Vegetation dynamics in burnt heather-gorse shrublands under different grazing management with sheep and goats     

B. M. Jáuregui  R. Celaya  U. García  K. Osoro 《Agroforestry Systems》2007,70(1):103-111

Vegetation dynamics in previously burnt shrublands dominated by gorse (Ulex gallii) in north-west Spain were studied during 4 years under different grazing managements with sheep (Gallega breed) and goats (Cashmere or local breed). Initially (Period 1), treatments consisted of sheep or goat grazing on four plots (two replicates). After two grazing seasons, the plots were split in two and the treatments were reversed in four of the subplots; sheep were placed in subplots previously grazed by goats and vice versa (Period 2). The results from Period 1 showed that goats control the regrowth of gorse (from 19.6 to 14.2% of cover) more effectively than sheep (17.8 to 27.0% cover; P < 0.05), favouring the increase in herbaceous plants (from 21.5 to 42.1% of cover under goat grazing and from 22.1 to 26.6% under sheep grazing; P < 0.01). In Period 2, after changing treatments, there was a clear effect of the previous management (P < 0.01), conditioning the dynamics of the different plant components. Where the same animal species were maintained for 4 years, the differences between sheep or goat grazing on gorse and herbaceous plant dynamics increased (24.4% of gorse and 35.2% of herbaceous plant cover under goat grazing vs 43.8% of gorse cover and 19.1% of herbaceous plant cover under sheep grazing). Animal species change buffered the differences between sheep and goats during the second Period.  相似文献   

Transverse shrinkage in G-fibers as a function of cell wall layering and growth strain     

Chang-Hua Fang  Bruno Clair  Joseph Gril  Tancrède Alméras 《Wood Science and Technology》2007,41(8):659-671

Transverse drying shrinkage was measured at microscopic and mesoscopic levels in poplar wood characterised by an increasing growth strain (GS), from normal to tension wood. Results show that: (a) the drying shrinkage, measured as a relative thickness decrease, was significantly higher for G-layer (GL) than for the other layers (OL), GL shrinkage was not significantly correlated with GS, and OL shrinkage was negatively correlated with GS. (b) In gelatinous fibre (G-fibre), lumen size increased during drying and this increase was positively related with GS, but in normal wood fibre, lumen size decreased during drying. These findings suggest that GL shrank outwards (i.e., its internal perimeter increases), so that its shrinkage weakly affected the total cell shrinkage and the mesoscopic shrinkage was controlled by the OL shrinkage which shrank inwards (i.e., its external perimeter decreases). (c) Measurements done on 7 × 7 mm2 thin sections evidenced a negative correlation between transverse shrinkage and GS, significant in T direction but weak in R direction. These observations at both levels allow to discuss the contribution of GL to the mesoscopic shrinkage of tension wood.  相似文献   

Foreword     

Anssi Niskanen  Heimo Karppinen 《Small-Scale Forestry》2007,6(4):329-330

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Host selection of small cedar longicorn beetle, <Emphasis Type="Italic">Callidiellum rufipenne</Emphasis> (Coleoptera:Cerambycidae), on Japanese cedar, <Emphasis Type="Italic">Cryptomeria japonica</Emphasis>, in terms of bark water content of host trees     

Masafumi Ueda  Ei’ichi Shibata 《Journal of Forest Research》2007,12(4):320-324

We caught the adults of a secondary wood-boring insect, Callidiellum rufipenne (Motschulsky), on Japanese cedar, Cryptomeria japonica D. Don., trees and logs with manipulated bark water contents to clarify the mechanism of host selection by C. rufipenne. More C. rufipenne were trapped when the bark water content range was ca. 120–200%. Fewer C. rufipenne were trapped at higher and lower bark water contents. These findings indicate that C. rufipenne adults do not simply select weakened or dying trees. Bark water content is one of important factors for C. rufipenne choosing their host for oviposition.  相似文献   

Transcriptional and translational analyses of poplar anionic peroxidase isoenzymes     

Shinya Sasaki  Motoyuki Shimizu  Hiroyuki Wariishi  Yuji Tsutsumi  Ryuichiro Kondo 《Journal of Wood Science》2007,53(5):427-435

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The Japanese pulp and paper industry: an analysis of financial performance from 1991 to 2001     

Lars Lönnstedt  Hans-Olof Nordvall 《Journal of Forest Research》2007,12(4):278-288

