Height variation of transplanted seedlings of Scots pine in Finnish nurseries

The height variation of Scots pine (Pinus sylvestris L.) seedling stock was studied using data from annual inventories of seedling crops. The heights of 240 batches of 2-year-old and 3-year-old transplanted seedling from the years 1973–1986 grown at three nurseries in southern Finland were examined. From each batch, 100 clusters of three successive seedlings were systematically located and measured. The mean heights of the seedling batches ranged from 7.8 to 27.0 cm, with a mean of 14.1 cm. Within batch standard deviations ranged from 1.7 to 7.8 cm, with a mean standard deviation of 3.7 cm. There was considerable variation in the mean heights of seedling batches both within a given year and between years. However, estimated variance components of seedling height showed that year, batch and cluster effect each accounted for about 20 percent of the total variance, while seedling effect explained the remaining 40 percent. The implications of results for single tree and batch grading are discussed.     

木麻黄抗逆无性系苗期生长比较试验

采用通过筛选的2个木麻黄抗逆无性系与当地生长较好的惠2无性系进行水培育苗试验,结果表明:(1)不同无性系间苗高和地径差异不大,方差分析均未达显著水平。从遗传参数来看,3个无性系间苗高和地径的遗传力均为中等,分别为0.486和0.557,方差分量也不大,分别为66.06%、69.27%,苗高的遗传变异系数较小,其值为14.23%,而地径的遗传变异系数较大,其值为18.22%,利用苗高和地径指标对木麻黄抗逆品系和对照进行比较,不能取得较理想的结果;(2)不同无性系在侧根数、主根长、总干质量/总鲜质量等指标上均未达显著水平,且变异系数不大,仅为25.26%、13.70%、9.28%;但在地下部分干质量/地上部分干质量指标上达极显著水平,且变异系数较大,达46.42%。从苗木根系性状和生物量的遗传变异分析,木麻黄抗逆品系和对照没有什么差异。     

Grass interference limits resource availability and reduces growth of juvenile red pine in the field

The effects of competing grasses on resource availability, growth and ecophysiological characteristics of 3-0 red pine (Pinus resinosa Ait.) seedlings were examined the first two years following outplanting in Anoka County, Minnesota, USA. Equal numbers of seedlings were planted into suppressed and undisturbed grass communities in a sandy soil. Grass suppression was maintained throughout the first growing season, but partially discontinued thereafter on the site. During the first field season interference from grass reduced pine seedling root collar diameter, needle length, number of new root tips, and lateral root length by over 40%. Mean pre-dawn needle water potential was 0.55 MPa lower in undisturbed grass plots during a brief drought in year one, but otherwise water stress was not significantly (p=0.05) influenced by grass interference. The presence of grass also reduced, up to 50%, the photosynthetically active radiation reaching the seedling canopy. At the end of year one, total biomass N, P, K, and Ca content were significantly (p=0.05) less in seedlings growing in the undisturbed grass community. Nitrogen was deficient in seedlings growing in grass. After two growing seasons, seedling shoot length (p=0.03), root collar diameter (p=0.001), and needle length (p=0.001) were significantly less (40, 54 and 20%, respectively) for seedlings growing in undisturbed grass. Seedling growth reductions induced by grass competition were associated with multiple environmental stressors in the field and not restricted to water stress as was observed in earlier studies with pine species at low and mid-latitude sites.     

Why seedlings grow: influence of plant attributes

Successful forest restoration requires planting quality seedlings with optimal growth potential. Thus, nurseries need to produce seedlings with plant attributes that favor the best chance of successful establishment once they are field planted. From the mid-twentieth century on, research foresters have critically examined plant attributes that confer improved seedling growth under various restoration site conditions. This review examines the value of commonly measured seedling quality attributes (i.e., height, diameter, root mass, shoot-to-root ratio, drought resistance, freezing tolerance, nutrient status, root growth potential, and root electrolyte leakage) that have been recognized as important in explaining why seedlings with improved attributes have better growth after planting. Seedlings with plant attributes that fall within the appropriate range of values can increase the speed with which they overcome planting stress, initiate growth, and become “coupled” to the forest restoration site, thereby ensuring successful seedling establishment. Although planting high quality seedlings does not guarantee successful seedling establishment, it increases chances for successful establishment and growth.     

