Fig. 4: Response function for the drought recovery extended to subsequent year.
From: Widespread spring phenology effects on drought recovery of Northern Hemisphere ecosystems
a–h, Response function along each independent variable (x axis), including the start of growing season of the subsequent year (SOSsubsequent_year, d) (a), total precipitation during postdrought period (Precippost) (b), mean vapour pressure deficit during postdrought period (VPDpost) (c), dormant length (d) (d), SWE during dormant period (SWEdorm) (e), mean temperature during dormant period (Tempdorm) (f), mean NDVI in 6 months preceding the extreme drought events (NDVIpre) (g) and mean annual temperature in period 1982–2015 (MAT, °C) (h). Shaded areas of different colours in a–h are the 95% CIs for different vegetation types. The bootstrap method was used to compute the average over all the predictions of drought recovery and the 95% CI. The y axis in a–h shows the drought recovery (months). i, Normalized variable importance (unitless) for the drought recovery of different vegetation types. Four kinds of vegetation types were considered and compared, including evergreen forests, deciduous forests, shrubs and grasses (Methods). Precippre, total precipitation in 6 months preceding the extreme drought events; SOSdrought_year, the start of growing season of drought year; MAP, mean annual precipitation; PrecipCV, coefficient of variation of mean annual precipitation; TempCV, coefficient of variation of mean annual temperature; VPDpre, mean VPD in 6 months preceding the extreme drought events; Preciplag, total precipitation during the drought response lag period; and VPDlag, mean VPD during the drought response lag period. Numbers in the legend indicate the sampling size. z-scores were calculated for Precippost, VPDpost, SWEdorm, Tempdorm, NDVIpre, Precippre, VPDpre, Preciplag and VPDlag before the RF analysis.
