秦岭冷杉和巴山冷杉种群年龄结构及动态的比较分析

在秦岭林区对不同生境条件下濒危种秦岭冷杉(Abies chensiensis)和广布种巴山冷杉(Abies fargesii)种群的年龄结构、生命表、存活曲线以及时间序列预测进行了比较分析.结果表明:秦岭冷杉在各个坡向上幼龄林林木株数均明显小于巴山冷杉.在各个坡向上,秦岭冷杉均呈衰退型,而巴山冷杉均呈稳定型.坡向对秦岭冷杉种群存活曲线的影响比巴山冷杉的影响大.在未来的20、40及60a,秦岭冷杉种群Ⅱ、Ⅲ龄级的种群表现为先增后减的不稳定趋势,而Ⅳ龄级以后的种群表现为小幅度的增加趋势.巴山冷杉种群各龄级株数在未来的20、40及60a均呈明显的增加态势.最后,给出了对不同生境的秦岭冷杉应采取的具体管理措施.     

Comparison of growth response ofAbies andPicea species to climate in Mt. Norikura, Central Japan

Tree-ring chronologies were developed fromAbies mariesii Masters andPicea jezoensis ssp.hondoensis (Mayr) P. Schmidt collected at different altitudes of Mt. Norikura, central Japan. The tree-ring parameters of ring width and maximum density were measured by soft X-ray densitometry. The measurement series were detrended by fitting a 33-year cubic smoothing spline and autoregressive model. The correlation between species and between sites showed different responses of the species to climate in terms of ring width and maximum density. The correlation coefficient between sites within a species was higher than that between species for a site in the ring width, and the coefficient between species for a site was higher in maximum density. The correlation coefficient between tree-ring chronology and monthly climate data set showed different responses of radial growth to climate. The different response was probably explained by the difference in the length of the growing season. High summer temperature increased the maximum density of the two species and the radial growth inAbies mariesii. Summer precipitation correlated negatively to maximum density, but it did not affect the ring width of either species. The climatic signals could be extracted from ring-width and maximum-density chronologies of both species.     

沙松播种育苗技术

本文对沙松播种育苗技术进行了总结，为发展沙松优质种苗提供了技术。     

Difference in response to aluminum among Japanese coniferous species

Seedlings of Chamaecyparis obtusa, Cryptomeria japonica D. Don, and Abies firma Sieb. et Zucco were grown hydroponically for 4 weeks in the presence or absence of aluminum (Al) and with or without reduced pH. Under exposure to AI, root and shoot growth of C. obtusa was enhanced. A. firma showed the same tendency as C. obtusa, though not significantly. Only in C. japonica, growth was reduced with Al, especially shoot growth. In all the species, callose production in the root tips was observed in the presence of Al. A positive correlation was observed between the relative root callose content and relative root growth (r = 0.83), and significant root elongation with AI treatment was observed in all the species. Therefore, it is considered that callose deposition in the root tips of these species may not indicate the Al-induced root cell injury causing root growth inhibition. The highest callose content in the root tip and strong callose fluorescence in the epidermis and zones of cell contact were observed in C. obtusa. Since the Al translocation rate from roots to leaves was the lowest in C. obtusa and since significant growth enhancement was observed in the presence of Al, it is possible that the accumulation of callose in the root epidermis and in the zones of cell contact is related to Al-resistance in C. obtusa.     

Initial Effects of Intensity and Severity of Balsam Fir Tip Harvesting on Harvesting Intensity at the Stand Level,Tip Production,and Tip/Foliage Removal at the Tree Level,and Harvesters’ Production and Productivity

Balsam fir (Abies balsamea [L.] Mill.), which is widely used for floral greenery, is an important source of nontimber forest products (NTFP) from the northern forests of North America. Nonetheless, additional information is needed to refine and revise commercial tip-harvesting management guidelines to promote sustainable forest management. Therefore, a study was initiated to: (a) examine the socioeconomic impacts of and anticipate the potential biological responses to four contrasting harvesting practices; (b) discuss the implications of the results for the relevance and applicability of some specifications of management guidelines; and (c) assess the compatibility of tip harvesting while pursuing an objective of timber production.     

Long-Term Growth Responses of a Jeffrey Pine Stand to Mechanized Thinning and Prescribed Fire

Forest thinnings implemented with cut-to-length and whole-tree harvesting systems followed by underburning were evaluated for their effects on individual tree and stand level growth responses in pure, uneven-aged Jeffrey pine (Pinus jeffreyi Grev. & Balf.) accompanied by isolated California white fir (Abies concolor var. lowiana [Gord.] Lemm.). Based on both dimension and volume measures, trees of the unburned whole-tree treatment combination exhibited the greatest individual growth responses. At the stand level, a diminished volume growth response in the whole-tree treatment was especially pronounced in the burned portion, mostly attributable to exaggerated stocking losses, while a superior response in the unburned cut-to-length combination likely reflected not only the absence of detrimental fire impacts but also benefits of on-site slash retention. For stand level biomass, diminished growth in the whole-tree treatment was again evident, with that in the burned portion again most pronounced, while biomass accrual in the unburned cut-to-length treatment combination was generally comparable to that in the unthinned control. Increasingly utilized in forest restoration efforts in the western USA, the responses presented herein to these thinning and burning practices provide natural resource managers insight into potential compromised outcomes when implemented in Jeffrey pine and similar dry site forest types.     

