矮沙樱桃(Prunus pumila var. depressa)综述

矮沙樱桃(Prunus pumila var. depressa)是分布于北美洲的固沙灌木树种。在全面了解矮沙樱桃的生物学特性及原产地气候与立地条件的基础上,分析了此树种的生态价值与经济价值,其推广应用对丰富三北地区固沙树种的多样性,将林业的生态效益与经济效益进行有机结合,实现三北工程的可持续发展具有一定的积极作用。     

油茶优良无性系嫁接苗真假判别技巧

油茶(Camellia oleifera Abel)是我国特有的木本油料树种,也是世界四大食用木本油料树种之一。茶油的特性与橄榄油特性相似,其不饱和脂肪酸高达85%,长期食用可以降低血液中的胆固醇含量,有利于预防心血管疾病,并且对于糖尿病等疾病也有一定的预防治疗作用[1],因此日渐成为市场上深受人们喜爱的木本食用油和国家南方退耕还林工程中首选的经济林树种。     

依托科研实力 培育优质苗木

<正>湖南富林生物科技有限公司系湖南省林业科学院所属经济实体,紧密依托湖南省林业科学院强大的科研创新实力,着力推广和应用林业新技术、新成果、新专利及国家级、省级良种。为支撑湖南林业重大工程建设,公司培育了优质良种苗木,包括珍贵树种苗木(红椿、榉木、闽楠、桢楠、赤皮青冈、青冈栎、香樟、南方红豆杉等)、速丰林树种(杉木、马尾松、湿地松等)、园林树种苗木、经济林苗木以及生物能源树种苗木等。公司秉持"科技引领生态林业民生林业、服务全省林业重大工程、服务"三林"的经营理念,重点参与全省林业重大工程和城市绿化工程政府采购招标,满足生产单位及重大工程对各类优质苗木的需求,同时可提供相关项目规划设计与营林作业施工方案编制、技术咨询与服务等。     

基于AHP模块编程和KBE技术的河北省野生树种木材直接利用价值评价

河北省野生树种的木材直接利用价值情况是判断该树种是否为珍贵树种及珍稀濒危树种必不可少的内容,对其进行系统地评价对野生植物在木材应用领域进一步开发利用具有重要的现实意义。编程设计出层次分析法(AHP)模块,通过该模块支持的软件页面录入数值,确定木材直接利用价值的各级指标权重值;利用河北省林木种质资源普查数据,结合知识工程(KBE)技术,获得参评野生树种对应的木材直接利用价值的具体指标权重,获得综合权重值并进行聚类分析,总结出分为4级的木材直接利用价值的河北省野生树种。     

广西国家储备林工程珍稀树种资源调查与分析

加强国家储备林工程珍稀树种资源调查与分析,对我国林业资源增长由数量型向质量型转变具有重要意义。文中在了解广西人工培育珍稀树种用材林资源现状的基础上,按照统一标准、统一方法、统一评价原则,调查广西国家储备林(一期)工程珍稀树种培育实际情况,分析珍稀树种资源种类、分布、面积、生长状况等情况。结果表明:珍稀树种培育总体保存率较高,保存面积3 318.83 hm2,占总调查面积的88.66%,其中幼树生长质量整体较好;同时,广西国家储备林工程珍稀树种资源培育存在培育技术不够成熟、珍稀树种培育面积较小、部分作业编制不合理等问题。结合实际情况,提出积极探索珍稀树种栽培技术、加强林区基础设施建设、保证多渠道资金投入、重视作业设计科学性的建议,为科学制定珍稀树种资源发展规划、规范经营和管理珍稀树种资源、有效提升国家储备林建设质量提供参考。     

木豆籽实贮存辐射防虫的研究

木豆 [Cajanus cajan( L.) Millsp]又名三叶豆、鸽子豆 ,为蝶形花科 ( Papilionoideae)木豆属 ( Cajanus)多年生的常绿灌木 ,是热带亚热带地区尤其是干热河谷地区荒山造林、退耕还林、改善生态环境的优良先锋树种[1 ] 。云南省已把木豆列为长江中上游防护林工程、澜沧江防护林工程、怒江防护林工程及天保工程的造林树种之一。目前中国林业科学研究院资源昆虫研究所已成功开发出木豆蛋白饲料 [2 ]、香酥木豆 [3]等用途 ,但由于木豆籽实在贮存期的主要害虫豆象[Callosobruchs maculates( F.) ]危害十分严重 (自然存放 3～ 5个月后 ,至少 80…     

