Extended Data Fig. 8: Resilience trend calculated using a moving window approach exhibits large uncertainties. | Nature Ecology & Evolution

Extended Data Fig. 8: Resilience trend calculated using a moving window approach exhibits large uncertainties.

From: Warming and disturbances affect Arctic-boreal vegetation resilience across northwestern North America

Extended Data Fig. 8

(a) The vegetation resilience trend calculated by replicating the method as described in ref. 41 using the EVI data same as in this work during 2000–2019 across the ABoVE core domain. Key steps include deseasonalizing and detrending the 16-day EVI time series, calculating the long-term lag-1 autocorrelation of EVI (TAC), using long-term average forest density, background climate, climate variability and autocorrelation in climate as predictors (X) of a Random Forest regression model to model TAC, calculating annual lag-1 autocorrelation of EVI (TACt) and predictors (Xt) within a 3-year moving window, calculating the impact of autocorrelation in climate on the lag-1 autocorrelation of EVI (TACt|Xac) using the Random Forest regression model (RF(Xt)-RF(X-act, Xac2000)), factoring out the impact of autocorrelation in climate from the annual lag-1 autocorrelation of EVI (TACt-TACt|Xac), and computing the linear trend of the resulting enhanced annual autocorrelation of EVI. (b)-(c), The 5th percentile (b) and 95th percentile (c) of vegetation resilience trend from 100 times of pairwise bootstrapping the raw annual time series of lag-1 autocorrelation of EVI (TACt) with replacement. (d)-(e),The 5th percentile (d) and 95th percentile (e) of vegetation resilience trend from sampling the impact of autocorrelation in climate on the autocorrelation of EVI (TACt|Xac) 100 times from a Gaussian distribution centered around the prediction of the random forest regression model with a standard deviation calculated from the regression residuals. The difference between (b) and (c) indicates a large uncertainty of resilience trend arising from estimates of annual lag-1 autocorrelation, likely caused by a large fraction of missing data in high latitude regions. The difference between (d) and (e) indicates a large uncertainty due to a much lower explicative power of the Random Forest regression model in this region (30%) compared to that in the original global scale study (87%).

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