国产天然橡胶市场竞争力分析——关于加入WTO对我国天然橡胶业影响问题的讨论

从国内天然橡胶售价、单位面积产量水平、生产组织形式和整体技术水平、生产成本等方面 ,分析了国产天然橡胶的市场竞争力 ,着重讨论了我国国有植胶企业的社会成本问题 ,指出我国天然橡胶生产已具有占领国际天然橡胶市场一席之地的能力 ;对于植胶条件较优的云南垦区和海南岛一部分国营植胶农场 ,天然橡胶生产依然是经得起市场检验的支柱产业 ;控制国有植胶企业社会成本 ,加速生产技术创新和整体优化 ,是提高国产天然橡胶市场竞争力的关键     

当前云南植胶应加速推广的几项科技成果

<正> 云南植胶从1953年开始,现已有一定的基础。到1980年为止,植胶总面积73.5万亩,投产开割30万亩,年产干胶已达到1.7万吨的规模。 云南垦区处于北纬21°08′～24°49′,植胶海拔高度,哀牢山以东350～400米,以西900～1,000米,是我国纬度最北,海拔最高的植胶区。 在二十多年的植胶过程中,不断认识垦区的自然规律,总结正反两方面的经验教训,植胶科技水平不断有所提高。已初步形成了一套较为完整的植胶措施和制度,包括基了一批经过多年选择鉴定的外来和自育的品系。这是我省今后植胶继续前进的技术有础。本文对最近几年来取得的在橡胶生产上有较大使用价值的几项科技成果作出评价并提出加快应用的意见,以期发挥优势,推动我省橡胶生产的发展。     

云南西双版纳橡胶树死皮病高发原因及控制措施探讨

从宏观农业角度,探讨西双版纳植胶区植胶环境和经营管理条件与橡胶树死皮病(TPD)的关系,尝试说明该区域死皮病高发的原因,提出了通过改善生产管理控制该病害的措施。     

橡胶新品种勐养90—01有性系的选育

<正> 一、勐养90—01有性系选出的由来 勐养农场地处西双版纳植胶区北部,属二类型偏下植胶区。1973/1974年冬和1975/1976年冬的两次特大低温寒害,使我场80％以上的橡胶树都受到不同程度的危害。为立足抗寒植胶,从1977年开始以种植有性系为主。     

关于云南西双版纳丘陵山地的植胶海拔高度问题

<正> 云南橡胶垦区,以哀牢山为界,分为东,西两种不同类型的植胶区。哀牢山以西的植胶区,包括西双版纳、思茅、临沧和德宏等地(州)的宜胶地。这是一个独特的高纬度植胶区。如德宏州最北的胶园已接近北纬25度,西双版纳州的许多胶园分布在北纬22度线附近。形成这个高纬度植胶区的原因,是由于北部和东北部有高原以及横断山脉为屏障,冬季挡住了寒潮的直接侵袭,夏季由与横断山脉走向一致的水系引导,季风带来的暖湿气团可深入     

河口垦区橡胶宜林地避寒环境类型区的重新划分意见

本文认真总结了河口垦区发展橡胶30多年来的经验教训,对垦区植胶环境有了新的认识:它不属植胶的最适宜区,而是次适宜区,它虽具有热区优越的自然资源,但越冬条件不好,频繁的低温寒害是垦区发展橡胶的主要限制因素,必须立足抗寒植胶。同时,根据垦区以平流为主的混合型降温特点,对橡胶宜林地寒害类型区提出了重新划分的具体意见和方案。     

2009年滇东南植胶区橡胶树寒害回访调查报告

2009年对滇东南植胶区2007/2008年冬春橡胶树寒害后的实际损失和恢复状况进行回访调查认为,目前使用的各橡胶品种抗寒力和寒害后的恢复能力存在很大的差异,各植胶单位主要品种的配置仍很单一,以致削弱整体的抗灾减灾能力,灾后各单位的减灾措施各行其是,没有严格按技术规范去做,不能实现胶林应有的恢复效果。建议加强抗寒减灾救灾技术研究和应用,合理配置品种,严格执行和实施规程,才能建立和完善滇东南植胶区长效防御灾害科技体系。     

