Changing Global Vegetation-Climate interaction during recent decades

The atmosphere–land interaction is crucial to the climate and earth system through the exchange of energy, water, momentum and carbon among vegetation and atmosphere. In recent times, a great deal of variability in anthropogenic land use along with climate variability has greatly altered the terrestrial biosphere all around the globe. The global vegetation dynamics has garnered substantial attention due to its potential impact on food security, water cycle and terrestrial carbon sinks. The non-climatic factors have a very straightforward and regional impact on vegetation. However, there remains uncertainty regarding the response of the terrestrial ecosystems to climate change as vegetation-climate interactions is very intricate and intriguing. In the recent times, higher temperature (T) and evapotranspiration (ET) accompanied by insufficient precipitation (P) has depleted soil moisture (SM). We find temperature (T) is the dominant driver of global photosynthesis. Across biomes and land cover types, moisture availability (P and SM) is the key climatic control in tropical and arid but T in temperate and cold biomes. For croplands and forests, T is the predominant driver, but P is the key driver for grasses suggests Machine Learning (ML) based Random Forest (RF) model. However, there is decline in the control of temperature on photosynthesis due to saturation of boreal warming-induced greening and increasing dryness stress. The influence of water availability and energy has substantially grown on global photosynthesis. Interestingly, in regions where both increase in energy and decrease in water availability is present, the photosynthetic activity is largely moisture controlled. Therefore, the global photosynthesis is largely driven by moisture ahead of warmth and energy in the drying world.