湖北省水土保持监测站点径流小区布设及观测成果应用

科学布设水土保持监测站点和径流小区是水土保持监测网络建设的重要内容。由于原有的水土保持监测网络存在空间布局不均衡、监测设施不标准、监测功能定位不明确及不能满足新形势需要等问题，湖北省从2018年开始对全省水土保持监测网络进行优化布局和升级改造，包括优化监测站点的空间布局和对各监测点径流小区进行统一设计等。优化布局和升级改造后，实现了8个水土保持三级区水土保持监测站点全覆盖，明确了监测站点和径流小区的代表区域、功能定位和成果应用。湖北省水土保持监测网络升级改造中监测站点和径流小区的优化布局及观测成果的应用方案，可为其他省份水土保持监测网络升级改造工作提供参考。     

山东省水土保持监测站网优化布局分析

水土保持监测站网是水土保持监测工作的基础。山东省目前有省级水土保持监测站1处、市级水土保持监测站16处、水土保持监测点30个。在站网布局方面,山东省水土保持监测站网存在地区间分布不平衡、黄泛平原风沙国家级水土流失重点预防区水土保持监测点偏少、各水土保持区划间分布不均、水土保持监测站网的整体功能没有充分发挥等问题。针对这些问题提出建议:建立健全水土保持监测站网布局、建设和监测技术体系;对现有监测网络进行优化调整和现代化升级改造,按照统一规划、科学布局的原则,建成覆盖全省的要素齐全、布局合理、功能完善的水土保持监测网络;加强水土保持监测结果分析应用,促进监测成果的及时有效转化等。     

关于四川省水土保持监测点建设的思考

水土保持监测点作为全国水土保持监测网络与信息系统建设的神经末梢,承担着观测、试验、数据采集和传输的任务.监测点规划布局的是否科学合理直接影响整个水土保持监测网络的运行效果.从土壤侵蚀分布、流域分布、水土流失"三区"划分及与科研机构结合等方面论证了四川省水土保持监测点布局的合理性.此外,针对不同类型监测点的重点建设内容进行了阐述.根据四川省水土保持监测点建设的实际情况提出一些合理化建议.     

新疆水土保持监测站网优化布局与升级改造做法

新疆现有水土保持监测站点在布局、设备配置等方面与新形势下生态文明建设要求存在差距，不能全面反映区域水土流失状况，亟待优化升级改造。通过分析新疆监测站点建设现状和存在的问题，总结了在监测站点布局优化调整和运行管理工作上的做法和取得的成效，并对后期监测站点建设和管理提出建议，以期为推进区域生态文明建设，加强区域水土流失监测和监督管理提供借鉴和参考。     

关于山西省水土保持监测点现代化提升的思考

针对山西省水土保持监测点体系综合集成度不高、布局与结构有待优化、设施设备老旧损毁、服务功能不充分等问题,研究提出监测点现代化提升的主要对策。通过优化监测点体系,规范监测指标,搞好监测设施标准化改造和监测设备更新,推动点面结合、日常与应急结合的常态化、规范化动态监测,推进数据智能化分析与信息社会服务等主要举措,全面提升和充分发挥监测点所具备的综合集成动态监测、试验研究、数据共享、技术支撑等功能。     

中国水土保持监测站点布局研究

水土保持监测在中国资源节约型社会和环境友好型社会建设,迈向生态文明,履行国际公约的进程中,肩负着愈来愈重要的历史使命。通过对全国水土保持监测的历史回顾和现状分析,提出了优化布局原则。研究结果表明,水土保持监测站的布局应坚持水土流失类型区全面覆盖,充分利用现有相关监测站点,便于实施自动化监测,有利于长期运行和科学实用的原则。按此原则,全国共设不同侵蚀类型区监测点47个,七大流域、内陆河及较大外流河共选取62个干流监测断面点,55个重要支流监测断面点,42个国家级水土流失重点防治区分别设1个监测点,由土壤侵蚀监测点、水文监测点、重点防治区监测点构成中国水土保持监测控制站网,实施长期、定位监测。     

水土保持监测站点规范化建设与运行管理的思考

监测站点作为水土保持监测网络的"神经末梢",是水土保持监测的重中之重.总结了我国水土保持监测点建设的发展历程,分析了目前存在的问题,重点阐述了监测站点在设置与布局、设施设备、人员队伍、监测数据、运行管理、监测经费保障等方面开展规范化建设的内容.并提出了监测点规范化建设下一步工作建议,可为国家更好地开展全国水土保持监测站点建设与管理提供参考.     