云南河口植胶区橡胶林现状分析和发展建议

要:通过对2013年云南河口植胶区4个农场橡胶幼林普查资料和2000年以后多次低温寒害的分析表明:橡胶林更新时间和面积与寒害出现时间及危害程度有关;2000年后新植和更新种植的幼林普遍大量种植云研77-4新品种,过于单一的品种结构为植胶业留下新的隐患。针对橡胶林更新现状,提出要提高对胶园更新的正确认识,合理规划,多品种配置植胶,提高橡胶树群体抗御自然灾害的能力,及建设新一代高产稳产胶园的建议;并对在寒害频繁的河口地区如何巩固和发展天然橡胶产业进行了探讨,认为要转变理念,重新科学定位和规划植胶区域,探索经济、社会、生态效益更好的种植和经营模式,创建与其它产业经济互利共存的环境友好型生态胶园。     

抗寒植胶仍是云南垦区不容忽视的问题

根据赵振国研究员所言“30年冷周期”即将来临的预测,针对河口垦区不够重视橡胶树寒害问题的倾向,回顾了河口植胶半个世纪以来的橡胶树寒害及损失情况,提醒人们:寒害曾经发生,并且还会发生,云南垦区抗寒植胶不容忽视。     

几个橡胶无性系的产量与河口垦区的低温

<正> 河口垦区位于云贵高原东南边缘,为云南山原向河谷丘陵过渡的斜坡地带。西北高,东南低,河谷多为西北一东南走向,常年受东南季风所控制。冬季受回归路径的变性冷气流逆红河河谷长驱直入,西北、东北和偏东路径的冷空气亦可影响本区,唯其在逾越高原、下滑进入本区时,能量损耗较大,加之冷空气的焚风效应,增温减湿,强度降低;同时本区由西北向东南倾斜直至北部湾,使之过境快,因而影响不大,一般年份,仅造成轻微的辐射降温。这就形成了本区独特的植胶环境,既有别于我省西部植胶区,又有别于华南植胶区。是以回归路径冷空气影响为主的平流型降温植胶区(间或有其它三条路径冷     

Conservation value of forest plantations for bird communities in western Kenya

Tree plantations of native and exotic species are frequently used to compensate for forest loss in the tropics. However, these plantations may support lower species diversity and different communities than natural forest. We therefore investigated bird communities in stands of natural forest, different types of tree plantations and secondary forest in Kakamega Forest, western Kenya. We compared birds differing in habitat specialisation, i.e. forest specialists, generalists, and visitors. We recorded significant differences in mean species richness and number of individuals among the different forest types. Stands of natural forest and plantations of indigenous tree species comprised more species and individuals than plantations of exotic tree species and secondary forest. This was caused by a significant decline of forest specialists and generalists from natural forest and indigenous plantations to exotic plantations and secondary forest. Species composition of the bird communities did not differ between natural forest stands and plantations of a mixture of indigenous tree species, but clearly changed between natural forest and plantations of single tree species. These findings demonstrate that natural forest areas are needed for the conservation of forest bird diversity, but that plantations with a mixture of indigenous tree species can have similarly high conservation value.     

广东三岭山森林公园主要人工林碳汇功能及其经济价值评价

本文以广东三岭山森林公园的马尾松、尾叶桉、大叶相思人工林为研究对象，研究对比它们的碳储量和碳汇经济价值，为评价广东的3个优势造林树种的碳汇能力及为广东的造林选择提供依据。结果表明：3种人工林树种单位碳储量由大到小排列次序为：尾叶桉(166.89 t·hm-2)＞大叶相思(128.72 t·hm-2)＞马尾松(70.12 t·hm-2)。3种人工林平均碳汇经济价值按大小排列次序为：尾叶桉(45611.04元·hm-2)＞大叶相思(35179.18元·hm-2)＞马尾松(19163.80元·hm-2)。尾叶桉是这3种人工林中碳储量的主要部分，对广东三岭森林公园发挥着巨大的碳汇功能并具有强大的碳汇经济价值。因此，可以考虑在广东省碳汇造林时选择尾叶桉种植。     

不同林龄桉树人工林森林空间结构差异研究

采用空间代替时间的方法,对不同林龄桉树人工林的空间结构进行了比较研究。结果表明：不同生长阶段桉树人工林空间结构之间存在着差异。,桉树人工林1-年生增长迅速,呈对数增长;随林龄增加．郁闭度、枯枝落叶（厚度和覆盖率）表现为先增加后减少趋势。桉树人工林层次结构分明,各层优势植物种类基本相同,但不同林龄阶段,各层数量和分布广度（植株大小高矮、植物种类数量和覆盖率）有随林龄增加基本表现为“大-小-大”的趋势。聚类分析表明,林龄之间空间结构差异明显。     

The role of isolated old oak trees in maintaining beetle diversity within larch plantations in the central mountainous region of Japan

