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Extended Spring Indices, Continental United States, 1981 - Current Year


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USA National Phenology Network, 2016, Extended Spring Indices, Continental United States, 1981 - Current Year: ,,


The USA National Phenology Network has available a series of gridded products enabling researchers to analyze historical and contemporary data related to the Extended Spring Indices. The Extended Spring Indices are mathematical models that predict the "start of spring" (timing of leaf out or bloom for species active in early spring) at a particular location (Schwartz 1997, Schwartz et al. 2006, Schwartz et al. 2013). These models were constructed using historical observations of the timing of first leaf and first bloom in a cloned lilac cultivar (S. x chinensis 'Red Rothomagensis') and two cloned honeysuckle cultivars (Lonicera tatarica 'Arnold Red' and L. korolkowii 'Zabelii'). Primary inputs to the model are temperature and weather [...]


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The Extended Spring Indices have been used as an indicator of climate change by both the Environmental Protection Agency and the National Climate Assessment. The product suite supports understanding of spatial patterns in the timing of spring, including short-term forecasts to support resource management.

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