研究树种混交的意义、原理和方法

(接上期)三、树种间相互作用的方式与调节树种间的相互作用是混交林不同于纯林的主要特点,正确认识和处理各树种间的相互关系是营造混交林的主要问题。(一)树种间相互作用的方式:共同生活的树种间特别是全部森林植物之间相互影响的方式,是多种多样的。在教科书中,一般把它分成两大类:(1)直接关     

香桂栽植技术

<正>香桂(Cinnconomiori Petrophthan N． Chao),属樟科(Lauraceae) 樟属,既是一种常绿绿化树种,同时又是一种经济树种,适宜栽植范围广,经济效益高。香桂枝叶能提取黄樟油素,可直接用于出口。由于只利用枝叶,不会造成新的水土流失,是退耕还林工程理想的造林树种之一。     

彩叶树种在哈尔滨市公园绿地的应用

通过对哈尔滨市公园中的彩叶树种进行调查,统计了彩叶树种的种类,结果表明,彩叶树种应用的数量与应用的种类不多,主要应用的彩叶树种包括茶条槭(Acer ginnala)、金叶榆(Ulmus pumila‘Jinye’)、卫矛(Euonymus alatus)等15种。存在的问题是使用的彩叶树种过于单一,季相变化少,此外,在景观规划上还存在与其他园林要素(如山体、水体、园林建筑等)的组合配置效果较差、群落组成相对简单的问题。     

10种亚热带绿化树种净化大气能力初步研究

通过对香樟(Cinnamonum campora)、广玉兰(Magnolia grandiflora)、银杏(Ginkgo biloba)、朴树(Celtis sinensis)、乌桕(Sapium sebiferum)、桂花(Osmanthus fragrans)、马银花(Rhododendron ovatum)、含笑(Michelia figo)、杜鹃(Rhododendron spp.)、三角枫(Acer buergerianum)10种亚热带绿化树种对大气中的粉尘、N、S、Cl 4种有害物质的吸收净化能力的初步测定,结果表明:单位面积滞尘量最高的树种是朴树,氮吸收最高的树种是乌桕,硫吸收最高的树种是银杏,氯吸收最高的树种是杜鹃;乔木树种的全氮含量、全硫含量、单位面积滞尘量都比灌木树种的含量高,但是全氯含量比灌木树种的含量低;落叶树种的各净化指标平均值都比常绿树种的高.     

Daily sap flow and maximum daily trunk shrinkage measurements for diagnosing water stress in early maturing peach trees during the post-harvest period

We compared the sensitivity of two continuously recorded plant-based water stress indicators (sap flow, SF, and maximum daily trunk shrinkage, MDS) to detect changes in the water status of 4-year-old early maturing peach trees (Prunus persica (L.) Batsch cv. Flordastar grafted on GF-677 peach rootstock) during a cycle of deficit irrigation and recovery. The feasibility of obtaining SF and MDS reference equations for use in irrigation scheduling during the post-harvest period was also studied in trees irrigated in excess of crop water requirements. We found that MDS was a more sensitive and reliable detector of changes in plant water status than SF, making it a more precise tool for irrigation scheduling. Baseline relationships between SF or MDS and the climatic variables (air temperature, vapor pressure deficit (VPD) and crop reference evapotranspiration (ETo)) were established, despite some scatter in the data. Among the climatic variables, SF correlated more closely with ETo, whereas MDS correlated more closely with mean daily air temperature (T (m)). The fits of the regressions between MDS and ETo, midday air temperature and T (m) for individual periods were better than those obtained in the overall regressions, confirming that daily stem diameter variations must be considered not only in the context of plant water status but also in the context of plant carbon status.     

Usefulness of diurnal trunk shrinkage as a water stress indicator in plum trees

We compared seasonal changes in maximum diurnal trunk shrinkage (MDS) with seasonal changes in midday stem water potential (Psi(s)) over three years in plum trees grown in differing drip-irrigated regimes. In well-irrigated trees, day-to-day variations in Psi(s) and MDS were related to evaporative demand. Reference equations were obtained to predict MDS and Psi(s) values for well-irrigated trees as functions of environmental conditions. A decrease in plant water status toward the end of the growing season occurred even in the well-irrigated trees, probably reflecting a reduced volume of soil wetted by the drip irrigation system. Thus, for the prediction of Psi(s), different reference equations are required for the fruit-growth and after-harvest phenological periods. A seasonal change in the relationship between MDS and Psi(s) was observed, which compensated for the decrease in plant water status such that well-irrigated trees had similar MDS values during both the fruit-growth and after-harvest periods. The influence of tree size on the relationship between MDS and Psi(s) was also investigated. For tree trunk diameters ranging between 8 and 13 cm, MDS increased 13% for each cm of increase in trunk diameter, as a result of the thicker phloem tissues of the larger trees. This finding may allow extrapolation of Psi(s) predictions based on empirical relationships with MDS to plum trees of different sizes.     

