Climate and environment have a significant impact on vegetation growth in terrestrial ecosystems, particularly in mountainous regions like Pamir Mountains in Central Asia where sustainable gross primary production (GPP) and food security is a major societal challenge. Numerous in-situ studies have revealed the influence of one or two environmental factors on vegetation growth, but the maximum significant effect of climatic and environmental factors on GPP over time at a large scale remains unknown. This research explores spatiotemporal patterns of the lagged and cumulative effects of sixteen climate and environmental indicators on GPP from 2015 to 2023 in GBAO Central Asia using the most up to date MOD17H2 GPP product. Results demonstrate an early increase in GPP from winter 2015 to summer 2015, followed by a constant fall until January 2023, after which it begins to increase again. Matter and energy flow are well-combined in the Pamir Mountain ecosystem, where photosynthesis, carbon cycle, climate and environmental conditions, and solar energy conversion into chemical energy all contribute to the overall output known as GPP. This study emphasizes the critical relevance of understanding the legacy effect, namely the cumulative impact of climate and environmental influences on terrestrial ecosystems and propose enhancing GPP by adjusting composition, configuration, and policies to sustain food security.