公路病害及病害处治

对常见的公路病害种类、危害进行了预防与外治，并对公路翻浆水毁的预防与处治也进行了分析。     

林区公路冻胀与翻浆的处理

冻胀与翻浆是东北林区公路的常见病害,也是较难处理的病害。虽然引起冻胀与翻浆的原因很多,但主要是东北的林区公路路基内的水份,由于受负温差的影响,由温度高的深层沿着毛细孔向温度低的上层移动,并积聚在上层。当温度下降到冰点以下时,水变成冰,体积增大,导致冻胀病害发生;当春季温度升高时,路基上面先融化,水份因下层冻结无法向下层移动,引起翻浆。     

浅谈公路绿化对治理公路翻浆的作用

本文主要研究了近几年来黑龙江省公路翻浆的现状。探讨公路绿化对治理公路翻浆的作用。确定了治理公路翻浆的适宜绿化树种。     

翻浆对林区公路路面的危害及防治

翻浆破坏是林区公路路面主要破坏形式之一，特别是季节性冻土地区路面翻浆破坏更为严重。现将林区公路路面翻浆破坏产生的原因、造成的危害及防治措施作以研究、探讨。     

林区公路翻浆产生的原因和防治措施

论述了福建林区公路翻浆现象的危害性和形成原因,提出防治林区公路翻浆问题的主要措施。     

浅谈公路翻浆的成因和处治

分析了公路产生翻浆的原因，提出解决翻浆的措施。     

路基翻浆产生原因及防治

本文论述了路基翻浆产生的原因及其相应的预防措施;同时阐明只有防治与养护相结合,才能有效地避免翻浆的发生,提高公路的使用品质。     

冻土地区公路翻浆防治

本文主要介绍了冻土地区公路翻浆的成因及防治措施。     

浅谈道路翻浆及其防治方法

道路翻浆是指土基水份含量过大,在荷载作用下,使土基被剪切破坏出现弹簧和沉陷等变形,并有细泥挤出路面,它是我国北部寒冷地区特有的公路冻害之一。翻浆使车辆行驶速度下降,机件受损,增大燃料消耗,同时也给道路养护增加很多困难。目前防治道路翻浆主要采取排水、换土和铺沙等方法,笔者认为最好在道路设计施工时,首先考虑防治翻浆问题,根据道路所在地区的水文条件,选用合适的土质填筑并使路基达到一定的高度。     

林区公路翻浆的防治

林区公路翻浆的防治徐凤舞，汪照军随着林业建设的高速发展和林业生产规模的不断扩大，林区公路的修筑也在由少到多、由局部到整体地发展，一个遍在林区的公路网系正在形成。林区公路的快速发展适应了木材生产、运输和森林防火等的需要，但是部分道路产生的翻浆在一定程度...     

余姚地区松幽天牛发生情况及其在枯死马尾松根部分布规律的初步研究

调查了松幽天牛(Asemum amurense)在余姚地区的发生情况及其幼虫在枯死松树根内的分布规律。结果表明,松幽天牛在余姚地区1年发生1代,以幼虫在松树根内越冬。4月中旬开始化蛹,5月中旬成虫开始羽化,6月上旬成虫开始产卵,7月下旬卵开始孵化。松幽天牛在余姚地区的平均危害率达42.9%,其发生与土壤理化性质密切相关。松幽天牛幼虫在主、侧根内的分布数量差异显著,主根内的幼虫数显著多于侧根内。还依据松幽天牛的生活学特性提出了松幽天牛的防治措施     

枸杞果柄分离力与果实、果柄形态及内源激素含量间的关系

为了探讨枸杞果柄分离力与果实、果柄形态及内源激素间的关系,从而为枸杞鲜果新品种选育及其鲜果产业发展提供理论依据,分别以蒙杞2号和宁杞7号为试材,采用酶联免疫法测定了果实与果柄中ABA、IAA、GA_3、ZR的含量,分析了枸杞果实发育期内果实与果柄的形态及内源激素和果柄分离力间的关系。结果表明:果柄分离力随着果实的发育成熟而不断降低,其与单果质量、果实纵径、果实横径间均有显著的负相关性,其相关系数分别为-0.771、-0.862、-0.883;果柄分离力与果实中各内源激素的相关系数均较高,而与果柄中各内源激素的相关系数均较低。果实中的ABA含量在果实膨大初期开始上升,至果实成熟期,蒙杞2号果实中的ABA含量下降,而宁杞7号果实中的ABA含量仍较高;果实中的IAA含量逐渐下降,并显著低于果柄中的IAA含量,蒙杞2号果实中的IAA含量低于宁杞7号果实中的IAA含量;果实中GA_3与ZR的含量均逐渐下降,且宁杞7号果实中GA_3与ZR的含量均高于蒙杞2号的;果柄中GA_3与ZR的含量变化均不明显;ABA、GA_3、ZR在宁杞7号果实与果柄中的含量比均高于其在蒙杞2号果实与果柄中的含量比,宁杞7号果实中ABA/(IAA+GA_3+ZR)之值也高于蒙杞2号果实中ABA/(IAA+GA_3+ZR)之值。文中综合分析认为,ABA、GA_3、ZR在枸杞果实与果柄中的含量比和果实中ABA/(IAA+GA_3+ZR)之值均高可能是导致果柄分离力小的主要原因。     