湖北省水土保持监测站点的空间优化布局

[目的]对湖北省水土保持监测站点空间优化布局进行探究,为该区水土保持监测系统的完善、水土保持科学管理与决策提供支撑。[方法]收集湖北省土壤侵蚀相关资料,利用GIS空间分析功能开展湖北省土壤侵蚀强度分级评价,在此基础上应用尺度理论对监测站点进行空间优化布局,并对优化结果进行分析验证。[结果]经过优化研究,湖北省共需布设86个监测点,其中一级尺度12个监测点,二级尺度26个监测点,三级尺度布设48个监测点。经泰森多边形验证,优化后的站点布设合理,控制突出,层次分明。[结论]湖北省丹江口水库周边山地丘陵水质维护保土区、南阳盆地及大洪山丘陵保土农田防护区和鄂渝山地水源涵养保土区水土流失严重,需要在现有基础上进一步增加水土保持监测站点密度;江汉平原及周边丘陵农田防护人居环境维护区等地区水土流失轻微,可适当减少水土流失监测站点数量。     

水土保持监测点选址与标准化建设初探

水土保持监测点是全国水土保持监测网络的重要组成部分,是全国水土保持监测网络和信息系统二期工程建设的一项重要内容,同时也是整个监测网络和信息系统建设的基础,关系到能否及时准确地获取信息的重要工作.科学的选址、合理的规划、标准化的建设是开展本项工作的基础,只有在这些基础工作完善、科学合理的选址布设的基础上,才能研发监测点的设施设备以及监测管理手段,搞好数据化处理与传输和信息化建设,为发挥整个水土保持监测点的作用提供有效的监测作用.从水土保持监测点建设的作用和几个约束条件探讨入手进行了简要探索,仅供参考.     

开发建设项目水土保持监测点布局

开发建设项目水土流失是一种典型的人为加速侵蚀现象,其发生发展的机理较为复杂,水土保持监测工作的开展也具有一定的难度。监测点布局是水土保持监测的基础性工作,其合理性直接影响水土流失动态变化状况、水土保持措施实施及效果监测的科学性与客观性。目前尚缺乏统一的监测点布局规范,给监测设计工作带来了不确定性。综合考虑了自然条件和项目工程特性,采用分层抽样的基本思想,提出利用水土流失类型、地形地貌类型、土地利用类型和工程功能单元类型进行4级分区控制的开发建设项目水土保持监测点布局方法,构建了项目区-监测分区-监测点逐层细化的监测点布局方法,提出了不同项目水土保持监测的重点地段,旨在解决因自然条件、工程特性的差异而导致监测点布局困难的问题。     

Mechanisms of persistence of low numbers of bacteria preyed upon by protozoa

Tetrahymena pyriformis cultures were maintained when transferred serially in solutions containing 10⁵ to 10⁷Klebsiella pneumoniae cells.ml^?1, bacterial numbers that were observed to persist in the presence of protozoa. The number of cells of one strain of K. pneumoniae surviving predation in solution was essentially the same in the absence of an alternative prey as in the presence of a second K. pneumoniae strain. Toxins deleterious to protozoa did not appear as the animal consumed the bacteria. T. pyriformis reduced the abundance of Escherichia coli from about 10⁸ to 10⁶.ml^?1. but the latter number persisted for 15 days; however, in solutions containing chloramphenicol, the abundance of E. coli fell to 590 cells. ml^?1 in 15 days. In solutions containing the antibiotic, T. pyriformis reduced the Rhizobium sp. population from more than 10⁶ to less than 10³ cells in 10 days and K. pneumoniae from more than 10⁸.ml^?1 to zero in 18 days. An appreciable decline in abundance of these bacteria did not occur in the antibiotic-amended liquid free of protozoa. T. pyriformis did not greatly reduce Rhizobium sp. numbers when both were added to irradiated soil, but the predator caused the bacterial population to decline from 4 × 10⁸ to fewer than 10⁵.g^?1 in 16 days in chloramphenicol-treated soil. Colpoda sp. inoculated with Rhizobium sp. into soil sterilized by autoclaving only reduced the prey abundance from 10⁹ to 10⁸.g^?1, but the protozoan caused the bacterial population to fall to about 100.g^?1 in 15 days in the presence of the antibiotic. The population of Rhizobium sp. added to nonsterile soil dropped from in excess of 10⁸ to 6 × 10⁶.g^?1 in 29 days. but it declined to 550. g^?1 in the same period when chloramphenicol was also introduced. It is concluded that the ability of these bacteria to maintain themselves in solution and in soil is governed by their capacity to reproduce and replace the cells consumed by predation.     