不同种源水曲柳苗木生长的差异分析

研究了不同种源水曲柳幼苗的生长特性,并对其差异进行了分析。结果表明,不同种源间水曲柳幼苗的苗高、地径、主根长、侧根数及单株生物量存在显著地差异。综合评价以海林和林口种源的幼苗生长较优。     

草珊瑚不同播种育苗方式效果研究

试验采用营养袋播种育苗和田间苗床播种育苗2种方式进行草珊瑚苗木生长量的比较研究,结果表明：2种育苗方式对苗木的出土时间没有影响,但对种子的发芽率具有极显著影响,前者比后者提高29.3%。2种不同育苗方式的高径生长量、根系生长量及总生物量（鲜重）差异极显著;营养袋有利于苗木的高径生长和主根生长,总生物量比田间苗床播种苗提高30.4%;但侧根生长相比较差。为提高移栽成活率,在生产上提倡营养袋育苗。     

互叶白千层扦插苗质量评价及分级标准

对四川犍为地区引种栽培的互叶白千层扦插苗进行抽样调查,采用相关性分析、“x¯±s”法和主成分分析法对其苗木质量进行评价和苗木分级研究。结果表明:评定互叶白千层苗木质量可以苗高(H)、地径(D)和全株生物量作为表型指标,结合主根数量,并辅以根系长度作为辅助参考综合评价指标。提出了以苗高和地径作为该树种苗木分级的质量指标,并得出互叶白千层扦插苗的3级分级标准,Ⅰ级苗木:苗高>17.66 cm,地径>1.98 mm;Ⅱ级苗木:苗高为11.48~17.66 cm,地径为1.36~1.98 mm;Ⅲ级苗木:苗高<11.48 cm,地径<1.36 mm。可为互叶白千层苗木分级和筛选提供一定的理论依据。     

Provenance Variation in Seed Morphometric Traits, Germination, and Seedling Growth of Cordia africana Lam

Patterns of genetic variation in Cordia africana, a tropical timber species, were evaluated at the population level. Bulk seed samples were collected from six natural populations in Ethiopia and examined for variations in seed morphometric traits, seed germination, and seedling growth at nursery stage. Analysis of variance revealed significant differences among provenances in all studied attributes except root collar diameter after 4 months of growth. The provenance effect, as determined by broad sense heritability, was 71–98% for seed morphometric traits, 80% for germination capacity, 42% for germination energy, 57–58% for seedling height and 3–13% for root collar diameter. Seed weight showed a significant positive correlation with altitude and negative correlation with mean annual temperature of seed origin. Germination energy was significantly correlated with longitude and mean annual rainfall. Seedling parameters and geo-climatic variables of seed origin were fairly correlated. A significant intercharacter correlation was found between seed length and seed weight, between root collar diameter at the age of 4 months and seed length and weight, as well as between seedling height after 4 and 8 months of growth. It can be concluded that the observed patterns of variation will have implications for genetic resources conservation and tree improvement.     

Inter- and intra-provenances variations in seed size and seedling characteristics of Khaya senegalensis A. Juss in Burkina Faso

Within- and between-provenance variations in seed and seedling traits of Khaya senegalensis A. Juss were studied at INERA in Burkina Faso. Nursery grown seedlings from four provenances in Burkina Faso were used for the study. The studies revealed significant variability in all traits evaluated. Seed length and weight significantly varied among provenances and families within provenances, where Bopiel and Koyenga had the highest mean values. Height and root collar diameter of 1 year old seedlings significantly varied among families within provenances. Except leaf biomass ratio and carbon isotope ratio which varied significantly among provenances but not among families within provenances, all other seedling biomass traits—total plant biomass, stem biomass ratio, leaf biomass ratio, root biomass ratio, root shoot ratio, specific leaf area, and leaf area ratio were significantly affected by provenances and families within provenances. The magnitude of variation due to family effect ranged from 65 to 93 % for seed size traits, and from 4.5 to 17.8 % for seedling characters. Estimates of family heritability were moderate to high (0.67–0.95) for seed traits, but low to moderate (0.19–0.59) for seedling characters, indicating that much of the total variation in seed traits is due to the genetic effect. The two most prominent provenances, Koyenga and Bopiel, with higher seed size and greater seedling growth could be considered for an eventual K. senegalensis improvement program in Burkina Faso.     

