• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Conservation Biology >Using population projection matrices to evaluate recovery strategies for Snake River spring and summer chinook salmon
【24h】

Using population projection matrices to evaluate recovery strategies for Snake River spring and summer chinook salmon

机译：使用种群预测矩阵评估Snake River春夏奇努克鲑鱼的恢复策略

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

I explored the efficacy of alternative actions to recover threatened Snake River chinook salmon (Onchorhyncus tshawytscha). I compared the potential to increase population growth rates from two different actions: (1) habitat restoration efforts, aimed at increasing egg-to-smolt survival rate, and (2) dam breaching, intended to improve smolt-to-spawner survival. Eight dams obstruct the migration corridor these populations traverse as juveniles (downstream) and as adults (upstream), and a large portion of the juvenile migrants are collected and transported past most of the dams on barges or trucks. I applied sensitivity, elasticity, and direct perturbation analyses to an age-structured projection matrix to predict potential effects from simultaneous, nonproportional changes in multiple survival rates. Throughout the analyses, I explicitly incorporated alternative assumptions about the effectiveness of transportation, which is known to be influential. Results of the numerical experiments suggest that dam breaching has more potential to increase population growth rates than habitat restoration, except for the most optimistic assumption about the efficacy of transportation. I then fit the matrix to historical data to identify life stages in which actual decreases in survival rates have caused the observed declines in abundance. There was no reduction in egg-to-smolt survival, indicating that neither habitat deterioration nor hatchery impacts (in that life stage) caused the stocks to decline. The large decrease in smolt-to-adult survival rate from the historical period, when there were fewer dams, is consistent with the hypothesis that increased stress from transportation and passage through additional dams on the Snake River has elevated delayed mortality levels. [References: 21]
机译：我探讨了采取其他行动来恢复受威胁的蛇河奇努克鲑鱼（Onchorhyncus tshawytscha）的功效。我比较了通过两种不同行动来提高人口增长率的潜力：（1）旨在提高卵到软体动物生存率的栖息地恢复工作，以及（2）旨在提高从软体动物到产卵者生存的水坝溃坝。八个水坝阻塞了这些人口作为少年（下游）和成年（上游）穿越的移民走廊，并且大部分的青少年移民被收集并通过驳船或卡车运送到大多数水坝之上。我将灵敏度，弹性和直接扰动分析应用于年龄结构化的投影矩阵，以预测多种存活率的同时，非比例变化所带来的潜在影响。在整个分析过程中，我明确纳入了有关运输效率的替代假设，这是有影响力的。数值实验结果表明，除最乐观的运输效率假设外，破坏大坝比增加栖息地恢复具有更大的潜力来增加人口增长率。然后，我将矩阵与历史数据进行拟合，以确定生命阶段，在这些生命阶段中，实际生存率的下降导致观测到的丰度下降。卵到软体动物的存活率没有降低，表明栖息地的恶化和孵化场的影响（在那个生命阶段）都不会导致种群减少。从历史时期开始，到大坝数量减少时，到成年鲑的成活率大大降低，这与假蛇河运输和穿越其他大坝的压力增加导致延迟死亡率升高的假说相符。 [参考：21]

著录项

相似文献

  • 外文文献
  • 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