The performance of community organisers in promotion of community forestry in Leyte Province,Philippines     

Estela Estoria  John Herbohn  Steve Harrison 《Small-Scale Forestry》2004,3(3):363-384

A study was conducted to assess the role and effectiveness of community organisers in supporting the development of people’s organisations in achieving community-based forest management objectives in Leyte Province Philippines. Community organisers were found to be effective in forming people’s organisations (POs), motivating people to participate in voluntary activities organised by POs and encouraging cohesiveness among PO members. Community organisers manage to raise the level of environmental awareness and knowledge of members of people’s organisations, develop leadership interest and skills, create various livelihood opportunities and provide direction and facilitate the establishment of large tree plantations. However, the short duration of community organisers’ contracts (typically two years) is insufficient to establish mature and cohesive POs prepared to assume management on their own, including the management of tree plantations. Further, lack of training and funding support, low wages, delayed payment of salaries and limited time to work with people’s organisations, as well as the pressure to produce tangible outputs such the establishment of large tree plantations, prevents them from placing greater emphasis on the development and empowerment of the people.  相似文献   

Book review     

Jungho Suh 《Small-Scale Forestry》2004,3(3):469-470

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Signals of summer drought in crown condition data from the German Level I network     

Walter Seidling 《European Journal of Forest Research》2007,126(4):529-544

Crown transparency estimates of Scots pine, Norway spruce, common beech, pedunculate and sessile oak, annually surveyed between 1990 and 2004 within a grid over Germany, provide a suitable response variable to study drought effects on forest trees. Major climatic factors, available on a monthly basis as plot-specifically interpolated values and parameters of site and stand conditions, biotic and other relevant factors were used as predictors in different cross- and length-sectional, and longitudinal models. Stand age is a considerable and most constant driver of crown transparency in all species. Pine, spruce and beech responded—mainly with a delay of 1 year—with some foliar loss in areas where there was a surplus of temperature after the generally hot and dry summer of 2003. Parallel time-series analyses delivered species-specific geographic large-scale patterns with delayed or recent precipitation deficits or temperature surpluses. Even if beech is partly responding in current years with leaf loss towards precipitation surpluses, defoliation is especially high 1 year after hot summers, partly a result of high seed sets after such summers. Crown condition of oak responds in dry and warm areas according to the drought stress hypothesis, however, in cool and wet mountainous ranges oak responds after wet summers with higher defoliation. Longitudinal approaches revealed for all 4-tree species significant relationships between crown condition and deviations from the long-term means of temperature, precipitation but also global radiation and wind speed. Results do not always match the drought stress hypothesis, however, this is not to expect considering the heterogeneous site, stand and climatic conditions across Germany. Complex interactions of climatic and biotic factors also impede simple relationships. Soil-related clusters reveal higher sensitivity of spruce and beech towards climatic drought factors on more acid soils with thin humus layers. Also clusters constructed from plot-specific courses of defoliation reveal groups with rather closer relationships like a group of pine plots in the Oberpfalz, which seems to be especially sensitive to summer drought.  相似文献   

Canopy recruitment in the beech (<Emphasis Type="Italic">Fagus engleriana</Emphasis>) forest of Mt. Shennongjia,Central China     

Quanfa Zhang  Mingxi Jiang  Feng Chen 《Journal of Forest Research》2007,12(1):63-67

A dendrochronological technique was used to investigate canopy recruitment of beech (Fagus engleriana Seem.) trees in western Hubei Province of Central China by identifying growth releases through gap formation. The results indicated that 83% and 17% of the canopy trees regenerate in gaps and the understory, respectively. Radial growth analyses demonstrated that there are three modes for beech regeneration and canopy recruitment: (1) gap origin without suppression; (2) gap origin with period(s) of suppression; and (3) understory origin. Multiple periods of release and suppression imply that beech regeneration and canopy recruitment are very sensitive to gap formation.  相似文献   

Petroleum flotation technique upgrades the germinability of <Emphasis Type="Italic">Casuarina equisetifolia</Emphasis> seed lots     

V. Sivakumar  R. Anandalakshmi  R. R. Warrier  B. G. Singh  Mulualem Tigabu  P. C. Odén 《New Forests》2007,34(3):281-291

The germination of Casuarina equisetifolia Forst seed lots is low (40–50%) even when freshly collected. This study aimed at upgrading the germination performance by removing non-germinable seeds using petroleum flotation technique. Seeds collected from 19 individual trees in seedling seed orchards in India were assessed using X-ray to determine the proportion of different seed lot fractions. The feasibility of petroleum ether as a separation medium was tested. Morphological characters of floating and sunken seeds were further studied using image analysis technique to examine their effects on the separation efficiency. The X-ray analysis revealed a large quantity of shrivelled, empty and insect-damaged seeds, altogether accounting 50%, which were the causes of low percentage germination of un-graded seed lots (48%). Petroleum flotation resulted in 90% germination in the sunken fraction and 4% in the floating fraction. The separation was distinct for most seed lots, except few seed lots that had relatively low germination in the sunken fractions and more than 10% germination in the floating fractions. As a whole, petroleum flotation appears to be a feasible technique to upgrade the germination of C. equisetifolia seed lots, and its efficacy is influenced by wing surface area, seed density and wing quotient of filled and empty seeds.  相似文献   