Bark Beetle Demography in a Jeffrey Pine Stand as Influenced by Mechanized Thinning and Prescribed Fire

Forest thinnings implemented with cut-to-length and whole-tree harvesting systems followed by underburning were evaluated for their effects on bark beetle prevalence in pure, uneven-aged Jeffrey pine (Pinus jeffreyi Grev. & Balf.) interspersed with isolated California white fir (Abies concolor var. lowiana [Gord.] Lemm.). Based on pitch tube counts in a stand with a moderate bark beetle population in its pine component, the Jeffrey pine beetle (Dendroctonus jeffreyi Hopkins) generally preferred larger trees before treatment implementation, but after exhibiting mixed pretreatment tendencies concerning stand density demonstrated a posttreatment proclivity toward higher density. Cut-to-length thinning followed by underburning increased the pine beetle population while whole-tree thinning unaccompanied by burning reduced it. Tree mortality was induced by the bark beetle infestation but was not its sole cause. Pitch tube abundance on white fir far exceeded that on Jeffrey pine, and the greatest influence on the fir engraver (Scolytus ventralis LeConte) population was the prevalence of its host tree. The responses presented herein to these thinning and burning practices, which are being increasingly utilized in forest restoration efforts in the western USA, provide natural resource managers insight into potential forest health outcomes when implemented in Jeffrey pine and similar dry site forest types.     

极度濒危植物百山祖冷杉水培繁殖

1材料与方法1．1材料试材为百山祖保护区利用日本冷杉作砧木剪接繁殖的木质化枝条,粗0．2-0．5cm,生长健壮,无病虫害,每段枝条8-12cm,留部分叶片,每枝均含顶芽。剪好的枝条放在0．5％KMnO4溶液中,消毒30min,然后用清水冲洗3遍,备用。1．2方法试验因子：培养液,清水和霍格兰营养液;植物激素,10mg／L吲哚乙酸（IAA）和10mg／I。生根粉（ABT）。     

极度濒危植物百山祖冷杉水培繁殖

[目的]研究植物外源激素（ABT和IAA）和营养液对百山祖冷杉水培生根的作用。[方法]设清水不加任何激素（CK）、清水＋10mg/L ABT、清水＋10mg／L IAA、10mg/L ABT＋霍格兰营养液、10mg/L IAA＋霍格兰营养液5个处理进行水培百山祖冷杉,观察插条生根情况,统计愈伤形成率、生根率、生根数、根长等。[结果]ABT和IAA对百山祖冷杉水培愈伤诱导和生根率、生根数有明显促进作用,两者都适合在百山祖冷杉水培繁殖中应用;外源激素处理对最长根长和平均根长无规律性影响;有无营养液处理对百山祖冷杉水培繁殖前期各项均无影响,但在出根后会影响根的生长。[结论]研究为百山祖冷衫繁育提供了新思路,有望使其迅速脱离濒危现状。     

White-tailed deer activity reconstructed from tree-rings in eastern boreal Canada

We evaluated the potential of tree-ring techniques for the reconstruction of recent and past seasonal activity of introduced white-tailed deer in a boreal environment of eastern Canada. Hoof scrape scars on balsam fir stems and trampling scars on roots were used to reconstruct deer activity during the winter and snow-free seasons, respectively. Tree damage showed that there was continuous deer activity in the north-central part of Anticosti Island since the mid-1960s. High scrape scars along tree stems (3–3.5 m from the ground) indicate that 1975, 1976, 1981, 1983 and 1985 were years of intensive food search by deer on high balsam fir foliage. The annual number of hoof scrape scars was low between 1982 and 1985, when severe defoliation by the spruce budworm, combined with deer browsing, led to high fir sapling mortality, food depletion, degradation of the winter shelter forests and a decrease in deer activity. The lowest scrape scars 50 cm above ground correspond to the mean height of the residual snowpack in the shelter forest at springtime, when deer start searching for food in nearby open sites and use logging roads, where dead and bonsai-like fir predominate due to overbrowsing. The trampling scar age frequency distribution from two sites indicated that deer activity during the snow-free season started synchronously in the late 1960s. In response to degradation of winter shelter forests, deer may have moved from the southern part to the north-central part of the island and other sectors to survive. Deer-induced tree damage and tree-ring techniques can thus be used to reconstruct past seasonal activity of white-tailed deer.