无锡太湖丘陵引种北美栎树试验初报

在北亚热带地区太湖丘陵地引种美国红栎、南方红栎、北方红栎、柳叶栎、水栎的试验测定表明,上述国外栎树均能适应无锡气候,安全越冬、越夏,并正常生长发育,幼龄期尚未见明显病虫危害。3～5年生年均生长量为水栎>柳叶栎>南方红栎>红栎>北方红栎。秋叶变色期红栎最早,且红叶持续时间最长,柳叶栎变色较迟;水栎为半常绿型变色树种。从幼龄生长表现看,可选水栎、柳叶栎为丘陵地或低湿地优良景观用材树种,选红栎、南方红栎为城镇园林绿化观赏树种,在构建城市森林生态网络中扩大应用。北方红栎目前表现较差,尚待进一步观测。     

7种国外栎树引种苗期试验初报

于2000年和2001年从北美引进南方红栎、北方大果栎、水栎、柱栎、黑栎、北美白栎和英国栎等7个树种,15个种源在江苏进行育苗试验结果表明,不同树种、种源间发芽时间、场圃发芽率、苗高、地径生长性状有明显变异。种子发芽时间柱栎、黑栎依阿华和密苏里种源最早;其次为北方大果栎伊利诺斯种源、南方红栎阿肯色种源、黑栎安大略种源,水栎各种源发芽均迟。总出苗率以黑栎密苏里种源最高（达83.3%）,水栎得克萨斯种源和北方栎蒙大纳种源较低（仅为15.7%和20.0%）。1年生苗高生长量以英国栎最大,其次是南方红栎、北方大果栎和水栎,黑栎和北美白栎生长量最小。同时,还研究分析比较了不同树种苗高季节生长节律。     

3种北美栎树引种应用研究进展

纳塔栎、柳叶栎和弗吉尼亚栎是优良的北美树种,在我国引种种植已有10 a多时间,国内研究人员从引进、育苗、栽植、观测、筛选、扩繁和推广方面进行了大量试验研究。该文收集了相关文献,总结了这3种北美栎树在我国引种的研究进展,以期为今后的利用提供参考。     

5种北美栎树在我国长三角地区的引种生长表现

从美国东南部引进属于红栎组的纳塔栎、舒玛栎、水栎、柳叶栎和属于白栎组的弗栎,在我国长江三角洲平原地区多个地点和不同土壤类型条件下进行造林研究.采用1～2年生裸根苗经长途运输后进行栽种,纳塔栎、舒玛栎和水栎成活率达94％以上,柳叶栎为76％～81％,弗栎仅42％～50％.不同树种之间,幼年阶段的根系发育、枝梢生长习性、秋冬叶色变化和虫害状况存在明显差异.在3～6个地点水稻土上建立的前4种栎树人工林,8～10a后在保留密度900～1 500株·hm-2条件下,其年均径生长量和年均高生长量达到0.96～1.76 cm和0.8～1.33 m.在山坡红黄壤地上栽种的纳塔栎、舒玛栎和柳叶栎,其年均径生长量和年均高生长量分别为0.64～1.01cm和0.57～0.78 m.采用2～4年生带土弗栎苗在6个地点滨海盐土上造林的成活率达87％以上,在保留密度1 110～3 900株·hm-2条件下,其7～9 a林木年均径生长量和年均高生长量分别为0.78～1.13 cm和0.59～0.75 m.当树龄达6～9 a时,5种栎树均开始结实.研究表明,5种北美栎树在长江三角洲地区有较强的适应性,水栎、纳塔栎、舒玛栎、柳叶栎可以应用于平原地区生态景观林和城镇园林绿化建设,而弗栎在沿海防护林建设中具有推广前景.     

