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1.
毛竹丰产培育的技术措施   总被引:1,自引:0,他引:1  
毛竹,是我国竹类植物中分布最广的竹种。东起台湾,西至云南东北部,南至广东和广西中部,北至安徽北部,河南南部,在北纬24°~32°,东经102°~122°的广大区域均有分布,垂直分布从海拔几米到1000多米的地方都有生长。要求温暖湿润的气候条件,年平均温度为15℃~20℃,年降水量800~1800mm。  相似文献   

2.
毛竹,是我国竹类植物中分布最广的竹种。东起台湾,西至云南东北部,南至广东和广西中部,北至安徽北部,河南南部,在北纬24°~32°,东经102°~122°的广大区域均有分布,垂直分布从海拔几米到1000多米的地方都有生长。要求温暖湿润的气候条件,年平均温度为15℃~20℃,年降水量800~1800mm。对土壤条件要求较高,适宜酸性沙质壤土,既要水肥条  相似文献   

3.
云南竹林基地建设应重视竹种选择和发展区划问题   总被引:5,自引:0,他引:5  
云南省地形地势复杂,气候类型多样,又有众多的江河水系,为竹类植物的汇集.发育、繁衍和迁移、传播提供了十分有利的自然条件。全省竹种分布达28属220种以上,是世界竹类植物的起源地和现代分布中心之一,也是世界上著名的天然竹林分布区。  相似文献   

4.
墨西哥柏引种试验   总被引:3,自引:1,他引:2  
墨西哥柏(Cupressus lusitanicaMill)原产墨西哥及危地马拉,分布于北纬15—27°,海拔1300—3300米的山地,分布区年平均气温10—17℃,最冷月平均温度4—14℃,最热月平均温度20—30℃,年降雨量1000—1500毫米,夏雨型或均匀分布,旱季2—3月,原产地气候为亚热带温和的半湿润至湿润气候。  相似文献   

5.
普通油茶是我国中亚热带主要木本食用油料树种,分布在北纬22°—33°,东经98°—122°的广阔区域,无论是分布区的中心,还是分布区的边缘地带,其产量变幅很大,表现极不稳定。目前,对于影响油茶产量的主要因素是什么,还是众说纷纭,莫衷一是,深为各地经济林工作者所关注。本文将阐述作者对此一问题的一点意见。  相似文献   

6.
气候变化对我国珍稀濒危树种--珙桐地理分布的影响研究   总被引:18,自引:2,他引:16  
本文在珙桐地理分布规律研究的基础上 ,应用地理信息系统IDRISI和专门计算机软件 生态信息系统GREEN ,找出适宜珙桐分布的气候参数区间 ,并以此确定了珙桐的适宜分布区 ,在此基础上根据全球气候预测模型GCMs 预测的 2 0 30年气候变化的结果 ,就气候变化对珙桐地理分布的可能影响进行了模拟预测。结果表明 :到 2 0 30年珙桐的适宜分布区将发生改变 ,其中 ,适宜分布区的东界约向西移动 0°1 8′~ 1°1 8′ ,西界东南段约向东移动 0°1 8′~ 1°5 4′ ,北界和南界变化不大 ;2 0 30年适宜珙桐分布的面积比当前气候条件下适宜珙桐分布的面积约减少 2 0 %。本文还结合珙桐的生物学特性和生态学特性 ,就气候变化对珙桐影响的可能性作了进一步的讨论。  相似文献   

7.
云南竹类植物分布与资源区划研究   总被引:2,自引:2,他引:0  
云南是世界上木本竹子资源多样性最富集的地区之一。文章从竹类资源分布、竹种多样性及竹林类型3个方面对云南省竹类植物分布与资源区划进行了研究。根据云南省自然地理环境的巨大差异性和复杂多样化的生境条件,将云南竹类资源划分为滇中暖性中小型混合竹类区,滇东、滇东南热性大型丛生竹区,滇东北暖性中小型散生竹类区,滇南热性大型丛生竹类区,滇西、滇西南热性大型丛生竹类区,滇西、滇西北寒温性小型混生竹类区等6个区;分别论述了各分区地理位置、竹类植物区系特征等。此外,文章初步总结了云南省竹亚科植物资源,截至2017年底共记载竹种41属389种。依据竹类植物分布区气候特点,将云南省竹林分为热性竹林、暖性竹林、寒温性竹林3个植被亚型以及41个竹林类型。  相似文献   

