退耕还林(草)工程效益监测与评估技术

根据退耕还林工程对环境的直接影响,建立了效益监测指标体系,筛选出了54个指标因子,并对工程效益的评价方法进行了探讨.退耕还林(草)工程涉及面广、规模大、投入多,其工程效益监测和评估具有重要的意义.     

The influence of fire on rodent abundance at the N’washitshumbe enclosure site,Kruger National Park,South Africa

The relative population numbers of rodents were studied in nine habitats in and outside the N’washitshumbe enclosure site, Kruger National Park, before and after burning the firebreaks that surround the enclosure. Trap success was exceptionally high, and the field work is suspected to have coincided with a Mastomys population explosion. This genus dominated the small mammal communities before and after the burn, and never disappeared from the burnt patches. Its numbers also did not crash directly after the burn, as have been reported in most other studies. Movement from the burnt areas was observed, which may have had a significant impact on the numbers of rodents caught both inside the enclosure and in the more natural areas outside. Our study suggests that fire can be investigated as a tool to keep rodent densities down in areas where they are nuisance animals, especially when used in conjunction with models that forecast outbreaks of Mastomys. It also emphasizes the value of long-term studies informing management strategies for animal damage control and biodiversity and ecosystem conservation.     

Efficiencies of Chemical Techniques for Rice Grain Freshness Analysis

Two chemical methods which are commonly used for rice grain freshness determination were investigated for their efficiencies.Method 1 is made of bromothymol blue indicator,and the principle is based on indicator’s color which is changed in according to pH of the stored rice grains.Method 2 is based on peroxidase activity which deteriorates during storage of rice grains.Both methods were used for determination of fresh-aged rice index of six Thai-rice cultivars,four from non-waxy rice cultivars (KDML 105,Chai Nat 1,Chai Nat 2 and Phitsanulok 2) and two from waxy rice cultivars (San-pah-tawng and RD6).Rice samples were kept in the forms of paddy and polished rice.Fresh-aged rice indices were determined using both methods every two weeks over the storage period of 24 weeks (six months).It was found that both methods were capable of detecting fresh-aged rice indices.The color of chemical solutions changed with regards to the age of rice grains and it could be detected spectrophotometrically.Rice grains which have been kept as paddy provided more consistent results.Method 1 is recommended for industrial application as it is simple,efficient and inexpensive.     

鸭梨无公害生产环境及栽培量化指标与调控技术研究

通过多年来的系统研究,明确了鸭梨无公害生产的环境质量指标,制定了鸭梨无公害栽培果实品质性状、树体结构、产量水平及效益指标,以及果实重金属和农药残留限量指标,集成配套了相适应的栽培调控技术,包括水分调控、配方施肥、平衡修剪、疏花疏果、人工授粉、梨果套袋、病虫防治及适期采收等8项关键技术,为鸭梨实现无公害高品质栽培,提高国内外市场竞争力,增加经济效益和出口创汇提供了科学依据。     

Cd胁迫对花花柴幼苗生长和生理特性的影响

[目的]研究Cd胁迫对花花柴幼苗生长和生理特性的影响。[方法]在实验室条件下,研究不同浓度Cd胁迫对花花柴幼苗生长的影响,检测不同浓度Cd胁迫对花花柴的相对电导率、叶绿素含量、MDA含量、CAT、SOD及POD活性的影响效应。[结果]Cd能够抑制花花柴幼苗的生长,随着Cd处理浓度的增加,苗的发芽率、发芽势、活力指数、鲜重、干重、根长、株长呈降低趋势。随着Cd浓度的增加,花花柴叶片相对电导率显著增加,MDA含量有增加趋势,CAT、POD和SOD活性相应增加并有波动情况,叶绿素含量显著下降。[结论]花花柴对Cd胁迫具有很强的耐受力,可作为Cd污染环境生物修复的候选植物。     

南京市老城区法桐行道树健康状况研究

通过研究南京市老城区内法桐行道树的健康状况,提出行道树健康生长的影响因素,为行道树的养护管理提供参考。对南京市老城区内10条主要道路进行基础调查,在因子分析法建立健康评价综合模型的基础上,采用单因素方差分析法和多重比较法分析不同道路间健康综合评分和健康评价指标的差异。结果表明,各道路法桐行道树生长结构良好,整体健康综合评分为0.00,中等健康等级(26.2%)占比最大,其次为健康等级,占比21.5%,濒死等级占比20.6%,亚健康等级占比19.7%,不健康行道树占比12.0%,整体健康状况中等水平。不同道路法桐行道树间的健康综合评分与评价指标均具有显著差异(P<0.05),健康状况具体表现为：北京西路>江东中路>中山路>中央路>中山东路>升州路>广州路>汉中路>虎踞北路>珠江路。行道树长势、损伤情况等是影响其健康状况的重要因素,行道树所面临的主要问题集中在地表铺装与土壤硬化、病虫害、夜间光照以及修剪技术等方面,同时断枝倒伏等情况的发生也构成了对城市空间的安全隐患。适用于行道树的评价方法为因子分析法结合完整的评价指标体系,包含树...     