生长环境及收获期对野鸦椿属植物三萜类化合物含量的影响

【目的】研究不同生境和收获时间对圆齿野鸦椿不同部位总三萜类化合物积累的影响情况,为其药用价值和科学栽培的研究奠定基础。【方法】选择3个低海拔地区的8年生圆齿野鸦椿,分别于2014年11月和2015年3月采集其叶片、枝条和果实,选择高海拔地区6年生的野鸦椿和圆齿野鸦椿,于2014年8月分别采其叶片和枝条,对其总三萜类化合物含量进行了测定和比较分析。【结果】1)8月采集的叶片中三萜类化合物的含量,野鸦椿高于圆齿野鸦椿,且其含量差异呈显著性水平;但是,8月采集的枝条中三萜类化合物含量,野鸦椿低于圆齿野鸦椿。2)圆齿野鸦椿不同部位的总三萜类化合物含量存在差异,且2个月份采集的含量高低顺序均为叶片>枝条>果皮>种子,均以叶片中的含量为最高,依次为9.06%(农大)、7.14%(清流)和6.85%(邵武)。3)11月采集的圆齿野鸦椿样品中的三萜类化合物含量高于3月所采样品中的含量,其叶片中的总三萜类化合物含量最多可提高172.91%。4)圆齿野鸦椿叶片、果皮和种子中的三萜类化合物含量与试验地的海拔高度、年降水量均表现出极显著的负相关关系,与年均气温存在极显著的正相关关系,其叶片中的三萜类化合物含量还与年均无霜期呈正相关关系,其枝条中的三萜类化合物含量与各地理和气象因素之间的相关性均不显著。【结论】圆齿野鸦椿的叶片采收期长于野鸦椿;低海拔、较少降水量和年均气温较高有利于圆齿野鸦椿植株对三萜类化合物的累积,这3个因子可以作为圆齿野鸦椿适宜栽培区域的划分指标;夏季采摘野鸦椿叶片,秋冬季采摘圆齿野鸦椿叶片,所采叶片的总三萜类化合物的含量均较高。     

落叶松水曲柳纯林与混交林根际土壤中养分浓度的变化

在落叶松水曲柳纯林与混交林中,采集林地土和根际土,测定了氮、磷、钾浓度,目的是探讨养分条件变化在混交林增产上的作用。结果表明:混交林林地土全氮浓度和水解氮浓度与水曲柳纯林相近,但要高于落叶松纯林。水曲柳在混交林中根际土全氮和水解氮浓度与纯林中的相近,而落叶松在混交林中根际土水解氮浓度明显高于纯林中的。混交林林地土全磷和全钾浓度与两个树种的纯林相差不大。混交林林地土有效磷、有效钾浓度均高于水曲柳纯林,而且水曲柳在混交林中根际土的有效磷和有效钾浓度与纯林中的相比明显增加,分别高出44.1%~79.6%和13.5%~25.6%。这说明水曲柳在混交林中磷和钾的利用状况得到了改善。表2参15。     

Boron in forest trees and forest ecosystems

This review critically examines the role of boron (B) in forests in view of recent findings on B nutrition and the continuing occurrence of B deficiency. Many perceptions about the role of B in plants and its uptake and mobility have been altered since the last review on B in forest trees in 1990. Now there is evidence for a fundamental role of B in the formation of the pectic structure in primary cell walls in plants, and further roles in membrane function are being explored. In plants, channel-mediated B uptake, active B uptake and B uptake by mycorrhizas have been shown, B transporters have been identified, and B retranslocation has been shown. We explore these findings and their consequences on forest trees and on ecosystems that they dominate. Particular emphasis is placed on B retranslocation and B in mycorrhizal symbiosis, given their importance in trees.     

