Abstract:
Heuweltjies are earthen mounds found throughout the Succulent Karoo of South Africa and are inhabited by the termite Microhodotermes viator. Many have assumed that heuweltjies are constructed by the occupying termites. Consequently, heuweltjies have been used as an example of several important concepts in ecology and evolution: the extended phenotype, ecosystem engineering and niche construction. However, recent findings demonstrate that M. viator does not directly construct heuweltjies. Rather, termite colonies enrich the soil around their nests with plant nutrients, which promotes development of widely separated patches of denser vegetation. Eventual formation of heuweltjies represents a response of the physical environment to the windbreak effect of the denser vegetation patches (localized reduction of wind velocity and resultant deposition and accumulation of airborne sediment). Other structures constructed by the termites are justifiably regarded as extended phenotypes. Identification and investigation of a complex cascade of processes are required to more precisely assess the manner in which this termite species functions as an ecosystem engineer or niche constructor, thereby significantly influencing the availability of resources within local ecosystems. Environmental alterations that are either directly or indirectly generated by social animals that construct large, communal nests represent ecological processes that contribute significantly to local biodiversity. This article is part of the theme issue \'The evolutionary ecology of nests: a cross-taxon approach\'.
摘要:
Heuweltjies是在南非多汁的Karoo中发现的土丘,居住着白蚁MicrohodotermesViator。许多人认为heuweltjies是由占领白蚁建造的。因此,heuweltjies已被用作生态学和进化中几个重要概念的例子:扩展表型,生态系统工程和生态位建设。然而,最近的研究结果表明,M.viator并不直接构建heuweltjies。相反,白蚁群使它们的巢穴周围的土壤富含植物养分,这促进了密集植被广泛分离的斑块的发展。heuweltjies的最终形成代表了物理环境对密集植被斑块的防风作用的响应(风速的局部降低以及由此产生的空气沉积物的沉积和积累)。白蚁构建的其他结构被认为是扩展的表型。需要识别和调查复杂的级联过程,以更精确地评估这种白蚁物种作为生态系统工程师或生态位构建者的功能方式,从而显著影响当地生态系统内资源的可用性。由建造大型的社会动物直接或间接产生的环境变化,公共巢代表了对当地生物多样性做出重大贡献的生态过程。本文是主题问题“巢的进化生态学:跨分类单元方法”的一部分。