Evaluation of sap flow and trunk diameter sensors for irrigation scheduling in early maturing peach trees

Five-year-old early maturing peach trees (Prunus persica (L.) Batsch cv. Flordastar grafted on GF-677 peach rootstock) were subjected to three irrigation treatments from March 18 to November 10, 2006. Control plants (T0 treatment) which received irrigation in excess of their crop water requirements (1089.7 mm) were compared with plants watered according to sap flow (SF; T1 treatment) or maximum daily trunk shrinkage (MDS; T2 treatment) measurements, so as to maintain SF and MDS signal intensities (control SF/SF in T1 and MDS in T2/control MDS, respectively) close to unity. When SF or MDS signal intensity on at least two of three consecutive days was at or below unity, irrigation was reduced by 10%. When the MDS signal intensity on at least two of three consecutive days exceeded unity, irrigation was increased by 10%. During the experiment, estimated crop evapotranspiration was 704.9 mm, and the cumulative amounts of applied water in the T1 and T2 treatments were 463.2 and 654.5 mm, respectively. The MDS-signal-intensity-driven irrigation schedule was more suitable than the SF-signal-intensity-driven irrigation schedule because it was more sensitive and reliable in detecting changes in plant water status, preventing the development of detectable plant water stress. Moreover, it had no effect on fruit size. We conclude that peach tree irrigation scheduling can be based on MDS measurements alone. Changes in the irrigation protocol assayed were proposed to reduce MDS signal intensity deviations above unity, for example, by increasing the irrigation scheduling frequency or the amount of water applied, or both. Irrigation schedules based on maintaining MDS signal intensities close to unity could be applied when local crop factor values are unavailable.     

Crop load affects maximum daily trunk shrinkage of plum trees

We studied the effects of low fruit load (3-4 fruits cm(-2) of trunk cross-sectional area (TCSA), and high fruit load (6-7 fruits cm(-2) TCSA) on maximum daily trunk shrinkage (MDS) and trunk growth rates (TGR) over two seasons in plum (Prunus salicina Lindell) trees receiving full irrigation or deficit irrigation. Seasonal changes in MDS and TGR were compared with those in midday stem water potential (Psi(s)) and leaf stomatal conductance (g (s)). Crop load increased g (s) in fully irrigated trees approaching harvest. Although crop load did not affect plant water status in either watering regime, there were considerable differences in both MDS and TGR as a function of crop load. Compared with low-cropping [corrected] trees, MDS was 34% higher and TGR was 48% lower in high-cropping [corrected] trees. The differential responses of MDS and Psi(s) to crop load were a consequence of a higher MDS for a given Psi(s) in the high-cropping trees compared with the low-cropping trees. There was a linear increase in MDS with crop load, with a slope of 15.2 microm MPa(-1) per unit increment of crop load. In the fully irrigated trees, day-to-day variations in MDS were related to evaporative demand; however, the slope of the relationship between MDS and evaporative demand increased with crop load, indicating that different reference equations must be used to adjust for tree crop load when using MDS to determine plant water status and irrigation requirements.     

Site-specific water relations and stomatal response of Quercus ilex in a Mediterranean watershed

Intraspecific variations in the water relations and stomatal response of Quercus ilex L. were analyzed under field conditions by comparing trees at two locations within a Mediterranean watershed (l'Avic, Catalonia, NE Spain). Distinct environmental gradients exist between the two sites (referred to as ridge top at 975 m and valley bottom at 700 m) with greater soil depth for water storage, reduced radiation, reduced wind and higher water vapor pressure deficits at the valley bottom than at the ridge top. Osmotic adjustment and changes in tissue elasticiity did not significantly increase drought resistance in the trees studied. The leaf-to-air vapor pressure difference (Deltaw) threshold for inducing stomatal closure was higher at the ridge top (15.6 kPa MPa(-1) +/- 0.5 SE) than at the valley bottom (9.8 kPa MPa(-1) +/- 1.0 SE). However, increases in Deltaw beyond the threshold were followed by greater reductions in leaf conductance of trees at the ridge top than at the valley bottom. At both sites, maximum leaf conductance was related to predawn shoot water potential which, in turn, was related to watershed stream flow. The effects of water deficits during the dry summer of 1989 were more severe in trees at the valley bottom than at the ridge top. During periods of high evaporative demand, site-specific differences in the control of water loss led to more conservative water use by trees at the ridge top and, thus, to even greater drought avoidance (higher predawn water potentials) in late summer.     