百山祖冷杉枝叶营养元素含量与适生立地土壤养分关系分析

研究了百山祖冷杉(Abies beshanzuensis)分布区适生立地表层土壤养分及其与百山祖冷杉枝叶营养元素含量的相关性.结果表明,土壤pH5.11～6.42,土壤有机质含量、全氮含量、速效磷含量、速效钾含量分别为119.075 0g/kg、2.196 2g/kg、15.016 3mg/kg、136.215 2mg/kg;百山祖冷杉对土壤N、P、K富集能力均较高,而对微量元素富集能力较弱,且枝部和针叶均未检出Na元素;较高的土壤N含量,可相应显著提高百山祖冷杉叶N、K含量水平,较高的土壤P含量,则显著抑制百山祖冷杉叶对K和枝对N的积累水平,较高的土壤Cu含量显著降低了Cu元素在叶器官中的积累,而显著增加了枝条中Cu和Zn的积累水平,较高的土壤Fe含量则显著促进了针叶中Fe元素和枝中Fe、Mn元素的积累水平.     

The status and conservation of whooper swans (Cygnus cygnus) in China

There are five species of swan in the world. Three of them were recorded in China. They are whooper swan (Cygnus cygnus), whistling swan (Cygnus columbianus) and mute swan (Cygnus olor). Among them. whooper swan is the most famous in China. Whooper swan is a resident bird in China. They breed in Xinjiang Ugyur Autonomous Region. Inner Mongol Autonomous Region. Heilongjiang Province. etc., and winter in Qinghai. Shandong. Henan Province, etc, and the lower reaches of the Changjiang River. The total number in China is about 5.000 in breeding grounds and 15.000 in wintering grounds. Higher number were found in 1960s. Because of the changes in environment and hunting, of picking up eggs and of catching nestlings, their population is being reduced rapidly. They are in danger now. In order to protect the whooper swans, some protection measures must be taken, such as strengthening public education and scientific research, estabilshing a base of raising and breeding: developing international cooperation, strengthening the construction of natural reserves in the breeding and wintering grounds. Up to the end of 1993. 34 natural reserves have been established in China. (Responsible Editor: Sun Yueqi)     

Comparative study of the stoichiometric characteristics of karst and non-karst forests in Guizhou,China

Carbon (C), nitrogen (N), and phosphorous (P) levels and their stoichiometry in plant components (leaves, branch trunks, roots) of trees in a karst forest and non-karst forest are compared. The results show that the C contents, C:N and C:P ratios of dominant species in the karst forest were lower than those in the non-karst forest, but the N and P and the N:P ratio were higher;C:N:P ratios in plant organs of trees in the karst forest were in the order of trunks>roots>branches>leaves. However, C:N:P ratio in the non-karst forest trees were trunks>branches>roots>leaves. Moreover, ratio of C:N:P in trunks was highest and lowest in leaves in both forests. In non-karst forest trees, N:P was in the order of leaves> roots>branches>trunks. There were no significant differences in the ratio of N:P in different plant components of trees in the karst forest. However, in karst and non-karst forest trees, the ratio of N:P in leaves was highest;positive correlations between N and P contents, and N and N:P ratios were observed in both karst and non-karst forests (p<0.001). Negative correlations between P and N:P ratios (p<0.05) were observed in karst forest trees, while positive correlations were observed in non-karst forest trees.     

福建绿竹不同种源含水率与持水量研究

通过对永安和龙海绿竹不同种源含水率与持水量的研究,结果表明:不同种源的生物量与持水量呈正相关。林冠层持水量随生物量增加的幅度较大,而地下部分持水量较小,林下植被与凋落物层居二者之间。永安试验点各种源林冠层和地下部分的生物量与持水量高于龙海试验点,林下植被层生物量也高于龙海,但持水量低于后者。永安试验点的①、⑤、②号种源,龙海试验点的③号种源林冠层和地下部分生物量较大,持水量较高,永安试验点的⑧号种源,龙海试验点的④号种源2个指标均较小,林下植被与凋落物层的生物量与持水量则较高。     

Cambial Anatomy and Annual Rhythm of Secondary Xylem Development in the Twigs of Azadirachta indica A. Juss. (Meliaceae) Growing in Different Forests of Gujarat State

Abstract

Seasonal behavior of vascular cambium and development of secondary xylem were studied in the 2-3-years-old branches of Azadirachta indica A. Juss. (Meliaceae) growing in moist deciduous (MDF), dry deciduous (DDF) and scrub land (SF) forests of Gujarat State. Development of xylem began with the sprouting of new leaves in January in both MDF and DDF. Xylem production culminated in July in MDF whereas it reached peak in April and July in DDF. Cambial cells ceased to divide with the maturation of leaves in November and October in MDF and DDF, respectively. Mature xylem and phloem derivatives surrounded the cambium in December in MDF and November in DDF. Radial growth in the branches of trees growing in SF was found continuous throughout the year with peak cambial activity in April, July and November. In all the three forests, maximal radial growth was encountered in July when the rains were heavy. Cambial activity and xylem development showed significant correlation with the phenology of the trees in MDF and DDF whereas cambium was found active throughout the year and no correlation was found between the cambial activity and phenology in SF.