水曲柳床播不同密度对苗木生长的影响

水曲柳(Fraxinus mandshurica Rupr.)是东北地区三大珍贵硬阔叶用材树种之一,也是东北地区的重要造林树种。研究了不同育苗密度对水曲柳床播苗木生长的影响,结果表明,当密度达到100株/m^2时,为最优育苗密度,其苗高、地径、主根长、侧根数、生物量最优,有利于优质壮苗的培育。     

基质对侧柏网袋容器苗生长的影响

以泥炭土、炭化稻壳、珍珠岩、蛭石为原料,按体积配比制成9种不同配比基质,开展侧柏网袋容器育苗试验。结果表明:不同基质上生长的网袋容器苗,在苗高、地径的生长量和根系生物量上差异显著,以泥炭土50%、珍珠岩40%、蛭石10%为基质,培育的侧柏网袋容器苗苗高、地径的生长量和根系生物量均优于其他基质。侧柏高生长过程符合"S"型生长曲线,用Logistic生长曲线对侧柏苗高进行拟合,求一阶和三阶导数,得到生长快增期为46d,即播种后第36~78d,这一时段是培育侧柏壮苗的关键时期。     

控释肥和灌溉方式对栓皮栎容器苗苗木质量及造林效果的影响

[目的]探讨控释肥和灌溉方式对栓皮栎(Quercus variabilis Bl.)容器苗生长、养分含量、基质电导率(EC)及2年造林效果的影响,为培育高质量苗木提供参考。[方法]以栓皮栎容器苗为研究对象,采用双因素完全随机试验设计,设置5个施肥水平(以N元素含量为基准,5个施肥水平分别为:25、75、125、175、225 mg·株~(-1))和2种灌溉方式(上方喷灌(O)、底部渗灌(S)),测定栓皮栎容器苗形态指标、养分含量、根系生长、基质EC值及连续2年造林效果。[结果]表明:(1)施肥量和灌溉方式二者对苗木形态指标影响存在交互效应,225-O处理的苗木地径、根生物量、单株生物量最大,但根生物量、单株生物量在225-O、125-S、175-O处理之间差异不显著。225-S处理的苗高、茎生物量、茎根比最大,茎生物量在225-S与225-O之间差异不显著。(2)苗木茎、根的氮磷钾浓度和含量随施肥量的增加而增大,施肥量125、175、225 mg·株~(-1)处理之间的根氮、磷含量及单株磷含量差异不显著。(3)增加施肥量促进苗木根系的生长,施肥量为125、175、225 mg·株~(-1)处理之间的根系表面积、体积差异不显著。(4)基质EC值随施肥量的增加而增大,底部渗灌显著提高了基质上层、下层的EC值,基质上层、下层的最大EC值分别为4. 69、0. 56d S·m-1,没有对苗木生长产生不利影响。(5)和上方喷灌相比,底部渗灌显著地促进造林第1年幼树的树高、地径生长;造林第1年、第2年的树高和地径均随施肥量的增加而增大,造林第2年,施肥量125、175、225 mg·株~(-1)处理之间的树高、地径差异不显著。[结论]底部渗灌提高了栓皮栎容器苗体内的养分含量,促进了造林第1年幼树树高、地径的生长。施加控释肥有利于苗期苗木质量的提高及造林后苗木的快速生长。综合考虑苗木质量、经济效益、环境利益,培育栓皮栎容器苗可选择底部渗灌和控释肥量为125 mg·株~(-1)的组合(以N元素含量为基准)。     

Variation in seed and seedling traits among natural populations of <Emphasis Type="Italic">Trigonobalanus doichangensis</Emphasis> (A. Camus) Forman (Fagaceae), a rare and endangered plant in southwest China

