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1.
琅琊山珍稀树种开发与保护 总被引：2，自引：0，他引：2
榆科树种琅琊榆、醉翁榆、青檀、榉村是琅琊山主要珍稀树种。前两者为濒危树种,根据其生态学特性创造更新条件、采取保护措施已迫在眉睫。后两者是北亚热带石灰岩山地重要建群种,具有十分独特的生态学意义。急需采取措施,以保证珍稀树种后继有树,维护琅山景观生态持续稳定。 相似文献
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榆科树种琅琊榆、醉翁榆、青檀、榉树是琅琊山主要珍稀树种。前两者为濒危树种，根据其生态学特性创造更新条件、采取保护措施已迫在眉睫。后两者是北亚热带石灰岩山地重要建群种，具有十分独特的生态学意义。因而，急需采取措施，以保证珍稀树种后继有树，维护琅琊山景观生态持续稳定。 相似文献
3.
皖东石灰岩山地次生林演替趋势与树种的生理特性分析 总被引：13，自引：0，他引：13
本文在研究分析琅琊山天然森林群落演替趋势、榆科树种生理生态特性以及皖东石灰岩地区立地分类的基础上 ,探讨了皖东石灰岩山地的适宜造林树种 ,从而为加速北亚热带石灰岩山地的绿化提供理论依据。研究结果表明 ,青檀、榉树、琅琊榆、醉翁榆等榆科树种 ,由于在生理上对高钙、干旱的石灰岩生境有较好适应性 ,同时在群落演替过程中具有相对稳定性 ,因而是皖东石灰岩山地造林绿化的适宜树种 相似文献
4.
裂叶榆一年生播种苗的年生长规律及育苗技术要点 总被引：1，自引：1，他引：1
裂叶榆(Ulmus laciniata Mayr.),属榆科落叶乔木。分布东北小兴安岭、长白山和河北、山西等地。辽宁省主要分布在东部山区。裂叶榆生长快,对环境适应性强,木材用途广,经济价值高,是东北地区优良用材树种之一。裂叶榆播种育苗当年出圃。苗木在年 相似文献
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中国榆科植物果实,种子形态及聚类分析的研究 总被引：1，自引：0，他引：1
对中国产榆科８属、２６种植物的果料和种子形态进行了研究，包括果核表面的电阄扫描。编制了种子、果实分属检索表，简要记载了榆科８属果核表面电镜扫描特征。以果实、种子形态特征为主，参阅花粉和种子油脂肪酸资料及腊叶标本，进行了３６个性状的聚类分析。参阅其他有关文献，支持把剌榆属Ｈｅｍｉｐｔｅｌｅａ及榉属Ｚｅｌｋｏｖａ划归榆亚科Ｕｌｍｏｉｄｅａｅ，把朴亚科由榆科中独立成朴科Ｃｅｌｔｉｄａｃｅａｅ的意见。 相似文献
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垂榆嫁接育苗技术试验 总被引：1，自引：0，他引：1
垂榆嫁接育苗技术试验段玉忠，柳枫（张掖地区林果业研究所）垂榆Ｕｌｍｕｓｐｕｍｉｌａｖａｒ．ｐｅｎｄｕｌａ又名倒榆，属榆科，白榆属，树冠呈伞形，枝叶茂密，柔枝下垂，树形优美，是城乡庭院绿化树种之一，也是人们比较喜爱的观赏树种。在我区由于苗木较缺，影响了... 相似文献
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榆树对榆毛胸萤叶甲的抗虫性研究 总被引：2，自引：0，他引：2
通过对自然状态下１９种榆树榆毛胸萤叶甲发生量的调查，以产卵量和１、２龄幼虫发生高峰幼虫量为指标，用模糊聚类分析法将其分为高抗树种、抗性树种、感虫树种和喜食树种４类，其中（１）高抗树种为椿榆、太行榆、大叶榆和蜀榆；（２）抗性树咎为旱榆、黑榆、毛榆榔榆、琅琊榆、多脉榆、白榆×椿榆、天优２和天优３；（３）感虫树种为白榆、明陵榆、大果榆、美洲榆和红叶明陵榆；（４）喜食树种为多脉×明陵。野外幼树套笼饲养表明 相似文献
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通过对自然状态下１９种榆树榆毛胸萤叶甲发生量的调查，以产卵量和１、２龄幼虫发生高峰幼虫量为指标，用模糊聚类分析法将其分为高抗树种、抗性树种、感虫树种和喜食树种４类，其中：（１）高抗树种为椿榆、太行榆、大叶榆和蜀榆；（２）抗性树种为旱榆、黑榆、毛榆、榔榆、琅琊榆、多脉榆、白榆×椿榆、天优２和天优３；（３）感虫树种为白榆、明陵榆、大果榆、美洲榆和红叶明陵榆；（４）喜食树种为多脉×明陵。野外幼树套笼饲养表明，榆毛胸萤叶甲幼虫取食抗性较强树种太行榆、椿榆和黑榆叶子后不能存活，幼虫死亡率均为１００％。 相似文献
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长序榆福建种群的天然更新与繁殖 总被引：3，自引：0，他引：3
长序榆（Ulmuselongata）是80年代初由我国植物学家根据采自浙江省遂昌县的标本发表的新种，其分类位置隶属于榆科榆属总序榆组（Sect．Chaetoptalae），其中3种产于北美，而长序榆是该组在东亚的唯一代表，为我国特有。这一树种的发现对研究北美和东亚植物地理学具有重要意义。长序榆星散分布于我国浙、闽、皖、赣，不久前在陕南也有发现，大树已不多见，处于临危状态。该种树干通直圆满，生长迅速，其木材的气干密度、顺纹抗压强度、抗弯弹性模量、顺纹抗拉强度、冲击韧性和硬度等材性指标均优于同属其它树种，与榉树相似，为优良用材树… 相似文献
11.
