###### Abstract  
Warmer or cooler spring in northern high latitudes will, for the most part, directly impact gross primary productivity (GPP) of ecosystems, but also carry consequences for the upcoming seasonal GPP. Spatiotemporal patterns of these legacy effects are still largely unknown but important for improving our understanding of how plant phenology is associated with vegetation dynamics. In this study, impacts of spring temperature anomalies on spring, summer and autumn GPP were investigated, and the dominant drivers of summer and autumn GPP including air temperature, vapor pressure deficit and soil moisture have been explored for northern ecosystems (>30\"N). Three remote sensing products of seasonal GPP (GOSIF-GPP, NIRv-GPP and FluuSat-GPP) over 2001-2018, all based on a spatial resolution of 0.05\({}^{\circ}\), were employed. Our results indicate that legacy effects from spring temperature are most pronounced in summer, where they have stimulating effects on the Arctic ecosystem productivity. Spring warming likely lessens the harsh climatic constraints that govern the Arctic tundra and extends the growing season length. Further south, legacy effects are mainly negative. This strengthens the hypothesis that enhanced vegetation growth in spring will increase plant water demand and stress in summer and autumn. Soil moisture is the dominant control of summer GPP in temperate regions. However, the dominant meteorological variables controlling vegetation growth may differ depending on the GPP products, highlighting the need to address uncertainties among different methods of estimating GPP. c 20221420072022142007  
delayed senescence of plants, however, soil decomposition can also increase, leading to net carbon losses of the ecosystems during this season [12]. Nevertheless, the legacy effects of spring temperature (\(T_{spring}\)) anomalies on seasonal GPP is known to a lesser degree. Currently, even the state-of-the-art terrestrial biosphere models struggle to implement them [3]. As noted by [5], most carbon-cycle models seem to overestimate the positive legacy effects on GPP caused by spring warming and underestimate the potential influence of built-up water stress. Accurately assessing direct and legacy effects of seasonal warming on vegetation productivity is important, as vegetation is a key component of the global carbon, water and energy cycles, and its responses may trigger biogeochemical and biophysical climate feedback [13]. A proper understanding of these highly dynamic systems is crucial, particularly for our general ability to accurately predict and mitigate climate impacts, as well as adapting our society to a changing climate [14]. Recent works [5; 6; 15] indicate that annual GPP can be suppressed or stimulated by both cooler and warmer springs. For example, boreal forests have seen a dampening effect on peak summer productivity related to early springs [16; 17]. The suppressed vegetation productivity in summer can be caused by soil moisture deficits resulting from winter precipitation and early onset of vegetation. Other northern ecosystems, mainly dominated by graminoids, lichens and deciduous shrubs, have been shown to benefit from a fairly early date of snowmelt, as many such species are unable to accelerate or adapt their rate of phenological development [18; 19]. The delayed outcome, or carry-over effect, thus depends on a combination of several factors, including meteorological and environmental conditions, vegetation composition and phenological responses of vegetation, but as of now, a comprehensive understanding of how these factors interplay remains lacking. Earlier research in this area has attempted to address these questions utilizing data sets with relatively coarse resolution (50 \(\times\) 50 km\({}^{2}\)) based on the Normalized Difference Vegetation Index (NDVI) (e.g., [10; 16]). As vegetation response to warming is spatially non-uniform, such a coarse resolution may fail to represent explicit details of greening and browning trends of different ecosystems.