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This paper examines the historical phases of Finnish forest planning from the 1960s to the present day in support of the rational future development of forest planning for family-owned forest holdings. The ‘historical types’ of work—craft work, mass production, process enhancement, and mass customization have been recognized in the Finnish planning discourse to date. Indications of mass customization are typical in the present developmental discussion of forest planning. There are some signals in the current planning debate that are calling for the next activity principle, co-configuration. A forthcoming type of forestry extension activity, labelled adaptive planning, is described in this paper to explicate the demands imposed by a future planning system. The present analysis informs also other contexts outside of Finland, where public and private institutions that support family forest owners face post-industrial challenges.  相似文献   
2.
We studied the location and distribution of a bacterial isolate, a Mycobacterium sp., in buds of Scots pine (Pinus sylvestris L.). Using a probe specific for the 16S rRNA of the Mycobacterium sp., the bacterium was found by in situ hybridization in the meristematic tissues of 40% of all bud samples examined. Because we had previously found other bacterial and fungal endophytes in the meristematic tissues of Scots pine buds, we studied their occurrence in buds during shoot development and dormancy. Using probes targeted to the 16S or 18S rRNA of the endophytes Mycobacterium sp., Methylobacterium spp., Pseudomonas spp. and Rhodotorula minuta, endophytes were found in association with growing tissues, with Methylobacterium spp. being the dominant species. Endophytes were detected in abundance before elongation or differentiation of a bud, but once a tissue was fully developed, endophytes were no longer detected. Metabolic activity of the endophytes was suppressed at the onset of, and during, dormancy of Scots pine, but recovered before the following growing season.  相似文献   
3.
Two mycoplasmas were grown in pure and mixed cultures in glucose calf-serum broth with initial pH 7.8. Sensitivity to pH was also tested. The main data for Mycoplasma bovirhinis and Mycoplasma dispar, respectively, in pure cultures were as follows: lag phase, days: <1, 1–2; log phase: 1–2, 1–4; relatively stationary phase: 0–1, 2–4; decline phase (to the extent roughly logarithmic): 2–6, 5–10; maximal titers: 5 × 107 to 109, 5 × 106 to 108 color changing units per 0.2 ml; highest pH, approximately, at which decline started: 7.7 and 7.0; definitely toxic initial pH: 5.6, 6.8; relative production of acidity; less, more. Decline either shortly ended in loss of viability or, correlated with higher pH levels, led to a prolonged maintenance in lower numbers. The decline of M. bovirhinis was postulated to be essentially caused by an autotoxic product/products other than H+.

In mixed cultures an antagonistic effect due to the faster growing M. bovirhinis against M. dispar was recorded. The effect varied according to the initial numbers of organisms and their ratio. Two mechanisms seemed to be active: 1. decrease of pH somewhat below neutrality led to the death of the sensitive M. dispar; 2. M. dispar, when present in relatively high initial numbers, was inhibited by M. bovirhinis during the latter's logarithmic growth at pH-levels above 7.0, the inhibition ending shortly afterwards. A rapidly inactivated product/products of M. bovirhinis metabolism, inhibitory to M. dispar was posited. The results offer an improved insight into diagnostic practices for M. dispar.  相似文献   

4.
In this study, an interactive forest planning process corresponding to the practical demands was developed and further tested in a challenging forest planning situation in northeastern Finland. The process includes prior preparation of alternative stand-level treatments and a small amount of holding-level forest plans; an interactive planning session consisting of the primary choice of the forest owner's profile; the owner's selection of the best holding-level plan; and finally a local improvement of this plan. The method as a whole aims to bridge the gap between the prevailing planning culture that has developed for private forest planning over three decades in Finland and the planning approach suggested by multiobjective forest planning theory. The usability and characteristics of the process were evaluated through an exercise set given to both forestry students and forest professionals. Tests of the process indicated, among other things, that comparison particularly of stand-level alternatives and offering owners the possibility to make changes and truly affect the end-result of the planning process are seen as important characteristics of the process.  相似文献   
5.
Air moisture is one of the main factors causing the greenhouse effect, but humidity has not been thoroughly studied at the ecosystem level. In 2006 a free-air humidity manipulation (FAHM) facility was established in Estonia to investigate the effect of humidity on the performance of two tree species—silver birch (Betula pendula Roth.) and hybrid aspen (Populus tremula L. × P. tremuloides Michx.). The trial is located on an Endogleyic Planosol of former arable land and offers the opportunity to change relative air humidity through controlled artificial misting and drying. We measured the CO2, CH4 and N2O emission from the FAHM system using closed chamber and gas-chromatograph techniques from July 2009 to October 2010. Measurements were carried out once a month in three humidification (h) plots and in three control (c) plots. The vegetation period was rainy in 2009, but the next summer was relatively dry. The dry summer interacted better with the humidification. The CO2 flux decreased when the air moisture was higher than in the control plots. The soil acted as a sink for methane. Less CH4 was oxidized in the soil with increased humidity. Emission of N2O did not correlate with air humidity, although one could observe a clear tendency that there was a smaller N2O flux during the period with increased humidity. Expectedly, CO2 emission and CH4 consumption demonstrated strong positive correlations with soil temperature.  相似文献   
6.
竹材中密度纤维板的初步研究   总被引:3,自引:0,他引:3  
本文探索了用竹材作原料生产中密度纤维板(MDF)的技术可行性,研究了与MDF质量有关的一些因素。试验结果表明:胶粘剂和防水剂的添加量、热磨和热压条件对板材性能有显著影响。控制好这些工艺参数,可以生产出合格的竹材中密度纤维板。  相似文献   
7.
The effect of decreased nitrogen rates (90, 60 and 30 kg N/ha) with and without irrigation on celery yield quantity and internal quality were studied in field experiments in 1993 and 1994. The decreased nitrogen rates reduced yields in both years. In the dry and warm conditions of 1994 nitrogen × irrigation interaction was clearly observed; irrigation increased yield more at higher nitrogen rates than at lower nitrogen rates. In the rainy conditions of 1993 irrigation did not effect the yield level.On the other hand, in both years, decreased nitrogen rates increased dry matter, vitamin C and dietary fiber contents, and nitrogen had a minor effect on total sugar content. In 1994 alpha- and beta carotene and thiamin were also analyzed but nitrogen had no effect on them. Irrigation increased dry matter and total sugar contents at the two lowest nitrogen rates in 1994, but decreased vitamin C contents in both years. There was also slight evidence that irrigation might decrease alpha- and beta-carotene and thiamin contents.  相似文献   
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9.
We investigated the effects of light fuel oil and hydraulic oil on the invertebrate populations of deciduous forest soil. On 9 May 1973, 6.251 oil m?2 was spread on test plots. At the last sampling in October 1974 22% of the fuel oil and 47% of the hydraulic oil remained in the soil. Both types of oil almost totally destroyed the populations of microarthropods, and practically no recovery was observed by the end of the study. Fuel oil destroyed most Enchytraeidae but about half the enchytraeid population survived the hydraulic oil. Immediately after treatment with fuel oil the population of nematodes decreased, but after July 1973 their numbers were twice those found in control plots. Hydraulic oil had no immediate effect, but gradually the numbers of nematodes increased to many times that of the control plots. During the second year, the numbers of nematodes decreased.  相似文献   
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