在人工模拟干旱的条件下,研究了自美国引种培育的岩榆、南方岩榆和国产白榆1 a生幼苗的叶片相对含水量(RWC)、电导率和叶绿素含量的变化情况,同时调查水分胁迫后期幼苗的存活率.结果表明:水分胁迫初期,3种榆树幼苗的叶片RWC、质膜透性、叶绿素a、叶绿素b及叶绿素总量均呈增加趋势;水分胁迫中期(第24天)白榆、南方岩榆的叶绿素总量呈现最大值,后开始缓慢下降,而岩榆仍继续上升至第30天后才开始下降,但各种幼苗叶片叶绿素a/b均增加.自然干旱初中期的RWC下降缓慢,后期失水迅速,白榆失水速率明显快于岩榆、南方岩榆.水分胁迫后期白榆叶片出现萎蔫,叶缘叶尖枯黄均早于南方岩榆、岩榆,萎蔫枯黄总数也最多,其次分别是南方岩榆、岩榆.因此,岩榆最耐干旱,南方岩榆次之,白榆较不耐旱. 相似文献
12.
Li Jicheng She Hua Jiao SenlinDailing Forestry Experimental Bureau of Heilongjiang ProvinceLiu YongchunNortheast Forestry University 《林业研究》1993,4(2):57-63
In order to improve the quality of seedlings and economic benefits,rare--earth experiments were carried out on eleven seedling-age-types of four silvicultral treespecies.Some indexes such as the increment,biomass and chlorophyl content weredetermined.The results showed that rare-earth can improve the growth in height anddiameter,increase the bioprductivity and increase the mean benefit by887766.29 yuan/hm~2.It is an effective method to improve the quality of seedlings for the characters such as lowcost and easy grasping.And the method can be widely used in seedling. 相似文献
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Since its inception nearly 15 years ago, environmental certification has become an important issue in the wood products industry. One research question that has been examined is the potential willingness for supply chain participants to pay a premium for certified products or raw materials to offset certification costs. This study examines stated willingness to pay for four wood products from the perspective of U.S. consumers. Data was collected in 1995 and 2005 from the population of U.S. residential consumers to detect changes in willingness to pay for certified wood products along time and increase the statistical strength of the model. Results of an ordered probit model suggest that higher probabilities of paying a premium are associated to consumers who seek out certified products and who believe certification can lessen environmental impacts such as tropical deforestation. There is also a strong relationship between respondent income and willingness-to-pay. Despite the current industry structure in the U.S. that has adopted a mass-certification strategy that does not place price premiums on certified products, results suggest that such premiums may exist for imported certified tropical wood products. Analysis of marginal effects suggests consumers' willingness to pay a 10% premium for three of the four certified items studied. Niche markets may potentially be exploited in the U.S. and price premiums captured by wood products manufacturers in tropical regions and/or American importers. 相似文献
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在温室内用盆栽法栽植了1年生茶条槭、山梨和山桃苗木,并采用4种土壤水分处理,土壤相对含水量分别为75.0%、61.1%、46.4%和35.4%。结果表明:随土壤含水量降低,3树种苗木净光合速率,蒸腾速率和气孔导度均下降,土壤含水量最低时,茶条槭苗木各生理指标降低幅度最大,山梨和山桃次之。茶条槭和山梨水分利用效率随土壤含水量的减少呈降低趋势,山桃水分利用效率呈升高趋势。水分胁迫下,3树种苗木根分配生物量显著增加。茶条槭在水分胁迫下,根冠比增加幅度最大,山梨次之,山桃最小。此外,茶条槭叶形态可塑性强,随土壤含水量降低,茶条槭单叶叶面积和总叶面积显著减小,叶厚度增加。山梨和山桃在水分胁迫下单叶叶面积及总叶面积无显著变化。综合3树种苗木在水分胁迫下的生理和形态指标及生物量分配的变化,茶条槭对水分胁迫的适应能力强于山桃和山梨。表3参31。 相似文献
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简要介绍了美国主要南方松的天然分布、生长习性、本土人工种植情况、遗传改良状况及主要工业用途等。提出了江西省各生态区适栽松种。 相似文献
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干旱是主要的环境胁迫因子之一,严重影响植物的分布与生长发育。通过选取辽宁阜新章古台沙地1年生榆树幼苗为材料,采用盆栽控水方法,设置田间持水量80%、60%、40%和20%等4个水分处理梯度,研究干旱胁迫对榆树幼苗株高、基径及叶片、茎和根系生物量分配的影响。结果表明:随着干旱胁迫程度增加,幼苗茎和根系的生物量逐渐降低;但轻度干旱胁迫增加了株高和基径的生长,提高了叶片生物量,以抵御干旱胁迫的影响。中度干旱胁迫下,增加了根系生物量分配的比例,从而更利于获取水分资源适应干旱环境;重度干旱胁迫下幼苗无法存活。在科尔沁沙地,栽植榆树幼苗保证存活生长的最低田间持水量为40%。 相似文献
