Kalin Arroyo Mary T, Cavieres Lohengrin A, Castor Carmen, Humaña Ana María
Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile e-mail:
Oecologia. 1999 Apr;119(1):126-132. doi: 10.1007/s004420050768.
The persistent soil seed bank (viable seeds >1 year) and standing vegetation were investigated in the upper alpine belt (3250 m) in the Andes of central Chile, 33° S. Nine species (eight in standing vegetation) were found in a total persistent seed bank of 899 seeds m. Seven additional species were represented by physically intact, non-viable seeds. Over 90% of the persistent seed bank was concentrated in Montiopsis sericea (Portulacaceae), Pozoa coriacea (Umbelliferae), Phacelia secunda (Hydrophyllaceae) and Oxalis compacta (Oxalidaceae). Examination of the seed/cover ratio revealed different propensities for persistent seed bank formation among species, and annuals formed persistent seed banks more frequently than perennial species. Abundance in the standing vegetation had predictive value for abundance in the persistent seed bank only when non-persistent seed bank species in the standing vegetation were discarded from the analysis. At the local scale, species diversity in the persistent seed bank and standing vegetation were correlated, but compositional similarity was low. Secondary down-slope dispersal promoted by frost heaving in combination with runoff, and life-form correlates are discussed as possible factors accounting for poor correspondence between the persistent seed bank and the standing vegetation at a local scale. The high Andean seed bank is similar to or larger than that reported for two Arctic tundra sites, but smaller than for a northern hemisphere subalpine site. If seed bank size is considered in relation to plant cover, the Andean seed bank greatly exceeds that of one Arctic site. Our study constitutes the first demonstration of a sizable persistent seed bank at an alpine site in the South American Andes and in southern hemisphere temperate mountains in general.
在智利中部安第斯山脉南纬33°的高海拔地带（3250米），对持久土壤种子库（存活种子>1年）和现存植被进行了调查。在总计899粒种子/平方米的持久种子库中发现了9个物种（现存植被中有8个）。另外7个物种由物理上完整但无活力的种子代表。超过90%的持久种子库集中在绢毛山梗菜（马齿苋科）、革质波佐草（伞形科）、二裂叶紫草（紫草科）和紧凑型酢浆草（酢浆草科）中。对种子/覆盖比的检查揭示了不同物种形成持久种子库的不同倾向，一年生植物比多年生植物更频繁地形成持久种子库。只有当分析中排除现存植被中不持久种子库的物种时，现存植被中的丰度才对持久种子库中的丰度具有预测价值。在局部尺度上，持久种子库和现存植被中的物种多样性相关，但组成相似性较低。讨论了冻胀与径流共同促进的二次下坡扩散以及生活型相关性，认为这些可能是导致局部尺度上持久种子库与现存植被对应性差的因素。安第斯山脉高海拔地区的种子库与报道的两个北极苔原地点相似或更大，但小于北半球亚高山地区的种子库。如果将种子库大小与植物覆盖度相关联考虑，安第斯山脉的种子库大大超过了一个北极地点的种子库。我们的研究首次证明了在南美洲安第斯山脉的一个高山地点以及一般南半球温带山区存在相当规模的持久种子库。
