诸城市土地整治规划的区域统筹与协调

随着诸城市土地整治工作的不断推进,其区域综合性特点越来越明显,面临的环境也更为复杂,统筹和协调的重要性也愈加突出。统筹诸城市区域城乡土地整治,需要按照城乡一体化发展的要求,全域规划,全域整治;统筹诸城市区域土地整治需要按照不同区域土地利用状况,明确整治方向和重点,实行差别化整治。同时,要加强诸城市规划间协调,提高土地整治综合效益。     

A cross-system analysis of sedimentary organic carbon in the mangrove ecosystems of Xuan Thuy National Park, Vietnam

A cross-system analysis of bulk sediment composition, total organic carbon (TOC), atomic C/N ratio, and carbon isotope composition (δ¹³C) in 82 surface sediment samples from natural and planted mangrove forests, bank and bottom of tidal creeks, tidal flat, and the subtidal habitat was conducted to examine the roles of mangroves in sedimentation and organic carbon (OC) accumulation processes, and to characterize sources of sedimentary OC of the mangrove ecosystem of Xuan Thuy National Park, Vietnam. Sediment grain sizes varied widely from 5.4 to 170.2 μm (mean 71.5 μm), with the fine sediment grain size fraction (< 63 μm) ranging from 11 to 99.3% (mean 72.5%). Bulk sediment composition suggested that mangroves play an important role in trapping fine sediments from river outflows and tidal water by the mechanisms of tidal current attenuation by vegetation and the ability of fine roots to bind sediments. The TOC content ranged from 0.08 to 2.18% (mean 0.78%), and was higher within mangrove forests compared to those of banks and bottoms of tidal creeks, tidal flat, and subtidal sediments. The sedimentary δ¹³C ranged from − 27.7 to − 20.4‰ (mean − 24.1‰), and mirrored the trend observed in TOC variation. The TOC and δ¹³C relationship showed that the factors of microbial remineralization and OC sources controlled the TOC pool of mangrove sediments. The comparison of δ¹³C and C/N ratio of sedimentary OC with those of mangrove and marine phytoplankton sources indicated that the sedimentary OC within mangrove forests and the subtidal habitat was mainly composed of mangrove and marine phytoplankton sources, respectively. The application of a simple mixing model showed that the mangrove contribution to sedimentary OC decreased as follows: natural mangrove forest > planted mangrove forest > tidal flat > creek bank > creek bottom > subtidal habitat.     

Pattern and pathways for mercury lifespan bioaccumulation in Carcinus maenas

Carcinus maenas is an important and exploited natural resource in temperate estuaries, being consumed by local populations and also used as fish bait. Through bioaccumulation and bioamplification processes occurring in polluted estuarine ecosystems, this species may directly or indirectly represent a major pathway for Human contamination. No information is available on the overall lifespan bioaccumulation pattern of mercury for this species, which would be an invaluable tool for assessing the risks associated with C. maenas harvest in contaminated areas. Taking that in mind, the main objectives of this work were to clarify the lifespan bioaccumulation pattern of mercury for this species. A consistent lifespan accumulation pattern was found for this species, both for total and organic mercury, and coherent differences were found between genders, suggesting different physiological responses to contamination. From our results two scenarios emerge: (a) for low mercury contamination areas where the diet is the major pathway for metal uptake, with higher levels in muscle and hepatopancreas (twice as high as in gills) and higher organic mercury fractions (as high as 80-90% in muscle), crabs bioaccumulate with age and (b) on high contaminated areas, environmental exposure is predominant, with higher levels found in gills (reaching 0.8 mg kg(-1)), lower organic fractions and no mercury increment with age. Detoxification strategies, dietary differences and species mobility may account for these two accumulation patterns.     

海草床食物链有机碳传递过程的研究进展

海草床是重要的近海生态系统,生产力极高,可为海洋动物提供良好的栖息地和丰富的有机碳食源;人类活动引起近岸海域的富营养化,可能会改变海草床有机碳源组成和性质,进而影响植食动物和次级消费者的摄食过程及其食物链能量传递效率,从而影响海草床的生物资源产出功能。归纳总结了国内外海草床食物链碳传递过程各方面的研究进展,主要包括:①海草床有机碳源组成及食源贡献;②海草床初级消费者对有机碳源的摄食;③海草床食物网营养级结构及其能量传递;④富营养化对海草床有机碳源组分结构及其成分的影响;⑤海草床食物链能量传递效率对富营养化的响应。在此基础上,提出了未来的研究重点:①联合运用总有机物的稳定同位素比值法、脂肪酸标志法和特定化合物稳定同位素分析方法,加强定量研究海草床各有机碳源的贡献、食物网营养结构图谱、关键碳流途径及其季节性变化规律;探究关键消费者成体和幼体的有机碳源差异,弄清生长阶段的食性转化过程。②结合野外观测、原位围隔实验和室内模拟实验,深入探讨富营养化对海草床有机碳源组成(海草与附生藻类等)及其化学成分(营养质量和次生化合物)的影响,海草等初级生产者成分变化对植食动物和次级消费者摄食过程的影响,以及牧食食物链和碎屑食物链的组成和碳传递效率等的响应机制。     

