Hydrologic regime and the conservation of salmon life history diversity
Hydrologic regime and the conservation of salmon life history diversity
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DOI：
10.1016/j.biocon.2006.01.019
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发表时间：
2006-07-01
影响因子：
5.9
通讯作者：
Holsinger, Lisa
中科院分区：
文献类型：
--
作者：
Beechie, Timothy;Buhle, Eric;Holsinger, Lisa
濒危太平洋鲑生活史多样性研究。生物多样性是其持续存在的重要因素，保护这种多样性是恢复工作的一个关键要素。保存和恢复生活史特征的多样性部分取决于影响其表达的环境因素。我们分析了年过程线模式和生活史之间的关系。特徴（产卵时间，产卵年龄，年龄在迁出，身体大小）的普吉湾奇努克鲑鱼（Oncorhynchus tshawytscha），以确定当前和历史多样性的环境指标。根据月平均流量模式，我们确定了三个水文制度：融雪为主，融雪为主，过渡。在融雪为主的地区，奇努克种群的溪流型生活史比例较高（幼鱼在淡水中的居住时间> 1年），产卵者年龄较大，并且往往比在冰川为主的地区的种群在一年中产卵早。有几个现存的普吉湾人口占主导地位的流型生活史，作为几个人口与高比例的流型鱼已被灭绝的建设大坝，防止迁移到融雪为主的河段。因此，少数现存的种群是保护的高度优先事项。河流型和海洋型（幼鱼在淡水中居住< 1年）生活史之间的遗传差异水平较低，这表明允许部分现存种群在水坝以上的栖息地定居可能会重新表达被抑制的生活史特征，从而创造更广泛的河流型生活史空间分布。气候变化最终可能会限制一些保护工作的有效性，因为溪流型奇努克可能依赖于逐渐减少的融雪主导的栖息地。爱思唯尔有限公司出版
Life history diversity of imperiled Pacific salmon Oncorhynchus spp. substantially contributes to their persistence, and conservation of such diversity is a critical element of recovery efforts. Preserving and restoring diversity of life history traits depends in part on environmental factors affecting their expression. We analyzed relationships between annual hydrograph patterns and life history. traits (spawn timing, age at spawning, age at outmigration, and body size) of Puget Sound Chinook salmon (Oncorhynchus tshawytscha) to identify environmental indicators of current and historic diversity. Based on mean monthly flow patterns, we identified three hydrologic regimes: snowmelt-dominated, rainfall-dominated, and transitional. Chinook populations in snowmelt-dominated areas contained higher proportions of the stream-type life history (juvenile residence > 1 year in freshwater), had older spawners, and tended to spawn earlier in the year than populations in rainfall-dominated areas. There are few extant Puget Sound populations dominated by the stream-type life history, as several populations with high proportions of stream-type fish have been extirpated by construction of dams that prevent migration into snowmelt-dominated reaches. The few extant populations are thus a high priority for conservation. The low level of genetic distinction between stream-type and ocean-type (juvenile residence < 1 year in freshwater) life histories suggests that allowing some portion of extant populations to recolonize habitats above dams might allow re-expression of suppressed life history characteristics, creating a broader spatial distribution of the stream-type life history. Climate change ultimately may limit the effectiveness of some conservation efforts, as stream-type Chinook may be dependent on a diminishing snowmelt-dominated habitat. Published by Elsevier Ltd.