The influence of site conditions on Senecio sylvaticus seasonal abundance, soil moisture dynamics, and Douglas-fir seedling water stress
The influence of site conditions on Senecio sylvaticus seasonal abundance, soil moisture dynamics, and Douglas-fir seedling water stress
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DOI：
10.1007/s11056-021-09897-4
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发表时间：
2021-11
期刊：
影响因子：
2.2
通讯作者：
R. J. Cowden;M. Wightman;C. Gonzalez-Benecke
中科院分区：
文献类型：
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作者：
R. J. Cowden;M. Wightman;C. Gonzalez-Benecke
研究了新栽花旗松幼苗与入侵性早系植物如森林千里光（Senecio sylvaticus[L.]（千里光属），可以产生影响树苗生理、生长和死亡可能性的干旱条件。然而，具体的影响千里光对土壤水分动态和诱导水分胁迫在新种植的树苗在不同的网站条件尚未量化。这项研究量化了这些相互作用在三个对比网站在美国太平洋西北部：海岸山脉，喀斯喀特山麓，以及西部俄勒冈州中南部山谷的边缘。我们测试了千里光和道格拉斯冷杉幼苗之间的竞争是否对土壤水资源的千里光丰富的地区造成增加水分胁迫的树苗。千里光表现出高度的可塑性，在整个网站增加其寿命和芽：根响应土壤水资源的增加。千里光也有两倍以上的根面积的影响，道格拉斯冷杉。总的来说，更大的千里光丰富与更大的土壤水分枯竭，这与土壤水分枯竭增加花旗松水分胁迫。这种响应的大小不同的网站，干燥的网站有最大的变化，千里光生物量分区，最高可观察到的水枯竭，和最大量的花旗松水分胁迫。所提出的结果可以是有用的，以确定有效的森林植被管理制度，考虑千里光存在的影响，在不同的立地条件下的花旗松幼苗干旱胁迫。
Competition for soil water resources between newly planted Douglas-fir seedlings and aggressive early-seral plants, such asSenecio sylvaticus[L.] (Senecio), can create drought conditions that impact tree seedling physiology, growth, and likelihood of mortality. However, the specific impact of Senecio on soil moisture dynamics and inducement of water stress in newly planted tree seedlings across varying site conditions has not been quantified. This study quantified these interactions at three contrasting sites across the U.S. Pacific Northwest: the Coastal Range, the Cascade foothills, and the fringe of south-central valley of Western Oregon. We tested whether competition between Senecio and Douglas-fir seedlings for soil water resources in areas of high Senecio abundance caused increased water stress in the tree seedlings. Senecio demonstrated a high degree of plasticity across sites increasing its lifespan and shoot:root in response to increased soil water resources. Senecio also had more than twice the root area of influence as Douglas-fir. Overall, greater Senecio abundance was associated with greater soil moisture depletion and this soil moisture depletion was correlated with increased Douglas-fir water stress. The magnitude of this response varied across sites; the dry site had the greatest shifts in Senecio biomass partitioning, the highest observable water depletion, and the greatest amount of Douglas-fir water stress. The presented results can be useful for determining effective forest vegetation management regimes by considering the impact of Senecio presence on Douglas-fir seedling drought stress across different site conditions.