26种乡土树种苗木生长规律及育苗技术的系统研究

通过对省沽油科圆齿野鸦椿、壳斗科8种、木兰科2种、冬青科2种、山茶科4种、蔷微科2种、桃金娘科的赤楠、八角科的莽草、槭树科的五裂槭、交让木科1种、金缕梅科3种等26种亚热带乡土树种的种子预处理、种子主要播种品质参数测定、对苗木的苗高、地径、主根长、大于5cmI级侧根数、根幅、冠幅、鲜叶重、鲜干枝重、鲜根重的测定,以及对苗木物候、苗木生长节律进行研究,从而得出上述树种的较为系统的育苗技术。     

Afforestation trials with Prosopis chilensis (Mol.) Stuntz and Prosopis flexuosa D.C. in the Dry Chaco, Argentina

In implantation trials carried out with Prosopis chilensis and Prosopis flexuosa, the following variables were considered: implantation time (December and March), implantation technique (direct seeding and seedling transplantation) and age of the seedlings at the time of transplantation (60, 105 and 150 days). Survival was evaluated for more than 9 months after implantation and trials were repeated in 3 consecutive years.

Results from both species were similar and they show that survival after transplantation was higher (60–80%) than from direct seeding (35–45%). Survival from transplantation was independent of the size and age of the seedlings and it was less affected by climatic conditions than direct field sowing. Survival from direct seeding was higher in March than in December. The best time for either implantation alternative would be the end of the summer or beginning of fall, when climatic conditions increase the probability of seedling survival.     

Relative contribution of initial root and shoot morphology in predicting field performance of hardwood seedlings

Single and multiple linear regression techniques were used to explain the capacity of initial seedling root volume (Rv) and first-order lateral roots (FOLR) relative to shoot height, diameter, and fresh mass to serve as important indicators of stock quality and predictors of first- and second-year height and diameter on an afforestation site in southern Indiana, USA. This was accomplished for northern red oak (Quercus rubra L.), white oak (Quercus alba L.), and black cherry (Prunus serotina Ehrh) seedlings graded into four Rv categories at establishment. Field survival was high (85–97%) for all species. Initial diameter, height, fresh mass, and Rv provided similar predictive ability of second-year field response for absolute height (R² = 0.59–0.77) and diameter (R² = 0.50–0.73) for both oak species. Initial seedling Rv was a better predictor of field response than FOLR for both oak species, though not for cherry. Multiple-variable models accounted for a greater proportion of the total variation in seedling field height and diameter than did single-variable equations. The high R² (up to 0.95) of regression models suggests field performance of these species can be reliably predicted and confirms the importance of initial seedling morphology in dictating early plantation performance.     

Effects of sludge on germination and initial growth performance of Leucaena leucocephala seedlings in the nursery

A study was carried out to determine the influence of different types of sludges （municipal, industrial and residential） on field germination, growth and nodulation of L. leucocephala seedlings in the nursery. Before sowing of seeds, different combinations of sludges were incorporated with the nutrient deficient natural forest soils. Field germination, nodulation status and physical growth parameters of seedlings （shoot and root length, vigor index, collar diameter, leaf number, fresh and dry weight of shoot and root and total dry biomass increment） were recorded after three and six months of seed sowing. Field germination, nodulation status and growth parameters were varied significantly in the soil amended with sludges in comparison to control. The highest number of nodule was recorded from soil amended with residential sludge （ 1：1 ） and highest fresh and dry nodule weight was also found from the same combination in both three and six month old seedlings. In case of growth parameters, the highest growth was recorded from soil and residential sludge （ 1：1 ） combination compared to control. From the study, it can be recommended that soil amended with residential sludge （ 1：1 ） provide better field germination, growth and nodule formation of L. leucocephala in degraded soil.     

Germination and seedling growth of Quercus vulcanica: effects of stratification, desiccation, radicle pruning, and season of sowing

Effects of stratification, desiccation, radicle pruning, and season of sowing on Quercus vulcanica germination and growth were studied to identify optimum nursery procedures for artificial regeneration of this species. Following stratification (0, 2, 4 and 8 weeks), acorns were germinated, and acorn moisture content and germination performance were also determined at various times during desiccation. In early December unsprouted acorns were planted in containers, and in early April sprouted acorns, which had been stored in polyethylene bags at 4 °C, with radicles left intact or with radicles pruned back to 1.0 cm were planted in containers.Stratification for 2 and 4 weeks did not increase germination percentage but significantly increased germination rate. Germination percentage of the seeds dropped when the moisture content of the seeds was reduced by desiccation, and the critical minimum moisture content of the recalcitrant Q. vulcanica acorns was found to be 11–16%. Spring sowing of sprouted acorns altered the morphology the containerized seedlings and caused the formation of significantly more main roots, but resulted in significantly less shoot height and shoot dry weight. Spring-sown sprouted acorns had also a significant advantage over the fall-sown unsprouted acorns in seedling survival, and thus nursery personnel should not be concerned if acorns sprout before sowing.     

