mineralization and TIN were both decreased by fire. At the less intensely burned site, fire resulted in increased TIN in the soils from the more xeric landscape position, and greater soil organic C in soils from the intermediate soil moisture areas. Path analysis produced models for fire-induced changes in C and N dynamics capable of explaining 26–69% of the observed variation using combinations of landscape and fire behavior. Losses of N to volatilization from these single fires were generally < 1 kg N/ha, and thus could not be expected to ameliorate the effects of atmospheric N deposition in these sites.     

A dynamic landscape simulation model for the alkaline grasslands on Songnen Plain in northeast China

a dynamic model was developed to simulate the variation of spatial species distribution patterns of the meadow steppe grasslands on Songnen Plain in northeast China. Simulation was performed to study the interaction between soil alkalization and vegetation development with special consideration given to spatial processes such as horizontal species migration and horizontal diffusion of soil alkali. The coverage of five species,Calamagrostis epigeios, Aneurolipidium chinense, Puccinellia tenuiflora, Aeluropus littoralis andSuaeda corniculata, and soil alkali were selected as 6 state variables. A positive feedback mechanism embedded in the model was that when the total plant coverage is large enough, the soil undergoes de-alkalization, which in turn helps improve further the plant growth condition. The de-alkalization is due to the improved soil physical properties indicated by a large amount of soil non-capillary pores coexisting with a large amount of below-group root biomass which allows alkaline solutes to leach from surface soil to underground water by means of precipitation. On the other hand, when the plant coverage is too small, soil alkalization takes place due to the deterioration of soil physical properties indicated by a small amount of plant root biomass and a large amount of capillary pores which enables evapotranspiration to bring up alkaline solutes to the surface soil. The alkalization of surface soil further hinders plant growth. The model was implemented using a software tool, SPAMOD, developed at Institute of Botany, the Chinese Academy of Sciences. The simulation results showed that the model was in very close agreement with five year field observations on a one-hectare fenced alkaline grassland, implying that the modeling approach used in this research is very appropriate for grassland landscape studies; that the spatial processes reflected as horizontal species migration and horizontal diffusion of soil alkali are very important for the recovery ofA. chinense, the major grazed species with rhizoma as its main reproduction mechanism; and that the vanishing rate ofS. corniculata, an indicator of serious soil alkalization, is very sensitive to the variation in the soil physical properties.     

The long-term influence of past land use on the Walker Branch forest

Forest structure and composition influence patterns of insect outbreaks and can be explained on the Walker Branch watershed by past land use (timber harvest and agriculture), soils, aspect, and slope. In particular, pine bark beetles caused large losses of pine on sites that had been used for agriculture, on Fullerton silt loam soils, and on north-to-northeast and east-to-southeast exposures. Hickory bark beetles had a high impact on hickory biomass on Bodine soil areas that were forested in 1935 and sloped greater than 11%. Thus, prior land use can have an indirect effect on future disturbances.Because forest disturbances can affect nutrient distribution, land use can also indirectly affect nutrient availability. For example, locations of hickory bark beetle outbreaks experience a large flux of calcium from dead wood to soil because hickory accumulates large amounts of calcium in woody tissue. The research demonstrates a link between past land use, insect outbreaks, and calcium cycling.     

The land unit — A fundamental concept in landscape ecology,and its applications

The land unit, as an expression of landscape as a system, is a fundamental concept in landscape ecology. It is an ecologically homogeneous tract of land at the scale at issue. It provides a basis for studying topologic as well as chorologic landscape ecology relationships. A land unit survey aims at mapping such land units. This is done by simultaneously using characteristics of the most obvious (mappable) land attributes: land-form, soil and vegetation (including human alteration of these three). The land unit is the basis of the map legend but may be expressed via these three land attributes. The more dynamic land attributes, such as certain animal populations and water fluxes, are less suitable as diagnostic criteria, but often link units by characteristic information/energy fluxes.The land unit survey is related to a further development of the widely accepted physiographic soil survey see Edelman (1950). Important aspects include: by means of a systems approach, the various land data can be integrated more appropriately; geomorphology, vegetation and soil science support each other during all stages (photo-interpretation, field survey, data processing, final classification); the time and costs are considerably less compared with the execution of separate surveys; the result is directly suitable as a basis for land evaluation; the results can be expressed in separate soil, vegetation, land use and landform maps, or even single value maps.A land unit survey is therefore: a method for efficient survey of land attributes, such as soils, vegetation, landform, expressed in either separate or combined maps; a means of stimulating integration among separate land attribute sciences; an efficient basis for land evaluation. For multidisciplinary projects with applied ecologic aims (e.g., land management), it is therefore the most appropriate survey approach.Within the land unit approach there is considerable freedom in the way in which the various land attribute data are integrated. It is essential, however, that: during the photo-interpretation stage, the contributions of the various specialists are brought together to prepare a preliminary (land unit) photo-interpretation map; the fieldwork data are collected at exactly the same sample point, preferably by a team of specialists in which soil, vegetation and geomorphology are represented; the final map is prepared in close cooperation of all contributing disciplines, based on photo-interpretation and field data; the final map approach may vary from one fully-integrated land unit map to various monothematic maps.     