8.
云南箭竹的资源分布状况调查初报   总被引:2,自引:1,他引:1  
对分布在我国西南地区的云南箭竹的资源状况进行调查.结果发现云南箭竹的分布范围较广,其分布区介于北纬24°13'~28°58'之间,其生长适应海拔范围大概为1 700~2 600 m;最冷月的平均气温要大于4.2℃,年平均气温要介于17.8~19.7℃,年极端低温不能低于-11.2℃,≥10℃的积温不低于3 788.3℃;年降雨量平均为1 054.8 mm,介于559.4~1 600.0 mm之间,年平均有霜日数不能多于123.5d.目前发现云南箭竹共有3个变异类型即原变型,东坡竹和脱毛昆明实心竹,东坡竹主要分布在大理鸡足山,脱毛昆明实心竹主要分布在昆明市西山和嵩明县.  相似文献   

9.
日本落叶松引种育苗试验初报   总被引:1,自引:0,他引:1  
日本落叶松 ( Larix kaempferi)原产地日本 ,落叶乔木 ,高达 35m,胸径 1 m,适应范围广 ,前期生长较快 ,抗病性较强 ,在我国引种栽培已有 88年历史。日本落叶松的天然分布区为北纬 35°2 0′~ 38°1 0′。东经约为1 36°4 5′~ 1 40°30′的范围内 ,垂直分布于海拔高 90 0~ 31 0 0 m之间。日本落叶松是喜光树种 ,根系较浅 ,对气候的适应性较强 ,在年平均气候 2 .5~ 1 2℃ ,年降水量 50 0~1 40 0 mm的气候下都能生长。日本落叶松较华北落叶松有萌动迟、封顶及落叶晚、生长期的顶端优势强等特性 ,是良好的建筑材料。根据日本落叶松的生物…  相似文献   

10.
油茶栽培分布与立地分类的研究   总被引:39,自引:1,他引:38  
何方  何柏 《林业科学》2002,38(5):64-72
油茶立地分类即是在其栽培分布区各类生境对油茶适生程度的分类 ,是因地制宜规划发展油茶生产 ,进行宏观调控的科学依据。立地类型划分是油茶宜林地选择的技术方法。本项研究是在 1981年开始 ,历时 2 0a的相关研究基础上进行的。研究证明油茶栽培分布主要在北纬 2 3°30′~ 31°0 0′ ,东经 10 4°30′~ 12 1°2 5′。属中亚热带东段湿润季风区 ,包括湖南等 11省 (区、市 )的全部或部分。在分布区内共划分出 32个立地区 ,今后我国发展油茶应限制在立地区内。并根据地貌、坡度、土层厚度进一步划分出 36个不同的立地类型  相似文献   

11.
Although several Armillaria species have been reported in Turkey, there is little information about their ecology in Turkish forests. In this study, we investigated five forest stands, approximately 5–74 ha in size, in Kastamonu province in the Black Sea Region of Turkey for the presence of Armillaria species in stumps and logs. The stands were mixed Abies nordmanniana ssp. bornmülleriana and Pinus sylvestris forests managed using a selective cuttings system; the proportion of fir in the total number of stems and stumps ranged from 36 to 98%. Based on sequence analysis of the internal transcribed spacer and intergenic spacer regions of the rDNA, all rhizomorphs sampled from the stumps and logs were of Armillaria ostoyae. The size of the genets was estimated with random amplified microsatellites analysis of the isolates and ranged from single stumps to approximately 450 m2. One to seven genets were found in each stand. These results indicate that the genets had arisen from spores and vegetative spread was limited on most sites.  相似文献   

12.
通过对上海松江中央公园内65株特大银杏树白蚁为害情况的调查,发现该公园银杏受害率为100%,其中存在活白蚁的银杏占总量的56.9%,采用毒土处理、粉剂疗法、建立白蚁监测点等措施,经过两次灭杀,活白蚁的灭杀率达到92.3%和93.3%,从而使存在活白蚁银杏树的比例从56.9%下降到2.7%,白蚁发生情况明显降低。  相似文献   

13.
随着人们安全健康意识提高,食品中农药残留问题更加受到重视,本文综述了样品预处理研究进展及农药残留快速检测技术研究进展,并简单分析介绍各种方法的优缺点。  相似文献   

14.
建平半干旱地区石质山地造林技术研究   总被引:1,自引:0,他引:1  
研究了不同植物在石质山地的造林成活率、土壤化学性质随造林年限的变化和造林措施对土壤化学性质和植物胸径、树高年净生长量的影响。结果表明:不同植物在石质山地的成活率在21%~85%之间,其中白榆和沙打旺的成活率分别为81%和85%,而小叶杨、刺槐、栾树的成活率均在70%左右;植被能明显提高石质山地不同土层的有机质、全N、P2O5含量,但提高程度随土层深度、养分种类和造林年限的不同而不同;在同一土层,生物复合肥料、菌剂和保水剂均显著提高土壤有机质含量(p〈0.01)并显著降低土壤P2O5含量(p〈0.01);只有保水剂可引起土壤全K含量的明显升高;生物复合肥料、菌剂和保水剂均显著提高白榆、小叶杨、刺槐、栾树树高和胸径的年净生长量,但保水剂的提高程度最高。  相似文献   