Seed Size as a Predictor of Germination Success and Early Seedling Growth in ‘Hollong’ (Dipterocarpus macrocarpus Vesque)

In species with seeds losing viability shortly after dispersal and exhibiting inherently low germination, quick decisions are required with respect to seeds that should be selected to maximize germination success and vigorous growth of seedlings. In ‘hollong’ (Dipterocarpus macrocarpus Vesque), I address the following questions: (a) are seeds that germinate randomly distributed within a seed population, (b) are subpopulations of viable and non-viable seeds separable, (c) does seed size predict which seeds germinate and (d) does seed size predict time required for germination and seedling vigour? Two estimators of seed size, diameter and weight, demonstrated a significant positive linear relationship endorsing assumption that accumulation of mass increases with increase in diameter of seeds. A threshold for selection of potential seeds for germination could not be derived from diameter measurements since seeds in an entire range of diameter did or did not germinate. All seeds <11 g did not germinate, but this threshold lies at the far lower end of the weight range and allows rejection of only a few seeds and acceptance of many seeds that will not germinate. A risk of potential seeds being rejected or non-viable seeds being picked exists if selection was derived from either diameter or weight. However, viable seeds could be better predicted from a scatter-plot of diameter on x-axis and weight on y-axis. Seeds showed a fan-shaped scatter and those developing the lower blade of the fan did not germinate while those following the handle were successful. Hence, two subpopulations segregated, but with a fuzzy edge. Mean diameter and mean weight of germinated seeds were significantly greater than those of ungerminated seeds. Most ungerminated seeds were those that had relatively smaller weight compared to their diameter. Although some large diameter seeds with small weight did germinate, but failed to develop into seedlings. Germination time and seedling vigour parameters (height, leaf number and collar diameter) were correlated both with diameter and weight. However, weight appears to have mattered more than diameter in germination success and early seedling growth.     

厦门地区常见绿化树种的种苗培育技术初探

通过多年的园林苗圃试验与生产实践 ,对一些厦门地区常见的绿化树种的采种期、种子处理、种子贮藏、育苗方法及苗木抚育等种苗培育技术进行了较为全面的探讨     

兴安落叶松落叶量和幼苗发生动态的研究

采用野外试验的方法,研究了兴安落叶松原始老龄林下兴安落叶松的更新条件。在所研究的四种林型的兴安落叶松原始老龄林之间,更新差别表现在下种、发芽和存活三方面。种子年时,老龄林下种量每平方米达到300-1000粒,各林型落种量从大到小的顺序为:赤杨落叶松林→丛桦落叶松林→草类落叶松林→杜香落叶松林。一年中的幼苗发生过程可分为四个时期,种子萌发主要在6月,幼苗死亡主要在7月,而8月份幼苗种群变化较小。从有利于落叶松种子萌发和幼苗存活的方面来说,各林型的顺序是:丛桦落叶松林>杜香落叶松林>赤杨落叶松林>草类落叶松林。这个顺序主要取决于土壤表层的湿度,即土壤湿度越大,发芽数和存活数越多。     

观赏槭树的苗期试验初报

观赏槭树育苗试验表明,不同树种、种源间种实发芽率差异较大。发芽率较高的种类有樟叶槭(92%)、鸡爪槭(90%)、三角枫(90%),其次是复叶槭(85%)、红花槭(82%)、橄榄槭(76%)和元宝槭(75%);茶条槭、五角槭、罗浮槭发芽率均小于70%。1年生苗高生长量以复叶槭最大(113.98 cm),其次是三角枫(101.21 cm);樟叶槭和鸡爪槭1年生苗生长量中等,当年生长量分别为62.43 cm和71.74 cm;罗浮槭、青榨槭和橄榄槭1年生苗高生长量较小。季节生长节律有3种类型:橄榄槭、鸡爪槭、元宝槭、茶条槭等几种槭树表现为第1类型(前期生长型),即5月前苗木缓慢生长,6~7月进入速生期,7月以后苗木渐渐停止生长,速生期较短。复叶槭和青榨槭表现为第2种类型:1年生苗全年高生长有2次高峰,出现在6月和9月;樟叶槭和三角枫季节生长节律表现为第3种类型:5月生长缓慢,6月生长开始加快进入速生期,一直持续到8月底,速生期长。三角枫、橄榄槭、鸡爪槭、元宝槭、茶条槭、复叶槭和青榨槭等几种槭树表现出较强的抗寒性,樟叶槭和罗浮槭抗寒性较差。     

雨豆树播种前预处理对种子发芽和种苗发育的影响

播种前对雨豆树(Albizia saman (Jacq.) F. Muell.)的种子进行了5 种预先处理,研究种子预先处理对种子发芽和苗圃种苗发育的影响。实验是在孟加拉吉大港大学林业与环境研究所的苗圃进行。研究结果表明,在种子末端修剪(处理4)提高种子发芽率50%,在冷水中浸泡24 小时(处理1)提高种子发芽率42%,在开水中浸30 秒后再在冷水中浸泡24 小时(处理2),种子发芽完全被抑制。处理4 和处理1 的种子发芽率、种苗初期形态生长和生物量都明显高于对照组。因此,这2 种播种前的种子预处理方法,可用于提高雨豆树种子发芽率和促进早期壮苗生长。图2 表3 参30。