ROBOT型林木球果采集机

应用林木球果采集机可以在基本不损伤母树的前提下，进行大面积机械化采集林木球果。对森林生态保护，森林更新、减轻工人劳动强度，保 证人工安全，提高采种效率等方面都有重要意义。     

Hydraulic drive and control system of the cone collecting robot

BasicstructureoftherobotThebasicstructureoftherobotincIudesthreeparts'pickingmanipuIator,runningpart(crawIertractor),computernumericalcontroIsystem.TheshapeofthemanipulatoroftherobotwasshowninFig.1.ThemanipuIatorhastWo6-mlongarms.onthetopoftheforearm,therearetWotooth-likepickingcombs,O.5minwidthando.85minlength,madeof6oSi2MnsteelandweredrivenbythehydrauIicsystem.Thecombscanswayleftandright,turnupanddown,andcanopenandcloseliketooth.Fig.1.GeneralstruCtureoftherobot1.Machineffamei2.Rotaryd…     

自动调节风量聚集器式气力集尘装置的研究

本文论述了自动调节风量聚集器式气力集尘装置的结构、工作原理、特点及设计方法。分析结果表明，这是一种通用、灵活、经济实用的气力集尘装置。     

A soil seed bank in a mature conifer plantation and establishment of seedlings after clear-cutting in southwest Japan

Compositions and spatial distribution patterns of buried viable seeds, and demographic transition from buried viable seeds to seedlings after clear-cutting were examined in a 75-year-old conifer plantation in southwest Japan. A part of the plantation was cleared in December 1997 and study plots were set up on a cleared site and a preserved site. Soil samples (a total of 105 l for the preserved plot and 90 l for the cleared plot) were collected from surface soils in spring 1998 and were incubated in a greenhouse for 120 days. There were an estimated 1064 buried viable seeds per square meter from 67 species in the preserved plot and 1754 seeds/m² from 53 species in the cleared plot. The soil seed bank was from mostly low density species with some high density species, and contained many pioneer species that were absent in the floor vegetation. Buried viable seeds were clumped together, especially in gravity-dispersal species. Although plenty of buried viable seeds were pooled in the soil, few seedlings emerged on the forest floor. In contrast, a number of seedlings, including many pioneer species, emerged in the cleared plots, showing a positive correlation between seed weight and germination rate. It is assumed that dominance of the seedlings established after clear-cutting depends on germination rates and/or growth rates of the seedlings rather than the initial density of buried viable seeds. These results suggest strong contribution of the soil seed bank to the establishment of the secondary vegetation after disturbance in a mature conifer plantation.     

EFFECTIVENESS OF ACEPHATE IMPLANTS IN PROTECTING CONES FROM INSECT DAMAGE IN SOME CONIFERFORESTS OF NORTHEASTERN CHINA

lNTRoDUCTloNInChina,onlyafewexperimentshavebeenperfbrmedtotestinsecticidessusceptibletopreventconesandseedsfrominsectdamage(Anonymousl986,GaoBuquetal.l99l,YueShukuil992,LiuYikong1993).Moreover,thesetestsonlyconsistedofsprayingchemi-cals,thatmayinduceharInfulconsequencesuponenvironment.TheintensifiedeffoftofafforestationinNortleasternChinarecentlyrequiredtoestablishlnyenumbersofseedorchards,aswellasparent-trCestands,inordertoprovideforesterswithhigh-qualityseeds,especiallyinlarch.Thispr…     

Effect of thinning intensity on tree growth and temporal variation of seed and cone production in a Pinus koraiensis plantation

Thinning of Korean pine (Pinus koraiensis Sieb. et Zucc.) is used to facilitate timber and cone production. The present study in Northeast China investigated the effects of thinning intensity on individual tree growth, temporal variation in cone yield, and seed quality in Korean pine plantation. In 2005, five thinning intensity levels (none, extreme, heavy, moderate and light) were set in 15 permanent plots in a 32-year-old Korean pine plantation at Mengjiagang Forest Farm, Jiamusi City, Heilongjiang Province. We recorded tree growth and seed cone production from 2013 to 2016, i.e., from 8 to 11 years after thinning. Except for height growth, thinning increased tree growth (diameter at breast height and crown size) and improved cone yield. The extreme thinning treatment (to 300 trees per hectare) resulted in the largest tree diameter, tree volume, crown size and 4-year cone production per tree. The highest cone yield per tree in the mast year (2014) was observed when stands were thinned to 500 trees per hectare (heavy thinning). Although the best cone and seed quality and the largest cone and seed mass per tree were recorded in the heavily thinned stand, no significant differences were found between heavy and moderate thinning stands (750 trees per hectare). At the stand level, the moderately thinned stand had the highest basal area, stock volume and seed cone production per stand. Our results suggest that thinning to 750 trees per hectare will improve timber and cone productivity in 40-year-old P. koraiensis stands.     

