摘要:

The relationship between stem and branch growth of common ash (FraxinusexcelsiorL.) was studied from cumulated annual increments of stems and branches determined by stem and branch analysis on 19 unforked trees aged 12–60 years. An allometric relationship between branch length and cumulated stem growth above the branch base was modified to account for an additional tree height effect, and fitted to the pooled branch and stem data. The crown dimensions of trees were derived from the branch growth equation and an average mean branching angle, by solving a crown radius equation. This crown profile prediction method was checked individually on tree samples by comparing observed and simulated crown radii; satisfying results were obtained, except for some trees that were suppressed for a long period.

ISSN:0045-5067    

DOI:10.1139/x94-299

出版商:NRC Research Press    

年代:1994

数据来源: NRC

摘要:

The distribution of the fumigants methylisothiocyanate (MITC), Vorlex, and chloropicrin, used to controlPhellinusweirii(Murr.) Gilb., was assessed 10 years after application to sites near the bases of living Douglas-fir (Pseudotsugamenziesii(Mirb.) Franco). MITC was detected up to 8 m above the original application site, and fumigants were present at the highest levels near the pith of the tree. MITC was detectable as far as 2.1 m down the roots in trees treated with the largest dosage, and Vorlex was detectable 1.5 m from the application site. Levels of chloropicrin were generally greater than levels of MITC or Vorlex, but chloropicrin was detected only up to 3 m above the application site; lower water solubility probably accounted for the restricted diffusion of this chemical. The results indicate that fumigants can diffuse for considerable distances through Douglas-fir boles and roots. Further studies are underway to establish the efficacy of the concentrations measured in these trees.

ISSN:0045-5067    

DOI:10.1139/x94-300

出版商:NRC Research Press    

年代:1994

数据来源: NRC

摘要:

Height growth at 10 years from striking was assessed for clonally replicated full-sib black spruce (Piceamariana(Mill.) B.S.P) families tested at three locations in central Nova Scotia. Variance components were interpreted according to an additive–dominance–epistasis genetic model and used to derive comparative estimates of gain from various selection and deployment strategies. Field performance at 5 and 10 years was compared with that of the original ortets and families growing in a 25-week greenhouse study, by means of phenotypic and genetic correlation, and rank-change analyses. Between age 5 and 10, the additive portion of the total genetic variance for height decreased from 66 to 38%, while the dominance portion increased from less than 3 to 13%, and the epistatic portion from 31 to almost 49%. As a consequence, narrow-sense heritability estimates were lower at age 10 and gain estimates also decreased, particularly for those strategies that capture gain primarily from additive effects. Although correlations between field performance and early growth measurements were generally poor, the strongest were found at the half-sib level; full-sib correlations were somewhat weaker and those between clone means and early ortet performance were small and not statistically significant. The strongest age–age correlations were those that involved family mean seedling weight in the greenhouse. Family rankings based on early oven-dry biomass production also showed the most consistent agreement with ranking after 5 and 10 years of field testing, although the analyses suggest that effective early selection is probably limited to culling the worst 25% of the families based on biomass. Genotype–environment interactions were statistically significant, although these were limited to only 2% of the phenotypic variance in height growth; furthermore, strong genetic correlations between environments suggested that these interactions have little impact on selection efficiency.

ISSN:0045-5067    

DOI:10.1139/x94-301

出版商:NRC Research Press    

年代:1994

数据来源: NRC

摘要:

Two plantations were established in the village of Whapmagoostui-Kuujjuaraapik to determine the effects of two types of fertilizer (fast or slow release) and two types of mulch (plastic or organic) on native woody species growth and survival in subarctic Quebec. In the first plantation, the species tested wereSalixplanifoliaPursh,Alnuscrispa(Ait.) Pursh,Piceaglauca(Moench) Voss, andPinusbanksianaLamb. Four growing seasons after planting, cuttings ofS.planifoliahad the highest survival of all four species (96% in control plots) and a very good growth (4.8 mm and 5.7 cm growth in diameter and height, respectively). The performance ofA.crispawas also very good (77% survival in control plots; 5.1 mm and 7.5 cm growth in diameter and height, respectively), whilePiceaglauca(17% survival in control plots; 0.6 mm and −9.0 cm growth in diameter and height, respectively) andPinusbanksiana(31% survival in control plots; 2.4 mm and 5.7 cm growth in diameter and height, respectively) performance was poor. The application of a slow-release fertilizer enhanced plant growth of all four species, but reduced the survival ofA.crispa, particularly when a plastic mulch was used. Otherwise, mulching had no significant effect on either growth or survival of any of the other species. In the second plantation, established on a more exposed site, the survival ofS.planifoliawas lower (77% in control plots) than in the first plantation, and the application of a fast-release fertilizer there had a negative effect on plant growth. These latter results appear to be related to freezing injuries and winter killing of vegetative buds. Organic mulching did not influence plant growth on this second site, but the utilization ofAlnuswood chips increased the survival ofS.planifoliacuttings. We recommend the use ofS.planifoliaand also ofA.crispafor revegetation purposes in subarctic Quebec. Application of a slow-release fertilizer can increase plant growth, but should not be combined with the use of plastic mulches, as plant survival is then negatively affected.

ISSN:0045-5067    

DOI:10.1139/x94-302

出版商:NRC Research Press    

年代:1994

数据来源: NRC

摘要:

A method is proposed for adjusting small-sample-based stock and stand table entries from point, double sampling with a ratio of means estimator. The proposed adjustment uses the characteristics of the ratio of means estimator, ensures that totals from the stock and stand tables match the large sample estimates, and preserves the volume–basal area ratio by DBH class before and after adjustment. Bias and variance estimates for the adjusted stock table entries are presented.

ISSN:0045-5067    

DOI:10.1139/x94-303

出版商:NRC Research Press    

年代:1994

数据来源: NRC

摘要:

Partial and total measures of factor productivity are presented for the pulp and paper industries of the United States and Canada, from 1959 to 1987. Total factor productivity was measured with (1) a Tornqvist–Theil index, (2) a nonparametric index with translating hypothesis, and (3) a nonparametric index with distance functions. Method 1 implied a constant return to scale translog production function. Methods 2 and 3 removed any assumption on the functional form of the production function. Furthermore, method 3 allowed for fully disaggregated outputs. Methods 1 and 3 gave similar results within countries: an increase in total factor productivity of 0.7% per year in the United States and of 0.5% per year in Canada. Method 2 gave rates of growth of total factor productivity that were twice as high, but unreliable because of the assumptions of the method. From 1961 to 1984, when comparable data are available, methods 1 and 3 gave growth rates of total factor productivity that were significantly higher, statistically, in the United States than in Canada. Nevertheless, the differences seem to be too small to be of economic significance.

ISSN:0045-5067    

DOI:10.1139/x94-304

出版商:NRC Research Press    

年代:1994

数据来源: NRC

摘要:

Crown structure for 9- to 30-year-old loblolly pine (PinustaedaL.) trees in unthinned plantations was quantified via analysis of branch diameters and location, both along and around the bole, using data from 68 trees. The trees ranged in size from 11.1 to 31.6 cm in diameter at breast height and from 8.30 to 25.67 m in total height, and were growing in Piedmont and Atlantic Coastal Plain stands. Three equations were used to describe the diameter distribution of branches. Circular statistics were used to examine branching patterns around the bole. A system of two equations was developed to predict the total number of branches within a crown. A series of three equations was used to describe the mean of and range in diameters within a whorl. Attempts at modeling the height above ground to branches (whorls) were unsuccessful; therefore, equal height growth per year was assumed and whorls were placed within each year of growth in concordance with the literature. Similarly, predicting the number of branches within a whorl of a certain height was difficult, and overall percentages were employed. Analysis of branch azimuths on a whole-tree basis indicated that a uniform, or regular, distribution was appropriate (and not a "circular normal" distribution). Finally, circular correlation was used to analyze rotational patterns within and between whorls, and a strong positive correlation was found for consecutive whorls of the same number of branches. From this study it was concluded that modeling crown structure is difficult, with much variation occurring among trees.

