Simms E L
Department of Botany, Duke University, 27706, Durham, NC, USA.
Oecologia. 1987 Mar;71(4):541-547. doi: 10.1007/BF00379294.
Aboveground growth, reproduction, and foliar nitrogen and phosphorus contents of two ericaceous shrub species were compared over two seasons in (a) an undisturbed shrub bog (pocosin), and (b) a factorial fertilization design in which three levels each of nitrogen and phosphorus were added in all possible combinations. One species, Zenobia pulverulenta, is deciduous whereas the other species, Lyonia lucida, is evergreen. In the nutrient-poor undisturbed pocosin the two species exhibited similar foliar nitrogen and phosphorus concentrations and aboveground growth rates. Neither species flowered. In response to nutrient-addition Zenobia increased growth rates more than Lyonia. Foliar phosphorus concentrations of both species increased in response to enhanced phosphorus availability. in the first season neither species flowered in any treatment. In the second season Zenobia flowered only in the fertilized plots, with the most flowering in the high phosphorus treatments. I conclude that, by virtue of high growth rates and efficient use of nutrients and despite differences in leaf phenology and morphology, both Lyonia and Zenobia are successful in a competitive community under conditions of extremely low phosphorus availability. However, unlike Lyonia, Zenobia can take advantage of temporarily increased nutrient availability, which occurs following fire in the pocosin, to increase growth and reproduction.
在两个季节里，对两种杜鹃花科灌木的地上生长、繁殖以及叶片氮磷含量进行了比较，实验设置如下：（a）在一个未受干扰的灌木沼泽（泥炭地）；（b）采用析因施肥设计，将氮和磷各设置三个水平，并进行所有可能的组合添加。一种植物是落叶的粉状泽诺比亚（Zenobia pulverulenta），另一种是常绿的亮叶珍珠花（Lyonia lucida）。在营养贫瘠且未受干扰的泥炭地中，这两个物种的叶片氮磷浓度和地上生长速率相似，且都未开花。施加养分后，粉状泽诺比亚的生长速率比亮叶珍珠花增加得更多。随着磷有效性的提高，两个物种的叶片磷浓度均有所增加。在第一季，任何处理下两个物种都未开花。在第二季，粉状泽诺比亚仅在施肥的地块开花，在高磷处理中开花最多。我得出结论，尽管叶片物候和形态存在差异，但凭借高生长速率和对养分的高效利用，亮叶珍珠花和粉状泽诺比亚在极低磷有效性条件下的竞争群落中都能成功生长。然而，与亮叶珍珠花不同的是，粉状泽诺比亚能够利用泥炭地火灾后暂时增加的养分有效性来促进生长和繁殖。
