Speciation and xerophilous adaptation of plants in the Lomas Vegetation along the Pacific Coast of South America

1. 1991年在智利北方广泛形成洛马斯植被。我们调查了这些社区的宏观尺度分布，以及在塞罗蓬塔德瓦卡斯，约50公里以西的科皮亚波，北方智利的地方尺度分布。比较气象资料，群落的宏观格局似乎不受地形条件的影响，是由6月和7月的降雨产生的。蓬塔德瓦卡斯群落的局部尺度格局明显受地形条件的影响，表现出与“雾-降水”格局相同的地形效应.在Cerro蓬塔德瓦卡斯的洛马斯植被的东南面斜坡上进行了植物生产力的调查。有四种类型的植被：Calandrinia，Cristaria，Cordenia（Tiquilla）和Fortnetia。对每种类型的生物量和水势进行了测量。生物量与低生产力草地相近。C的水势 关于我们 随着气温的升高，istaria和Cordenia的数量逐渐减少，而其他种类的数量在整个白天基本保持不变.蓬塔德瓦卡斯地区的植被分为三个类型的基础上的优势种：Calandrinia，Cristaria和Cordenia（Tiquilla）社区。在10月30日和11月5日对各林分的植被进行了调查，根据物种数和每个物种的最高高度和覆盖度，并采取了10个土壤样品（25 cm × 25 cm × 2cm）。从土壤样品中挑选出种子的成分。为了研究种子在地下的寿命，将Calandrinia、Cristaria和Nolana的种子分别埋在地下5cm深处，每种种子200-300粒。预计在下次调查时将检查每个物种的种子发芽率，以估计其种子寿命。少

1. The lomas vegetation was broadly formed in northern Chile in 1991. We investigated the macro scale distribution of these communities, as well as the local-scale distribution in Cerro Punta de Vacas, about 50km west of Copiapo, northern Chile. Comparing the meteological data, the macro-scale pattern of the communities, which seemed not to be influenced by topographical conditions, were produced by June and July rainfall. The local-scale pattern of the communities of Punta deVacas were markedly influenced by topographical conditions, exhibited the same topographic effect as found in "fog-precipitation" pattern.2. An investigation on plant productivity was carried out on the south-east faced slope of lomas vegetation at Cerro Punta de Vacas. There were four types of vegetation : Calandrinia, Cristaria, Cordenia (Tiquilla) and Fortnetia. Biomass and water potential were measured on each type. The values of biomass were similar to those of low productivity grassland. Water potential of C … More ristaria and Cordenia decreased according as rising of air temperature, while the other species maintained nearly same value throughout the daytime.3. The vegetation of Punta de Vacas area is classified into three types based on the dominant species : Calandrinia, Cristaria and Cordenia (Tiquilla) community. Both on 30th of October and 5th of November, the vegetation at each stand was surveyed according to number of species and the highest height and coverage of each species, and ten soil samples (25cm x 25cm x 2cm) were taken. Seeds were sorted out of the components selected from soil samples. Although the identification of these buried seeds was unsatisfactory, there were more species and seeds in number in the sample collected from the Calandrinia stand. In order to examine seed longevity under the ground, 200-300 seeds of each Calandrinia, Cristaria and Nolana were buried in the depth of 5cm under the ground surface. The seed germination rates of each species is expected to be examined in the occasion of next survey, for estimation of their seed longevity. Less