Nilsson M-C, Zackrisson O, Sterner O, Wallstedt A
Department of Forest Vegetation Ecology, Faculty of Forestry, Swedish University of Agricultural Sciences, S-90183 Umeå, Sweden e-mail:
Department of Organic Chemistry 2, Lund University, P.O. Box 124, S-22100 Lund, Sweden, , , , , , SE.
Oecologia. 2000 Apr;123(1):122-128. doi: 10.1007/s004420050997.
Our purpose was to characterize the relative competitive and phytotoxic potential of two closely related dwarf-shrub species, Empetrum nigrum and E. hermaphroditum, which form clones in a mosaic pattern in post-fire successions of the boreal forest of northern Sweden. We determined morphological and growth parameters of both species, performed bioassays and chemical analysis, and established field experiments to explore possible differing interference effects on trees by the two species. Both Empetrum species had very similar morphological and growth characteristics. E. hermaphroditum exerted considerably greater negative effects than E. nigrum against Pinus sylvestris and Populus tremula seed and seedlings. These negative effects were related to the different substitution of a bibenzyl in the two species. The effect on seed germination of the two bibenzyls isolated from E. nigrum and E. hermaphroditum was compared with that of other simple phenolics; the latter were found to be inactive, indicating a specific phytotoxic component in the bibenzyls. P. sylvestris seeds planted into clones of both species in the field revealed that E. hermaphroditum had much stronger inhibitory effects than did E. nigrum and the addition of activated carbon partially reversed these effects. Seed germination, biomass and survival of P. sylvestris after four seasons were significantly lower in E. hermaphroditum- than in E. nigrum-dominated plots. We conclude that while both Empetrum species are superficially very similar morphologically, they have vastly different effects on tree seed germination, seedling establishment and growth. These effects appear to be due, at least in part, to the different chemical profile of the two species.
我们的目的是描述两种亲缘关系密切的矮灌木物种，即黑果岩高兰（Empetrum nigrum）和两性花岩高兰（E. hermaphroditum）的相对竞争潜力和植物毒性潜力，它们在瑞典北部寒温带森林火灾后的演替过程中以镶嵌模式形成克隆体。我们测定了这两个物种的形态和生长参数，进行了生物测定和化学分析，并开展了田间试验，以探究这两个物种对树木可能存在的不同干扰效应。两种岩高兰物种具有非常相似的形态和生长特征。相较于黑果岩高兰，两性花岩高兰对欧洲赤松（Pinus sylvestris）和欧洲山杨（Populus tremula）的种子及幼苗产生的负面影响要大得多。这些负面影响与两种物种中二苄基的不同取代有关。将从黑果岩高兰和两性花岩高兰中分离出的两种二苄基对种子萌发的影响与其他简单酚类的影响进行了比较；结果发现后者无活性，这表明二苄基中存在特定的植物毒性成分。在田间将欧洲赤松种子种植到两种物种的克隆体中，结果显示两性花岩高兰的抑制作用比黑果岩高兰强得多，添加活性炭可部分逆转这些效应。在两性花岩高兰占主导的地块中，欧洲赤松种子在四个季节后的萌发、生物量和存活率显著低于黑果岩高兰占主导的地块。我们得出结论，虽然两种岩高兰物种在形态上表面非常相似，但它们对树木种子萌发、幼苗定植和生长的影响却大不相同。这些影响似乎至少部分归因于两种物种不同的化学特征。
