【摘要】 胡杨、灰叶胡杨种间比较,果穗、种子在树冠上的垂直分布均表现为树冠上层最多,中层居中,下层最少,树冠南北侧相比较,南侧果穗量多于北侧。单果种子量在树冠各层次上差异不显著。胡杨单果重是灰叶胡杨的2.68倍,千粒重是灰叶胡杨的1.33倍,单果种子量是灰叶胡杨的2.14倍,单株种子量是灰叶胡杨的1.28倍,而单株果实量灰叶胡杨是胡杨的1.59倍。同一个种不同居群间比较,胡杨、灰叶胡杨均是单株果穗数和果穗果实数各居群间都存在差异,胡杨各居群间单果重、单果种子量差异不显著,而灰叶胡杨各居群间单果重及单果种子量差异极显著。表明胡杨在物质和能量上对后代的投资能力强于灰叶胡杨,生殖策略是通过较高的单果种子量来保证一定数量的单株种子量;而灰叶胡杨单果种子量较低,却是通过较高的单株果量来保证单株种子量,并且较小的种子占据空间生态位的潜能较胡杨占优势。更多还原

【Abstract】 The spatial distribution and quantitative characteristic of Populus euphratica and Populus pruinosa fruits from different inhabited environment were studied. The results showed that the number of fructification was allocated to different crown according to definite percentage, the percentage order was upper > middle >lower and south>north, but there weren’t significant differences among quantity of seed per fruit in upper, middle and lower parts of crown from different populations. Compared Populus euphratica with Populus pruinosa, Per fruit weight, thousand kernel weight, quantity of seed per fruit, quantity of seed per tree of Populus euphratica were 2.68, 1.33, 2.14 and 1.28 times than that of Populus pruinosa, respectively. However, the number of fructification per individual tree of Populus euphratica was 1.59 times than that of Populus pruinosa. Compared to different population from the same specie, whether Populus euphratica or Populus pruinosa were all significant differences among number of fructification per individual plant and fruit per fructification. In addition, per fruit weight and quantity of seed per fruit were not significant differences in different population of Populus euphratica, and that of Populus pruinosa was contrary. This indicated that Populus euphratica was higher than Populus pruinosa in matter and energy investing to progeny, and its reproduction strategy was the bigger quantity of seed per fruit insure definite quantity of seed per tree. But the quantity of seed per tree of Populus pruinosa was insured by the number of fructification per tree, and its potential occupied space niche was higher than that of Populus euphratica.更多还原