(Non-)linear phenological trends in an ecosystem with multiple growing seasons derived from AVHRR-NDVI time series

According to the change-point analysis, 800 (= 61.6%) GIMMS series show at least 1 significant change in their annually integrated NDVI. Among these series 121 show more than 1 change. If a series encloses a change, its most significant one is linked to a shift of 5.5% of its 24-year mean on average. This underpins the need for including such non-linear aspects in the framework of trend analysis for vegetation dynamics in the Inland Delta. The spatial distribution of changes illustrates Fig. 2. About 28% of the changes appear from 1992/93 to 1993/94 and about 15% from 1986/87 and 1987/88 each. While the shifts from 1992/93 show up at the southern part, the earlier shits are located in the central and northern part of the Inland Delta.