...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Experimental Marine Biology and Ecology >Effects of nutrient enhancement on the fecundity of a coral reef macroalga
【24h】

Effects of nutrient enhancement on the fecundity of a coral reef macroalga

机译：营养增加对珊瑚礁大型藻繁殖力的影响

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

On coral reefs, there is concern that increased nutrient supply (e.g. due to eutrophication) causes increased algal growth and hence increased algal abundance, in turn causing colonisation and invasions of coral populations, resulting in reef degradation, or a coral-algal phase shift. For example, species of Sargassum, a highly seasonal, large, brown seaweed, are suggested to be colonising corals on inshore coral reefs of the Great Barrier Reef, as a result of anthropogenic increases in terrestrial runoff of sediments and nutrients. However, implicit in this argument is the assumption that nutrient-related increases in growth will lead to increased fecundity (and/or propagule success), since without such changes, increased abundance can only occur by vegetative means. Whilst plausible, there is no experimental evidence for this assumption in coral reef algae. We here present an initial study in which experimental increases in nutrient supply apparently did not lead to increased fecundity of Sargassum siliquosum; rather, density and biomass of receptacles were reduced in nutrient-enhanced algae. There was little effect of nutrient treatments on the proportional allocation of biomass to reproductive and vegetative structures: nutrient enhancement led to similar decreases in biomass of reproductive and vegetative tissue. Tissue nutrient levels indicated effective enhancement of nitrogen supply, although phosphorus levels were not different across nutrient treatments. The reduced fecundity with increased nutrients may reflect either a genuine inhibition by higher nutrient levels, as found in previous studies, or accelerated maturation, causing increased tissue losses due to more advanced seasonal senescence. Either way, this exploratory experiment provides initial evidence that nutrient effects on tropical coral reef macroalgae may be complex, and does not support the assumption that increased nutrient supply will result in a numeric increase in populations of Sargassum spp. Our results should not be taken as an unequivocal demonstration that nutrients inhibit fecundity overall, but illustrate the need to distinguish between effects on different life-history processes (e.g. growth and reproduction). For increased growth of pre-exising individuals to contribute to algal invasions and phase shifts, that growth must result in either increased fecundity, or increased propagule success.
机译：在珊瑚礁上，人们担心养分供应的增加（例如由于富营养化）会导致藻类生长增加，从而增加藻类丰度，进而引起珊瑚种群的定居和入侵，从而导致珊瑚礁退化或珊瑚-藻类相移。例如，由于人为增加了沉积物和养分的陆地径流，Sargassum是一种高度季节性的大型棕色海藻，被认为是在大堡礁近岸珊瑚礁上定居的珊瑚。但是，该论点隐含了这样一个假设，即与营养有关的生长增加将导致繁殖力（和/或繁殖成功）增加，因为如果不进行此类改变，则只能通过营养手段增加丰度。尽管有道理，但在珊瑚礁藻类中没有这一假设的实验证据。我们在这里提供了一项初步研究，其中营养物供应的实验性增加显然并未导致西葫芦的繁殖力增加。相反，营养增强型藻类降低了容器的密度和生物量。营养处理对生物量按比例分配到生殖和营养结构的影响不大：营养增加导致生殖和营养组织生物量的下降相似。组织营养水平表明氮供应有效增强，尽管不同营养水平下磷水平没有差异。随着营养水平的增加，繁殖力降低可能反映了先前研究发现的更高营养水平的真正抑制作用，或者加速了成熟，由于更高级的季节性衰老导致组织损失增加。无论哪种方式，该探索性实验都提供了初步的证据，即营养成分对热带珊瑚礁大型藻类的影响可能很复杂，并且不支持营养成分增加将导致Sargassum spp种群数量增加的假设。我们的结果不应作为营养素总体上抑制生育力的明确证明，而应说明需要区分对不同生活史过程（例如生长和繁殖）的影响。为了使预先存在的个体的生长增加以促进藻类入侵和相变，该生长必须导致繁殖力增加或繁殖成功。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号