Population structures of the widespread Australian conifer Callitris columellaris are a bio-indicator of continental environmental change

Massive environmental changes have occurred since European settlement of Australia more than 200 years ago. We examined the demographics of Callitris columellaris F. Muell. (Cupressaceae) across Australia as a potential bio-indicator of environmental change. This species is a widespread obligate seeder with large reproductive potential but is sensitive to fire and herbivory. We measured variation in tree size, stem density, basal area, and seedling recruitment among 90 sites that encompassed a wide range of climates and landscape settings across Australia. Soils from each site were analysed for pH, %C, % N and %P. We also noted evidence of fire and herbivory. Climate at each site was classified as tropical, temperate or arid. Case studies and published literature are used to illustrate the contrasting effects of disturbance in the three climate zones. Climate had a strong influence on stand basal area, density of juveniles and proportions of seedlings and saplings in a population, as well as on prevailing disturbance regimes. Structure of Callitris populations was not strongly associated with soil fertility. In the arid zone overall, and in many individual populations, there were relatively few juveniles and evidence of a chronic recruitment deficit during the last 100-200 years, consistent with reported adverse effects of introduced herbivores on Callitris regeneration. By contrast, most tropical and temperate populations conformed to a negative exponential distribution, consistent with frequent regeneration. Many temperate sites showed extremely dense juvenile populations. In the tropics, juvenile density is lower, probably because of frequent, relatively mild fires that kill many juveniles but few adult trees. We conclude that C. columellaris is a sensitive bio-indicator, and is in decline across much of arid Australia, reflecting the inherent vulnerability of ecosystems in regions with low productivity.     

Impacts of Coriaria nepalensis colonization on vegetation structure and regeneration dynamics in a mixed conifer forest of Indian Central Himalaya

This study evaluated impacts of Coriaria nepalensis Wall.colonization on soil characteristics,vegetation structure and composition,regeneration status and expected future compositional changes,biomass and carbon stock in tree species of a mixed conifer forest of Central Himalaya.Three sites(1 ha each in an old landslide area)differing in Coriaria density(low:20 individuals ha^-1;medium:120 indiv.ha^-1;high:190 indiv.ha^-1)were used to enumerate the tree species.A total of 9 tree species and 2830 individuals were recorded from the three study sites that represented a gradient of Coriaria density.Number of species varied from 3 to 7 and the individuals from 690 to 1270 per site with lowest numbers at low Coriaria density and highest at medium Coriaria density.The number of seedlings increased with increasing Coriaria density,and the sites were unique in their seedling composition,indicating marked temporal dynamics.Site wise regeneration analysis showed that regeneration was poor at the site with low Coriaria density and good at the high-density site where many species emerged as seedlings.These results indicate that the ameliorative effects of Coriaria in terms of soil buildup,and accumulation of nutrients and organic matter helped more species to colonize the area.This facilitative ability of Coriaria can be used to restore degraded forest ecosystems of Indian Central Himalaya.     

小兴安岭红松球果采集管理措施的探讨

经过对小兴安岭红松经营区物候特点和经营模式的调查分析,对红松球果采集提出了管理建议。     

伐区采集作业方式对森林生态环境的影响分析

通过分析伐区几种主要的采集作业方式对森林生态环境的影响，结果表明择伐和架空索道集材两种作业方式对森林生态环境的影响最小。     

红松采种林经营技术及管理措施的探讨

以通化县林业局三棚林场为例,论述了红松采种林基地建设的有关技术设计方案及经营管理措施。进而阐述了保护和开发好吉林省东部地区红松优良种质基因资源,对恢复吉林省东部森林生态系统,改善生态环境,建设生态省,实现可持续发展的战略规划具有重大意义。     

云杉球果锈病流行规律的研究

通过定点系统观察，云杉球果锈病病原菌Ｔｈｅｋｏｐｓｏｒａａｒｅｏｌａｔａ（Ｆｒ．）Ｍａｇｎｕｓ．担孢子５月中旬开始飞散，侵入期为５月下旬，病害初期症状出现在６月下旬，锈孢子在７月下旬前后形成，８月中旬锈子器成熟。病情变化与气象有一定相关性，其回归预测模型为Ｙ＝－２４２．６８－５．７３ｘ１－１．０３ｘ２＋４．０２ｘ３－１．９３ｘ４－２．５７ｘ５＋５４２．８４ｘ６＋２６８．６２ｘ７＋０．９２ｘ８复相关系数Ｒ＝０．９９８６＊＊＞Ｐ０．０１＝０．７３４８。病害分布与林木所处位置有关，病情从重至轻的顺序为，南＞北＞东＞西；山脊＞山中＞山脚；海拔高＞海拔低；纯林＞混交林；离转主远＞离转主近     

昭通市核桃优树收集圃的营建与管理技术

通过对昭通市核桃优树收集圃的建设,探索和积累了一些成功的做法和经验。昭通市核桃优树收集圃的建成,对昭通市的核桃优种繁育、发展规模、目标任务、推广使用和生产技术指导等方面打下坚实基础。对今后发展昭通核桃产业建设具有十分重要的作用。     

