Abstract: Yoda's -3/2 power rule or law of self-thinning based on the isometric scaling growth of plant, as well as a -4/3 law of self-thinning based on the energy equivalence ecological theory and the allometric relationship between metabolic rate and body mass of individuals are reviewed. Although the existence of a general self-thinning trajectory with a slope of -3/2 is questioned extensively, there is no evidence to reject the -3/2 power rule as the upper limit boundary line, below which all size-density trajectories possibly occur, and to accept the -4/3 power rule as the substitute. The authors suggest a re-evaluating of the -3/2 as well as -4/3 power law of self-thinning, from the first principles to the representation.

Key words: -3/2 power law, -4/3 power law, plant population, self-thinning, self-thinning boundary line, energy equivalence, allometry, isometry

摘要： 由密度导致的植物种群的自然稀疏现象，是植物种群生态学研究的热点。但关于植物自然稀疏规律（种群密度和个体平均质量的幂律关系）的机理，却有两类截然不同的理论解释，分别对应着-3/2和-4/3幂律。作者重点介绍这两类自然稀疏幂律的代表性理论模型： Yoda的-3/2自疏法则和基于WBE模型的-4/3自疏规律，以及它们各自的理论基础。由于研究方法等原因，目前的数据尚不足以否定一条自疏上限线的存在，也不能令人信服地推翻-3/2而确立-4/3幂值的自疏规律。

关键词: -3/2幂律, -4/3幂律, 植物种群, 自然稀疏, 自疏边界线, 能量相当, 异速生长, 等速生长