两种退耕还林模式对土壤微生物优势类群的影响

以两种退耕还林模式的桦木林地、苦竹林地和农耕地(对照)为对象,对各样地土壤微生物优势类群数量的季节性动态变化、垂直分布特征及其与土壤酶活性的相关性进行了研究。结果表明,土壤微生物的优势类群为微球菌属(Micrococcus)、芽孢杆菌属(Bacillus)、链霉菌属(Streptomyces)、游动放线菌属(Actinoplanes)、酵母菌(未定属)、木霉菌属(Trichoderma)这6类。两种退耕还林模式下土壤优势微生物类群数量存在差异,春、夏、秋三季均为苦竹林所占比例最大,冬季为桦木林最大。两种林地和农耕地土壤微生物优势类群数量季节性变化规律为微球菌和酵母菌在夏、冬季较大,春、秋季较少;芽孢杆菌在秋季最大,夏季最小;游动放线菌与木霉菌数量在四季中变化不大;链霉菌是夏季最高,冬季最少。各优势微生物类群数量的垂直分布特征表现为微球菌、游动放线菌、木霉菌随土壤层的加深其数量逐渐降低,芽孢杆菌、链霉菌数量则随土壤层的加深而逐渐增加,酵母菌随土壤层的加深其数量减少,但趋势不明显。两种林地对各优势微生物类群数量的根际效应为:链霉菌和木霉菌的R/S值大于1,酵母菌的R/S值小于1,微球菌和游动放线菌在桦木林的R/S值大于1而在苦竹林小于1。在优势微生物类群和土壤酶之间,微球菌与转化酶,芽孢杆菌与纤维素酶,木霉和游动放线菌与过氧化氢酶,酵母与脲酶呈显著正相关关系。     

Evidence of Long-Range Transport of Pollutants from the Size-Fractionated Ionic Composition of Aerosols in the Jeju Island of Korea

The ionic composition of total suspended particulate (TSP) and fine (PM_2.5) fractions was investigated from an 1,100 site in the middle of Mt. Halla in Jeju Island, Korea from March to November 2006. The sum concentrations of cation and anion species in TSP fraction were 205 ± 170 and 183 ± 164 neq m^?3, respectively, while those for PM_2.5 as 118 ± 129 and 88.5 ± 89.3 neq m^?3, respectively. In TSP, the concentration of the major ions changed in the order of SO₄ ^2? > NH₄ ⁺ > Ca²⁺ > Na⁺ > NO₃ ^? > Mg²⁺ > K⁺ > Cl^?, while its PM_2.5 counterpart as NH₄ ⁺ > SO₄ ^2? > Ca²⁺ > NO₃ ^? > Na⁺ > Mg²⁺ > K⁺ > Cl^?. Inspection of the temporal variabilities of ionic components indicated that most ions peaked in spring or fall months. The back trajectory analysis showed that the atmospheric composition of the major ionic species was affected fairly sensitively by long-range transport from China under the favorable meteorological conditions. In contrast, the lowest ionic concentration levels were seen most abundantly, when air masses passed from South Sea. Hence, the analysis of ionic concentration data suggests that their distributions are controlled by the combined effects of various source processes including the most prominent Chinese origin and the meteorological condition favorable for such transport.     

