Forest Growth-and-Yield Modelling

Abstract

Examples of effective growth-and-yield model implementation and use are documented throughout the forestry world. However, in the perspective of sustainable forestry, comparing the development of management requirements with growth-and-yield research backgrounds, some doubts arise concerning basic research hypotheses. The conflict between the necessary simplification implied in models development and the essential complex nature of forests plays a key role in the issue. Furthermore, present modelling concepts stem from a traditional framework relying at the fundamental perception level on the enforcement of external regulations on the forest, having some predetermined optimal structure as a goal. If tomorrow's strategic planning places in the forefront of the framework Oldeman's paradox “objectives are best achieved by first forgetting them in favour of forest survival and complexity maintenance,” we will really face quite a sharp concept change. Yet, it is important to clearly focus the role of models as potential adjuncts to the professional judgement and wisdom of foresters given their rational scientific character as learning, communication and screening tools. What is attainable is not the high precision of quantitative predictions, at least as far as complex biological systems such as forests are concerned. Compact representations (e.g., minimal models and “modeles simples”) with few state variables and a biologically-driven content may provide reasonable indications on future states over a wide range of conditions, contributing to operational forest management guidelines within an adaptive framework.     

Rehabilitation of Former US Military Lands Bordering the Panama Canal

Summary

The Panamanian government is currently negotiating with the United States to determine the extent of the cleanup of US military bases along the Panama Canal. The withdrawal of the US will be completed December 31, 1999. At present, there is no mechanism to ensure that the US will fund, assist with, or assume liability for environmental hazards left on former US Department of Defense lands. Known contamination consists of unexploded munitions on former firing ranges used by the US Army, Navy, and Air Force. Most of these areas are forested with forests of varying age, type, and structure. Complete cleanup could involve complete deforestation of the former bases and firing ranges. The Nature Conservancy has evaluated the ecology of the lands using their “Rapid Ecological Assessment” protocol. The US plans for the lands to become protected areas with warning signs and jersey barriers to protect the public. Panama wants assurance that future cleanup and potential legal damages will be paid for by the US. This paper attempts to summarize the current situation and recommends a potential strategy to both conserve the most biologically diverse forest while maximizing the level of rehabilitation of the areas. It is based on observations and interviews made during a ten-day trip to the Panama Canal Watershed, as well as on news articles, fact sheets from a peace advocacy organization, and primary sources such as correspondence between the US and Panama and minutes from meetings.     

省级农科院建立分院的探索与思考 ——以河南省农业科学院长垣分院为例

农业科研院所承担着农业科技创新与成果转化的重任,是国家农业科技创新体系的重要组成部分,为创新院地合作新模式,找准需求结合点与合作发力点,从合作的理念、方式、领域、机制入手,探索高效运行的新模式,实现院地合作共赢,河南省农业科学院在河南省率先与长垣市政府合作共建河南省农业科学院长垣分院(以下简称"长垣分院"),长垣分院是...     

基于贝叶斯MSSV-ST金融波动模型的股市特征及机制转移性研究

历史上书院形态呈现多样化的特征,除授受儒家学说的教学型书院外,佛道的宗教书院、官员休憩的园林书院、宗族的祠堂书院等以不同形式存在。书院形态的多样性因社会向慕、威权压力和书院的民间性等原因而发生。认识书院形态的多样性,对从整体上把握书院发展史,认识书院文化形成的多元取向,形成多学科交叉的书院研究或有帮助。     

四库提要文献的比较与研究

四库提要从四库馆臣最初撰写的分纂稿到最后形成的《四库全书总目》之间，经过了撤换、增补、复校等过程，内容、文字、体例等都有不少变化，存在许多差异。提要的差异与文献的修改、缮录底本的改换、馆臣的擅改、誊录监生的随意删节与疏忽、特定的政治因素以及馆臣的学术观念等有关。四库提要文献的比较研究可以充实学术思想史的研究，充实文献学学科理论建设，也可为四库馆的管理研究提供例证。     

省级农业科研单位英文网站的现状调查与建议

本文对我国省级农业科研单位英文网站的现状进行调查,从建站意识、设计风格、适用性、后续更新等问题进行分析,结合国外优秀农业和科研网站的设计理念,从网站设计、内容设置和信息技术角度,提出了改进方法及建议。     

南宋书院的学祠与学统

宋代书院与理学的发展密切相关。理学家形成的学统及道统观念，对书院祭祀制度的完备产生了深刻的影响。南宋时期的理学家有一种强烈的建构书院学统，以确立书院在儒家道统史上的意义、地位的精神追求，他们通过创建书院学祠，开展书院祭祀活动，以完成这一文化使命与道义责任。     

长江流域书院与长江文化

中国古代最具特色的书院制度,其起源、发展、普及的重心一直是长江流域。一方面,中国文化重心南移是长江流域书院崛起的历史条件与文化原因;另一方面,长江流域对唐宋以降的长江文化进一步发展起到重要的推动作用     

新时期科技解决"三农"问题的创新与实践

黑龙江省农业科学院2003年始,通过科技园区、专家大院、科技培训、致富项目对我省十弱县进行科技帮扶.3年来,以农业科技专家大院为基地,"零距离"接触农民,搭建了农业技术推广平台;以农业科技示范园区为载体,集成展示农业新成果,构建了农业新技术示范高地;以科技项目为依托,集聚农业生产要素,扶壮了一批县域经济主导产业龙头,取得农业标准化水平、农民科技素质、粮食产量、农民收入"四个"提高的显著成效.开创了全国院县共建的先河,提高了科技向现实生产力的转化速度,探索出了一条新时期科技解决"三农"问题的有效途径.