半干旱地区杨树丰产栽培技术研究

采用正交试验设计,对杨树人工林丰产栽培技术进行8a的试验研究,结果表明:4m×2m小区蓄积最高,4m×4m小区蓄积连年增长量最高;含碳酸盐黑钙土的干旱地区施磷肥最好;整地深度50～60cm为宜;最佳组合为每穴施磷肥150g、4m×2m密度、整地50～60cm。     

半干旱地区杨树速生丰产技术经验

实现杨树速生丰产 ,与树种的选择、苗木质量、造林技术 ,林分经营管理密切相关 ,是半干旱地区实现杨树速生丰产的关键和根本保证     

半干旱地区杨树新品种选育初报

文章通过青杨派的种间杂交,在半干旱地区的杨树新品种选育中,在4龄树时初选出金科5号优良无性系。金科5号在耐干旱、耐盐碱、速生等方面表现优良。     

半干旱地区杨树引种应用综合评述

在半干旱地区，杨树造林通过不间断地引种更新，提高了本地区杨树品种优良化水平，对增加林木生长量和提高生态防护功能效果显著。在杨树引种的工作中，结合本地区的气候特点和自然条件，坚持适地适树和循序渐进的原则，就能实现预期的引种效果。     

半干旱地区杨树中幼林的经营管理

杨树是喜光、喜水、喜温、喜肥的树种,因具有早期速生和无性繁殖两大特点,成为我国北方的主要造林树种。针对其早期速生性的特点,笔者认为应加强杨树中幼林水肥、土壤、树体、密度、生物灾害的管理,提高成活率、保存率、成材率、出材率,以保证和增加经营者收入。     

辽西半干旱地区杨树秋季造林技术

辽西半干旱地区降雨量少，空气干燥，风沙大，蒸发量大，土壤沙化，造林成活率低，是该地区杨树发展的一个亟待解决的问题。近年来为了提高杨树造林成活率，采用了固体水、保水剂和覆盖地膜等方法并取得了一些效果，但使造林成本显著增加，方法也相对复杂，使大面积造林受到一定的限制。此期间，我们在杨树人工林造林     

我国北部寒冷半干旱地区杨树引种和选择

我们从1984年开始在辽宁建平县北部老哈河沿岸进行杨树引种与抗寒选择试验。经过半个轮伐期测试,现已筛选出五个可供在本区推广的欧美杨和美洲黑杨耐寒良种无性系。一、试验地区自然概况本项试验设置在辽宁省建平县北部的国营黑水机械化林场。地理位置:东经119°15′—119°38′,北纬41°52′—42°22′。试验地区属于温带半干旱季风型大陆性气候区,主要气象指标为:年平均气温5.5℃,极端最低气温-31.4℃,≥10℃年积温2810℃,年平均日照2963h,年无霜期128天,年     

半干旱地区杨树死因及防控

近几年,内蒙古自治区赤峰市敖汉旗局部地区个别地段杨树发生死亡现象,直接威胁该旗尤其是北部生态安全,威胁生态建设成果,威胁群众经济利益。一、杨树死亡原因1.树种不适。适地适树是造林绿化的一项基本原则,杨树成活、成材对水肥等条件有着严格的要求,部分造林户为了追求经济效益,在不适合杨树生长地块栽植杨树,导致成活难、成     

半干旱地区杨树中幼林经营管理技术

杨树是一个喜光、喜水、喜温、喜肥的树种，且因具有早期速生和容易无性繁殖两大特点，成为我国北方的主要造林树种。针对其早期速生性，应加强杨树中幼林水肥、土壤、树体、密度、生物灾害的管理，提高成活率、保存率、成材率、出材率，保证和增加经营者收入。     

速生杨树品种生长差异性研究

片林试验地中 ,中林 4 6杨和 0 38杨的胸径生长比沙兰杨、山海关杨高 17.9%～ 2 9% ;树高生长高 2 5 .5 %～ 4 0 .4 % ;单株材积高 6 7.5 %～ 12 1.8%。林网试验地中 ,中林 4 6杨和 0 38杨的胸径生长比沙兰杨、山海关杨高 2 6 .6 %～ 4 7.3% ,树高生长高 18.9%～ 35 .8% ;材积高 86 %～190 .3%。     

滩地淹水胁迫对杨树生长影响的研究

不同淹水时间滩地8年生黑杨派南方型无性系胸径，树高生长均存在显著差异；随着林龄的增加，差异有所减小，表明其耐水淹能力随林龄的增加而有所增强。以单株材只，林木保存率为依据，划分不同淹水条件滩地的杨树宜林性，提出相应的林种规划，并开展生长预测研究。     

