A financial evaluation of two contrasting silvicultural systems applicable to Pinus taeda grown in north-east Uruguay

The Loblolly pine (Pinus taeda L.) plantation area in north-east Uruguay was 108 000 ha in 2008. Recent industrial capacity developments have resulted in major structural changes. Silvicultural system selection depends on site productivity, costs, timber prices and public policies. This study aimed to assess economic returns for two silvicultural systems in north-east Uruguay, in scenarios with and without a plantation subsidy: System I, with a short, 12-year rotation, primarily for small logs; and System II, with a longer, 24-year rotation. For System I, the underbark volume was 198 m³ ha^?1 (mean annual increment16.5 m³ ha^?1 y?¹) and land expectation value (LEV) at a 9.7% discount rate was US$561 ha^?1 and US$442 ha^?1, with and without subsidy, respectively. System II resulted in 318 m³ ha^?1 underbark volume (13.2 m³ ha^?1 y^?1) and the LEV was US$860 ha^?1 and US$771 ha^?1, with and without subsidy, respectively. System I was more profitable than extensive cattle husbandry only when the distance to mill was equal to or less than 60 km and wood millyard prices were equal to or higher than US$27.8 m^?3 and US$28.8 m^?3 with and without subsidy, respectively. Values for System II, in which the main product was a mix of sawlog diameters, were positive and higher than those for System I, both with and without subsidy. If a company invested in forest plantations without due provision for early silvicultural treatments, such as pruning and precommercial thinning, a high risk of financial loss would ensue. Long-rotation sawtimber regimes similar to System II would be more profitable and offer a lower risk of financial losses. The results suggest subsidy withdrawal in Uruguay should not lead to changes in silvicultural systems; in fact, it rendered regimes designed for low-value wood, such as System I, even less advisable.     

View of Resuscitation for Wood Construction Building in China

The building mainly made of wood is called woodconstruction building. Wood includes log, lath,wood-based panel and engineered wood. Woodconstruction building mostly refers to houses forliving. Wood construction building has long historyin China. Three thousand and five hundred yearsago, the frame system with tenon to join girderwas basically formed and gradually matured tillTang Dynasty. Many great wood constructionbuildings have passed hundreds or even thousandsof years of history (Fan Che…     

论期前违约制度--履约期待权的救济措施

履约期待权救济措施在英美法系中称为"期前违约"或"预期违约"制度.英美法的期前违约制度包括预期拒绝履行与期待贬损.我国合同法引进了英美法的期前违约制度,但不是完整的引进,而只是引进了部分内容.合同法仍然是以不安抗辩权制度为主,期前违约制度与不安抗辩权制度有很大的区别.期前违约制度在司法实践中缺乏操作性,应尽快完善我国合同法的期前违约制度.     

市场价格稳定性的定性分析

本文利用蛛网模型对市场价格的稳定性进行定性分析．引入反应系数，它用于反映生 产者对市场的估计和决策，同时考虑了消费者对价格的预期，作为一种对现实经济运动的合理 描述有着重要的意义     

从《天净沙》的六种译文看接受美学理论

本文从接受美学理论的两位主要创始人伊瑟尔和姚斯的意义未定性理论和期待视野理论入手，并以马致远的《天净沙》及其六种译文为例分析了诗歌语言的模糊性和期待视野，笔者认为正是诗歌中的诸多未定性的点和意义空白召唤读者展开联想，而读者期待视野的差异性又使这些联想各不相同，从而不同的译者给出了不同的译文。     

谈砌体结构的现状及发展

本文对砌块建筑的发展近况、发展特点进行了描述和归纳，并对今后发展提出了看法。     

Economic Analyses of Rubber and Tea Plantations and Rubber-tea Intercropping in Hainan, China

This study uses land expectation value (LEV) as a criterion to conduct economic analyses of natural rubber (Hevea brasiliensis) and tea (Camellia sinensis var. assamica) monoculture, and rubber-tea intercropping. We calculated LEV by using the Faustmann model that combines annual revenue flow from latex production with final timber harvest of rubber trees. Production and cost data were collected from Xinwei Farm in Hainan, China. We found that rubber-tea intercropping generated higher LEV than rubber and tea monoculture under current socio-economic circumstances. Sensitivity analysis has been conducted to examine the impacts on land expectation value by interest rate, prices of natural rubber and tea, and labor costs.     

测绘生产技术体系发展的回顾与展望

从发展的角度回顾了传统的大地测量、摄影测量、地图制图技术发展到GPS、RS、GIS的过程。分析了现今“3S”技术的特点,并展望了数字测绘技术生产体系的发展前景。     

电动拖拉机发展历程与研究现状综述

电动拖拉机作为农业节能减排的重要工具,也是未来农机装备产品的发展和转型方向之一,国内外进行了大量技术研究与产品尝试。从电动拖拉机技术角度入手,对电动拖拉机发展的各个阶段及其典型产品进行了梳理,总结了各发展阶段的技术特点与影响电动拖拉机技术发展的主要因素。基于国内外现有研究成果,对电动拖拉机研究的方案与设计技术、控制技术、仿真与试验技术的研究现状进行了分析,总结了各方向现有研究成果的特点。结合发展经历与研究现状,对未来电动拖拉机产品与技术的发展方向进行了展望。     

我国土地整理中存在的问题及发展展望

在我国现阶段，土地整理在增加耕地而积与确保粮食安全方而发挥着重要的作用。为此，在论述月前我国土地整理中存在问题的基础上，对土地整瑚的未来发展方向进行了展望，指出土地整理应朝着规范化、产业化、一体化、生态化和法制化等5个方向发展。