Stuefer Josef F, Hutchings M J
Department of Plant Ecology and Evolutionary Biology, Utrecht University, P.O. Box 800.84, NL-3508 TB, Utrecht, The Netherlands.
School of Biological Sciences, University of Sussex, BN1 9QG, Brighton, Falmer, Sussex, UK.
Oecologia. 1994 Dec;100(3):302-308. doi: 10.1007/BF00316958.
Clonal fragments of Glechoma hederacea L. (Lamiaceae) were subjected to environments in which light and nutrients were supplied with a strictly negative association in space, i.e. when one of these resources was in ample supply the other was scarce. Treatments were chosen to simulate environments in which clones grew either within homogeneous conditions or across patch types (heterogeneous conditions). The hypothesis was tested that reciprocal translocation (i.e. exchange of both nutrients and assimilates) between connected groups of ramets would increase biomass production of clones growing under heterogeneous conditions compared to that of clones growing in homogeneous conditions. A cost-benefit analysis was carried out to test this hypothesis. Results suggested that reciprocal translocation did not occur at the structural scale considered in this experiment; no evidence was found for a significant effect on whole clone biomass of assimilate and/or nutrient translocation between clone parts experiencing contrasting levels of resource supply. It is suggested that predominantly acropetal movement of resources and the pattern of integrated physiological unit formation in G. hederacea are the main properties responsible for the lack of mutual physiological support between connected clonal fragments growing in differing habitat conditions. These properties are expected to promote clonal expansion and the exploitation of new territory, rather than sustaining clone parts in sub-optimal patches of habitat for prolonged periods of time.
对连钱草（唇形科）的克隆片段进行了实验，使其处于光照和养分在空间上呈严格负相关的环境中，即当其中一种资源供应充足时，另一种资源则稀缺。选择了不同处理方式来模拟克隆体在同质条件下或跨越斑块类型（异质条件）生长的环境。研究人员检验了这样一个假设：与在同质条件下生长的克隆体相比，相连分株组之间的相互转运（即养分和同化物的交换）会增加在异质条件下生长的克隆体的生物量产量。为此进行了成本效益分析来验证这一假设。结果表明，在本实验所考虑的结构尺度上并未发生相互转运；没有证据表明，在经历不同资源供应水平的克隆体部分之间，同化物和/或养分的转运对整个克隆体生物量有显著影响。研究表明，资源主要向顶移动以及连钱草中整合生理单元的形成模式，是导致在不同生境条件下生长的相连克隆片段之间缺乏相互生理支持的主要原因。预计这些特性会促进克隆体的扩张和新领地的开拓，而不是长时间维持克隆体部分在次优生境斑块中的生长。