城乡绿化优新落叶乔木景观树引种选择

针对江苏无锡地区城乡绿化树种较单一,引进兰果树、南酸枣、无患子、光皮树、江南桤木、黄山栾树、灯台树、北美红栎、柳叶栎、水栎和苏柳J799、J842、J1011、J841及落羽杉优良种源(苏杉1号)等优新落叶乔木景观树种。实践表明,都能适应当地自然条件,多数表现适应性强,速生、病虫害较少,移植4 a达到或超过绿化用基本标准。     

宜兴市引乐属种源和杂交松试验初报

于１９９９年３月在宜兴市林场建立美国栎属（包括柳叶栎５个种源、红栎２个种源）,杂交松（杂种Ｆ１代,父本、母本）以及对对种青冈、麻栎、小叶栎和马尾松等共１４个处理的引种试验林。通过１ａ观测,其生长和保存率存在显著变异。（１）美国栎属生长变异极显著,树种间比较是柳叶栎〉红栎〉青冈。在柳叶栎中以９８１８号最大,９８２２号最小。红栎种源间无差异。造林成活率由于是采用容器苗造林,达９５．００％～１０．００％     

北美栎树无性繁殖试验

对引种的北美栎树进行的扦插与嫁接繁殖试验结果表明:柳叶栎、纳塔栎和水栎1年生实生母树上的穗条,具有一定的扦插繁殖潜力。以200×10-6ABT6号处理纳塔栎插穗,生根率达52%;以100×10-6ABT6号处理水栎插穗,生根率达22.0%,以100×10-6ABT6号处理柳叶栎插穗,生根率达70%。但从6年生柳叶栎母树上采穗,并进行相同处理扦插后则不能生根,愈合率仅为7.2%。上述3种栎树的扦插生根能力顺序依次为柳叶栎>纳塔栎>水栎;全光喷雾设施的生根效果优于封闭式扦插。生根剂ABT6号处理优于NAA处理和NAA VB2处理。以麻栎为砧木,对纳塔栎、红栎和水栎等进行春季枝接后,60 d后的成活率分别为47.5%~61.2%,47.5%和13.3%~15.0%,且春季枝接的效果优于秋季芽接。     

临沂地区红叶栎树引种试验研究

在临沂地区首次引种试验了火焰红栎、沼生栎、欧洲红栎等3个红栎树种,观测研究了物候期、环境适应性、生长指标及观赏特性等,结果表明:3个红栎树种在临沂地区长势良好,能够正常越冬、越夏,生长速度中等,可以完全适应本地的气候、土壤条件,环境适应性优良,是适合在临沂及周边地区发展的优良观赏树种,推广应用前景广阔。     

宜兴市引种美国栎属种源和杂交松试验初报

于 1999年 3月在宜兴市林场建立美国栎属 (包括柳叶栎 5个种源、红栎 2个种源 ) ,杂交松(杂种F1代 ,父本、母本 )以及对照树种青冈、麻栎、小叶栎和马尾松等共 14个处理的引种试验林。通过 1a观测 ,其生长和保存率存在显著变异。 (1)美国栎属生长变异极显著 ,树种间比较是柳叶栎 >红栎 >青冈。在柳叶栎中以 9818号最大 ,982 2号最小。红栎种源间无差异。造林成活率由于是采用容器苗造林 ,达 95 0 0 %～ 10 0 0 0 % ,种间和种源间变异不显著。但保存率变异显著 ,以柳叶栎 9816号和青冈最高 ,为 98 0 0 %～ 90 0 0 % ,红栎 982 1号和柳叶栎 982 3号最低 ,为 6 5 70 %～6 5 80 % ,比造林成活率有很大降低。 (2 )杂交松F1代最大 ,父本次之 ,母本最小。造林成活率和保存率差异均不显著 ,一直保持在平均 99 0 0 %     

东海县引种美国栎属种源和杂交松试验初报

于１９９９年３月在东海县李埝憷场营建美国栎属３个种,１５个种源（包括柳叶栎９个种源,北方红栎３个种源,红栎３个种源）,杂交松（杂种Ｆ１代和父本、母本）以及对照树种青冈、麻栎、小叶栎和火炬松等共２２个处理的引种试验林。通过１ａ观测初步结果为：（１）美国栎属树种和种源间的生长和保存率变异极显著。生长量在树种间比较是：柳叶栎〉红栎〉北方红栎〉青冈。在柳叶栎中以９８１８号生长量最大,９８１１号生长量最小。     

