Observation: life history of spotted knapweed.
Observation: life history of spotted knapweed.
复制标题
观察：斑矢车菊的生活史。
DOI：
10.2307/4003610
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
R. Sheley
中科院分区：
文献类型：
--
作者：
J. Jacobs;R. Sheley
斑knapweed （Centaurea maculosa Lam.）是一种非本土杂草，在北美西部的大片牧场上肆虐。生活史模型已被用于确定调节杂草种群动态的关键过程，并可能在制定和测试综合杂草管理策略方面具有价值。我们的目的是描述斑knapweed的生活史。在1994年8月至1996年10月的无雪期间，每月在2个地点监测人口统计特征。将数据整理到生活史表中，并进行敏感性分析以确定影响种子产量的关键过渡阶段。研究期间，两个地点的花斑knapweed种子产量在998 ~ 7815粒/m2之间。到达土壤的种子平均分别占站点1和站点2种子产量的41%和50%。在这两个地点，只有不到6%的种子在秋季到达土壤发芽。在1号和2号地点，4月和6月种子到达土壤的比例分别达到了36%和20%。1995年8月和1996年6月，斑knapweed幼鱼密度达到高峰。峰值与夏季干旱期的开始相对应。植物从1995年6月和1996年5月开始脱壳。敏感性分析表明，初夏成虫存活率、夏末成虫存活率、幼年成虫向成年成虫的过渡以及每成年成虫的种子产量是斑knapweed种子产量的关键阶段。在这些阶段减少斑knapweed种群的管理策略可能对斑knapweed种群的生长和传播产生最大的影响。建立了基于生活史人口统计数据的斑knapweed种群动态模型，该模型可用于斑knapweed综合策略的设计和测试。
Spotted knapweed (Centaurea maculosa Lam.) is a non-indigenous weed infesting large areas of rangeland in western North America. Life history models have been used to identify key processes regulating weed population dynamics and may be valuable in developing and testing integrated weed management strategies. Our objective was to characterize the life history of spotted knapweed. Demographic attributes were monitored monthly during snow free periods beginning August 1994 through October 1996 on 2 sites. Data were arranged into life history tables, and sensitivity analysis was performed to determine key transition phases affecting seed output. Spotted knapweed seed production ranged from 998 to 7815 viable seeds/m2 at both sites during the study. Seeds reaching the soil averaged 41 and 50% of seed output at sites 1 and 2, respectively. Less than 6% of seeds reaching the soil germinated in the fall at both sites. Recruitment peaked in April at 36% and in June at 20% of seeds reaching the soil on sites 1 and 2, respectively. Spotted knapweed juvenile density peaked August 1995 and June 1996 at both sites. Peaks corresponded with the beginning of the summer dry period. Plants bolted beginning June 1995 and May 1996. Sensitivity analysis identified early-summer juvenile survivorship, late-summer adult survivorship, transition from juvenile to adult, and seeds produced per adult as critical stages for spotted knapweed seed output. Management strategies that reduce spotted knapweed populations at these stages are likely to have the greatest impact on spotted knapweed population growth and spread. A weed population dynamics model using the life history demographic data was developed and can be used to design and test integrated spotted knapweed strategies.