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青檀,为我国特产树种。其适应性强,在石灰岩山场生长良好,较耐旱和瘠薄,根系发达,萌蘖性强,可经营矮林作业以截取枝条。枝皮富有纤维,绵韧易剥,是制造宣纸的特需原料。一、播种育苗青檀种子具有生理休眠特性,且种子个体的休眠深度差异较大。种子催芽方法,一是将种子装入木桶内, 相似文献
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The competition-density (C-D) effects for mean mass for tree, stem, branch and leaf were analyzed in Acacia auriculiformis stands. Mean tree mass-density and mean organ mass-density were well explained by the C-D equation of tree and the C-D equation of tree organ, respectively. An equation describing the relationship between mean leaf area u and density was formulated that fit the u-data well. The relationship between mean tree mass w and the ratio of each organ to mean tree mass (wo/ w) was examined. With increasing w, the stem mass ratio wS/w increased, whereas the branch mass ratio wB/w and the leaf mass ratio wL/w decreased. The yield difference between the lowest-density stand and the high-density stand became greater with stand growth. However, the yield of the mid-density stand was slightly lower than the yield of the high-density stand during the experimental period. To produce the most desirable combination of demanding individual-tree size and relative high stem yield, the mid-density is recommended as proper planting density for future management of A. auriculiformis stands. 相似文献
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《技术与市场》2007,(1):6
我国太阳能资源十分丰富,目前最主要的利用方式是用于城乡居民热水供应,我国太阳能热水器已经安装了6000万平方米,预计2020年和2050年将分别达到2.7亿和5亿平方米,将替代高峰电力8000万千瓦和2亿千瓦,节约1200万千瓦和30000亿千瓦时的电能.我国太阳能热水器已经成为太阳能利用中应用最为广泛、产业化发展最迅速的领域,太阳能热水器的生产量和使用量都居世界第一.至2003年底,全国太阳能热水器使用量达到5200万平方米,占全球使用量的40%以上.目前我国太阳能热水器生产厂家超过3000家,年生产量超过1000万平方米,全真空玻璃管热水器在世界市场上占据主导地位. 相似文献
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收集了11省(市)23县(市)的23个鱼腥草种质资源,在浙江省丽水市林业科学研究所百果园基地进行种源特性观察试验,结果表明,23个种源从形态特征上可分为二大类,一类为生长初期叶绿色,茎节间较长,生长盛期叶翠绿色,叶缘波状,茎浅红色;另一类为生长初期叶带紫红色,茎节间较短,生长盛期叶墨绿色,叶近全缘,茎紫红色、浅红色或绿色。物候期较为一致,可分为破土萌芽长叶期(2月下旬到3月下旬)、快速高生长期(3月底到4月中旬)、开花结果期(4月下旬到6月底)3个阶段。不同鱼腥草种源在高、径生长和蒴果、种子数量等方面均存在显著差异。高生长以18号(浙江嵊州)种源最好,平均高度达83.08cm,15号(安徽绩溪)种源最低,仅为41.08cm;径生长以4号(云南会泽)种源最好(0.5063cm),15号(安徽绩溪)种源最差(0.3cm)。综合性状以4、18、19(浙江长兴)、12(浙江嘉善)、5(贵州安顺)、17(浙江泰顺)等种源表现较好,能获得较高的生物量。单果序蒴果数以7号种源(河南正阳)最多,达83.4颗/果序,蒴果内种子数以10号种源(广函柳州)最高(22.67粒/蒴果),综合蒴果和种子数量以10、5号种源较好。 相似文献
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2008年4月1日,湖南省怀化市召开森林消防应急营成立大会,并举行了检阅仪式和实战演习.森林消防应急营共有340人,下设4个连和1个特勤队.人员分别由中坡国家森林公园护林员、国有泸阳林场一线产业工人和武警怀化支队官兵、怀化军分区预备役战士、武警怀化消防支队官兵组成. 相似文献
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Soil organic carbon(SOC)mineralization is closely related to carbon source or sink of terrestrial ecosystem.Natural stands of Larix olgensis on the Jincang forest farm,Jilin Province were selected to investigate the dynamics of SOC mineralization and its correlations with other soil properties in a young forest and mid-aged forest at soil depths of 0–10,>10–20,>20–40 and>40–60 cm.The results showed that compared with a mid-aged forest,the SOC stock in the young forest was 32%higher.Potentially mineralizable soil carbon(C0)in the young forest was 1.1–2.5 g kg^-1,accounting for 5.5–8.1%of total SOC during the 105 days incubation period and 0.3–1.5 g kg^-1 in the mid-aged forest at different soil depths,occupying 2.8–3.4%of total SOC.There was a significant difference in C0 among the soil depths.The dynamics of the SOC mineralization was a good fit to a three-pool(labile,intermediate and stable)carbon decomposition kinetic model.The SOC decomposition rate for different stand ages and different soil depths reached high levels for the first 15 days.Correlation analysis revealed that the C0 was significantly positively related with SOC content,soil total N(TN)and readily available K(AK)concentration.The labile soil carbon pool was significantly related to SOC and TN concentration,and significantly negatively correlated with soil bulk density.The intermediate carbon pool was positively associated with TN and AK.The stable carbon pool had negative correlations with SOC,TN and AK. 相似文献
