沈阳市部分街路银杏树枯黄原因分析及解决对策

银杏是原产于中国的优良药用和观赏树种，沈阳以南、广州以北均有栽培，由于对其生物学特性和生态习性了解不深刻，管护投入不足，以及气候异常的影响。造成了沈城街路银杏树生长缓慢，甚至出现部分地区、部分街路枯黄的现象。通过取样调查和系统分析认为，银杏根部土壤条件不良，道路及管线工程对根系的破坏是导致枯黄的根本原因，5月下甸干旱和干热风是导致枯黄的促成原因。在此基础上提出了解决问题的措施。     

南湾水库库区及上游湿地资源调查分析

南湾库区湿地处于北亚热带向暖温带过渡区 ,因而形成了南湾库区湿地气候的复杂性及生物的多样性     

牡丹江五林镇马桥水库险情及成因分析

本文介绍了笔者在工作中对《黑龙江省牡丹江市五林镇马桥水库大坝安全分析评价》过程中的认识,说明了该水库的险情特点,并分析了水库险情的形成原因。     

春季大风天气特点及预报指标分析

春季(3-5月)是过渡季节,因为冷暖空气交换加剧,偏西大风和偏南大风交替出现。该季节大风的特点是大风次数多、范围广、强度大、持续时间长。一场大风常持续三天,因此有"风三"的说法。西南大风使气温猛升,空气湿度迅速减小,形成高温干燥天气,常常引起城市和森林火灾,给国家和人民生命财产带来巨大损失。因此准确预报大风天气,加强防范,意义重大。通过多年工作积累和对多年天气图普查,现对春季大风天气形势和预报指标进行分析总结。     

实验室化学污染的原因分析及思考

实验室产生的污染物常常被人们忽视,实验室废物的特点是种类多样,成分复杂,变化特别大,而污染大多是人因失误造成的,因而潜在的危害也与日俱增.实验室排放的废气、废渣、废液等,不仅污染环境还严重地危害了人类的生命与健康.因此,对实验室污染的问题的研究及有效地控制污染,刻不容缓.     

重庆市林业有害生物发生特点及原因分析

本文论述了我市林业有害生物的发生情况、发生特点，并重点分析了发生的原因     

定南县桉树冻害原因分析及预防措施

2010年定南县遭遇强冷空气的侵袭,境内的桉树冻害十分严重,损失巨大。对桉树冻害情况进行调查分析,并提出桉树冻害后的救助措施和预防措施     

垂直轴汽油机过热原因分析及解决措施

分析了垂直轴汽油机机体过热的主要原因,并提出解决措施。     

福建省森林火灾中伤亡事故原因分析及对策

在广泛查阅福建森林防火相关资料及亲临森林火灾现场调查的基础上.系统地分析了福建省‘1971年以来,森林火灾扑救中人员伤亡情况、死亡原因,并对典型案例进行深入研究,提出了避免发生森林火灾扑救人员伤亡事故的对策.     

湖北生态公益林绩效评价指标分析及改进建议

通过对湖北生态公益林绩效评价指标进行分析,指出其在评价公益林建设质量和资金管理过程中,存在评价指标不全面、部分指标没有细化或量化、指标描述抽象或模糊以及没有采用分级评价方式等问题,针对这些问题提出了改进建议,并采用逻辑分析法对该指标体系进行了重新构建,旨为林业部门公益林绩效评价提供参考和科学依据。     

植被恢复与重建过程中小流域降雨及水沙变化特征研究

以女儿寨小流域为研究对象，着重研究了植被恢复与重建过程中小流域系统的降雨和水沙变化特征，并对植被恢复过程中的总体减沙水平做了分析。结果表明：①受大气环流的影响，小流域年际降雨量差异较大；小流域降雨年内时间分布极为不均，集中性很大，主要集中在汛期（4-8月），但年内降雨量的月间分布趋势基本一致。②小流域迳流年际变化很大，迳流年内分配不均。迳流集中是该小流域迳流变化的一个显著特征：小流域的植被恢复与重建对洪峰的出现和洪峰流量具有明显的延缓和削减作用。③径流（Qi）主要来源于降水（Pi），二者呈明显的一元线型关系：Pi=115．7678＋2．7386Qi。④小流域的年输沙模数与年迳流量的变化规律基本一致，小流域年内产沙也高度集中，且与降水、迳流关系密切，小流域的土壤侵蚀主要由汛期的强降水引起。⑤随着小流域大面积、高标准的生态环境建设，1990年至2004年间小流域的输沙模数呈锐减之势，植被恢复与重建起到了显著的减沙效应。     

苹果园春季典型月份和花期水量平衡分析

利用水量平衡原理,对肥城市潮泉镇苹果园春季典型月份果园水分的收入与支出情况进行分析,确定其果园水分的亏缺与盈余状况,从而制定相应的灌溉措施。通过典型月份和花期2个时间段的水分平衡状况进行研究,试验结果表明,在不进行任何形式灌溉的情况下,典型月份果园水分总体上处于亏缺状态,水分的亏缺量为19mm。典型月份日均蒸腾量为1.86mm;花期日均蒸腾量为1.97mm,花期内水分消耗量要更明显一些。     

The impact of beaver dam removal on the chemical properties of water in drainage ditches in peatland forests

ABSTRACT

Despite near-extinction in the nineteenth century, after efficient restoration measures the population of Eurasian beaver (Castor fiber L.) in Latvia currently is viable and growing. While the ecological effect of the species on water quality and biodiversity is generally positive, the high number of animals in production forests often creates challenges for management. Drainage ditches are among the most favoured habitats of beavers resulting in flooded stands, reduced tree growth and economical losses. The aim of the study was to evaluate the chemical properties of water in forest drainage ditches, affected by beaver activity, and their changes after the dam removal. Chemical composition of surface water in ditches was analysed in sampling points above dam, below dam and in the ditch itself after removal of the dam; results compared to pristine beaver site nearby on a small stream. Results did not show significant differences between concentrations above and below dams. After removal of the dams, significant increase in DOC, N-NO₃ ^-, N-NH₄ ⁺ and TSS concentrations and significant decrease in TP concentrations were observed in some of the sites. Observed concentrations of all measured parameters were significantly lower in pristine beaver site than in beaver sites on drainage ditches.     