Spatial components of biotic diversity in landscapes of Georgia,USA

Traditional measures of species diversity and spatially-explicit measures of landscape diversity (derived from Romme 1982) are used to compare biotic diversity in six landscapes across Georgia, USA; two each from the Appalachian Highlands, Piedmont, and Coastal Plain. Species richness and evenness of plots generally increased from the Coastal Plain to the Appalachian Highlands. Community richness, landscape contrast, and landscape heterogeneity increased from the Appalachian Highlands to the Coastal Plain, opposite the gradient of topographic complexity. Coastal Plain landscapes possessed greater contrast and heterogeneity than landscapes in the other two physiographic provinces. This high level of landscape diversity is interpreted as a response to two factors: the increased role of human activity in shaping landscape structure, and the increased range of soil moisture regimes encountered in the sand-rich substrates of the Coastal Plain (from permanently flooded hydric communities to well drained xeric uplands only a few meters higher in elevation).     

Bush cover and range condition assessments in relation to landscape and grazing in southern Ethiopia

Progressive growth of bush cover in dry savannahs is responsible for declines in range conditions. In southern Ethiopia, the Booran pastoralists assisted our understanding of spatial patterns of bush cover and range conditions in 54 landscape patch types grouped into six landscape units within an area of 30000 km². The size of landscape patches sampled was 625 m². We assessed the relationships between bush cover, grass cover and bare soil and grazing pressure and soil erosion and changes in range condition. Externally, political conflicts and internally, break down of land use, and official bans on the use of fire promoted bush cover and the decline in range conditions. Bush cover was negatively correlated with grass cover, and positively correlated with bare soil. Grass cover was negatively correlated with bare soil and grazing pressure in most landscape patch types. Grazing pressure was not significantly correlated with bush cover or bare soil, while soil erosion was directly related to bare soil. Soil erosion was absent in 64% of the landscape patch types, and seemingly not a threat to the rangelands. The relationship between bush cover, grass cover, bare soil and soil erosion is complex and related to climate, landscape geology, and patterns of land use. Main threats to range conditions are bush climax, loss of grass cover and unpalatable forbs. Currently, >70% of the landscape patch types are in poor to fair range conditions. Decline in range conditions, unless reversed, will jeopardise the pastoral production system in southern Ethiopia.     

昆虫生态学的研究进展

从昆虫分子生态学、昆虫化学生态学、昆虫行为生态学、昆虫信息生态学以及昆虫种群生态学这五个方面对近年来的研究情况进行综述,以期为昆虫生态学的发展、害虫的综合治理提供研究方向。     

Growth of rose roots and shoots is highly sensitive to anaerobic or hypoxic regions of container substrates

Commercial greenhouse cut rose plants commonly have shallow root systems, even in well-drained substrates. We studied rose plant responses to a wide range of soil air-filled porosity values to determine tolerance to low soil aeration. ‘Kardinal’ rose plants on ‘Natal Briar’ rootstock were grown for 11 weeks in containers holding 2.5 l of Yolo loam soil. The soil had been treated with a polyacrylamide soil conditioner to stabilize aggregates after they had been separated into three size fractions: coarse (1–2 mm), medium (0.1–1 mm), and fine (<0.1 mm). Plants were irrigated frequently to keep the soil at container capacity. Total new root growth was greatest in the medium and coarse soil fractions, which had average air-filled porosities of 7.6% and 15.9%, respectively. The fine soil fraction, which had an average air-filled porosity of 1.3%, had almost no root growth. In all soil fractions, roots were absent or scarce in regions of soil that were anaerobic or hypoxic. Highest root length densities occurred at air-filled porosity values of 12–17%, and no new roots grew at air-filled porosity values below 3%. Shoot yields were lower for plants in the substrate with low air-filled porosity, and their leaves had lower stomatal conductance, chlorophyll content, mid-day water potential, and macronutrient concentrations. Frequent irrigation that precludes aeration of the lower regions of the substrate profile will result in shallow root systems and could lead to decreased yields.