美国栎属种源引种、变异研究:种子及苗期生长变异

对从美国３个州（宾夕法尼亚、纽约和田纳西州）引进的栎属３个树种北方红栎、柳叶栎和红栎的２１个种源进行了两次播种和容器育苗试验。初步掌握了栎属种子砂床播种、芽苗移栽、容器育苗的关键技术。对栎属种子的发芽、芽苗和苗木的生长过程等有了一定的了解。发现栎属不同树种间和种内种源、家系间在种子体积、千粒重、发芽率、３０ｄ萌叶率和苗高生长等性状均存在极显著变异,试验数据表明种子体积北方红栎为大（其中宾夕法尼亚州家系１７２最大）,其次是红栎和柳叶栎。千粒重以北方红栎为重（其中宾夕法尼亚州家系１７２最重）,其次是红栎和柳叶栎。发芽率为北方红栎最高（其中宾夕法尼亚州家系１９１为１００％）,其次是红栎和柳叶栎。３０ｄ萌叶率和苗高生长以柳叶栎为高（田纳西州种源９７０１ＴＮ最高）,其次是红栎和北方红栎。在种间和种内不同种源、家系间种子千粒重与年终苗高生长相关不显著。     

北美橡树嫁接育苗试验

采集适合湘南地区栽培的北方红栎、猩红栎、娜塔栎、沼生栗栎和柳栎等北美橡树品种的枝条作为接穗,以麻栎实生苗为砧木,开展北美橡树嫁接育苗试验。试验结果为:就嫁接成活率而言,北方红栎的最高,为99.34%;其次是猩红栎的,为98.14%;沼生栗栎和柳栎的分别为94.15%和92.86%;娜塔栎的最低,为76.09%;各品种嫁接成活率排序为北方红栎>猩红栎>沼生栗栎>柳栎>娜塔栎。就保存率而言,北方红栎的最高,为89.40%;其次是柳栎的,为71.79%;沼生栗栎和猩红栎的分别为39.13%和32.28%;娜塔栎的最低,为29.29%;各品种嫁接苗保存率排序为北方红栎>柳栎>沼生栗栎>猩红栎>娜塔栎。不同北美橡树品种间苗高、地径均存在显著差异。就苗高而言,猩红栎及娜塔栎的较高,猩红栎的为149.08cm,娜塔栎的为140.88cm,两者间无显著性差异;北方红栎、沼生栗栎、柳栎的较低,北方红栎的为106.44cm,沼生栗栎的为95.20cm,柳栎的为110.00cm,且三者苗高生长均显著劣于猩红栎及娜塔莉。就地径而言,北方红栎的最大,为16.36mm,且显著优于其他品种;猩红栎与娜塔栎间无显著差异,其地径分别为13.28mm和11.87mm;沼生栗栎与柳栎间无显著差异,其地径分别为9.17mm和8.77mm,且两者均显著劣于其他品种。     

美国栎属种源引种,变异研究：幼树年高生长节律和物候期的变异

对定植在江苏省林业科学研究院苗圃（南京）内的美国栎属３个树种,１９个种源、家系（包括柳叶栎９个种源、家系,北方红栎６个家系,红栎４个种源）的２年生幼树进行了年高生长节律和物候期（包括展叶期、叶变色期和落叶期）的定期观测（分别每３～１５ｄ观测１次）。结果表明：（１）３个树种在南京年高生长节律差异显著。柳叶栎在生长期内抽梢次数较多,在５次以上,基本呈连续生长趋势。生长节律呈快（５月）－慢（６月）－最快     

苏州市引种美国栎属种源试验初报

苏州市郊和吴县市林场于 1999年 3月引进美国栎属 2个树种 ,8个种源 (包括柳叶栎 6个种源 ,红栎 2个种源 ) ,用青冈、麻栎和小叶栎为对照 ,进行培育大苗试验。经 1a观测 ,结果是 :柳叶栎的生长量和成活率均高于红栎。在柳叶栎种源中 ,以 9816 ,9818号生长量和成活率较高     

柳叶栎不同种源生长变异研究

从柳叶栎原产地美国宾夕法尼亚、田纳西、阿肯色和路易斯安娜等4个州引进9个柳叶栎种源,于1999年分别在江苏东海县、宜兴市等地进行造林试验,对试验林进行了8 a观测,调查了造林当年成活率和3 a时保存率,测定了树高、地径、幅冠等生长指标。结果表明,9个不同种源间生长有显著差异,其树高、地径和冠幅的遗传变异系数分别为8.26%~11.42%,14.14%~18.9%和5.9%~13.6%。1~8 a时,柳叶栎种源的树高和地径年际间相关显著,具有早期选择潜力。按综合指数评定法,初选出9818号和9817号2个综合性状表现好的优良种源,其树高和地径比参试种源平均值增加10.6%和13.9%。     

