南方红豆杉生物学、生态学特性及培育技术

为拓宽紫杉醇原料来源,昌宁县1998年起开展南方红豆杉引种种植,对南方红豆杉生物学、生态学特性进行了10多年观察,并研究不同的生境、不同的种子贮藏方法、扦插和实生育苗对南方红豆杉苗木生长的影响。研究结果表明,南方红豆杉的生理成熟期为7 a;雌雄比例约为7∶1;坡向因子对红豆杉高生长影响显著,阴坡红豆杉生长明显好于阳坡,红豆杉生长对湿度的要求较高;侧枝扦插所培育苗木无顶端优势,生长差,生产上种植红豆杉应选择种子播种育苗造林;种子覆土厚度以2.0~2.5 cm为佳,需加强出土不久幼苗的病虫害防治;营养袋直播育苗效果最好;鲜叶含水量随季节变化而变化,3月含水量最低。     

间作玉米对南方红豆杉幼苗生长的影响

研究了间作玉米对南方红豆杉幼苗生长的影响。结果表明：有玉米间作较无玉米间作的苗圃地南方红豆杉幼苗成活率提高6．66％,主梢生长提高29．68％,侧梢生长提高11．74％;主梢和侧梢生长规律不同,主梢的生长节律为双峰型,而侧梢为单峰型,速生期出现的时间也有差异。     

杉木林林分郁闭度对南方红豆杉幼树生长的影响

不同的杉木林郁闭度对在其林下套种的南方红豆杉的造林成活率、树高、胸径、冠幅生长都有显著影响。郁闭度为0．45～0．55时,南方红豆杉造林成活率最高,幼树长势也最好。     

南方红豆杉叶浸提液对小麦种子萌发与幼苗生长的影响

采用滤纸培养皿法研究了南方红豆杉叶浸提液对小麦种子萌发与幼苗生长的影响。研究结果发现,红豆杉叶浸提液对小麦种子的萌发和幼苗生长存在不同程度的抑制作用。低浓度的南方红豆杉浸提液促进小麦种子的萌发,高浓度浸提液抑制小麦种子的萌发。当浸提液浓度为6g/mL时,小麦种子的萌发率达到最高。南方红豆杉叶浸提液对小麦幼苗根系生长产生显著抑制作用。随着浸提液浓度的升高,小麦须根的长度逐渐下降,但不定根的数目逐渐增加。当浸提液的浓度为10g/mL时,根长抑制率达到42.48%。方差分析结果表明,南方红豆杉叶浸提液对小麦的根生长产生显著的抑制作用。对小麦幼苗的茎生长、根的生物量和茎的生物量均表现为低浓度的浸提液促进茎的生长和生物量的增加,高浓度浸提液则抑制茎的生长和生物量增加。研究结果表明,南方红豆杉浸提液表现低浓度时促进种子的萌发、须根数目的增加、茎的生物及生物量的增加,高浓度时则产生一定的抑制作用,而对根长的生长表现为显著的抑制作用。     

稀土微肥对南方红豆杉幼苗营养生长的影响

以3~5 a苗龄南方红豆杉幼苗为研究对象,设置喷施和灌溉两个处理,探究不同浓度梯度稀土微肥对南方红豆杉营养生长的影响。试验结果表明,在一定浓度范围内,稀土微肥处理对南方红豆杉幼苗的株高、地径以及枝条的生长均有明显的促进作用;随着稀土微肥量增加,各项生长指标呈现出明显的“低促高抑”现象,其中1.05 mmol/株用量灌溉处理效果最佳,与CK相比,株高增加35.9%,地径增加12%,新梢长度增加17.13%,分枝数量增加57.69%,均达到显著水平。适当浓度的稀土微肥处理可以有效促进南方红豆杉幼苗的生长与分化。     

坡位对南方红豆杉和檫树混交林早期成效影响

进行了坡位与南方红豆杉和檫树混交林早期生长的关系的试验。结果表明:坡位对1年、2年南方红豆杉和檫树混交林的成活率和树高均有不同程度的影响,成活率、树高之间存在显著至极显著差异。1年、2年成活率、树高均为下坡(C)中坡(B)上坡(A)。下坡1年、2年南方红豆杉:成活率分别为95.4%和93.3%(分别比其均值大4.9%和6.9%),树高分别为67.2 cm和104.6 cm(分别比其均值大17.1%和23.6%)。下坡1年、2年檫树:成活率分别为97.0%和97.0%(分别比其均值大2.3%和2.9%),树高分别为131.8cm和166.6cm(分别比其均值大7.5%和4.8%)。下坡对南方红豆杉和檫树混交林早期生长较为有利,上坡对南方红豆杉和檫树混交林早期生长则较为不利。     

