游牧文化、草地利用方式变迁与现代生态系统管理 — 以内蒙古锡林河流域为例

锡林郭勒草原位于内蒙古自治区中部，草地面积居我国11片重点牧区之首，是我国温带典型草原的核心分布区和重要的草地畜牧业生产基地。长期以来，锡林郭勒草原作为我国北方地区的一道重要的绿色生态屏障，有效地阻止了草原腹地的土壤侵蚀、沙化以及来自中亚和我国西部的沙尘侵害，对于维持整个华北地区，特别是京、津大都市的生态环境安全起着极其重要的作用。然而，近几十年来，由于人类活动的强度干扰锡林郭勒草原发生了严重退化，生产力显著降低，草原的生态服务功能日益衰减。本文以锡林郭勒草原传统的游牧文化和草地利用方式的变迁作为切入点，以锡林河流域为案例，深入分析了社会驱动力在草地退化过程中的主导作用，目的在于揭示土地利用方式的变化、农牧业人口的剧增和牲畜数量在时间和空间分布的变化趋势与锡林河流域草地退化的关系，进而探求锡林河流域草地畜牧业的可持续发展途径。同时，近年来由于草地退化速度的加剧和草地退化面积的不断扩张，以及世界许多资源保护计划和可持续发展项目的失败，人类原始的土著文化对当地生态环境的保护和维持作用，引起了自然和社会科学界共同的关注，本文应用草地调查和社会调查的方法以及GIS技术对锡林河流域草地退化时空分布规律及其成因进行了研究。 原始游牧是锡林郭勒草原历史悠久的草地利用方式，而草原游牧文化则是蒙古族传统文化的重要组成部分。随着人类社会不断地走向文明和现代化，传统的游牧逐渐地被半定居和定居定牧的方式所取代，蒙古族传统的草原游牧文化也随之走向衰落。本文采用社会调查方法对锡林河流域已经结束了50多年的游牧利用方式进行考察，探讨了不同土地利用方式时空格局，以及土地利用方式变迁对草地退化格局的影响，进而强调了传统的草原游牧文化对于人类的行为规范、价值观念、环境保护和维持生态系统功能的重要意义。 以1984年和2004年开展的大量草地调查数据为基础，结合同期的TM数据，分析了20年来锡林河流域草地退化程度及其空间分布，结果发现锡林河流域草地退化面积达到70％之多，从东南向西北草地退化程度明显加剧。同上世纪80年代中期相比，锡林河流域植被在近20余年来的变化状况表现为：局部恢复，部分地区变化不明显，总体上呈现出不断恶化的发展势头。通过对位于 锡林河流域的锡林浩特市及其邻近地区的社会驱动因子的分析，并应用统计学和GIS空间分析的方法，对锡林河流域土地利用、牧业人口和牲畜数量等因子在近35年来的变化过程进行了系统研究，发现土地利用变化、人口的急剧增加、以及过度放牧是导致锡林河流域草地退化加剧的主要原因。 在上述分析的基础上，以适应性生态系统管理和可持续性科学的基本理论为指导，对锡林河流域的生态环境保护和草地畜牧业的可持续发展提出了一些具体的建议和措施。

Systematic studies on 3d-3d and 3d-4f multimetallic complexes with interesting magnetic and/or luminescent properties

324 p.

Aritmetiikasta algebraan : Muutoksia osaamisessa peruskoulun päättöluokalla 20 vuoden aikana

From Arithmetic to Algebra. Changes in the skills in comprehensive school over 20 years. In recent decades we have emphasized the understanding of calculation in mathematics teaching. Many studies have found that better understanding helps to apply skills in new conditions and that the ability to think on an abstract level increases the transfer to new contexts. In my research I take into consideration competence as a matrix where content is in a horizontal line and levels of thinking are in a vertical line. The know-how is intellectual and strategic flexibility and understanding. The resources and limitations of memory have their effects on learning in different ways in different phases. Therefore both flexible conceptual thinking and automatization must be considered in learning. The research questions that I examine are what kind of changes have occurred in mathematical skills in comprehensive school over the last 20 years and what kind of conceptual thinking is demonstrated by students in this decade. The study consists of two parts. The first part is a statistical analysis of the mathematical skills and their changes over the last 20 years in comprehensive school. In the test the pupils did not use calculators. The second part is a qualitative analysis of the conceptual thinking of pupils in comprehensive school in this decade. The study shows significant differences in algebra and in some parts of arithmetic. The largest differences were detected in the calculation skills of fractions. In the 1980s two out of three pupils were able to complete tasks with fractions, but in the 2000s only one out of three pupils were able to do the same tasks. Also remarkable is that out of the students who could complete the tasks with fractions, only one out of three pupils was on the conceptual level in his/her thinking. This means that about 10% of pupils are able to understand the algebraic expression, which has the same isomorphic structure as the arithmetical expression. This finding is important because the ability to think innovatively is created when learning the basic concepts. Keywords: arithmetic, algebra, competence