ISSN:0045-5067    

DOI:10.1139/x94-305

出版商:NRC Research Press    

年代:1994

数据来源: NRC

摘要:

Hybrid poplar clone NC–5339 (Populusalba×Populusgrandidentatacv. Crandon) was genetically modified for glyphosate (N-(phosphonomethyl)glycine) tolerance byAgrobacterium-mediated transformation with genetic constructs (pPMG 85/587 and pCGN 1107) that included the mutantaroAgene for 5-enolpyruvylshikimate-3-phosphate (EPSP) synthase (EC 2.5.1.19) and the neomycin phosphotransferase selectable marker gene. pCGN 1107 also harbored the coding sequence for a chloroplast transit peptide and the CaMV 35S promoter fused to the mutantaroAgene. Transformants were selected for kanamycin tolerance, and integration of thearoAgene was verified by Southern blot analysis. Cuttings of NC-5339 and the derived transformants were rooted and grown in glasshouses at separate locations, with maximum photosynthetic photon flux density of 1600 and 750 μmol•m−2•s−1. Productivity was assessed by growth studies and photosynthesis measurements at both locations. Glyphosate tolerance was tested by (i) measurement of chlorophyll concentration in herbicide-treated leaf discs and (ii) whole-plant spray tests. Plants transformed with construct pCGN 1107 were the most herbicide tolerant. Perhaps high-level expression of thearoAgene by the CaMV 35S promoter, transport of mutant EPSP synthase into the chloroplasts, or both facilitated glyphosate tolerance. Plants grown at higher photosynthetic photon flux densities (1600 vs. 750 μmol•m−2•s−1) had significantly higher maximum net photosynthesis (19.8 vs. 16.2 μmol•m−2•s−1) and more biomass accumulation (47.6 vs. 33.7 g). However, there were no significant differences between NC-5339 and transformants within location for net photosynthesis or any growth parameter. Genetic modification of hybrid poplar NC-5339 for glyphosate tolerance did not adversely affect plant productivity at either location.

ISSN:0045-5067    

DOI:10.1139/x94-306

出版商:NRC Research Press    

年代:1994

数据来源: NRC

摘要:

Douglas-fir (Pseudotsugamenziesii(Mirb.) Franco) trees, both healthy and infected byInonotussulphurascens(Pilát) M.J. Larsen, F.F. Lombard, & J.W. Clark (Phellinusweiriisensu lato), were fumigated with chloropicrin or methylisothiocyanate at a site in the Oregon Coast Range. Ten growing seasons later, vegetation cover on plots around treated and untreated individuals was evaluated to determine fumigant effects on nontarget plants. Total plant cover and individual species cover forBerberisnervosaPursh andStokesiellaoregana(Sull.) Robins were significantly reduced in the chloropicrin treatment plots. The dominant shrub,GaultheriashallonPursh, was little affected in chloropicrin plots. Slightly greater species richness andRubusursinusCham. & Schlecht. cover in chloropicrin plots were attributed to higher light levels and other factors associated with reduced shrub cover on the treated plots. Multivariate analysis showed little overlap in plant community structure between chloropicrin-treated and control plots. Detection of effects due to the methylisothiocyanate treatment was hindered by the lack of strictly paired control trees. The results are discussed in relation to the retrospective nature of the study.

ISSN:0045-5067    

DOI:10.1139/x94-307

出版商:NRC Research Press    

年代:1994

数据来源: NRC

摘要:

Results are presented of genetic variation and growth decline due to pollution for 11 European populations, 1 Turkish population, and 1 Siberian population of Scots pine (PinussylvestrisL.) growing in a provenance experiment established in 1912 in Pulawy, southeastern Poland. Since 1966 this area has been subjected to acute pollution from a nitrogen-fertilizer factory emitting high levels of SO2, NOx, NH3, and other toxic compounds. A significant negative correlation was found between genotype polymorphism indices and radial growth decline since 1966 assessed using tree-ring analysis (r = −0.58,P = 0.04). Populations with the highest values for genotype polymorphism index, numbers of alleles per locus, and numbers of genotypes per locus exhibited less of a decline in radial growth than those populations with lower values for these parameters. The results provide experimental support for the hypothesis that genetically richer populations are better adapted to changing conditions and suggest that such populations are less sensitive to air pollution in terms of growth reduction.

ISSN:0045-5067    

DOI:10.1139/x94-308

出版商:NRC Research Press    

年代:1994

数据来源: NRC