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1.
苗圃转让     
今年顺义区苗圃绿化、美化苗木达1120多种、1.12亿株。其中油松、白皮松、华山松、雪松、桧柏、侧柏等常绿树13157亩,1650万株,占育苗总面积的23%;连翘、碧桃、榆叶梅、紫叶李、紫蔽、紫荆、月季、玫瑰、黄刺梅、黄杨、女贞等花灌木5468亩,1455万株,占育苗总面积的10%;白腊、元宝枫、栾树、国槐、银杏、合欢、龙爪槐、杜仲、千头椿、金丝柳、各种品种杨等落叶乔木37375亩,8095万株,占育苗总面积的67%。  相似文献   

2.
大丽花块根繁育和栽培技术   总被引:2,自引:0,他引:2  
大丽花(Dahlia pinnata Cav)菊科,大丽花属,多年生草本,原产墨西哥,又名大丽菊、大理花、天竺牡丹、西番莲、地瓜花,具有植株粗壮、花期长、花朵硕大,品种繁多、花色鲜艳、适应性强等特点。是美化公园,布置庭院、花坛、花境以及切花陈设的较好花卉材料。大丽花为世界名花之一,目前世界约有3万多个品种,我国有500余品种。  相似文献   

3.
木棉(Gossampinus malabarica)又名攀枝花、红棉、英雄树、烽火树,属木棉科木棉属落叶高大乔木.木棉广泛分布在我国四川、云南、贵州、广西、广东,生长在江河沿岸、山地阳坡及村边道路旁,喜光、耐高温,对土壤要求不苛刻.在四川攀枝花地区木棉树于1月-2月份开花,先花后叶,花色艳丽,有红色、金黄、淡黄色等颜色,树形高大伟岸,是优良的园林绿化树种.木棉树现是攀枝花市市花和广州市市树,在园林绿化中常作行道树、庭荫树、景园树、盆景树等.木棉经嫁接后2 a-3 a开花,嫁接苗可作盆景矮化栽培,观赏价值高.本文介绍了木棉的嫁接育苗技术.  相似文献   

4.
To improve multi-environmental trial(MET)analysis,a compound method—which combines factor analytic(FA)model with additive main effect and multiplicative interaction(AMMI)and genotype main effect plus genotype-by-environment interaction(GGE)biplot—was conducted in this study.The diameter at breast height of 36 open-pollinated(OP)families of Pinus taeda at six sites in South China was used as a raw dataset.The best linear unbiased prediction(BLUP)data of all individual trees in each site was obtained by fitting the spatial effects with the FA method from raw data.The raw data and BLUP data were analyzed and compared by using the AMMI and GGE biplot.BLUP results showed that the six sites were heterogeneous and spatial variation could be effectively fitted by spatial analysis with the FA method.AMMI analysis identified that two datasets had highly significant effects on the site,family,and their interactions,while BLUP data had a smaller residual error,but higher variation explaining ability and more credible stability than raw data.GGE biplot results revealed that raw data and BLUP data had different results in mega-environment delineation,test-environment evaluation,and genotype evaluation.In addition,BLUP data results were more reasonable due to the stronger analytical ability of the first two principal components.Our study suggests that the compound method combing the FA method with the AMMI and GGE biplot could improve the analysis result of MET data in Pinus teada as it was more reliable than direct AMMI and GGE biplot analysis on raw data.  相似文献   

5.
Natural spruce-fir mixed stand is one of the main forest types in the world,and also has huge ecological,economic and social benefits.According to the structural characteristics and succession laws of natural spruce-fir forest,it is urgent and significant to develop scientific management measures for natural spruce-fir mixed stand in line with local conditions.The article outlined the characteristics of the distribution and structure, regeneration and succession laws of natural spruce-fir forest,and analyzed the current situation and existing problems of natural spruce-fir forest management.The following recommendations were eventually made:1) In no cutting area,all logging activities should be banned.In a restricted cutting area,the cutting intensity should be generally controlled within 15%of the stock volume before cutting.On the commodity forest management area, the appropriate cutting intensity should be determined according to the volume per hectare,determine and classification management should be implemented in accordance with the characteristics of forest,to ensure the scientific selective cutting.2) Closure for afforestation,planting and repair planting should be adopted on vegetation-intensive land,sparse shrubs covered land and harvesting slash,in order to accelerate natural regeneration.3) The in situ conservation should be conducted in nature reserves and scientific experiment stations of rare and endangered species,such as Abies chensiensis,Picea neoveitchii,Abies vuanbaoshanensis,to reduce human destruction.4) It is supposed to collect seeds in time,establish nursery,actively establish forest, expand artificial population and promote natural regeneration.  相似文献   

