Climate sensitivity of reproduction in a mast-seeding boreal conifer across its distributional range from lowland to treeline forests
Climate sensitivity of reproduction in a mast-seeding boreal conifer across its distributional range from lowland to treeline forests
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从低地到林线森林分布范围内的肥大播种北方针叶树繁殖的气候敏感性
DOI：
10.1007/s00442-013-2821-6
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发表时间：
2013
期刊：
影响因子：
2.7
通讯作者：
J. Johnstone
中科院分区：
文献类型：
--
作者：
C. Roland;J. Schmidt;J. Johnstone
桅杆播种针叶树，如云杉表现出同步生产的大种子作物在广泛的地区，气候因素可能触发的偶发性高种子生产。因此，迅速变化的气候条件可能会改变优势物种桅杆的克里思和空间格局，并可能产生深远的生态后果。了解未来的生态系统，包括北方森林，这可能是占主导地位的桅杆播种物种的生殖动态，需要确定具体的线索，驱动跨景观梯度和年之间的生殖输出的变化。在这里，我们使用了1986年至2011年在美国阿拉斯加内陆海拔梯度的三个地点收集的年度数据，以产生第一个定量模型，用于气候控制P. glauca种子的降落和种子活力，一种占主导地位的北方针叶树。我们确定了积极的种子和夏季降水量增加和夏季温暖减少之间的关联，除了前一年的种子。种子活力表现出鲜明的对比反应，与夏季温暖的正相关性，在所有年份的分析，除了一个，特别是积极的反应，温暖和潮湿的条件下，在种子的一年。最后，我们发现，在高海拔地区，由于种子活力显着降低，P. glauca的繁殖潜力显着降低。我们的研究结果表明，该物种的繁殖潜力的主要变化可能会发生在不同的景观位置，在变暖的反应，减少繁殖成功的地区容易受到干旱胁迫的对比，目前受夏季凉爽的温度限制的高海拔地区的成功率增加。
Mast-seeding conifers such as Picea glauca exhibit synchronous production of large seed crops over wide areas, suggesting climate factors as possible triggers for episodic high seed production. Rapidly changing climatic conditions may thus alter the tempo and spatial pattern of masting of dominant species with potentially far-reaching ecological consequences. Understanding the future reproductive dynamics of ecosystems including boreal forests, which may be dominated by mast-seeding species, requires identifying the specific cues that drive variation in reproductive output across landscape gradients and among years. Here we used annual data collected at three sites spanning an elevation gradient in interior Alaska, USA between 1986 and 2011 to produce the first quantitative models for climate controls over both seedfall and seed viability in P. glauca, a dominant boreal conifer. We identified positive associations between seedfall and increased summer precipitation and decreased summer warmth in all years except for the year prior to seedfall. Seed viability showed a contrasting response, with positive correlations to summer warmth in all years analyzed except for one, and an especially positive response to warm and wet conditions in the seedfall year. Finally, we found substantial reductions in reproductive potential of P. glauca at high elevation due to significantly reduced seed viability there. Our results indicate that major variation in the reproductive potential of this species may occur in different landscape positions in response to warming, with decreasing reproductive success in areas prone to drought stress contrasted with increasing success in higher elevation areas currently limited by cool summer temperatures.