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重阳木,为大戟科重阳木属落叶乔木,生长高大,枝叶茂密,树姿优美,城镇绿化多见孤植大树或小片成群栽植。重阳木深根性,抗风力极强,又是生长快的阳性树种之一,有些地方用以作防护林或用材林,效果很好。2005年,祁门县对赤岭口公路两旁重阳木进行病虫害调查,发现重阳木白带黑斑蛾幼 相似文献
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不同造林方法对马尾松林分生长和分化的影响 总被引:1,自引:0,他引:1
对容器苗工程造林、裸根苗工程造林和裸根苗一般造林的马尾松林分进行跟踪分析认为,在立地条件较好的情况下(Ⅰ、Ⅱ类地)选择马尾松容器苗工程造林,对林分树高、胸径的生长较为有利,分化程度小,能达到速生丰产的要求;在立地条件较差的林地上(Ⅲ类地以下)选择棵根茵工程造林较为经济;裸根苗一般造林的马尾松林分生长缓慢,林分分化程度大,不符合速生丰产的要求。 相似文献
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台湾杉、秃杉引种栽培试验及生长效果分析 总被引:3,自引:0,他引:3
通过在福建省闽清美菰林场引进台湾杉与秃杉进行育苗和造林试验,结果表明:相同或不同海拔营造台湾杉与秃杉纯林,其两种树种间或不同海拔之间的林分主要指标的生长量差异不显著。试验还表明台湾杉与秃杉是福建省高海拔山地造林较为优良的用材树种,速生期长,可以扩大造林范围。 相似文献
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穴植方式对油松造林成活率与成本的影响 总被引:1,自引:0,他引:1
油松幼苗采用单株、双株两栽植点、3株丛植3种不同穴植方式进行栽植,运用标准地调查法,调查并分析了其造林成活率与投入成本。研究结果表明:油松穴植的成活率主要与栽植技术和造林地有关,单株、双株两栽植点、3株丛植成活率都达到95%以上,三者基本没有差异。从造林成本来看,单株费用最少,效果较好。建议在今后大面积造林中,大力提倡每穴单株造林。 相似文献
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Willow buffer strips are a promising vegetated filter for the reduction of non-point source pollution from agricultural land
to watercourses resulting from the rapid growth of shoots and from the large amount and distribution of roots. A greenhouse
experiment tested the hypothesis that a new planting method, planting cuttings horizontally, exhibited more biomass production
and more effective filter than did planting cuttings vertically. Due to the different times taken for shoots break through
the soil surface, the summed height of all shoots of horizontally planted cuttings was significantly smaller than that of
the vertical ones at the beginning of the growth period. The difference in the height of all of the shoots between planting
orientations decreased with time. After 16 weeks growth, the biomass of the stem, leaves and fine roots was not affected by
the planting orientation. The coarse root biomass was larger in the horizontal treatments and decreased with increased density.
The total biomass, as well as the biomass of stem or leaves, of each treatment, increased with increased planting density.
The individual plant biomass, as well as that of the stem or leaves, decreased with increased planting density. Compared with
the unplanted control treatment, the planted treatments significantly reduced the total-N, NO3-N, PO4-P and SO4-S leaching. The planting orientation did not affect the nitrate leaching. The horizontally planted cuttings were slightly
more effective for reducing the SO4-S leaching and the vertically planted cuttings were slightly more effective for reducing the PO4-P leaching. Lower PO4-P leaching was observed only with higher planting density. With regard to the horizontal planting method, further studies
are needed to explore the influence of different willow clones, the size of cuttings, pre-planting treatments, planting geometry
(configuration) and soil conditions on survival, the number of shoots produced, the biomass production and the amount and
distribution of roots. 相似文献
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通过研究川东北丘陵地叶用银杏不同栽植密度对其生长量和叶产量的影响,获得高经济效益的合理密度调控方向,为生产实践提供理论支持。本文以2年生“开江皇1号”银杏为供试材料,采用单因素试验设计,分别作5种不同栽植密度处理,连续三年观测研究不同栽植密度对叶用银杏生长量及叶产量的影响。结果表明,在川东北的地理环境条件下和一定的密度范围内,叶用银杏基地建园首年,栽植密度对其地径和侧枝影响不大,随着树龄增加,栽植密度过大的叶用银杏园相比低密度园,其地径生长量和侧枝数呈减缓增长趋势,不同栽植密度对叶用银杏树高生长无显著性影响;当叶用银杏低于4.5年生,栽植密度为10万株·hm?2时,其叶产量比栽植密度为1.4万株·hm?2的低密度处理的叶产量高2.76倍,叶产量达到20428.00 kg·hm?2,在5.5年生时,栽植密度为10万株·hm?2的高密度栽植处理,其叶产量比4.5年生时下降15.93%,而栽植密度为1.4万株·hm?2的低密度栽植处理,其叶产量却高达41322.60 kg·hm?2,是同年生高密度栽植处理叶产量的1.41倍。因此,在川东北丘陵区,叶用银杏盛产期前,基地栽植密度最高可保持10万株·hm?2,随着树龄增加,栽植密度应逐年降低,盛产期时,密度宜保持在1.5万株·hm?2左右,这样可做到单位面积经济效益最大化。 相似文献
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调查了海南香荚兰人工荫棚集约栽培、分散栽培和活荫蔽树下粗放栽培种植园的生产投入、种植面积、生产管理情况、管理特点和产量水平,提出今后香荚兰生产应控制集约的种植面积,发展分散式种植和粗放式种植 相似文献
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为了探讨适合北方地区文冠果造林的技术体系,特选择整地深度、栽植时间、栽植密度3个因子开展研究,比较了不同因子处理下文冠果的生长情况,结果表明:北方地区文冠果造林前整地深度以30 cm左右为佳,春季栽植的效果比秋季栽植好,适宜的株行距为2 m×2 m,结实量为16841个·hm-2,种子产量为221.8 kg·hm-2。 相似文献