The effect of organic matter on the structure of soils of different land uses

In this study, the soil structure of two soils (Haplic Chernozem and Eutric Fluvisol) of different land uses (forest, meadow, urban and agro-ecosystem – consisted of four crop rotations) in Slovakia was compared. The soil aggregate stability was determined with a dependence on the chemical composition of plant residues. The quantity and quality of the organic matter was assessed through the parameters of the C and N in size fractions of dry-sieved and water-resistant aggregates. The soil structure of the forest ecosystem was evaluated as the best of all of forms of land use. Differences in the soil structure under the grass vegetation of a meadow (natural conditions) and urban ecosystem were also recorded. The agro-ecosystem was characterised by a higher portion (55.95%) of the most valuable (agronomically) water-resistant aggregate size fraction of 0.5–3 mm. Values of the carbon management index showed that the larger water-resistant aggregates were, the greater were the changes in the organic matter (r = ?0.680, P < 0.05). In addition, a smaller content of dry-sieved aggregates of the 3–5 mm size fraction was observed with higher contents of soil organic carbon (SOC) (r = ?0.728, P < 0.05) and labile carbon (C_L) (r = ?0.760, P < 0.05); there were also greater changes in the soil organic matter and vice versa, higher contents of SOC (r = 0.744, P < 0.05) and C_L (r = 0.806, P < 0.05) greater contents of dry-sieved aggregates of size fraction 0.5–1 mm. The soil structure of agro-ecosystem was superior at a higher content of cellulose (r = ?0.712, P < 0.05) in the plant residues. The higher content of cellulose and hemicellulose in the plant residue of a previous crop was reflected in a smaller C_L content in the water-resistant aggregates (r = ?0.984, P < 0.05). A correlation was observed between a high content of lignin in the plant residue and a smaller SOC content in the water-resistant aggregates (r = ?0.967, P < 0.05). Lastly, a higher content of proteins in the plant residues (r = 0.744, P < 0.05) supported a greater content of dry-sieved aggregates of the 0.5–1 mm size fraction.     

Simulation of the Mathematical Model of Composting Process of Sewage Sludge

An integrated model was developed to simulate the temporal change and spatial variation of temperature and spatial distribution of TM (total mass) and MC (moisture content) of the final compost for composting process of sewage sludge. The model included biodegradation kinetics of organic matter and balance equations of energy and mass. First-order assumption was applied to describe the biodegradation process with correction functions of temperature, oxygen, MC, and FAS (free air space). The transfer process was considered in balance equations of energy and mass. A finite difference method was used to solve the model. Two trials of 0.21 m³ were run to estimate parameters and evaluate the simulation. The model could predict TM and VS (volatile solid) of the final compost well, temporal trend of oxygen concentration and water removal, and also a good fitting of the temporal and spatial change of temperature. H_rx (reaction enthalpy of biodegradable volatile solid) and η_BVS (mass fraction of biodegradable volatile solid) were considered the most sensitive parameters based on the sensitivity analysis. Future research was suggested to focus on reasonable humidity assumption, measuring accurate value of thermodynamics and kinetics parameters of sewage sludge, and simulating the composting process with different aeration modes and turning of the pile.     

pH对磷钾铝石形成的影响

Effects of column temperature and flow rate on separation of organic acids were studied by determining nine low-molecular-weight organic acids on reversed-phase C18 column using high performace liquid chromatography(HPLC) with a wavelength of UV(ultraviolet)214 nm and a mobile phase of 18 mmol L^-1 KH2PO4 buffer solution (pH2.1).The thermal stabiltiy of organic acids was determined by comparing the recoveries of organic acids in different temperature treatments.The relationships between column temperature,flow rate or solvent pH and retention time were analyzed.At low solvent pH,separatioin efficiency of organic acids was increased by raising the flow rate of the solvent because of lowering the retention time or organic acids.High column temperature was unfavorable for the separation of organic acids.The separating effect can be enhanced through reducing column temperature in organic acid determination due to increasing retention time.High thermal stability of organic acids with low concentrations was observed at temperature of 40℃-45℃,Sensitivity and separation effect of organic acid determination by HPLC were clearly improved by a combination of raising flow rate and lowering column temperature at low solvent pH.     

Change of hydrophysical properties of clayed minerals due to the influence of soluble salts

It was revealed that the influence of soluble salts on the hydrophysical properties of clayed minerals depends on the nature of minerals, the properties and state of salt (in solution or sorbing), and the region of fundamental hydrophysical characteristics (FHCH). The treatment of clayed minerals by NaCl, MgCl₂, Ca(CH₃COO)₂, and ZnCl₂ solutions increased their water-retention in the range NaCl > MgCl₂ > Ca(CH₃COO)₂ ≈ ZnCl₂. Pb(CH₃COO)₂ decreased the water-retaining ability of clayed minerals in all the FHCH range. A differential characteristic of the action MgCl₂, Ca(CH₃COO)₂, and ZnCl₂ on smectite is decrease of capillary water deduction.     