Effects of flood duration and season on germination of black,cherrybark, northern red,and water oak acorns

Effects of flood duration (0, 10, 20, and 30 days) and season (winter and spring) on acorn germination were tested for two upland oaks [black and northern red oak (Quercus velutina Lam. and Q. rubra L.)] and two bottomland oaks [cherrybark and water oak (Q. pagoda Raf. and Q. nigra L.)]. Acorns were stratified for 30 days before flooding at a depth of 15 cm along the edge of a small pond. After flooding, acorns were sowed in sand-filled plastic cups and germinated for 40 days. Flood duration and season strongly affected radicle and epicotyl emergence of the upland oaks, but effects were generally limited to spring flooding. Embryo axes of the upland oak acorns were severely damaged with as little as 10 days of spring flooding. Almost no epicotyls developed, but radicles developed from the connective tissues between embryo axes and the cotyledons of many acorns. Spring flooding also significantly increased the percentage of decayed acorns for the upland oaks. In contrast, germination of the bottomland oaks was slightly improved by flooding during both seasons. Results demonstrated that the effects of flooding on the distribution of species within bottomlands can begin with seed storage and germination.     

Changes in respiration and chemical content during autumnal senescence of Populus tremuloides and Quercus rubra leaves

Changes in respiration rate, chemical content and chemical concentration were measured in leaves of field-grown Populus tremuloides Michx. and Quercus rubra L. trees throughout the growing season and autumnal senescence. Chlorophyll, soluble sugar, N, P, K and Mg contents and concentrations all declined during leaf senescence, whereas Ca content and concentration increased. Leaf dry mass per area declined 24 and 35% in P. tremuloides and Q. rubra, respectively, during senescence. In leaves of both species, respiration rates peaked during leaf expansion in the spring and then declined, as a result of reduced cytochrome-mediated respiration, to reach relatively constant rates by midsummer. In senescing P. tremuloides leaves, respiration rates remained relatively constant until mid-October and then declined rapidly. In senescing Q. rubra leaves, respiration rates increased in late September, as a result of the appearance of residual respiration that could not be reduced by respiratory inhibitors, and then declined quickly in early November. No changes in alternative pathway respiratory activity were observed in leaves of either species during senescence until late autumn when rates declined. Because respiration rates were correlated with both leaf sugar and nitrogen content during leaf senescence, we conclude that respiration rates were maintained or increased during leaf senescence to supply energy for degradation and mobilization of chemical constituents.     

Foliar temperature-respiration response functions for broad-leaved tree species in the southern Appalachians

We measured leaf respiration in 18 eastern deciduous forest tree species to determine if there were differences in temperature-respiration response functions among species or among canopy positions. Leaf respiration rates were measured in situ and on detached branches for Acer pensylvanicum L., A. rubrum L., Betula spp. (B. alleghaniensis Britt. and B. lenta L.), Carya glabra (Mill.) Sweet, Cornus florida L., Fraxinus spp. (primarily F. americana L.), Liriodendron tulipifera L., Magnolia fraseri Walt., Nyssa sylvatica Marsh., Oxydendrum arboreum L., Platanus occidentalis L., Quercus alba L., Q. coccinea Muenchh., Q. prinus L., Q. rubra L., Rhododendron maximum L., Robinia psuedoacacia L., and Tilia americana L. in the southern Appalachian Mountains, USA. Dark respiration was measured on fully expanded leaves at 10, 15, 20, 25, and 30 degrees C with an infrared gas analyzer equipped with a temperature-controlled cuvette. Temperature-respiration response functions were fit for each leaf. There were significant differences in response functions among species and by canopy position within species. These differences were observed when respiration was expressed on a mass, nitrogen, or area basis. Cumulative nighttime leaf respiration was calculated and averaged over ten randomly selected nights for each leaf. Differences in mean cumulative nighttime respiration were statistically significant among canopy positions and species. We conclude that effects of canopy position and species on temperature-respiration response functions may need to be considered when making estimates of whole-tree or canopy respiration.