Stomatal characteristics of riparian poplar species in a semi-arid environment

Several native poplar species meet at the margins of their natural distributions in southern Alberta, Canada. In this semi-arid area, poplars are obligate riparian species but they occupy several intergrading ecoregions. Populus deltoides Bartr. ex Marsh predominates in the warmest and driest eastern prairie ecoregions; P. balsamifera L. occupies the cooler and wetter western parkland and montane ecoregions; and P. angustifolia James and hybrids between the species occur in the intermediate grassland ecoregions. We investigated stomatal characteristics of these poplars in 51 genotypes collected across the range of ecoregions and grown in a semi-arid common garden. Stomatal length differed among genotypes within species but did not differ among species, ranging from 19 to 22 microm. Total stomatal densities (adaxial plus abaxial) differed among genotypes within species but were similar among species (290-420 stomata mm(-2)). Single-surface stomatal densities differed among species and consequently, the ratio of adaxial:abaxial stomatal density also differed, ranging from 0.94 for P. deltoides to 0.27 for P. balsamifera, with intermediate stomatal density ratios in P. angustifolia and hybrids. In a subsequent study of a subset of the same genotypes, stomatal density was correlated with stomatal conductance (r2 = 0.75) and the conductance ratios differed among species in the same manner as the stomatal density ratios. We conclude that: (1) diverse poplar genotypes respond similarly to a semi-arid environment by producing comparatively small and dense stomata; (2) differences in stomatal density underlie differences in stomatal conductance and differences among species in stomatal density ratio or conductance ratio may reflect adaptation to climatic differences among ecoregions; and (3) there is substantial variation in stomatal characteristics within and among species and hybrids in this area that could be useful for the selection and breeding of poplars adapted to different climatic conditions.     

SV杨树专用肥施肥效应研究

通过对I-107杨的肥效对比试验表明:在黄土地区,施用SV杨树专用肥对1～2a生的杨树株高、地径的促增长效果显著。其中对扦插的杨树苗施SV杨树专用肥1a后,株高、径粗增长率分别比对照提高13.14%和44.62%;1a生杨树施SV杨树专用肥后,当年径粗增长率比对照提高47.93%,比施等量氮磷钾化肥提高45.35%。所以,SV杨树专用肥对幼苗期杨树的促生长作用明显。     

嫩江平原半干旱地区杨树人工林主要病害防治技术

嫩江平原半干旱地区杨树人工林由于品种过于单一,病害种类逐年增多,病情也在加重。资料显示目前在该地区杨树上已发现22种病害,严重影响了树木的生长和材质,同时也降低了其应有的防护效能。文章列举了杨树发生普遍、危害较为严重的烂皮病、杨枯梢病、杨树冰核细菌性溃疡病等3种病害,同时对不同的病害提出相应的防治措施。     

黑龙江省西部半干旱地区主要抗旱造林技术

1 整地保墒技术 在平坦缓坡地带可在造林前的1～2年秋季进行整地,深度20～25 cm.干旱沙地则在春季进行带状整地,带宽2～3 m,整地深度20～25 cm.水土流失严重的丘陵低山区,采取穴状和鱼鳞坑整地.据测算在造林前1年秋季整地可提高土壤含水率1.6%以上,该项措施已在该区普遍推广,并且作为造林绿化最基本的技术环节.     

丘岗地区杨树造林技术

对丘岗地区杨树造林地选择、造林整地标准,栽植材料的选择,栽植季节,修枝、病虫害防治技术等方面进行了初步探讨,为在丘岗地区营造杨树提供了科学理论基础和依据。     

Towards standardised crown condition assessment in poplar plantations

? This work aims at developing new tools for rapid assessment of forest health indicators in poplar plantations.

? Crown transparency and discoloration were visually evaluated in all trees of four 15 m-radius sub-plots in 32 poplar clonal plantations, which were chosen according to a factorial scheme with three factors: tree age, site quality and understorey vegetation management. A subset of trees was assessed using digital photos processed with a semi-automatic image analysis system (the CROCO software) in order to compare visual and digital crown transparency estimates.

? Poplar crown conditions were better in young stands and rich sites. Harrowing understorey vegetation improved tree health in poor sites. Samples of 20 trees per stand provided the same information about crown transparency and discoloration as 60 trees. Calibration curves of digital crown transparency estimates were successfully fitted against visual crown transparency estimates. The same effects of stand age and site quality could be detected with digital crown transparency as response variable.

? The use of digital photos processed with CROCO in ca. twenty trees per stand is therefore recommended to accurately and objectively monitor crown condition in clonal poplar plantations.