Old oak trees (Quercus crispula Blume) that are remnants of former old-growth forests have been isolated singly or as small patches within a matrix of conifer plantations in the central mountainous region of Japan. Fifty-six aerial Malaise traps were deployed around seven isolated oak trees within larch [Larix kaempferi (Lamb.) Carrière] plantations and at seven larch plots within larch plantations. The species richness and composition of beetles (Cerambycidae, Curculionidae, Elateridae, Chrysomelidae, and Lycidae) around the oak trees were compared to those in the larch plantations. Species richness was higher around the oak trees than in the larch plantations, and the species composition differed. A number of saproxylic beetles were characteristic of isolated old oak trees. These results emphasize the importance of isolated old oak trees for maintaining beetle diversity in larch plantations and raise the possibility that further losses of these isolated oak trees could eliminate many individuals and reduce beetle diversity in larch plantations.     

云南绿春县天然次生林和4种人工林树冠层蚂蚁群落多样性

[目的]探讨天然次生林和人工林及人工林树种选择对树冠层蚂蚁群落多样性的影响。[方法]运用树栖蚂蚁陷阱法调查云南省绿春县天然次生林和4种人工林的树冠层蚂蚁群落、植物多样性及植物垂直密度变化。[结果](1)共采集蚂蚁标本17 998头,隶属于6亚科29属68种。(2)树冠层蚂蚁多度:紫胶林-玉米混农林紫胶林桉树林橡胶林天然次生林。(3)树冠层蚂蚁丰富度:紫胶林-玉米混农林紫胶林天然次生林橡胶林桉树林。(4)树冠层蚂蚁ACE估计值:紫胶林-玉米混农林紫胶林天然次生林桉树林橡胶林。(5)树冠层蚂蚁多度和丰富度与枯落物盖度、300 cm处垂直密度和乔木郁闭度呈显著或极显著负相关,而与植物盖度显著正相关;ACE估计值与枯落物盖度、草本植物盖度和乔木郁闭度显著负相关,与175 199.9 cm区段内垂直密度显著正相关。[结论]人工林对蚂蚁多样性保护有一定积极作用,尤其选择乡土树种保护效果更显著,对人工林进行合理的管理有利于保护生物多样性。     

Assemblages and species diversity of wood destroying termites in different land use systems in Western Ghat, India

Spatial distribution, abundance and assemblage of termites depend mainly on the local conditions and habitats in which they thrive. Striking differences are observed in the species richness, number of clades and functional diversity of termite assemblage between different habitats. This study aim was to examine effect of human interference in the diversity of wood destroying termite in forest areas as well as managed and unmanaged plantations in South India. Termites attacking trees and wooden logs were collected from forest areas, managed plantations and unmanaged plantations. The termites collected were identified and compared for species abundance, richness and species diversity. Results show that the species composition and species diversity of the wood destroying termites vary according to the conditions. The species diversity measures revealed that there is a significance variation among the forest fauna and plantations. The forest areas have the highest species composition compared to plantations. Species richness is high forest areas. Even though the abundance of termites are more in unmanaged plantations, there is no significant difference related to species diversity among the managed and unmanaged plantations.     

宜昌市郊柏木人工林林下植被发育及生物量研究

通过对宜昌市郊柏木人工林从幼龄林、中龄林至近熟林3个阶段林下植被发育及生物量的研究,结果表明:林下乔木、灌木和草本植物数量有不同程度增加,但常绿树种几乎没有增加;林下灌木层由强阳性种趋向中性种,林下草本层由栗褐苔草和地果占优势变为蕨类植物占优势;柏木更新不良显著影响林下灌木层和草本层平均高度和平均盖度的变化,但总体趋势是增加的,只是平均密度有所下降;林下草本层和死地被物层的生物量呈增加趋势,但受柏木更新不良影响,灌木层生物量呈现出先减少后增加的变化趋势。     

