Drought in the US 2010-2011.
SPEI has recently been used to predict pine mortality in SW forests. When the SPEI is below -1.68 for at least 11 months, pinyon and ponderosa pines cannot grow and mortality soon follows. (Kolb, T.E., 2015. A new drought tipping point for conifer mortality.Environmental Research Letters, 10(3), p.031002.)
|Long-term drought graph for NM.|