6.
蚊子、苍蝇、螳螂、臭虫、蜘蛛、蚂蚁之类害虫,在家庭、工厂、办公室、医院、学校、酒店等地,随处可见,无处不入.这些昆虫不但给人们的生活带来很多烦恼,更重要的是,他们导致疾病传播,从而严重危害人们的身体健康.所以,根除害虫,改变居住环境,早已成为人们关注的问题.  相似文献   

7.
肥胖是一种常见的慢性疾病,它是由于生理化机能的改变而引起的体内脂肪沉积量过多,造成体重增加,导致机体发生一系列病理、生理变化的病症.肥胖症是一种全身性代谢疾病,除引起身体外形的改变外,过多的脂肪可带来物理性的负荷,还是各种疾病的"培养箱".肥胖人群平均寿命明显低于正常体重的人群,同时肥胖症还是心血管疾病、糖尿病、脂肪肝、肿瘤的温床,它是一种营养代谢性疾病.减肥首先必须从能量的摄入入手,减少热能的吸收.  相似文献   

8.
当前现代化的航天、航空、汽车、机械、电子、民用建筑、化工等行业迫切要求具备很高的力学性能及耐热、耐磨、耐化学性能的材料.因此高分子材料发展的一个重要方向就是通过对现有聚合物进行物理和化学改性,使其进一步高性能化、结构化、工程化.北京化工大学研制的聚氯乙烯合金是通过挤出机的力学、化学作用及接枝、复合技术使聚氯乙烯塑料工程化,成为物理性能可与ABS相比拟的新材料.聚氯乙烯合金具有高流动性、高韧性,完全可以代替ABS注塑计算机、电视机、冰箱、照相机、仪表等外壳.聚氯乙烯合金还具有良好的耐寒性,可制作各种规格的异型材,包括门窗、上水管道等.产品市场前景好,具有很强的竞争力,有很好的经济效益和社会效益.  相似文献   

9.
According to the unification principle of system structure and system function of the Water Resource Conservation Forests,seven factors were selected from stand spatial structure,trees structure and healthy of woods,the multifunction management optimization model target was confirmed by using nonlinearity multi-objective programming approach, and the target function-stand spatial structure homogeneity index was defined to establish spatial optimization models with restraining conditions set up in diversity of stand structure and spatial structure.The spatial structure of available typical stand in the wet land area in southern Donting Lake was optimized by means of selective cutting and reinforcement planting.The results showed that the spatial structure was improved obviously and trees diversity and stand health were not weakened.It’s suggested that the established optimization model can effectively guide multifunction management,stand structure optimization and the steadiness of ecological ecosystem and it is convenient and operable in practice,and it’s very important to protect and recover ecosystem of Water Resource Conservation Forests.  相似文献   

10.
This paper proposes an automatic method of pore combination recognition,which is an important feature to hardwood recognition.After extracting edge from wood microscopic cross-section, based on area histogram of the similar circle regions,the method classifies all regions into two classes with maximum between-class variance,so as to distinguish the pore from other textures,which are similar in shapes but different in sizes.Meanwhile, second objective function about average area of closed regions is used to improve the pore segmentation performance.At last,the method uses adjacency degree of pore set to judge pore combination.The experiments demonstrate that the task of pore segmentation can be completed successfully for all kinds of pore distribution and combination,and also the correct combinations of pores are given.  相似文献   

