共查询到20条相似文献，搜索用时 187 毫秒
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酸雨对树木微观伤害的研究 总被引：1，自引：0，他引：1
酸雨污染对森林植物的伤害，已引起国内外广泛关注。湖南农业大学于１９９８年１０月作了模拟酸雨对树木叶片微观伤害的试验研究，现将结果报导如下。 酸雨对叶肉细胞的伤害 用显微镜观察到，受酸雨伤害的主要是一些薄壁的叶肉细胞，其结构受到破坏，细胞质、叶绿体渐渐被解体，伤害严重的仅存细胞空腔，有的细胞壁也遭破坏，仅留细胞壁碎片。试验表明，随着酸雨的ＰＨ值变小，对叶肉细胞的伤害越严重。 从试验所选樟树、柑橘、泡桐、马尾松４种树叶的受害情况得出结果，除像樟树叶那样对酸雨反应不敏感的树种外，一定ｐＨ值的酸雨对树木叶… 相似文献
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模拟酸雨对黄槐幼苗生长的影响 总被引：6，自引：0，他引：6
采用4个pH值梯度的模拟酸雨溶液喷洒法处理黄槐幼苗,探讨不同pH值[pH2．0、3．0、4．0、5．6（对照）]的模拟酸雨对黄槐在叶伤害、高生长、地径、根长、叶面积、叶绿素含量和土壤pH值等方面的影响,并以叶片的损伤程度来分析该植物对酸雨污染的敏感性反应,同时在光学显微镜下观察了不同pH值模拟酸雨处理对黄槐幼苗叶片解剖结构的影响,初步研究了黄槐对酸雨的抗性能力。研究结果表明,黄槐可以忍耐pH3．0或以上的酸雨,具有较强的抗酸雨能力,可作为酸雨污染地区应用的园林绿化树种。 相似文献
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本文在对缙云山常绿阔叶林几个树种幼苗进行模拟酸雨试验的基础上，初步探讨了林木因受酸雨危害而发生的生理生态适应机理。 相似文献
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重庆地区的森林和空气污染对森林的影响 总被引：1，自引：0，他引：1
本文讨论了重庆地区的森林植被、分布及其土壤的特性,估计了森林的叶生物量和吸收SO_2的容量;简介了重庆地区酸雨、酸雾、HF、SO_2的污染特点,并分析了这些污染因子对马尾松等树木的伤害情形。通过分析比较,发现在若干污染因子中,超负荷的硫沉降是导致重庆南山马尾松衰亡的重要的污染因子之一。 相似文献
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林木非生物胁迫抗性基因工程研究进展 总被引：2，自引：0，他引：2
干旱、极端温度和盐害等非生物胁迫因子是制约林木生长的重要因素。由于林木生长周期长, 且抗逆机制极为复杂, 长期以来, 如何改良林木对非生物胁迫的抗性一直是育种学家的难题。然而, 随着基因工程技术的发展, 人们可以在基因水平上改造林木, 提高其抗逆能力。文中主要介绍了林木抗逆基因工程的研究进展, 探讨了目前基因工程技术应用于林木抗逆育种研究存在的问题, 并对其应用前景进行了展望。 相似文献
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绿洲防护林体系缓解霜冻作用的调查研究 总被引：3，自引：1，他引：2
通过对2004年5月3日晨发生在内蒙古河套平原的大面积霜冻调查显示,绿洲防护林在减轻霜冻方面具有明显作用。由于树体降温放热、林网对气流的阻挡作用以及林冠层对热辐射的影响等,防护林结构较完整的区域冻害明显轻于防护林不够完整的区域;寒流进入林网区后,产生霜冻的能力随纵深距离增大而逐步衰减。加强绿洲防护林体系建设、完善林网结构、重视农田周围闲散荒地的造林绿化对缓减霜冻具有重要意义。 相似文献
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特大雨雪冰冻天气对林业有害生物的影响及防控对策 总被引：1，自引：0，他引：1
本文使用线路踏查和样地调查相结合的研究方法,研究了雨雪冰冻天气对林木寄主植物、林业有害生物的影响,并讨论了应对因灾而引起的次生性林业有害生物的预防性措施。结果表明雨雪冰冻天气对林木寄主植物造成了严重机械损伤,同时还产生了严重的生理性冻害,为后期次生性林业有害生物的发生埋下了隐患;对林业有害生物的直接影响是“双刃剑”效应：一方面,对各种以相对裸露方式生存的有害生物的发生是极其不利,另一方面,对弱寄生侵染性病害和大多数以隐蔽方式生存的害虫的发生是十分有利的,间接影响是造成次生性林业有害生物的发生量增加．发生种类增多,并随雨雪冰冻天气受灾程度的增强而逐渐增多。 相似文献
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Simone Perret Marc Baumgartner Hans Kienholz 《European Journal of Forest Research》2006,125(2):101-110
Rockfall is a major threat to settlements and transportation routes in many places. Consequently, the protective function of mountain forests has recently gained particular interest. However, much is still unknown about the ideal properties of protective forest stands. Therefore the present paper discusses a method for the inventory and analysis of tree injuries in a rockfall-damaged forest stand. With this method, the interrelation between stand geometry and rockfall injuries in a subalpine Polygalo chamaebuxi-Piceetum was examined. The study site of 0.3 Ha is located in the transit zone of frequently passing, small rockfall fragments (~10 cm in diameter) causing healable tree injuries. Tree and injury parameters were recorded and analysed as to injury number, height and size. The spatial distribution of the 157 trees (diameter at breast height dbh>5 cm) in the stand as well as of the 1,704 identified rockfall injuries showed a very uneven pattern. As expected, number, height and size of the injuries generally declined with increasing distance from the cliff as well as due to higher stem densities. In contrast, results indicated that the dbh of trees has no significant influence on the number of injuries per tree. However, this study showed a clear interrelation between tree and injury distribution: in general, large trees close to the cliff and smaller trees with a high density further down the slope seem to be favourable for good protection. At least an uneven-aged, multilayered stand should be sustained. Overall, the combined analysis of stand geometry and injury parameters provides information on the spatial distribution of rockfall and on the influence of tree arrangements. 相似文献
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In fall (November 2005) and winter (February 2006), we collected current-year foliage of native red spruce (Picea rubens Sarg.) growing in a reference watershed and in a watershed treated in 1999 with wollastonite (CaSiO(3), a slow-release calcium source) to simulate preindustrial soil calcium concentrations (Ca-addition watershed) at the Hubbard Brook Experimental Forest (Thornton, NH). We analyzed nutrition, soluble sugar concentrations, ascorbate peroxidase (APX) activity and cold tolerance, to evaluate the basis of recent (2003) differences between watersheds in red spruce foliar winter injury. Foliar Ca and total sugar concentrations were