This article discusses the determinants of profitability expressed as return on capital among Japanese pulp and paper companies. Return on capital is measured as income before tax related to stockholders’ equity. Return on capital has been divided into profit margin and asset utilization rate. The hypothesis is that return on capital can be explained by mill size, productivity, product line, financial situation, and use of wood resources. The dataset consists of 13 larger Japanese pulp and paper companies listed in Pulp &; Paper Statistics. Data on financial performance, production, and use of wood fibers were collected for the period 1991–2001. The average return on equity for the studied companies is 4.2%. Labor productivity has increased quite significantly, from about 600 to 1,000 kg/employee and year. An econometric analysis indicates that the best model fit is found when the asset utilization rate is used as the dependent variable. Significant variables are, among others, asset utilization rate lagged one time period (?), labor productivity (+), capital productivity (?), paper production as a share of total paper and board production (?), total value of assets on the books (?) and solidity (+). This may indicate that the total value of assets on the books is large in relation to the total production of paper, paperboard and pulp.  相似文献   

Temporal and spatial changes in Bt toxin expression in Bt-transgenic poplar and insect resistance in field tests     

Yiwen Zhang  Jun Zhang  Jinping Lan  Jinmao Wang  Junxia Liu  Minsheng Yang 《林业研究》2016,27(6):1249-1256

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Shoot development and dieback in progenies of Nothofagus obliqua     

Javier Puntieri  Javier Grosfeld  Marina Stecconi  Cecilia Brion  María Marta Azpilicueta  Leonardo Gallo  Daniel Barthélémy 《Annals of Forest Science》2007,64(8):839-844

Shoot growth and dieback were compared among progenies of nursery-grown seedlings of Nothofagus obliqua belonging to seven progenies of the same provenance (Quila-Quina, Argentina). First-year shoots consisted of one growth unit (GU) and second-year shoots of one or two GUs. The probability of development of two GU was similar for all progenies. Progenies were different in terms of shoot size, terminal bud abscission, the extent of shoot dieback after shoot extension and the node of origin of the relay shoot on the first shoot. Plants with a second-year shoot consisting of two GUs had a thicker stem and more nodes than those with single-GU shoots. The selection of N. obliqua seed trees based on architectural traits suitable for forestry development at specific sites must contemplate variability among progenies and their probabilities of successful development under different conditions.  相似文献   

Genetic analysis of selected almond genotypes and cultivars grown in Turkey using peroxidase-gene-based markers     

Hasan Pinar  Mustafa Unlu  Sezai Ercisli  Aydin Uzun  Mustafa Bircan 《林业研究》2016,27(4):747-754

Peroxidase plays important roles in many stress-related interactions and catalyzes important reactions in various physiological processes. Since peroxidase played critical roles in the evolution of almond(Prunus dulcis Miller(D.A Webb) syn P. amygdalus Batsch), peroxidase-gene-based analyses may increase the understanding of evolution of this species. Peroxidase gene polymorphism(POGP) markers were used to determine genetic diversity and relationships among 69 Turkish genotypes/cultivars and 27 foreign almond cultivars by using unweighted pair group method with arithmetic mean(UPGMA) analysis. This study is the first evaluation of the use of POGP markers for diversity analysis in almond.Totally, 83 fragments were obtained from eight peroxidase primer pairs, and polymorphism was identified as 94 %.Similarity level among the genotypes ranged between 0.63 and 0.93, and all materials were distinguished. In general,Turkish and foreign genotypes were mixed in clusters since they share a common genetic background and gene migration among the sites. Clusters were not based on geographic regions except for some minor groupings. This study indicated that peroxidase gene markers can be reliably used to determine genetic relationships in almonds.  相似文献   

Field attraction of Cerambyx welensii to fermentation odors and host monoterpenes     

Israel Sánchez-Osorio  Gloria López-Pantoja  Antonia M. Paramio  José L. Lencina  Diego Gallego  Luis Domínguez 《Journal of pest science》2016,89(1):59-68

Cerambyx welensii Küster is one of the greatest threats to Quercus suber L. and Quercus ilex L. in Spain. Efficient control methods for this species are currently being tested, and the use of traps baited with food-related products for their monitoring and control has been proposed. Cerambyx welensii adults prefer to colonize old or decayed trees, in which cortical exudates frequently release fermentation odors. Fermentation-related compounds, such as ethanol, have been cited as attractants to various hardwood woodborers (as Cerambyx cerdo L.), used either alone or sometimes in combination with other host odors. In this work, we conducted field experiments to ascertain whether chemical blends mimicking fermentation odors were attractive for C. welensii. To this end, we used three types of traps (multiple funnel, cross-vane and single-funnel) baited with six synthetic blends including one or more fermentation-related chemicals (ethanol, ethyl acetate, 3-methyl-1-butanol, acetaldehyde, 2-methyl-1-propanol and 2-methyl-1-butanol), various food-related products (beer, melon and red wine mixed with peach juice) and host monoterpenes (α-pinene, β-pinene, limonene, α-phellandrene and camphene). At high release rates (5–11 g/day), various synthetic blends proved attractive irrespective of trap type. Our results contribute to understand the impact of volatile organic compounds in host selection by woodborers infesting deciduous trees. The results hold promise for optimizing trapping strategies to control C. welensii within an integrated pest management framework.  相似文献