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lntroductionAtmosphericconcentrationofCo2isrisingdra-maticaIIyandadoubIingofthepresentconcentrationwouIdoccurinmidnextcentury,duetoburnoffossilfuelanddestroyofforest(Gates1983,Tauszetal.1996).EIevatedatmosphericCO2willchangeitsgradientdistributioninforestecoboundary,andwillproduceagreateffectontreesandthewholeforestecosystem.Atpresent,studiesoneffectsofelevatedCozonplantshavebeenapopuIartopic,especiallyoncropsrice(BateretaI.199o).HaveIkaetal.(1984)hasgainedmanyachievementsonsoybean.How-e… 相似文献
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The relative susceptibility to fusiform rust of provenances of 6 European species of pine was tested at Athens, Georgia U.S.A. Needle and stem spots caused by rust were found on the seedlings of all the species and their provenances. Several maritime pine and Aleppo pine seedlings showed particular longitudinal cracks caused by the fungus mycelium in the stem; those of Austrian pine and of Swiss Mountain pine had a violet zone around the cotyledons due to the presence of the fungus mycelium in the needle tissues. If the percentage of galled seedlings is taken into consideration, the test results indicate that Aleppo pine, Austrian pine and Italian stone pine are more susceptible to infection than are maritime pine, Swiss Mountain pine or Scots pine. 相似文献
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We tested the effects of ectomycorrhizal (ECM) inoculation on greenhouse-grown white spruce (Picea glauca (Moench) Voss) and jack pine (Pinus banksiana L.) seedlings to be used for revegetation of salt-affected tailing sands resulting from the exploitation of oil sand in northeastern Alberta, Canada. White spruce and jack pine seedlings were inoculated with three ECM fungi selected for their in vitro tolerance to excess Na+ and Cl-: Hebeloma crustuliniforme (Bull) Quel. UAMH 5247, Laccaria bicolor Maire (Orton) UAMH 8232 and a Suillus tomentosus (Kauff.) Sing., Snell and Dick isolate from a salt-affected site. The physiological responses of the seedlings to a gradient of NaCl concentration (0, 50, 100 and 200 mM) were assessed over four weeks by: (1) Na+ accumulation and allocation; (2) chlorophyll a fluorescence; (3) growth, (4) water content; and (5) organic osmolyte accumulation. Jack pine seedlings were more sensitive than white spruce seedlings to increasing Na+ and Cl- concentrations. Both species showed decreasing biomass accumulation, and increasing concentrations of organic osmotica and Na with increasing NaCl concentration. White spruce seedlings inoculated with the S. tomentosus isolate had the best growth response at all NaCl concentrations tested. Although jack pine seedlings inoculated with the L. bicolor or S. tomentosus isolate exhibited the highest growth in the 50 and 100 mM NaCl treatments, both fungi increased the photochemical stress and dehydration of their hosts in the 200 mM NaCl treatment. At the latter concentration, jack pine seedlings inoculated with H. crustuliniforme showed the greatest tolerance to salt stress. Although the different fungi altered the physiological response of the host in different ways, inoculation with salt-stress-tolerant ECM fungi increased growth and reduced the negative effects of excess NaCl. Use of controlled mycorrhization may increase survival of coniferous seedlings used for revegetation of salt-affected sites. 相似文献