11.
杨树刺槐混交林下沙质土壤腐殖物质特性   总被引:6,自引:0,他引:6  
研究了沙质土壤种植杨树、刺槐纯林和混交林后土壤腐殖物质特性变化的状况。研究结果表明:与无林地相比,沙地土壤种植树、刺槐纯林和混交林后土壤有机C和腐殖质C增加,土壤胡敏酸的光密度值增大,胡敏酸/富啡酸比值上升,E4和Ec值提高,色调系数(△logK)降低和相对色度(RF)升高,土壤松结合态腐殖物质(Ⅰ)和紧结合态腐殖物质(Ⅲ)以及松/紧(Ⅰ/Ⅲ)比值均有不同程度的增加,土壤稳结合态腐殖质(Ⅱ)的含C量占土壤全C的比例有不同程度的下降,表明土壤腐殖物质的聚合程度提高,腐殖物质的芳香核原子团增多,芳化度和芳化分子复杂程度以及腐殖化程度均得到提高,腐殖物质的品质变佳,土壤熟化度增大,土壤供肥保肥的能力增强,土壤肥力得以提高。培肥土壤的效果以种植杨树枣槐混交林为,其次为刺槐纯林,再次为杨树纯林。  相似文献   

12.
杨树、水杉林带枯落物对土壤微生物C、N的影响   总被引:11,自引:0,他引:11  
钟哲科  高智慧 《林业科学》2003,29(2):153-157
杨树 (Populusspp .)、水杉 (Metasequoiaglyptostroboides)是我国亚热带滨海盐土的重要造林树种 ,它们生长快且能耐轻度盐碱 ,因此常被作为这一地区复合农林业的理想树种 (钟哲科等 ,1 996 )。由于滨海地区处于陆地和海洋的交界处 ,自然环境较为恶劣 ,自然灾害频繁 ,因此复合农林业系统的研究和应用已成为保障这一地区农业持续稳定发展的重要措施。关于林木对小气候调节、改善生态环境等研究已有不少报道 ,但关于林木枯落物在复合农林业系统中对土壤微生物的作用 ,研究仍很少。植物枯落物是复合农林…  相似文献   

13.
黄土区人工林的土壤持水力与有效水状况   总被引:33,自引:0,他引:33  
以晋西北黄土区河北杨林,小叶杨林和柠条灌木林为对象,就各人工林地的土壤持水力和在4个不同降水的土壤有效水动态特点进行了研究。结果表明,林地间土壤持水力和比水容量为:河北杨林〉小叶杨林〉柠条灌木林。各林地的土壤持水力和供水力普遍偏低。  相似文献   

14.
毛白杨光合作用与土壤水分间关系的研究   总被引:2,自引:0,他引:2  
对不同土壤水分条件下生长的3~4 a生毛白杨幼林根系分布层土壤水分的动态监测和叶片光合作用的定期测定表明,毛白杨幼树光合作用速率与土壤水分呈正相关;净光合速率随土壤水分变化的轨迹呈S形曲线。在田间持水量40%~60%范围内,光合速率因水分下降而急剧降低,光合作用速率的日变化也与土壤水分含量有关,持续干旱对光合作用影响更大。  相似文献   

15.
沙地杨树刺槐人工混交林的改良土壤功能及养分互补关系   总被引:12,自引:1,他引:11  
杨树刺槐混交林是我国北方地区沿河及滨海沙地上成功的固氮树种和非固氮树种人工混交林。本文在简单介绍混交林生长情况的基础上,主要对林地土壤养分改良及其种间N、P养分互补关系进行了阐述。指出杨树刺槐混交林生产力提高主要是因为林地土壤养分(特别是N素养分)的极大改善及树种间N、P养分的互补。混交林土壤N素养分水平提高的根本原因是林地土壤微生物活性高,加快了含N较高枯落物分解速度,增强了土壤氨化及硝化强度。而杨树刺槐种间的N、P养分互补则主要表现在混交林中杨树可将吸收入体内的P素通过根系接触转移给相邻的刺槐,而刺槐则可将固定的N素通过根系接触转移给杨树,而且N、P转移的强度很大。这种奇妙的树种间养分互补机制对杨树刺槐混交林幼林期生产力提高是有重大意义的。  相似文献   

