Response of vegetation growth and productivity to spring climate indicators in the conterminous United States derived from satellite remote sensing data fusion
Response of vegetation growth and productivity to spring climate indicators in the conterminous United States derived from satellite remote sensing data fusion
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DOI：
10.1016/j.agrformet.2014.04.001
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发表时间：
2014-08-15
影响因子：
6.2
通讯作者：
Henebry, G. M.
中科院分区：
文献类型：
--
作者：
Kim, Youngwook;Kimball, J. S.;Henebry, G. M.
春季温度强烈影响植物物候，包括萌芽，冠层发育和作物种植期。最近的春季变暖与更早和更长的非冰冻季节的趋势相吻合，一般较早的春季冠层开始和植被生产力的增加，在接壤的美国（CONUS）。然而，较早的春季开始增加了霜冻灾害的风险，对生产力有潜在的负面影响。霜的敏感性和脆弱性是异构的CONUS域，而霜冻事件的发生，强度和区域影响是很难从稀疏的气象站监测。为了提高区域霜冻风险监测能力，我们开发了跨越长期的春季霜冻日（SFD）和春季霜冻损害日（SFDD）指标，（>30年）的记录，通过整合每日景观冻融（FT）状态的卫星微波遥感记录和基于光学-IR传感器的季节开始（SOS）和高峰日（DOP）的物候记录我们发现区域SFD趋势（-1.6天十年（-1）; p< 0.1）与春季变暖一致，而SFDD通常增加（1.5天十年（-1）; p< 0.1）。春季变暖减少了霜冻的发生，但更早的SOS趋势反而增加了植被霜冻破坏的风险。SFD和SFDD的变化的生态意义进行了评估，使用卫星派生的植被总初级生产力（GPP）和植被绿度（EVI 2）异常。较高的SFD和SFDD水平与春季植被生长减少一致，但只有SFDD表现出显著性（p
Spring temperatures strongly influence plant phenology, including budburst, canopy development, and crop planting period. Recent spring warming coincides with earlier and longer non-frozen season trends, and generally earlier spring canopy onset and vegetation productivity increases over the conterminous US (CONUS). However, earlier spring onset increases frost damage risk, with potential negative impacts to productivity. Frost sensitivity and vulnerability is heterogeneous over the CONUS domain, while the occurrence, intensity and regional impact of frost events are difficult to monitor from sparse weather stations. To enhance regional frost risk monitoring capabilities, we developed spring frost day (SFD) and spring frost damage day (SFDD) metrics spanning a long-term (>30 year) record by integrating a satellite microwave remote sensing record of daily landscape freeze-thaw (FT) status and optical-IR sensor based phenology record of start of season (SOS) and day of peak (DOP) canopy cover.We find a decreasing regional SFD trend (-1.6 days decade(-1); p< 0.1) coincident with spring warming, while the SFDD is generally increasing (1.5 days decade(-1); p< 0.1). Spring warming is reducing frost occurrence, but an earlier SOS trend is paradoxically increasing vegetation frost damage risk. The ecological significance of the SFD and SFDD changes were evaluated using satellite derived vegetation gross primary production (GPP) and vegetation greenness (EVI2) anomalies. Higher SFD and SFDD levels coincide with reduced vegetation growth in spring, but only the SFDD shows significant (p