Research Progress of the Transfer Process of Organic Carbon Through Food Chain in Seagrass Bed

Seagrass beds are highly productive coastal ecosystems, which provide good nursery habitat and abundant Organic Carbon Sources (OCS) as food for marine animals. Human activities have led to widespread eutrophication in coastal areas. Eutrophication may alter the composition and properties of OCS, thereby affecting the feeding process of herbivores and secondary consumer, and energy transfer efficiency in food chain. This may affect the production function of biological resource in seagrass beds. Based on the summary of the foreign and domestic researches, primary achievements were systematically reviewed in this paper in five aspects: the composition of OCS and their contribution, feeding process of herbivore, food web structure and energy transfer efficiency, and their responses to eutrophication. Future researches that should be emphasized were also prospected. With the combined application of stable isotope analysis for bulks and tissues, fatty acid biomarkers and compound-specific stable isotope analysis, the quantitative study of the contribution of OCS, food web structure, key carbon flow pathway and their seasonal change patterns should be enhanced. Meanwhile, the differences of OCS between larval and adult stages of key consumers will need to be further examined to clarify the transformation of their feeding habits. Through field investigation, in-situ mesocosm and laboratory simulation experiments, the effects of nutrient increase on the structure (seagrass and epiphyte, etc.) and chemical composition (nutritional quality and secondary compounds, etc.) of OCS, the response of feeding process of herbivore and secondary consumer to the alteration of chemical compounds in primary producers, and the response mechanism of carbon transfer efficiency of the grazing food chain and detritus food chain need to be further studied.     

Nematode response to metal, PAHs and organic enrichment in tourist marinas of the mediterranean sea

The structure of nematode assemblages was investigated in the sediments of two different tourist marinas in the Mediterranean Sea and related to pollution variables. Nematode densities and generic compositions were determined, as were concentrations of heavy metals, PAHs and organic matter. Results showed different assemblages at the two marinas, with a dominance of the genera Paralongicyatholaimus and Daptonema. Significant correlations between nematodes and concentrations of environmental contaminants were found. In particular, Paralongicyatholaimus showed a significant negative correlation with Cu concentrations and was almost absent at the stations where higher Cu concentrations were found. The presence of sensitive/tolerant nematode genera represents a promising tool to identify areas subjected to a higher level of disturbance and to define the correct environmental management strategy for harbors.     

Methodological framework to select plant species for controlling rill and gully erosion: application to a Mediterranean ecosystem

Many studies attribute the effects of vegetation in reducing soil erosion rates to the effects of the above‐ground biomass. The effects of roots on topsoil resistance against concentrated flow erosion are much less studied. However, in a Mediterranean context, where the above‐ground biomass can temporarily disappear because of fire, drought or overgrazing, and when concentrated flow erosion occurs, roots can play an important role in controlling soil erosion rates. Unfortunately, information on Mediterranean plant characteristics, especially root characteristics, growing on semi‐natural lands, and knowledge of their suitability for gully erosion control is often lacking. A methodological framework to evaluate plant traits for this purpose is absent as well. This paper presents a methodology to assess the suitability of plants for rill and gully erosion control and its application to 25 plant species, representative for a semi‐arid Mediterranean landscape in southeast Spain. In this analysis determination of suitable plants for controlling concentrated flow erosion is based on a multi‐criteria analysis. First, four main criteria were determined, i.e. (1) the potential of plants to prevent incision by concentrated flow erosion, (2) the potential of plants to improve slope stability, (3) the resistance of plants to bending by water flow and (4) the ability of plants to trap sediments and organic debris. Then, an indicator or a combination of two indicators was used to assess the scores for the four criteria. In total, five indicators were selected, i.e. additional root cohesion, plant stiffness, stem density, the erosion‐reducing potential during concentrated flow and the sediment and organic debris obstruction potential. Both above‐ and below‐ground plant traits were taken into account and measured to assess the scores for the five indicators, i.e. stem density, sediment and organic debris obstruction potential, modulus of elasticity of the stems, moment of inertia of the stems, root density, root diameter distribution, root area ratio and root tensile strength. The scores for the indicators were represented on amoeba diagrams, indicating the beneficial and the weak plant traits, regarding to erosion control. The grasses Stipa tenacissima L. and Lygeum spartum L. and the shrub Salsola genistoides Juss. Ex Poir. amongst others, were selected as very suitable plant species for rill and gully erosion control. Stipa tenacissima can be used to re‐vegetate abandoned terraces as this species is adapted to drought and offers a good protection to concentrated flow erosion and shallow mass movements. Lygeum spartum can be used to vegetate concentrated flow zones or to obstruct sediment inflow to channels at gully outlets. Stipa tenacissima and Salsola genistoides can be used to stabilize steep south‐facing slopes. The methodology developed in this study can be applied to other plant species in areas suffering from rill and gully erosion. Copyright © 2009 John Wiley & Sons, Ltd.     