Soil Quality for Rice Productivity and Yield Sustainability under Long-term Fertilizer and Manure Application

Productivity and sustainability of rice-rice cropping system depend upon the soil quality which is primarily governed by application of fertilizers and manures. However, such information is limited and hence, the present investigation was carried out in a 9-year-old long-term fertilizer experiment at Bhubaneswar, India. There were seven treatments (control, application of 100% NPK, 150% NPK, 100% NPK + Zn, 100% NPK + FYM, 100% NPK + Zn + B, and 100% NPK + Zn + S) laid out in randomized block design with four replications. Indicators of soil quality (physical, chemical, and biological) were diagnosed from 30 numbers of soil properties measured on the post-wet season soil and soil quality was assessed taking productivity and sustainability of dry season rice as goal functions. Results revealed that the highest productivity and sustainability of dry season rice was found with application of 100% NPK + FYM. This treatment, in general, showed better physical, chemical, and biological properties than rest of the treatments. The highest soil quality index (SQI) was recorded in 100% NPK + FYM (0.941) treatment followed by 150% NPK (0.826) with CEC diagnosed as the only key indicator for rice productivity. For yield sustainability in dry season, reserve K and total N were important contributing 89% and 11%, respectively to the SQI. Therefore, these soil properties could be used to monitor soil quality in wet season. Application of FYM along with 100% NPK could sustain the productivity of dry season rice by improving soil properties under subtropical rice-rice system.     

城市绿地植物群落优化配置方法初探

植物群落是城市绿地的基本组成单元,群落结构的合理性是影响城市绿地健康稳定发展的关键。针对城市绿地群落结构中存在的树种选择违背适地适树原则、多样性不足,初植密度过大,植物配置跟风、结构不合理等问题;从优化植物群落配置的角度出发,分别从"树种选择—种植密度—配置模式—组合评价体系"等角度总结出当前国内对于城市绿地植物群落优化调控的方法和先进经验,提出了从物种选择、密度指标和格局设计等方面进行源头控制,加强群落结构动态发展管理和控制配置比例,根据评价体系不断升级城市绿地群落结构等优化策略。     

基于指示Kriging法的土壤盐渍化与地下水埋深关系研究

在北方干旱、半干旱的地下水浅埋区,土壤盐渍化是土地资源退化的主要原因,防治土壤盐渍化是农业和生态环境可持续发展的重要保障。该文以内蒙古河套灌区解放闸灌域为例,运用指示Kriging法绘制并比较了不同阈值下地下水位埋深和土壤表层含盐量的概率分布图,从概率空间分布的角度分析研究了土壤盐渍化与地下水位埋深之间的关系,从而将这方面的研究从通常的农田尺度扩大到灌域尺度。结果表明:1)土壤盐分和地下水位埋深空间变异强度均为中等,且具有中等的空间自相关性,球状模型拟合变异函数的效果较好;2)在灌域尺度上,解放闸灌域4月底土壤表层发生中度、轻度盐渍化时地下水位临界埋深分别为2.0、2.5m,西南及中东部地下水位埋深小于临界埋深的概率较大,是土壤返盐的高风险区;3)3月底地下水位埋深对土壤返盐的影响比4月底更大一些,这表明地下水位埋深对土壤返盐的影响具有一定滞后效应,只有地下水位埋深小于临界深度的状态维持一段时间,才会造成土壤中度或轻度盐渍化。     

越橘品质指标评价

【目的】 探讨越橘品质指标间的相互关系,构建和完善越橘品质性状的综合评价体系,为合理评价越橘品质提供理论参考。【方法】 以92份越橘果实为材料,测定单果重、果形指数、果实硬度、维生素C含量、可溶性固形物含量、可滴定酸含量、固酸比7项品质指标,运用相关分析揭示指标间的相互关系,运用正态分布理论进行品质指标概率分级,利用因子分析确定越橘品质评价指标,运用层次分析确立评价指标的权重并建立指标评分标准。【结果】 越橘品质指标间离散程度差异很大,其变异系数分别为67.12%（固酸比）、45.46%（可滴定酸含量）、35.28%（单果重）、23.48%（维生素C含量）、18.23%（可溶性固形物含量）、18.05%（果实硬度）和6.05%（果形指数）。可滴定酸含量和维生素C含量均服从正态分布,概率值P均大于0.05,果形指数、果实硬度和可溶性固形物含量去掉个别极端值后,也服从正态分布,单果重的概率值P为0.0494,接近0.05,视为符合正态分布,固酸比呈偏态分布。可滴定酸含量和固酸比之间呈极显著的负相关,相关系数为-0.81742,二者间存在极显著的幂函数变化趋势,决定系数R ²为0.9005。筛选出4项越橘品质代表性指标,包括可溶性固形物含量（甜味指标）、可滴定酸含量（酸味指标）、维生素C含量（营养指标）和果实硬度（质地指标）,4项代表性指标划分为5个等级,即极低、低、中、高和极高。建立4项代表性指标评分标准,将92份越橘果实划分为3个等级,即优等、中等和差等。 【结论】 越橘品质代表性指标包括可溶性固形物含量、可滴定酸含量、维生素C含量和果实硬度,建立的4项品质指标评分标准可用于越橘品质的科学评价与分类。