闽南山地木荷林套种南方红豆杉的试验

为了解南方红豆杉在闽南山地生长所需的环境条件,开展了木荷林下套种南方红豆杉的试验研究,结果表明,在较高郁闭度的木荷林中套种南方红豆杉,随木荷林郁闭度的增大,南方红豆杉的树高、地径和生物量降低,叶绿素含量减少,养分含量下降。郁闭度为0.5的木荷林套种南方红豆杉,其生产力最高,叶绿素含量和养分含量均最大。     

南方红豆杉山地造林的坡向和苗木类型选择

坡向是影响南方红豆杉造林成活率和造林质量的重要因素,造林以选择阴坡或半阴坡为优,并且以2年生幼苗造林效果较好。此处,宿土苗春季造林成活率和秋季造林成活率都极显著高于裸根苗造林。     

遮荫网遮光度对南方红豆杉大田播种育苗苗木保存率和生长的影响

研究了4个遮光处理(即全光照、遮光度50%、遮光度70%和遮光度80%)下南方红豆杉(Taxus chinensis var.Mairei),1年生大田播种育苗苗木保存率以及苗木生长情况,结果表明:南方红豆杉幼苗苗木保存率随遮光度的递增而增加;遮光度为80%的处理下,苗木保存率最高,达到了80.5%,而全光照时则反之,仅有16.2%;南方红豆杉幼苗苗高和地径生长随遮光度的递增也呈现出递增的趋势;不同遮光度间苗高、地径生长差异均极显著;80%遮光度下南方红豆杉大田播种育苗效果最佳。     

南方红豆杉裸根苗不同处理对造林效果的影响

通过对南方红豆杉裸根苗不同处理造林对比试验,结果表明:采用生根剂、保水剂和杀虫剂对南方红豆杉裸根苗进行处理,能显著提高造林成活率、造林保存率,促进地径、树高和冠幅生长;生根剂、保湿剂和杀虫剂同时混合使用的效果最好。     

茶条槭山梨山桃苗木对土壤水分胁迫的适应性

在温室内用盆栽法栽植了1年生茶条槭、山梨和山桃苗木,并采用4种土壤水分处理,土壤相对含水量分别为75.0%、61.1%、46.4%和35.4%。结果表明:随土壤含水量降低,3树种苗木净光合速率,蒸腾速率和气孔导度均下降,土壤含水量最低时,茶条槭苗木各生理指标降低幅度最大,山梨和山桃次之。茶条槭和山梨水分利用效率随土壤含水量的减少呈降低趋势,山桃水分利用效率呈升高趋势。水分胁迫下,3树种苗木根分配生物量显著增加。茶条槭在水分胁迫下,根冠比增加幅度最大,山梨次之,山桃最小。此外,茶条槭叶形态可塑性强,随土壤含水量降低,茶条槭单叶叶面积和总叶面积显著减小,叶厚度增加。山梨和山桃在水分胁迫下单叶叶面积及总叶面积无显著变化。综合3树种苗木在水分胁迫下的生理和形态指标及生物量分配的变化,茶条槭对水分胁迫的适应能力强于山桃和山梨。表3参31。     

人工云杉林试验林窗环境特征及对幼苗存活的影响

本实验在四川省理县米亚罗人工云杉林中制造实验林窗,对林窗和林下的土壤温度、空气温度、空气相对湿度、光照强度、土壤pH值和土壤含水量进行动态监测。结果表明：相比于林下,实验林窗内土壤和空气温度分别增加0.46℃和0.35℃,实验林窗内的光照强度增加了69.7%。实验林窗内空气相对湿度比林下的略高,土壤pH值和土壤含水量在实验林窗和林下没有显著变化,但存在一定季节动态。对两种生境下云杉更新幼苗存活调查结果显示,林下生境中更新幼苗全部死亡,而实验林窗中幼苗存活率高达23.75%。总之,云杉人工林制造实验林窗尽管对诸多环境因子影响并不明显,但是光照强度的增加显著提高了更新幼苗的存活率。     

