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We used GIS on a regional scale to estimate and compare supply potentials and costs of small-scale logging systems, a mini-forwarder and a 4-ton truck operated by private logging contractors, and manual logging and a light truck operated by individual forest own- ers, with the mechanized operational system of the Forest Owners' Asso- ciation. Total potential yields of timber and logging residues were esti- mated as 418,895 m3 and 254,962 m3, respectively. The economic bal- ances were estimated and available amounts were projected as supply potentials from profitable sub-compartments. As a result, available amounts of timber and logging residues were estimated at 375,466 m3 (89.9%) and 203,850 m3 (80.0%), respectively. Because their transport expenses were lower than for other systems the most profitable sub-compartments were operated by private logging contractors who sold logging residues at a plant. The profitable sub-compartments operated by individual forest owners were few because the extracting distances were usually greater than 20 m. Raising logging residue prices from 3,000 yen·m-3 to 4,080 yen·m-3 or 6,800 yen·m-3, and establishing forest roads, which reduced some extracting distances to less than 20 m, increased the number and area of profitable sub*compartments, and increased available amounts of logging residues.  相似文献   
3.
Selective absorption (SA) of K over Na (i.e. the preferential absorption of K over Na) has been proposed as a Na tolerance mechanism but genotypic variation for this trait has not been assessed with sugar beet in the field. Thus, the aim of this study was to explore the variation of SA in 14 sugar beet cultivars and to relate SA with yield and root quality in two sites of central Greece (Amfithea and Pyrgetos). Genotypic variation for SA was significant and the SA values were higher in Pyrgetos, the site with the lower soil K and Na concentrations. In Pyrgetos, a favourable environment for sugar beet growth, cultivars yielded more and root quality was better. In that site, a negative relationship between SA and yield (fresh root weight, sugar yield) was found indicating that strong Na exclusion from root is a disadvantage for high yielding. Negative SA–yield relationships were evident in Amfithea when five cultivars with very low SA values (<1.00) were excluded from the analysis. Combined all the cultivars, curvilinear functions were the best-fitted curves for the SA–yield relationships. In Amfithea, where sugar beets had lower water content in root (WCR), a significant, positive correlation between SA and % sucrose content in fresh root weight was found. This finding was ascribed to the dilution of sucrose in roots due to the increased WCR as a result of the increased root Na concentration. In both sites, SA was positively related with root K concentration and negatively with Na concentration. The positive correlations between SA and root α-amino N concentration indicated that sugar beet N nutrition could be affected by the genotypic ability to exclude Na from the root.  相似文献   
4.
Abstract

This article examines the implications and limitations of First Nations forestry negotiations in British Columbia (BC), Canada by assessing how effectively the Tl’azt’en Nation is able to realize benefits under the current form of negotiations. The primary goal of the Tl’azt’en Nation has always been to defend their Aboriginal interests within their ancestral lands, which would entail the cessation of clear-cutting on their traditional territory. Although the community has pursued some economic opportunities in the forestry sector to improve their socioeconomic conditions, despite their efforts, the socioeconomic status of the community remains unchanged. The collective experience of the Tl’azt’en Nation illustrates that simply obtaining certain forest tenures and short-term-based revenue sharing agreements does not adequately meet their forestry and self-sufficiency goals. Without addressing the fundamental issues and challenges facing the community, the current practice of forestry negotiations between the Provincial government and the Tl’azt’en Nation has produced no significant benefits to the community.  相似文献   
5.
The hippocampus is affected by various stimuli that include hyperglycemia, depression, and ischemia. Calcium-binding proteins (CaBPs) have protective roles in the response to such stimuli. However, little is known about the expression of CaBPs under diabetic conditions. This study was conducted to examine alterations in the physiological parameters with type 1 diabetes induced with streptozotocin (STZ) as well as time-dependent changes in the expression of two CaBPs changes of were being evaluated. Rats treated with STZ (70 mg/kg) had high blood glucose levels (>21.4 mmol/L) along with increased food intake and water consumption volumes compared to the sham controls. In contrast, body weight of the animals treated with STZ was significantly reduced compared to the sham group. CB-specific immunoreactivity was generally increased in the hippocampal CA1 region and granule cell layer of the dentate gyrus (DG) 2 weeks after STZ treatment, but decreased thereafter in these regions. In contrast, the number of PV-immunoreactive neurons and fibers was unchanged in the hippocampus and DG 2 weeks after STZ treatment. However, this number subsequently decreased over time. These results suggest that CB and PV expression is lowest 3 weeks after STZ administration, and these deficits lead to disturbances in calcium homeostasis.  相似文献   
6.
“红安苕”种薯资源评价及标准化栽培技术   总被引:1,自引:0,他引:1  
对国家地理标志保护产品"红安苕"种薯资源进行评价,研究国家地理标志保护产品"红安苕"标准化栽培技术。  相似文献   
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Strain K84 of Agrobacterium (formerly called A. radiobacter) has been a successful biocontrol agent of crown gall disease for almost 30 years all over the world. In spite of its demonstrated efficiency, the most important risk of failure when using strain K84 is the possibility of transfer of plasmid pAgK84 to pathogenic Agrobacterium strains. pAgK84 codifies production of and immunity to agrocin 84, the main factor involved in crown gall biocontrol by strain K84. Then, a second generation of strain K84 was obtained and the genetically engineered strain was called K1026. It contains a deletion in the transfer region of pAgK84. To date, a considerable number of studies have been performed to compare both strains in its ability to control crown gall, plasmid transfer, antibiotic production, root colonization and survival in the rhizosphere. The aim of this review is to discuss all this comparative available information which advises that strain K1026 should be used as a biopesticide to safeguard biocontrol of crown gall wherever strain K84 is employed.  相似文献   
9.
Grass tetany (Hypomagnesemia) potential of TAM Wintergreen Hardinggrass and 16 tall fescue lines and varieties was estimated by determining the K, Ca and Mg concentrations in the herbage and the ratio of K/(Ca + Mg) (milliequivalent basis). Data were obtained at four dates during a two‐year period to determine the environmental conditions under which selections should be made to achieve the greatest progress in decreasing the tetany potential of tall fescue and to determine if either of the grasses have high tetany potential in the North Texas area. Hardinggrass had a greater potential to produce grass tetany than tall fescue when grown on the Northern Blackland Prairie of Texas. There were significant differences in K, Ca and Mg concentrations and K/(Ca + Mg) ratio among dates and tall fescue lines. The average temperature for the 30 days before harvest was related to the mineral content and to the K/(Ca + Mg) ratio in all varieties. The K(Ca + Mg) ratio was highest at approximately 18°C but the Mg content fell below the 0.18% required for lactating beef cows when the average temperature for the 30 days before harvest was 22.4°C. Progress could be made in breeding for low grass tetany proneness but selections should be made over a wide range of temperatures considering both the Mg content and ratio of K/(Ca + Mg).  相似文献   
10.
赣苦瓜6号是以强雌系A1-1为母本、自交系B2-1为父本育成的苦瓜一代杂种,表现为早熟、丰产、优质、抗逆性强等优良特性。果实白绿色,长园筒形,单果重约0.5kg,粒瘤粗壮、苦味适中、口感脆嫩,品质优良。可早春或夏秋季栽培,一般产量4500kg/667m2。  相似文献   
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