The extent of genetic variation in seed and seedling traits of Trigonobalanus doichangensis, a rare and endangered tree in southwest China, was evaluated at the population level. Seeds were collected from four natural populations in the south and southwest Yunnan province, China. Significant differences (P < 0.05) between populations were observed in seed length, seed weight and seedling morphological characters. The analyses revealed that none of the seed and seedling traits had significant correlations with the geo-climatic variables of the populations. Among seed and seedling traits, significant correlations (P < 0.05) were discovered among seed length, seed weight and height of 30-day-old seedlings. Significant correlation (r = 1.00, P < 0.01) occurred also between the height and root collar diameter of 4-year-old seedlings. With the exception of seed width and seed germination percentage, 51–96% of total variation in other seed and seedling related traits was attributed to population effect, as determined by the broad sense heritability. In conclusion, these observations on variation in seed and seedling traits should be a reference point, when considering seed collection of this species for ex situ conservation and species restoration.     

Why seedlings survive: influence of plant attributes

Seedling survival and successful forest restoration involves many silvicultural practices. One important aspect of a successful forest restoration program is planting quality seedlings with high survival capability. Thus the nursery needs to create seedlings with plant attributes that allow for the best chance of success once a seedling is field planted. Since the mid-twentieth century, research foresters have critically examined plant attributes that confer improved seedling survival to field site conditions. This review describes the value of commonly measured seedling quality material (i.e. shoot height, stem diameter, root mass, shoot to root ratio, drought resistance, mineral nutrient status) and performance (i.e. freezing tolerance and root growth) plant attributes defined as important in answering the question of why seedlings survive after planting. Desirable levels of these plant attributes can increase the speed with which seedlings overcome planting stress, become ‘coupled’ to the forest restoration site, thereby ensuring successful seedling establishment. Although planting seedlings with these desirable plant attributes does not guarantee high survival rates; planting seedlings with desirable plant attributes increases chances for survival after field planting.     

贵州不同种源棕榈苗期生长性状比较及评价

为给贵阳地区棕榈人工造林的优良种源选择提供参考,以贵州省内遵义、毕节等18个市(县)的棕榈种子为试验材料,采用大田育苗的方法进行培育。对不同种源2年生棕榈苗的地上部分和地下部分的生长指标进行观测,并采用聚类分析法对棕榈种源进行类别划分,对其与种源地地理位置的相关性进行分析,采用主成分分析法对18个种源棕榈苗的生长性状进行综合评价。结果表明:不同种源2年生棕榈苗的高、地径、总根长、主根长、总根表面积、总根体积、根尖数及总生物量等指标均有显著差异(P<0.05),各指标的变幅分别为28.78~51.09cm、8.40~21.93mm、37.41~85.02cm、14.73~41.20cm、127.13~362.82cm2、5.52~19.55cm3、902~1536、4.64~12.32g。聚类分析结果表明,18个种源可分为2大类,其中罗甸、兴义、毕节为苗期生长性状表现较好的一类。相关性分析结果表明,原产地是低纬度和湿润地区的棕榈苗在试验区生长表现较好。主成分分析及综合得分排序的前3名分别为罗甸、兴义、毕节种源,与聚类分析结果一致。初步评价出罗甸、兴义和毕节种源为贵阳地区首选的棕榈种源。     

Effects of soil compaction on growth variables in Cappadocian maple (<Emphasis Type="Italic">Acer cappadocicum</Emphasis>) seedlings

This study investigates the effects of increasing soil penetration resistance (SPR) on seedling morphology and seedling architecture. When seedlings of deciduous Cappadocian maple (Acer cappadocicum Gled.) were grown in a greenhouse in a loamy soil under a wide range of soil compactions, all morphological variables studied changed significantly with increasing SPR. The relationships between increasing SPR and all morphological responses except lateral root length followed a negative quadratic curve. All biomass variables except lateral root biomass showed a bell-shaped response with respect to SPR, with a maximum biomass variable between 0.6 and 1.2 MPa, decreasing at higher soil compaction values. All allocation ratios were significantly affected by soil penetration resistance. Biomass allocation to roots was also affected by soil compaction. There was not a significant relationship between the specific stem length and increasing soil penetration resistance. The specific root length showed two trends to increasing SPR; it first decreased in response to the moderate compaction treatment (up to about 1.2 MPa), then increased significantly. We concluded that increasing soil compaction caused morphological changes to root and shoot sections of A. cappadocicum seedlings.     