Chemical Characterization of Biosolids from Three Spanish WWTPs: Transfer of Organics and Metallic Pollution from Urban Wastewater to Biosolids

The production of biosolids in three Spanish wastewater treatment plants (WWTPs) has been investigated. Biosolids produced from the treatment of urban wastewater in Spain are usually intended for agricultural use. The reliable production of biosolids mainly depends on both the quantity of suspended solids and the organic load influent to the treatment systems. The quality of the generated biosolids was independent of both the amount of treated water and the treatment process applied, with 20 to 25% dried matter, and 60 to 75%, 7% and 4% of organic matter, N and P, respectively, of the total matter. The biosolids contained ca. 11 to 19 g/kg of total metals in the dry matter, with Fe, Zn, Cu and Mn representing 97% of all of the metals present, and Hg being the minority metal. Such biosolids had the ability to concentrate the organic matter and metals from the wastewater up to 417 and 869 times, respectively, and thus, can be used in agricultural practice.     

泰安市城区旧县水源地岩溶塌陷演化过程分析

通过综合分析项目前期开展的塌陷群现场调查、物探、钻探、地下水动态长期监测等多项工作所获取的珍贵资料,将泰安市区划分为三个岩溶塌陷集中区,分别讨论了岩溶塌陷的发育条件、分布特征及成因演化过程,最后有针对性地提出了岩溶塌陷防治对策。研究结果表明,区内岩溶塌陷多发生于以下区域:(1)埋藏型岩溶区,地层岩性主要为奥陶纪-寒武纪灰岩、白云岩;(2)断裂及其影响带;(3)上覆土层厚度小于20 m,多层结构,即上部黏性土、中部砂类、下部黏性土区域;(4)岩溶地下水降落漏斗及其影响范围内。研究区岩溶塌陷是各种不良因素共同作用的产物,其中最重要的诱发动力条件为水动力条件,结合各类水文、地质、灾害资料,绘制岩溶塌陷与地层、降水、开采及岩溶水位关系图,可清晰地反映出在岩溶发育地区随着岩溶水开采量增大,岩溶水位随之降低,当岩溶水位低于基岩面后,岩溶塌陷开始发生,并且随着水位的降低及波动幅度的增大,塌陷次数明显增多的演化过程。      

地球化学工程技术修复江西某Pb超标耕地的应用

为了判别地球化学材料在土壤改良与重金属修复中的作用,本研究以江西龙南某地被稀土采矿废水污染而废弃的农耕地为对象,用黏土矿物等材料组成的三种修复方案对249 km2的废弃地进行修复。一周期后,比较修复前后土壤中重金属生物易迁移态的变化来评价该技术的有效性。结果表明,该地Pb超标程度最重,达101.50 mg·kg-1。Cd、Hg、As次之,分别为0.13 mg·kg-1、0.13 mg·kg-1、2.98 mg·kg-1,均超赣州市土壤背景值含量,超龙南地区土壤Pb的均值,修复目标为Pb。该地土壤中Pb的易迁移态含量与总量不显著相关。经地球化学工程技术修复后,Pb易迁移态降低了3.25%,修复效果明显。一周期后,Pb的易迁移态平均降幅为1.40%,修复效果稳定。修复效果最佳的方案C能使Pb降低幅度达到3.38 mg·kg-1,在经济上体现为最廉价,体现了地球化学工程技术的优势。