Boeken Bertrand
The Jacob Blaustein Institute for Desert Research, Sede Boqer Campus, Beer-Sheva, Israel.
Department of Biology, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
Oecologia. 1989 Aug;80(2):278-283. doi: 10.1007/BF00380164.
During five consecutive growing seasons (winters) ca. 110 plants of the desert geophyte Bellevalia desertorum were marked individually in a 25 m plot on a south-facing slope in the central Negev Desert of Israel. The number of rosette leaves of each plant was recorded, as well as whether it flowered and produced seeds. Multiple regression analysis of the data on the B. desertorum individuals showed that the reproductive state of a plant was determined by 1) its previous size and 2) the current conditions (rainfall), but not by previous conditions, nor by previous reproductive activity. Plant surveys supported these findings. These demographic results were consistent with the current understanding of the reproductive resource allocation pattern of B. desertorum. Flowering was most affected by rainfall until January of the same season, the number of leaves by rainfall until March and seed set was by the total annual amount. Surveys in populations ofB. eigii, a species of more mesic habitats in the Negev Desert suggested that in this species there is a negative effect of previous reproduction in combination with the previous and current conditions, which is also expected from its biomass partitioning pattern.The significance of demographic studies of individual plants in natural populations for the interpretation of experimentally determined resource partitioning patterns was discussed.
在连续五个生长季节（冬季）里，约110株沙漠地下芽植物以色列沙漠绵枣儿在以色列内盖夫沙漠中部一个朝南斜坡上的25米地块中被单独标记。记录了每株植物的莲座叶数量，以及它是否开花和结籽。对以色列沙漠绵枣儿个体的数据进行多元回归分析表明，一株植物的繁殖状态取决于1）其先前的大小和2）当前条件（降雨量），而非先前条件，也非先前的繁殖活动。植株调查支持了这些发现。这些种群统计学结果与目前对以色列沙漠绵枣儿繁殖资源分配模式的理解一致。开花受同一季节1月之前降雨量的影响最大，叶片数量受3月之前降雨量的影响，而结实则受年降雨量总量的影响。对生长在内盖夫沙漠中更湿润生境的埃氏绵枣儿种群的调查表明，在该物种中，先前繁殖与先前和当前条件相结合存在负面影响，这从其生物量分配模式来看也是预期的。讨论了自然种群中个体植物的种群统计学研究对于解释实验确定的资源分配模式的意义。