Deformation analysis of timber-framed panel dome structure I: simulation of a dome model connected by elastic springs     

Ying Gao  Masamitsu Ohta 《Journal of Wood Science》2007,53(2):100-107

This study develops an analytical method that enables the simulation of the deformation of timber-framed plywood panel dome structures, of which strength is largely governed by the rigidity of joints. A hybrid truss structure model was employed to analyze this structure. In this model, we aimed to incorporate the mechanical properties of bolted and nailed joints, which were employed to build the structures, although the present investigation focused on the deformation characteristics of a dome in which the panel elements were connected mutually by elastic springs. The results of the theoretical analysis are compared with those obtained by experiments. The simulated results were found to be in good agreement with the results of the experiments under similar loading conditions.  相似文献   

Comparative effectiveness of two alkylammonium compounds as wood preservatives     

Won-Joung Hwang  S. Nami Kartal  Yuji Imamura  Kunio Tsunoda  Katsumi Shinoda 《Journal of Wood Science》2007,53(4):332-338

This study describes a laboratory evaluation of the efficacy of two alkylammonium compounds [didecyldimethylammonium tetrafluoroborate (DBF) and didecyldimethylammonium chloride (DDAC)] when applied via vacuum impregnation or superficial treatment. Treated wood specimens were tested for their termite and microbial resistance under controlled laboratory conditions. The higher chemical retentions were needed to suppress the feeding by Coptotermes formosanus ≦3% mass loss in the multichoice test than in the no-choice test. The DBF and DDAC retention levels necessary to meet the performance requirement ≦3% mass loss after 12-week fungal exposure varied with wood species. The retention level of 3 kg/m³ for DBF and DDAC was generally high to keep the nondurable wood species free of decay. Although there was no difference between DBF and DDAC in the efficacy against decay and termite attack, the former slightly outperformed the latter as an antimold and antisapstain agent.  相似文献   

European forest accounting: general concepts and Austrian experiences     

Walter Sekot 《European Journal of Forest Research》2007,126(4):481-494

Within the European Union there exist three different frameworks for forest accounting at the national level. For purposes of the national accounts, the regulations of the European System of Integrated Economic Accounts (ESA) have to be observed. They require a distinction between forestry and logging and provide specific guidelines for the valuation of standing timber. In recognition of the special character of forests and forestry production, two satellite accounts are devoted to forestry: the Economic Accounts for Forestry (EAF) and the European Framework for Integrated Environmental and Economic Accounting for Forests (IEEAF). Although they were designed as complementary to the national accounts and refer to the same basic methodologies, the guidelines for forest accounting provided by the three manuals are not fully compatible. Just recently, a further integration and harmonization of the concepts for forest accounting has been proposed. Austria has implemented the valuation of the increment as an output of forestry as requested by ESA and produces the EAF tables on a regular basis. The possibilities for extending forest accounting to natural resource accounts for standing timber and the IEEAF have been investigated in terms of pilot studies. The Austrian experiences and results exemplify the problems and possible solutions associated with the adoption of the different European schemes. Data deficits and valuation issues restrict the significance of respective results to some degree, especially as regards forestry-specific extensions of the accounting schemes.  相似文献   

Probabilistic evaluation of the final moisture content of kiln-dried lumber using the bootstrap method     

Ken Watanabe  Tomoyuki Hayashi  Isao Kobayashi 《Journal of Wood Science》2016,62(6):479-486

This paper presents a probabilistic method of evaluating the final moisture content (MC) of lumber obtained at the end of the kiln-drying process. The final MC data of three different drying tests conducted in past studies were analyzed using the bootstrap method. Target MC was tentatively set below 20 % in the analysis. Two characteristic parameters representing the final MC were estimated with bootstrap confidence intervals. These parameters were the standard deviation (SD) and the percentage of the population that met the MC requirement of less than 20 % (P ₂₀). The histograms of the final MC and the subsequent goodness-of-fit tests revealed that the final MC data of two drying tests did not follow any classical probability distributions, including Normal, Log-Normal, Weibull, and Gamma distributions, thus indicating the need for nonparametric statistics. The uncertainty of the final MC could be evaluated with the estimated SD and P ₂₀. After deriving the relationships between P ₂₀ and the corresponding probability that P ₂₀ is not achieved, we demonstrated how such relationships could provide a kiln operator with information to facilitate better decision-making in optimizing a drying schedule.  相似文献   

The effects of temporal differences between map and ground data on map-assisted estimates of forest area and biomass     

Ronald E. McRoberts  Erik Næsset  Terje Gobakken 《Annals of Forest Science》2016,73(4):839-847

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