TMS天目丝增抗剂在落叶松育苗中的应用

应用2000,1000,500,250,125,62mLL-1TMS天目丝增抗剂对200株长白落叶松苗进行6小时浸根,在生长季节(5月30日至10月20日)对经过天目丝增抗剂处理的造林苗每隔15天测定一次苗木的高生长、地径、主根长度,侧根数。实验结果表明,天目丝增抗剂处理可以极大地促进长白山落叶松苗木生长并能提高苗木质量。500mLL-1TMS处理的苗木生长效果最好,与常规育苗相比,高生长平均增加42.5%,地径生长平均增加30.7%,主根长平均增加14.0%,侧根数平均增加31.6%;Ⅰ级苗和Ⅱ级苗各占一半,没有Ⅲ级苗,显著地提高了经济效益。表3参8。     

Effects of soil compaction on growth variables in Cappadocian maple(Acer cappadocicum) seedlings

This study investigates the effects of increasing soil penetration resistance(SPR) on seedling morphology and seedling architecture. When seedlings of deciduous Cappadocian maple(Acer cappadocicum Gled.) were grown in a greenhouse in a loamy soil under a wide range of soil compactions, all morphological variables studied changed significantly with increasing SPR. The relationships between increasing SPR and all morphological responses except lateral root length followed a negative quadratic curve. All biomass variables except lateral root biomass showed a bell-shaped response with respect to SPR, with a maximum biomass variable between 0.6 and1.2 MPa, decreasing at higher soil compaction values. All allocation ratios were significantly affected by soil penetration resistance. Biomass allocation to roots was also affected by soil compaction. There was not a significant relationship between the specific stem length and increasing soil penetration resistance. The specific root length showed two trends to increasing SPR; it first decreased in response to the moderate compaction treatment(up to about 1.2 MPa), then increased significantly. We concluded that increasing soil compaction caused morphological changes to root and shoot sections of A.cappadocicum seedlings.     

Container characteristics influence Pinus pinea seedling development in the nursery and field

The growth and development of Pinus pinea seedlings grown in different containers was followed through one growing season in the nursery and 3 years following outplanting in the field. The variables studied in the nursery were height, diameter, biomass of shoots and roots, nutrient uptake and root density. The measured field variables, height and diameter increment and survival, were correlated with the nursery variables. Container volume had the greatest influence on plant morphology. Containers with larger rooting volume had seedlings with larger height and diameter, greater nutrient content, and better field performance. Growing density was correlated with seedling morphology and nutrient concentration in the nursery. Among the variables that influenced container volume, the diameter of the container was the most important, while the depth of the container had a minor influence on seedling morphology.The best indicator of seedling development in the nursery was the ratio of container depth to container diameter, and the optimum ratio was 4. All containers produced seedlings with some root spiralling, including those containers with ribs. There was no relationship between either the number of spiralling roots or the angle of spiralling and container characteristics. Furthermore, root spiralling did not influence seedling performance following outplanting. Root density (root biomass/cm³) was inversely correlated with container volume but there was no correlation with either depth or growing density. The largest plants were produced with container volumes of 300–400 cm³, depth/diameter ratios of 4, and growing densities of 200–300 seedlings/m². These growing conditions will result in larger Pinus pinea seedlings coming out of the nursery, which will increase growth following outplanting.     

黧蒴栲芽苗截根移栽育苗及造林成效研究

为了提高黧蒴栲苗木质量和造林成活率,利用随机区组设计开展了黧蒴栲芽苗截根移栽、截根苗造林对比试验.结果表明：黧蒴栲芽苗截根处理对苗高、主根长、一级侧根数、叶干重、茎枝干重、根器官干重有极显著影响,对苗木地径、一级侧根长度有显著影响.芽苗截根处理后苗木高度增加17.51％、地径增加13.72％.不同剪叶处理方式对黧蒴栲苗木造林成活率有极显著影响,芽苗截根苗造林以剪叶75％效果最好,造林成活率达95.86％,而未剪叶苗造林成活率为57.69％;应用芽苗截根苗造林可提高造林成活率17.0％～24.0％,增加当年树高、地径生长量分别为18.22％、15.44％.