基于林相图的森林景观可视化

景观可视化是近30年来逐步发展起来的，特别是计算机软件、硬件技术的发展，使人们对复杂的自然系统进行模拟和可视化成为可能。并且，在环境决策中，公众的参与越来越普遍，积极的公众参与是可持续发展、生态系统管理和21世纪议程发起的基础和先决条件。因此，景观可视化已成为了公众交流和参与环境教育、气候变化、景观规划、林业管理、开发和建设项目的景观影响评价等方面的一种有效手段。 目前林业部门一直采用数字林相图对森林进行表述，但1）数字林相图的平面特性，虽然使用者可以通过等高线来理解森林所在的地形，但必须通过思维的分析转换过程；2） 数字林相图中树种用抽象的符号表示，阅读者要看懂图必须先将树种符号记住或一一对比，不直观；3）数字林相图中在同一小班内难以表现树种空间分布等信息。为了解决数字林相图的这些问题，本论文探索简便快捷的森林景观可视化的方法与应用。 采用三种数据源，即遥感影像数据、地形图数据、林相图数据，将地理信息系统的二次开发技术与VRML（虚拟现实模型语言）相结合，选用集成开发模式，基于.NET平台和ArcGIS Engine开发包，用vb.net语言进行开发，利用景观可视化技术构建并实现了森林景观的可视化。研究结果较直观地再现了该流域的主要景观类型，为流域的景观管理提供了一种全新的，更为直观的管理工具。该工具可以帮助人们进一步理解景观格局及其时间动态，可以对未来景观评价、生态规划提供各种预案，供社会和专家进行不同角度的评价。最后讨论了景观可视化研究中存在的主要问题，提出了一些解决办法，以及进一步的研究方向。

Land-cover changes in an urban lake watershed in a mega-city, Central China

Urbanization can exert a profound influence on land covers and landscape characteristics. In this study, we characterize the impact of urbanization on land cover and lacustrine landscape and their consequences in a large urban lake watershed, Donghu Lake watershed (the largest urban lake in China), Central China, by using Landsat TM satellite images of three periods of 1987, 1993 and 1999 and ground-based information. We grouped the land covers into six categories: water body, vegetable land, forested land, shrub-grass land, open area and urban land, and calculated patch-related landscape indices to analyze the effects of urbanization on landscape features. We overlaid the land cover maps of the three periods to track the land cover change processes. The results indicated that urban land continuously expanded from 9.1% of the total watershed area in 1987, to 19.4% in 1993, and to 29.6% in 1999. The vegetable land increased from 7.0% in 1987, 11.9% in 1993, to 13.9% in 1999 to sustain the demands of vegetable for increased urban population. Concurrently, continuous reduction of other land cover types occurred between 1987 and 1999: water body decreased from 30.4% to 23.8%, and forested land from 33.6% to 24.3%. We found that the expansion of urban land has at least in part caused a decrease in relatively wild habitats, such as urban forest and lake water area. These alterations had resulted in significant negative environmental consequences, including decline of lakes, deterioration of water and air quality, and loss of biodiversity.

Effect of plant architecture on the structure of epiphytic macro invertebrate communities in a Chinese lake

We examined the effect of different plant architecture types on epiphytic macroinvertebrates of a shallow macrophyte-dominated lake in China. Macroinvertebrates were sampled from four dominant submersed macrophytes in the lake - two dissected plants (Myriophyllum spicatum L. and Ceratophyllum demersum L.) and two undissected plants (Potamogeton maackianus A. Benn. and Vallisneria spiralis L.). Macro invertebrate richness showed significant differences among four submersed macrophyte habitats, and higher density per g of dry plant were associated with dissected plants than undissected plants. The average abundance in dissected plants was as three-six times as in undissected plants. The biodiversity of epiphytic macroinvertebrates was higher in dissected plants than undissected plants. Our results suggest that dissected plants provide different habitat for macroinvertebrates than dissected plant, and this concurs with the hypothesis that the former could support more epiphytic macroinvertebrates than the latter.