16.
金佛山方竹林水源涵养功能的初步研究   总被引:1,自引:0,他引:1  
金佛山方竹(Chimonbambusa utilis)不仅是材、笋两用竹种,而且是涵养水源,保持水土的优良竹种,但以往缺乏这方面的研究,为了较系统地揭示方竹蓄水保土的功能。本次对金佛山方竹的林冠层、枯枝落叶层、土壤层的蓄水保土功能加以调查;同时为了便于比较还结合调查其它的林分。通过研究其结果: 1.林冠截留量: 方竹>针叶混交林>针叶纯林 2.枯枝落叶层蓄水量亮叶水青冈—方竹林>方竹林>针叶混交林>针叶林 3.土壤层的蓄水功能方竹林>亮叶水青冈—方竹林>马尾松林>枫香×麻栎林从而,本研究将为防护林建设中重视竹子的功能与作用,为适地适竹,合理选择与配置树种提供较可靠的依据。  相似文献   

17.
植被恢复对高寒沙区土壤性质的影响   总被引:2,自引:1,他引:1       下载免费PDF全文
[目的]明确高寒沙区不同植被类型对土壤性质改良效果的差异,探讨各植被区沙地土壤恢复过程的异质性和人工林木的可开发利用潜力。[方法]以沙珠玉治沙试验林场内不同生长年限的人工植被为研究对象,分析高寒沙区6种植被类型区(乌柳、青杨、赖草、柠条、沙棘、柽柳)以及3个对照区(农田、流动沙丘、丘间沙地)土壤的机械组成、p H值、有机质及全N、全P、全K等理化性质指标。[结果](1)植被恢复生长51年后,从黏粒和粉砂粒增加的比例角度分析,土壤质地改良顺序为沙棘(206.3%)柠条(108.5%)青杨(70.5%)乌柳(56.8%)赖草(54.1%)柽柳(42.3%);从全N、全P和全K增加的比例角度分析,土壤养分改良顺序为青杨(198.2%)柠条(166.7%)沙棘(155.3%)乌柳(82.6%)赖草(75.4%)柽柳(53.9%),土壤全P含量偏低,平均0.42 g·kg-1;(2)植被恢复生长51年后,柠条、沙棘、青杨、赖草、乌柳和柽柳林下0 30 cm土壤有机质含量依次为20.19、18.25、30.81、23.57、22.13和10.62 g·kg-1,比流动沙丘或丘间沙地相应的提高了766.7%、702.4%、689.8%、517.4%、491.5%和343.9%。[结论]随着植被恢复年限的增加,土壤质地和养分状况得到显著改善,但土壤p H值的变异系数较小;各样地土层间有机质含量差距不断扩大,表聚性越来越明显,并且随深度增加各土层恢复效果存在滞后性。柠条和沙棘适宜在共和盆地推广种植,建议实施适当地抚育管理措施,以促进高寒沙区林场实现可持续经营发展。  相似文献   

18.
库布齐沙漠东北缘人工林土壤水分含量的变化   总被引:1,自引:0,他引:1  
在干旱季节研究了沙柳和杨树固沙林土壤含水量的变化,结果表明:随着固沙植被的恢复,土壤水分状况具有恶化的趋势。流动沙丘(对照)0~60 cm土层含水量好于沙柳林地,而在60 cm土层以下深度,土壤含水量有趋同的变化。杨树固沙疏林(郁闭度0.2)0~100 cm土层含水量高于对照(固定沙地),而郁闭度0.4及其以上的杨树固...  相似文献   

19.
在3种土壤含水率条件下,研究了I-69杨插条苗的苗高、叶面积等生长进程和生物量。不同供水条件下苗木的生长进程相似,低供水处理封顶期提早10~15d.生物量测定表明,I-69杨十分喜水,高供水处理(土壤含水率保持在田间持水量的96%)的生物量为低供水处理(土壤含水率为田间持水量的55%)的2.74倍。  相似文献   

20.
沙质海岸木麻黄混交林防护效能和改土效果研究   总被引:4,自引:0,他引:4  
通过木麻黄分别与厚荚相思、刚果 12桉、湿地松混交造林研究表明 :木麻黄混交林与木麻黄纯林相比能有效提高防风固沙效能和改善土壤的肥力状况 ,其中以木麻黄与厚荚相思混交表现得最明显 ;木麻黄与刚果 12桉混交次之 ;木麻黄与湿地松混交第三。木麻黄厚荚相思混交林是沿海地区沙质海岸理想的防护林类型  相似文献   

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