significantly higher in trees in the Ca-addition watershed than in trees in the reference watershed during both fall (P=0.037 and 0.035, respectively) and winter (P=0.055 and 0.036, respectively). The Ca-addition treatment significantly increased foliar fructose and glucose concentrations in November (P=0.013 and 0.007, respectively) and foliar sucrose concentrations in winter (P=0.040). Foliar APX activity was similar in trees in both watersheds during fall (P=0.28), but higher in trees in the Ca-addition watershed during winter (P=0.063). Cold tolerance of foliage was significantly greater in trees in the Ca-addition watershed than in trees in the reference watershed (P<0.001). Our results suggest that low foliar sugar concentrations and APX activity, and reduced cold tolerance in trees in the reference watershed contributed to their high vulnerability to winter injury in 2003. Because the reference watershed reflects forest conditions in the region, the consequences of impaired physiological function caused by soil Ca depletion may have widespread implications for forest health. 相似文献
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在酸性土壤中,铝对林木的毒害是限制林木生长、降低林木生产力、进而导致森林退化的主要因素之一。目前,国内外在林木铝毒害及耐铝机制方面已有较多的研究,但关于林木耐铝的生理和分子机制的综述性报道很少。文中综述了近年来林木对铝的富集、铝对林木生理和分子水平上的毒害等方面的研究进展,总结了林木耐铝的生理机制和分子机制,简要介绍了外源添加物对林木耐铝毒的调控机制,提出了今后有关林木铝毒需进一步研究的重点,以期为林木铝毒的深入研究提供参考以及为缓解我国酸性土壤林木铝毒害及森林的健康持续经营提供参考。 相似文献
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Foliar ozone uptake rates of different-sized black cherry (Prunus serotina Ehrh.) trees were compared within a deciduous forest and adjacent openings in north-central Pennsylvania during one growing season. Study trees included open-grown seedlings and saplings, forest understory seedlings and saplings, and sunlit and shaded portions of mature canopy tree crowns. Instantaneous ozone uptake rates were highest in high-light environments primarily because of higher stomatal conductances. Low ozone uptake rates of seedlings and saplings in the forest understory could be attributed partially to lower average ambient ozone concentrations compared to the canopy and open environments. Among the tree size and light combinations tested, ozone uptake rates were highest in open-grown seedlings and lowest in forest-grown seedlings. Despite lower ozone uptake rates of foliage in shaded environments, ozone uptake per net photosynthesis of foliage in shaded environments was significantly higher than that of foliage in sunlit environments because of weaker coupling between net photosynthesis and stomatal conductance in shaded environments. The potential for greater ozone injury in shaded environments as a result of greater ozone uptake per net photosynthesis is consistent with previous reports of greater ozone injury in shaded foliage than in sunlit foliage. 相似文献
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To control Monochamus alternatus and its amount of population is one of the effective ways on controlling Bursaphelechus xylophilus.The Japanese black pine which were badly harmed by M.alternatus were sprayed with the ditution from diluting fenitrothion · buprofezen 50%EC with water to 100 times, 200 times and 300 times. In this trial, the treatment is divided into two groups: one is of the different concentration but the same object (trees in the forest), the other is of the same concentration but different environmental condition (trees in the forest and felling trees indoor). Each treatment repeated five times. In the meantime, the check is not treated. After twice trial, the result indicated that the mortality rate of M. alternatus is 71.33%, 52.31% and 37.82% in the condition that trees in the forest were sprayed with the 100 times, 200 times and 300 times fenitrothion·buprofezen, and 69 69% in the condition that the felling trees indoor were spraded with 100 times fenitrothion·buprofezen, but the mortality rate of the check is only 8.92%. By this trial, it was also found that the dead adults of M.alternatus laid in the entrance of emergance hole, so enhancing the somatic character of fenitrothion · buprofezen can enhance the injury ratio of larva and pupae of M.alternatus. 相似文献
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松材线虫病 [Bursaphelechus xylophilus(Steiner et Bubre) Nickle]被称为“松树癌症”,是松树的一种毁灭性病害[1 ] ,列为我国森林病虫害之首。松褐天牛 (Monochamus alternatusHope)在松材线虫病的传播中起重要作用 ,因此 ,防治松褐天牛是松材线虫病治理工作中的一项重要内容[2 ,3] ,国内此方面的研究有过报道 [4,5] 。为进一步探索松材线虫病的治理途径 ,作者于 2 0 0 0年 3～ 1 2月应用 50 %杀螟·噻嗪酮乳油进行了防治松褐天牛的试验。现将结果报道如下。1 试验地及其林分状况试验地设在安徽省和县鸡笼山林场的代虎山 ,海拔 1 50 … 相似文献