Assembly rule for plant communities -for the development of invasion ecology-

基于当地植物区系生态特征的各种植物群落预测一直是生态学的重要研究主题。这种预测的结果可应用于新败血症引入前的入侵风险评估，以及全球变暖后的植物群落的预测。计算机模拟已成为此类研究的主要方法，但开发可靠的模型和获取可行参数的技术尚未建立。20世纪90年代以来，人们利用数据挖掘技术建立了预测植物群落的统计模型。作者从20世纪90年代初就开始了这方面的工作，并成功地预测了顶极森林的优势度和组成(Koike 2001)。作为本研究项目的结果，1.在小川群岛的杂草风险评估中，生物学特性对入侵的预测并不有效。假设的入侵目标(大范围和各种群落)可能不合适，目标应该是单个群落。2.出现在一个群落中的植物物种具有相似的生态特征。因此，各种植物群落只有一个单一的功能特征。3.根据本州中部暖温带(暖温带上限)已有的资料，以及本项目在暖温带最暖端(接近亚热带)和冷温带北端(靠近北方混交林带)的新修正数据，顶极森林总体上具有相似的聚集规律。耐荫性和最高身高是关键性状。遮荫不耐受(可能是高RGR)是草本植物群落的关键。人工林的社区集会规则因气候区域而异，可能因人的管理方法而异。

Prediction of various plant communities based on ecological traits of local flora has been important research theme for ecology. The results of such prediction should be applied for the assessments of invasion risk of new sepsis prior to introduction, and plant communities after global warming may also be predicted.Computer simulation have been major methods for such researches, however, technique to develop reliable model and to obtain feasible parameters have not yet establishes. Recently, statistical models to predict plant community have been developed since 1990s using data-mining technique. The author also started such works since early 1990s, and predicted dominance and composition of climax forests successfully (Koike 2001).As the results of this research project,1.In the Weed Risk Assessment for Ogasawara Islands, biological traits did not contributed the prediction of invasion effectively. The assumed target of invasion (wide area with various communities) may not suitable, and the target should be individual community.2.Plant species occurring a community have similar ecological traits. Thus, various plant communities have only a single functional trait. In application, we can use simple prediction model as a logistic regression.3.Based on the previously available data in warm-temperate zone in central Honshu (upper limit of warm-temperate zone), and new data corrected in this project in the warmest end of warm-temperate zone (close to subtropical) and northern end of cool temperate zone (close to boreal mixed forest zone), Climax forests have generally the similar assembly rule. Shade tolerance and tall maximum height was the key traits. Shade intolerance (probably high RGR) was the key for herbaceous communities. Community assembly rule for planted forests differ by climate zones probably by management methods of people.