三峡库区灌丛群落多样性的研究

通过对三峡库区灌丛群落的初步调查,该地区灌丛现有１５个群落类型,常见的球核荚灌丛,白栎灌丛,黄栌灌丛,其丰富度指数、多样性指数相对较高,而疏水柏枝灌丛、秋华柳灌丛物种相对单一,灌丛群落多样性在海拔梯度上未表现出明显的规律性,这可能与库区强烈的人为干扰活动有关。     

南水北调源区林业生态现状与发展对策

丹江口水库是南水北调中线工程的水源地。森林作为最大的陆地生态系统,对环境产生着巨大的生态效益。加强南水北调库区林业生态建设,对于提高源区森林的防护和涵养功能,维护库区生态环境,确保水质清洁安全关系重大。通过丹江口库区自然、社会、经济和林业生态建设现状及存在的问题分析,提出了库区林业生态建设对策。     

夏秋季节水肥调控综合措施对油茶促花保果效果的影响

为了提高盛果期油茶林的产量,针对当前成林油茶落花落果率高而保花保果率低的问题,就不同的保墒、根外追施微肥与植物生长调节剂及冬季修剪等水肥调控综合技术措施对油茶保花保果效果的影响情况进行了试验研究。结果表明:(1)采用覆草、根外追施0.1 g/L的尿素与100 mg/L的GA3的坐果率最高;修剪与保水措施对坐果率的影响较大。(2)对油茶成林4月与7月保果率的影响最大的分别为修剪强度与保水措施,追施0.1g/L的硼肥有利于提高油茶4月与7月的保果率。(3)滴灌、喷施0.10 g/L的硼肥与100 mg/L的GA3及轻度修剪后油茶花芽分化数量最高;植物生长调节剂对油茶7月花芽分化的影响最大。     

化学注浆在地下室防水补漏中的应用

本文阐述了在建设施工中,地下室防水渗漏的补漏措施和方法,介绍了一种新型化学注浆堵漏剂,从而为地下室防水渗漏或地下水地漏水的补就提供了一种新的方法。     

园林病虫防治中的农药污染及对策

该文简要介绍了城市园林应用化学防治受到农药污染的现状及园林病虫的特点 ,对防治园林病虫及控制环境污染的方法进行了探讨     

三峡库区柏木林研究

对三峡库区柏木林的实地调查和分析表明,三峡库区柏木林可分为11个群落类型,群落成层现象明显,可分为乔木层、灌木层和草本层;物种丰富度、多样性、均匀度在群落梯度上的分布规律均为:灌木层>草本层>乔木层;在海拔梯度上的分布无规律性,这可能与库区内强烈的人为干扰活动有关。     

Effect of soil water changes on photosynthetic characteristics of Taxodium distichum seedlings in the hydro-fluctuation belt of the Three Gorges Reservoir area

Four different kinds of water treatment were applied to examine the photosynthetic characteristics of baldcypress (Taxodium distichum) seedlings in the hydro-fluctuation belt of the Three Gorges Reservoir area. The aim was to shed light on the physio-ecological adaptation of this species to changing water levels for revegetation purposes. The water treatments were normal growth water condition (CK), light drought water stress (T1), growth under soil water saturation (T2) and growth with soil submersion (T3). T3 had the lowest content of photosynthetic pigment; T1 and T2 did not differ from CK in the content of chlorophyll and carotenoid. The ratio of chlorophyll a to b in the four groups ranged from 2.04 to 2.69 and the ratio of chlorophyll to carotenoid from 3.08 to 4.51. In group T1, the seedling of baldcypres had lower apparent light use efficiency, lower apparent CO₂ use efficiency and a lower net photosynthetic rate, with the net photosynthetic rate 24.9% lower than that of group CK. However, T2 and T3 did not differ from CK in apparent light use efficiency, apparent CO₂ use efficiency and net photosynthetic rate. Water use efficiency of the four treatments consistently increased as treatment was prolonged; the average water use efficiency of T3 was the lowest while that of CK was the highest. Correlation analysis showed that the net photosynthetic rate of baldcypress seedlings was positively related to transpiration rate, stomatal conductance, water use efficiency, apparent light use efficiency and apparent CO₂ use efficiency, but highly negatively related to the ratio of chlorophyll a to b. Net photosynthetic rate was not significantly related to the contents of chlorophyll and carotenoid, the ratio of chlorophyll to carotenoid, relative air humidity and intercellular CO₂ concentration. The transpiration rate was positively correlated with stomatal conductance and negatively related to water use efficiency. The results showed that different water treatments could effectively influence the baldcypress seedlings’ content of photosynthetic pigment, leaf gas exchange and apparent resources use efficiency. The results verified that the species T. distichum takes on the features of a water-tolerant and hydrophilic plant, which can be considered as one of the species for the building of a forest protection system for the hydro-fluctuation belt in the Three Gorges Reservoir area. Baldcypress should not be planted in drought-stricken soils. __________ Translated from Acta Ecologica Sinica, 2005, 25(8) [译自:生态学报, 2005, 25(8)]