食草作用对千里光和药用琉璃草种群动态的正负效应

Positive and negative effects of herbivory on the population dynamics of Senecio jacobaea L. and Cynoglossum officinale L.

作者信息

Prins A H, Nell H W

机构信息

Department of Population Biology, University of Leiden, P.O. Box 9516, 2300 RA, Leiden, The Netherlands.

出版信息

Oecologia. 1990 Jun;83(3):325-332. doi: 10.1007/BF00317555.

DOI:10.1007/BF00317555

PMID:28313002

Abstract

Herbivore effects were studied on populations of the biennial plant species Senecio jacobaea and Cynoglossum officinale. During a three year period (1985-1988) population characteristics (herbivory, number of seedlings, rosettes and flowering plants) were compared in-and outside exclosures, as well as parameters reflecting vegetation cover. In S. jacobaea, a strong negative effect of Tyria jacobaeae was found on seedling establishment, rosette growth and flowering. On the other hand, vertebrate herbivores (mainly rabbits) had an indirect positive effect by limiting the development of the surrounding vegetation (esp. grasses). The increasing vegetation cover in protected populations caused a reduction in germination, seedling- and rosette-growth. Herbivory on C. officinale was low (<10%), no direct effects of herbivores on plant populations were shown. Indirect effects of herbivory through an increasing vegetation were even more pronounced as in S. jacobaea. Therefore, although both plant species may first benefit from herbivore-exclusion, their populations are dependent on rabbits eating other plants (esp. grasses) and reducing competition.

摘要

研究了食草动物对两年生植物物种千里光和药用琉璃草种群的影响。在三年期间（1985 - 1988年），对围栏内外的种群特征（食草情况、幼苗、莲座叶丛和开花植物的数量）以及反映植被覆盖的参数进行了比较。在千里光中，发现大戟叶螨对幼苗建立、莲座叶丛生长和开花有强烈的负面影响。另一方面，脊椎动物食草动物（主要是兔子）通过限制周围植被（特别是草）的生长而产生间接的积极影响。受保护种群中植被覆盖的增加导致发芽率、幼苗和莲座叶丛生长的降低。药用琉璃草的食草率较低（<10%），未显示食草动物对植物种群有直接影响。与千里光一样，通过增加植被而产生的食草动物间接影响更为明显。因此，尽管这两种植物物种最初可能会从排除食草动物中受益，但它们的种群依赖于兔子食用其他植物（特别是草）并减少竞争。