黑河流域荒漠地区水分胁迫对梭梭苗木影响的试验研究(英文)

梭梭(HaloxylonAmmodendronBge,一种C4灌木)苗种植在15升的容器中,给予不同的水分胁迫处理,研究了其水分关系和气体交换特征。结果表明:当土壤水分含量大于11%时,梭梭苗有高的蒸腾量;土壤水分含量低于6%时,苗木就不能从土壤中吸取水分;很好供水的苗木的蒸腾量与潜在蒸发量成线型相关。气体交换测定发现,随着土壤水分含量的下降,造成了不同程度的气孔导度、叶蒸腾强度和光合作用的下降。对同一苗木而言,由于这个地区有高的水气压亏缺(VPD),很好和中度供水的苗木在气孔反应方面有较宽的范围,气孔在决定光合作用方面起着较小的作用,二者没有明显的线型相关关系。虽然水分胁迫使蒸腾速率比光合速率下降的更快,提高了水分利用效率,而较高的蒸发需求增加了蒸腾量,限制了光合作用,但是总的趋势是光合作用和蒸腾强度成线型相关。图6表2参15。     

辽西干旱丘陵区竹节壕整地对造林成活率影响的研究

辽宁省西部干旱低山丘陵区人工造林成活率较低影响辽西干地区植被恢复与重建,为探索这一生态问题,进行了采取竹节壕整地方式对土壤含水量、造林成活率影响相关试验研究。结果表明,采取竹节壕整地技术措施,对提高造林成活率及促进幼树生长具有显的作用,土壤含水量提高58．8％～64．3％,造林成活率可提高41．5％～45．9％,幼树高生长提高158％以上。     

Effects of soil moisture and light intensity on ecophysiological characteristics of Amorpha fruticosa seedlings

We investigated the combined effects of soil moisture and light intensity on the growth, development and ecophysiological characteristics of one-year old Amorpha fruticosa seedlings. Soil moisture and light intensity influenced the ecophysiological characteristics of Amorpha fruticosa seedlings. Soil moisture resulted in the decreases of growth rate, individual size, net photosynthetic rate, transpiration rate, leaf water loss rate (WLR), and biomass accumulation of plant parts, and led to increased leaf water saturation deficit (WSD). Under water stress, more photosynthetic products were allocated to root growth. With decreasing light intensity, net photosynthetic rate, transpiration rate, chla/b, water saturation deficit, water use efficiency, water loss rate and biomass accumulation declined, while Chla, Chlb, Chla+b and carotenoids (Car) increased and more photosynthetic products were allocated to stem and leaf growth. Maximum growth vigor, net photosynthetic rate and total biomass accumulation in Amorpha fruticosa seedlings was recorded at 75 80% soil water-holding capacity and 100% light density in greenhouse environments.     

Gas exchange and water relations of Fraxinus americana affected by flurprimidol

Effects of flurprimidol on plant water relations and leaf gas exchange were investigated in one-year-old white ash (Fraxinus americana L.) seedlings subjected to soil water deficits. Flurprimidol (20 mg kg(-1) of soil equivalent) was applied to the soil surface of pot-grown seedlings after shoot growth was completed. Two months after flurprimidol application, water was withheld from one-half of the seedlings. Leaf water relations and gas exchange parameters were measured 5, 7, 10, 14, 18 and 22 days after withholding water. Under both irrigated and nonirrigated conditions, flurprimidol treatment resulted in reduced net CO(2) assimilation rate and transpirational water loss of seedlings as a result of decreased stomatal conductance. Consequently, flurprimidol-treated seedlings had higher leaf water potential and relative water content than untreated seedlings. Nonirrigated flurprimidol-treated seedlings also had greater turgor and sap osmolality and lower osmotic potential at full turgor than seedlings in the other treatments, indicating that flurprimidol increased osmotic adjustment. Under water-stress conditions, water use efficiency was lower and gas exchange efficiency was higher in flurprimidol-treated seedlings than in untreated seedlings, suggesting that flurprimidol treatment enhances survival of plants subjected to soil water deficits.     