15.
植物经常暴露在各种生物和非生物的胁迫之下,这些胁迫会影响植物的生长发育和繁殖并最终导致植物死亡。为了抵御不利的环境条件,植物已经进化出复杂而精细的网络来感知胁迫并激活防御系统。为此,植物激活许多信号转导通路,这些信号转导通路可以改变一些胁迫响应基因的表达,从而引起植物形态、生理和生化的改变以适应逆境。DNA胞嘧啶甲基化是高等真核生物的主要表观遗传机制之一,在维持基因组稳定性和调节基因表达方面起着关键作用。表观遗传变异比遗传变异更为灵活。一旦环境条件发生变化,为了适应新的环境植物都会发生表观遗传的改变。许多研究表明DNA甲基化参与植物的发育和应激反应。基于相关研究对DNA甲基化进行了综述,对植物逆境胁迫有重要意义。  相似文献   

16.
木材碳封存研究进展   总被引:1,自引:1,他引:0       下载免费PDF全文
碳封存可以分工业封存和生物封存,工业封存包括地质封存、海洋封存、矿石碳化以及工业循环利用,这些方法能快速回收CO2,但工艺流程技术复杂,成本较高.木材碳封存是生物碳封存的一种类型,树木光合作用吸收的碳主要存贮在木材中.运用木材密度、微密度等检测仪器,通过确定木材密度变化,结合其含碳率来计量木材的碳封存过程以及封存过程中碳的分配格局,同时研究其与环境因子的相关性,可以为研究森林的碳吸收动态提供便捷的方法和科学的依据.  相似文献   

17.
The study focused on the success of regeneration on patch cuts in spruce-dominated stands in terms of stocking and tree height. It was based on an experiment in the Kainuu region in northern Finland. The experimental design included 8 stands with 58 clearcut patches of variable size (0.09–0.37?ha), on which either natural regeneration without site preparation or site preparation and planting of Scots pine was applied. A regeneration survey was conducted 13–15 growing seasons after treatments. Patches without site preparation had been restocked quite well from natural seed sources. The average number of trees was about 11,000?ha?1, of which 1700?ha?1 crop trees. With site preparation and planting, the stocking levels were also very high, 25,000 and 2100?ha?1, respectively. One hundred percent of the planted patches and 75% of the naturally regenerated patches had an acceptable density. Restocking was equally good across the range of patch sizes. Tree growth had been somewhat slower in the smallest patches than in the largest ones in the range. Natural regeneration was capable of yielding good regeneration results in most patches, especially when site preparation was applied. Stocking levels and height development were higher yet in the planted patches.  相似文献   

18.
Abstract

The success of natural regeneration on patch clear-cuts in Norway spruce stands in Southern Finland was examined in terms of stocking and tree height. The experiment was established in mature spruce stands in the submesic Myrtillus (MT) site type. In each of the eight study sites, three plots were treated with clear-cutting and planting, clear-cutting with partial tree retention and planting, and patch clear-cutting without site preparation, respectively. In three of the study sites, one plot with patch clear-cutting and site preparation was established. Each plot was 1 ha, out of which three patches of 40×40 m were clear-cut in the patch treatments. 10–11 years after cutting, the patches had on average 1316 crop trees ha–1, of which 91% were spruces. Some 27% of the stands were up to the target stocking level (≥1600 ha?1), and 36% were at least satisfactory (≥1300 ha?1). Site preparation did not yield greater stocking levels on patches, but that result is ambiguous due to a difference in initial stocking. The average spruce tree height in the patches (0.76 m) was much smaller than in the case of clear-cutting and planting (2.42 m). In conclusion, the patches had been restocked tolerably well with spruce and birch for practical purposes during the 10- to 11-year period, but the regeneration process had been very slow compared to clear-cutting and planting.  相似文献   

19.
To investigate the changes in microstructures of wood with elapsed time in the environment, CO2 adsorption onto dry wood was measured at ice-water temperature (273 K) for samples aged from 0.1 years to over 1000 years. The micropore size distribution was obtained using the Horvath-Kawazoe method. Micropores smaller than 0.6 nm in wood decreased in number with elapsed time in the environment, and a negative correlation was found between cumulative pore volume for pores smaller than 0.6 nm and elapsed time in the environment. Cumulative pore volume in the 1000-year sample was almost half of that in the 0.1- year sample. Micropores smaller than 0.6 nm in wood with a few decades or more of elapsed time increased in number after rewetting and drying. Consequently, microstructures of wood with longer time elapsed in the environment were considered to be more stable, because of longer-term thermal motion and possibly more repeated moisture adsorption and desorption and/or temperature variation in the environment.  相似文献   

20.
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