关于我国人工林长期生产力的保持

为了保持我国人工林的长期生产力和提高森林质量,达到可持续经营的目的。作者在以往研究工作的基础上,广泛收集了国内外有关成果与资料,概括论述了我国人工林森林生产力的现状、不能保持生产力的原因与机理以及长期保持人工林生产力的技术对策。按第八次清查的全国森林资源数据,每公顷蓄积量为89.79 m^3,其中天然林为104.6 m^3,人工林为52.76 m^3,人工林森林生产力明显低于天然林;我国优势树种人工林每公顷蓄积量也不高,如杉木为69.8 m^3,马尾松为56.2 m^3,落叶松为58.6 m^3,这些数据比日本2002年3月公布的人工林相似树种的数据低很多,如日本针叶树蓄积量为227.97 m^3·hm^-2,柳杉为295.83 m^3·hm^-2,落叶松为189.88 m^3·hm^-2。关于年生长量,按全国第七次资源清查的中龄林与近熟林的数据做统计:杉木人工林5.2~4.2 m^3·hm^-2,马尾松为3.2~1.8 m^3·hm^-2,柏木为3.4~3.2 m^3·hm^-2;但按作者掌握的我国重点或示范性、试验性小面积人工林生长量看,却很高,按我国编制的速生丰产林标准的生长量数据看比较高。我国大面积人工林生产力不高,短周期经营的杨树、桉树人工林也不高,主要原因是:(1)纯林化与针叶化严重。按第八次全国森林资源统计,纯林占人工林的85%,而且针叶化明显,人工乔木林10个优势树种中针叶林比例高达56.9%。人工纯林结构简单,生物多样性低,生物学上缺乏稳定性。人工纯林特别是针叶纯林,抗性低,抗自然灾害和大气污染能力均差,人工纯林维护地力的能力也弱。(2)集约育林的技术措施:立地控制技术未得到推广,适地适树适品种原则在育林中未能认真贯彻;密度、植被、地力控制技术也执行不力,大面积上的人工林仍属于粗放经营;连作引起林地土壤理、化、生物特性恶化,土壤质量衰退,导致林木生长不良,林分生产力逐代下降;造林作业造成水土流失,如杉木造林,传统的育林技术未得到明显改进,福建尤溪炼山后进行的3年观测结果表明,炼山和水土流失损失的有机质高达989.35 kg·hm^-2,养分586.26 kg·hm^-2。桉树在砖红壤进行的机耕整地,水土流失也很严重,不合理的造林作业,最终导致土壤质量与森林生产力下降。短周期培育人工林带来了2个重要问题,一是对林地肥力要求高,二是如何利用无性系才能保持长期生产力。短周期经营采用的无性系,生长速度快,生长量大,轮伐期短,养分需求量大,如刚果12号W5无性系,通常利用地上部分,以5~7 a的轮伐期计,消耗的养分达571.75 kg·hm^-2,我国培养短周期人工林的土壤质量本底原本普遍不高,如果采取连作,土壤有机质养分会明显下降,土壤质量衰退,并对其功能产生危害。我国杨树、桉树等人工林要达到短周期持续经营,还需要实行多无性系造林。我国人工林长期生产力保持的技术对策,应采取先进的集约育林措施,包括遗传控制、立地控制、密度控制、植被控制与地力控制。     

Teak (<Emphasis Type="Italic">Tectona grandis</Emphasis> L.) tree growth,stem quality and health in coppiced plantations in Java,Indonesia

Coppicing is an alternative reforestation tool for teak in the tropics, substantially reducing regeneration time/costs and associated demands for labor and seed when available. Growth rates of coppiced material are rapid in most situations, but stem/wood quality is a frequent concern. We compared coppiced teak plantations to paired seed-origin plantations, at ages 3, 8, and 13 years, on Forest State Corporation managed land located in Java, Indonesia. Teak trees were evaluated for height, diameter, lower-bole straightness, and presence of disease in both plantation types and at three ages. Mean height and diameter of trees in coppiced plantations were both significantly greater than that in their paired seed-origin plantations at all three ages. Furthermore, heights and diameters in coppiced plantations were higher than expected based on established growth tables for Java. Coppiced plantations were less symptomatic of disease than seed-origin plantations, which promises better wood production and quality. Lower-bole stems in coppiced plantations developed less straight than those in seed-origin plantations, but these deviations faded with time and will likely become insignificant within a 60-year rotation. Based on these results from existing coppiced plantations in Java, coppiced plantations can make a major contribution to teak production in Indonesia.     

桉树青枯病林地根际土壤营养分析

为了探讨桉树林地根际土壤营养状况与青枯病发生的关系,从广东省阳东县采集了3块不同健康状况样地的桉树林地根际土壤进行分析测定.结果表明:土壤pH值与桉树青枯病发病状况无显著相关性,土壤有机质、全氮、全钾含量在不同发病程度的样地间呈现健康林地＜中等发病林地＜严重发病林地的趋势.主成分分析表明,土壤有机质、全氮、全磷、有效磷4个成分的含量可能是反应桉树林地健康状况的主要因子.