水稻幼苗根系吸收NO3-对细胞膜电位的影响

利用玻璃微电极技术测定了扬稻6号(籼稻)幼苗根尖细胞在吸收不同NO3-浓度(0.01、0.02、0.1、0.2、0.5、1.0和2.0.mmol/L)过程中膜电位的变化。结果表明,1)水稻根系吸收NO3-引起膜的去极化,去极化到一定程度后出现复极化;有小部分水稻根表现为超极化。在0.01～1.0.mmol/L范围内,去极化大小随外界NO3-浓度的增加而增加,且差异显著(P0.05)。0.01.mmol/L.NO3-产生较小的去极化,平均为3.8.mV;0.5.mmol/L.NO3-产生了最大去极化,平均为40.2.mV;当外界NO3-浓度大于1.0.mmol/L时膜电位去极化大小呈下降趋势。根系吸收不同浓度的NO3-而使膜电位去极化的进程符合Michaelis-Menten动力学。2)复极化有部分复极化和完全复极化两种。超极化也有两种:一种是膜电位先超极化,后缓慢复极化;另一种是先出现一个小的去极化,然后是较大幅度的超极化。3)运输蛋白抑制剂PGO抑制了根系吸收NO3-而产生的膜电位的响应。4)对于经CaSO4溶液预培养的水稻来说,C2+主要引起膜电位超极化。     

不同砧木对脐橙幼树生长和叶片养分含量变化的影响

以体细胞杂种红桔+枳和红桔+粗柠檬、有性杂种Troyer枳橙和Sweingel枳柚作砧木的脐橙2年生嫁接苗为试材,利用盆栽试验研究了不同砧木对苗木生长和叶片养分含量年动态变化的影响。结果表明,红桔+枳的生长势和花量明显地优于其它砧木,红桔+粗柠檬的生长和花量介于2种有性杂种之间;砧木基本上不影响叶片N、P、K、Mg和Mn含量年变化,但明显影响叶片Ca、Fe和Zn含量的年变化;在同一个生长期,不同砧木对叶片养分含量有明显的影响。此外本文还讨论了体细胞杂种砧木的利用价值。     

Emission of carbon dioxide and dynamics of inorganic N in a gradient of alkaline saline soils of the former lake Texcoco

A plan was developed to apply biosolid to soil of the former lake Texcoco to fertilize the pioneer vegetation. Because, no information exists about how differences in electrolytic conductivity (EC) might affect mineralization of biosolid and dynamics of C and N in soil, 20 soil samples forming a gradient in EC ranging from 22 to 150 dS m⁻¹ were characterized, amended with 500 mg biosolid C kg⁻¹ dry soil and incubated aerobically at 22 ± 2 °C while production of CO₂, concentrations of ammonium (NH₄⁺), nitrite (NO₂⁻), and nitrate (NO₃⁻), and NH₃ volatilization were monitored at 22 ± 2 °C for 70 days. Soil characteristics showed large variations with maximum values often >10-times larger than minimum values. The production of CO₂ in the unamended soil ranged from 25 to 159 mg CO₂-C kg⁻¹ day⁻¹ and NH₃ volatilization from 0 to 189 μg NH₃-N kg⁻¹ day⁻¹_. Application of biosolid increased production of CO₂ significantly 1.4-fold and volatilization of NH₃ 11.5-fold. The EC explained most of the variation in production of CO₂, while particle size distribution explained most of the variation in volatilization of NH₃. The concentration of NH₄⁺ in the biosolid-amended soil decreased sharply in the first 14 days, with the EC explaining most of the variation found, and remained constant thereafter with a small increase at day 70. Significant increases in the concentration of NO₃⁻ were generally found in soil with EC < 64 dS m⁻¹. The EC explained most of the variation in production of CO₂, and dynamics of NH₄⁺ and NO₃⁻ while clay positively and sand content negatively affected NH₃ volatilization. It was found that increases in EC inhibited C and N mineralization in soil of the former lake Texcoco.