水分胁迫对混播草坪生理生态特性的影响

为了研究混播草坪抗水分胁迫能力,采用盆栽试验与大田试验相结合的方法,以草地早熟禾（Poa pretensis）单播草坪（简称T1）为对照,以草地早熟禾、高羊茅（Festuca arundinacea）、多年生黑麦草（Loli-um perenne）混播草坪（简称T2,混播比例为6∶2∶2）和草地早熟禾、紫羊茅（F．rubra）、细弱翦股颖（Agrostis tenuis）混播草坪（简称T3,混播比例为5∶4∶1）为研究对象,分析水分胁迫对混播草坪生理生态特性的影响。结果表明,随着水分胁迫增加,3种草坪的外观质量综合评价表现为T1＞T2＞T3;单播草坪土壤含水量、叶片相对含水量及根系活力下降幅度均低于混播草坪,变幅表现为T3＞T2＞T1;而叶片叶绿素含量均值表现为T1＞T2＞T3。3种供试草坪抗水分胁迫能力表现为T1＞T2＞T3,T1适宜的土壤含水量占田间持水量百分比范围为84．5％～94．8％,T2为80．4％～91．8％,T3为77．5％～90．7％。     

Daily patterns of stem size variation in irrigated and unirrigated Eucalyptus globulus

High resolution measurements of stem diameter variation provide a means to study short-term dynamics of tree growth and water status. In this 14-month study, daily changes in stem radius of Eucalyptus globulus Labill. seedlings were measured with electronic point dendrometers in a plantation in southern Tasmania, Australia. The daily patterns of stem expansion and shrinkage were classified into three phases: shrinkage; recovery; and increase in diameter from one maximum to the next, or increment. This study showed that rapid onset of even mild drought in irrigated trees caused distinct changes in daily patterns of stem diameter variation, particularly the duration of daily stem increment. The duration of the daily increment phase was directly related to increment magnitude. The dynamics of daily increment were significantly affected by mean minimum temperature, indicating a temperature limitation on metabolic processes underlying diameter growth in these trees. Most likely due to differences in conductance, the duration but not rate of the incremental daily expansion was greater in fast- than in slow-growing trees.     

Comparative productivity of Prosopis cineraria and Tecomella undulata based agroforestry systems in degraded lands of Indian Desert

Tree-crop interactions were monitored by measuring tree growth characters of Prosopis cineraria L.and Tecomella undulata L.and yields of Vigna radiata(L) in agroforestry systems in degraded lands of Indian Desert.Potential competition for resource between the trees and associated crop was analyzed by measuring soil water contents, soil organic matters and NH4-N at different depths of soil layers i.e., 0-25 cm, 25-50 cm and 50-75 cm in the experimental plots.The plots size were 16 m × 18 m(D1), 20 m × 18 m(D...     

Effects of compaction and water content on lodgepole pine seedling growth

Soil disturbance by heavy machinery usually causes a decrease in porosity and an increase in soil strength, which may limit access to nutrients and compromise seedling survival and growth. This study used a soil strength and a greenhouse experiment to assess the impact of compaction on lodgepole pine (Pinus contorta Dougl. Ex. Loud. var. latifolia Engelm.) seedling growth and the degree to which soil water influences the effects of compaction. A silt loam soil was collected from a forest landing in the central interior of British Columbia (BC) in the Sub-Boreal Spruce Biogeoclimatic zone. The silt loam soil was used in a soil strength experiment where soil with four water content levels (0.10, 0.18, 0.27, and 0.36 cm³ cm⁻³) was packed into 0.21 cm³ cores with three levels of compaction (74, 79, and 84% of maximum bulk density (MBD)). Soil strength was strongly affected by compaction and water content. In the greenhouse experiment, three water content levels (0.10–0.15, 0.20–0.30, and 0.30–0.35 cm³ cm⁻³) and three levels of compaction (67, 72, and 76% of MBD) were applied to soil in pots and 1-year old lodgepole pine seedlings were grown in the pots. Soil strength was highest (1275 kPa) for the high compaction and dry water content treatment in the greenhouse experiment. Though the soil strength for this treatment did not exceed 2500 kPa, the effect of compaction on growth was noticeable, with a decrease in diameter growth, total shoot mass, and new root mass as compaction increased at the dry water content. At dry water content and high compaction, foliar nutrient concentrations were greatest. Generally, water content had a greater impact on seedling growth than did compaction, at the levels of compaction used in this study. This study indicates that if there is a critical value for mechanical impedance of the conifer roots, it likely occurs below 2500 kPa. Our results are consistent with the explanation that soil strength incrementally affects root growth below 2500 kPa for this soil type. Expensive rehabilitation techniques may not be needed on lightly disturbed soils similar to that used in this study if soil water content is high enough throughout the conifer growing season to alleviate the effects of compaction on soil strength.