小叶杨种子贮藏试验研究

杨树种子粒小、种皮薄、含水量高,在一般条件下贮藏两个月即丧失发芽能力,生产上均采用随采随播的方法。由于杨树结实有周期性,为了增加苗木当年生长量,提高苗木质量需进行春播,于是,杨树种子贮藏技术的研究不仅在生产上有着重要意义,而且对延长小粒种子寿命的探索亦具有一定价值。我们从1980年开始对杨树种子进行了不同采种期、不同贮藏方法等多项试验研究,其目的在于确定小叶杨种子的最佳采种期、最优贮藏条件,探索采种期及贮藏方法的不同对种子品质的影响,并欲从中了解它们的相关性。     

油松株间种实性状多样性的研究

对同一栽培地点的不同油松植株的种实性状进行观测与分析,结果表明:株间的球果颜色与大小、果鳞位置、出种率、种皮与种翅颜色、种子重量、发芽指标等性状均存在广泛的多样性。株间种子重量变动在41.11～64.73 g之间,均值为52.36 g,差异极显著(F0.01=595.56**);株间种子发芽率变动在65%～100%之间,差异显著。株间遗传差异是导致种子性状多样性的主要原因。     

Broad-leaf species composition in Cryptomeria japonica plantations with respect to distance from natural forest

To address the pressing need to evaluate how conifer plantations can serve biodiversity functions in addition to other economic and social roles they play, we assessed the diversity of broad-leaf seedlings and saplings in Cryptomeria japonica plantations in Ogawa, Ibaraki Prefecture, Japan at increasing distances (0–1000 m) from old growth natural forest edge. For saplings, there was no overall significant trend in the frequency, species richness, and Shannon index with respect to distance. Seedlings on the other hand showed a decrease in frequency and species richness with increasing distance from the old growth forest, implying that should recruitment limitation occur in the plantations, it will be stronger at the seed-to-seedling transition than at the seedling-to-sapling transition. Assigning species into groups based on functional traits that are associated with recruitment and regeneration was more revealing. Relative frequency of species that are moderately shade-tolerant, are shrubs, have small seeds, and are frugivore-dispersed increased in the plantations. In comparison, species that are tall trees, have large seeds and are gravity-dispersed decreased in the plantations. Multi-trait analysis showed that propagule size was the trait that could best explain the difference in the distribution of broad-leaf species in the plantations. Based on our results, we suggest to policy-makers that plantation sizes be kept to within a few hundred meters wide, and should ideally be within dispersal distance of species from natural forests that could potentially be seed sources of broad-leaf species. Otherwise, steps must be taken to drive succession such that potentially recruitment-limited species may be able to overcome barriers to regeneration.     

V带变速传动塔轮直径和中心距的精确计算

本文分析对比了塔轮变速V带传动的两种不同计算方法的计算结果，计算结果还表明，塔轮的基准直径大多不能在基准系列中选取，而应由计算确定。     

采种梯夹树机构的优化设计

支臂式采种梯的夹树机构是采种梯的关键部件。夹树机构的性能,即夹持不同径级树干,夹持点位置是否准确是评价夹树机构的重要指标。夹树机构的设计,通常是根据被夹持的树径变化范围,按给出的最佳夹持点轨迹曲线,用作图法经多次试凑确定出一个较好的设计方案。用这种方法不仅效率低、精度差,而且在综合考虑结构布置、工艺等几个方面的要求时,欲对设计方案的好坏作出评价,是很困难的。所以,用解析法将夹树机构设计问题转化为一定的优化设计数学模型,再通过计算机最优化设计程序,可直接得出最优设计方案。     

班克松闭合型球果脱种方法及条件研究

班克松球果分开裂型和闭合型两种，闭合型球果在树上多年不开裂。章采用化学试剂浸泡脱脂和控温干燥箱加温干燥两种方法，试验了班克松闭合型球果的取种方法及条件。结果表明，用化学试剂脱脂法对球果开裂效果不明显，而用控温干燥箱加热温度为300℃，时间为27s时球果种鳞开裂整齐，种子发芽率高，其他试验各处理效果均较差。     

油松最佳采种时期的研究

对油松不同采种时期对种子质量影响问题进行了试验研究 ,结果表明 ,各种处理即不同的采种时期对种子质量影响明显 ,从 8月 15日开始 ,到 9月 2 9日的处理 ,种子千粒重、发芽率、发芽势差别极显著。从 8月 15日到 9月 14日种子质量虽有显著差异 ,但都属于不合格种子 ;从 9月 14日到 9月 2 9日种子都达到省标和国标 ,但种子质量随生长期延长 ,种子质量逐渐提高。综合研究可以确定油松最佳采种时期应为 9月 19～ 2 9日