电路理论在植物景观遗传学研究中的应用潜力分析

景观遗传学的迅速发展为研究异质性系统中的进化生物学问题提供了新颖的理论和方法。本文以电路理论(circuit theory)在植物景观遗传研究中的应用为主题,系统解析理论框架,明确其核心概念和生态学过程间的映射关系,从研究主题、方法和模型验证3方面综述近十年的相关文献,并在此基础上归纳了该理论的优势和局限性。其优势主要为:(1)可对多条潜在传播路径进行通盘考察并予以比较,有助于鉴别影响连接度的关键区域或廊道;(2)对哈迪-温伯格平衡假设和栅格大小不敏感,保证了模型的适应性;(3)模型要求物种对生境无明显经验积累,特别适合分布区形状不规则,以及连续广泛分布的物种,与许多植物的生物学特点相契合。该理论要求物种具有随机漫游和传播各向同性2个前提条件,限制了生物媒介类植物的适用度。在传播过程具有方向偏好的生态系统中,其应用也需慎重考虑。结合未来发展趋势,本文认为电路理论在植物景观遗传学研究中具有很好的潜力,但还需要依据具体的研究问题、物种习性、空间尺度和系统性质来进行科学的应用。

Analysis of the application potential of circuit theory in plant landscape genetics

The rapid development of landscape genetics provides innovative concepts and methodologies for evolutionary biology research in heterogeneous systems. This paper focused on the current application of circuit theory in plant landscape genetics. We demonstrated the theoretical framework of the model, explored the ecological meaning of the core concepts, and reviewed the related literature on three aspects: research theme, method and model validation. The advantages and limitations of this theory were summarized. We found the theory to be suitable for research on plant landscape genetics based on: (1) inclusion of multiple pathways enabling comparison and identification of critical habitats and corridors; (2) insensitivity for HW equilibrium and cell size making the model robust; and (3) no prior knowledge for intermediate habitat and broad range (or irregular range shape) prerequisite coinciding with many plant species. The theory has two premises: random walk and isotropic dispersal. Plants dispersing through a biotic agent may be less suitable for the circuit theory. Application in ecosystems with direct dispersal also needs prudence. Considering the prospect of circuit theory in plant landscape genetics, we argue a more rigorous model based on sophisticated consideration for research theme, species behavior, spatial scale, and system character.