珍稀濒危植物海南粗榧幼苗天然更新与环境因子的灰色关联分析

以1996—2005年观测数据为基础,运用灰色系统理论和方法,分析环境因子对海南粗榧种群内的海南粗榧植株各林龄存活率、幼苗高度增加比、幼苗高度增加值的影响。结果表明:年最高温度对各种群海南粗榧幼苗的存活率影响最大,年最低温度对各种群海南粗榧幼苗的植株高度年增加值影响最大,而土壤的厚度及湿度严重影响了海南粗榧幼苗的生长。因此,在保护海南粗榧野生种群的生长过程中,应注意其生长环境(主要是温度及土壤)对植株的影响,以便提高幼苗的存活率并改善植株生长状况。     

Adaptive responses of<Emphasis Type="Italic">Acer ginnala,Pyrus ussuriensis and Prunus davidiana</Emphasis> seedlings to soil moisture stress

One-year-old seedlings of Amur maple (Acer ginnala Maxim), Ussurian pear (Pyrus ussuriensis Maxim) and David peach (Prunus davidiana Carr) were planted in pots in greenhouse and treated with four different soil moisture contents (75.0%,61.1%, 46.4% and 35.4%). The results showed that net photosynthesis rate (NPR), transpiration rate (TR) and stomatal conductance (Sc) of seedlings of the three species decreased with the decease of soil moisture content, and Amur maple seedlings had the greatest change in those physiological indices, followed by Ussurian pear, David peach. Amur maple and Ussurian pear seedlings also presented a decrease tendency in water use efficiency (WUE) under lower soil moisture content, whereas this was reversed for David peach. Under water stress the biomass allocation to seedling root had a significant increase for all the experimental species. As to root/shoot ratio, Amur maple seedlings had the biggest increase, while David peach had the smaliest increase. The leaf plasticity of Amur maple seedlings was greater, the leaf size and total leaf area decreased significantly as the stress was intensified. No significant change of leaf size and total leaf area was found in seedlings of Ussurian pear and David peach. It was concluded that Amur maple was more tolerant to soil moisture stress in comparison with David peach and Ussurian pear.     

甘肃中部干旱地区抗旱造林(保水)技术浅议

在甘肃中部干旱区,造林成活的关键因素是水分,如何增加、保持土壤及苗木水分,提高造林成活率仍是当前和今后干旱造林研究的主要内容之一。就增水、保水提出了八条技术措施。重点对反坡梯田整地技术进行充分论证、肯定,认为此方法值得大力推广应用。     

Morphological and water-stress characteristics of three Douglas-fir stocktypes in relation to seedling performance under different soil moisture conditions

This one-time greenhouse study examined the phenology, morphology, frost hardiness and response to moisture stress of three Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stocktypes from the same seed lot. The types were mini-plug^TM transplants (MPT), 1+1 bareroot transplants (1+1), and 2+0 bareroot seedlings (2+0). In late summer and fall before lifting, 2+0 seedling set bud before 1+1 seedlings, 1+1 seedlings before MPT seedlings. The 2+0 seedlings appeared slowest to acquire frost hardiness in fall and seemed to deharden most rapidly in spring. Although the 2+0 seedlings were taller than the MPT stocktype, MPT and 2+0 seedlings were relatively similar in other morphological respects, but 1+1 seedlings were much larger. All stocktypes were potted on January 20, 1989, placed in a greenhouse, and subjected to 39%, 18%, 16%, or 6% soil water content (% dry weight) until the end of the experiment in mid-July 1990. The largest decrease in pre-dawn xylem water potential occurred with 16% and 6% soil water content; pre-dawn xylem water potential averaged over the three stocktypes generally declined 219% from low to high soil moisture stress. The 1+1 seedlings used more water than the other two stocktypes, and at maximum soil moisture stress, plant moisture stress increased in the order: MPT <2+0<1+1. During the 6-month greenhouse experiment, the larger 1+1 stocktype showed the most absolute growth, but the smaller stocktypes grew more on a relative scale. Growth of the stocktypes appeared to be related to differences in morphology and water-use patterns as the seedlings competed for available water within each pot. The results show that MPT seedlings, a new stocktype, performed as well as the more traditionally used 2+0 and 1+1 seedlings and that stocktype selection is important in reforestation efforts.