Middle East North Africa (MENA) and Indian Thar desert dust storms pathway as game changer of Phosphorus depositional pattern in Asia's largest Grassland

Abstract

Abstract Dust particles make up almost all of the atmospheric phosphorus, which accounts for 82% of the total phosphorus in the world. Phosphorus (P) is an important nutrient for terrestrial ecosystems, playing a critical role in influencing primary productivity and hence ecosystem dynamics. The deposition of airborne dust, particularly from arid and semi-arid regions, has been recognized as a significant source of phosphorus input in distant ecosystems. The study area, the Banni Plains, is a semi-arid ecosystem with a unique geological history, that has suffered from degradation due to varied natural and anthropogenic reasons. It is located in arid tract of western India (23º 19' to 23º52' N latitude and 68º 56' to 70º32' E longitude).Soil samples were collected from 10*10 km grid locations in the grassland before, after 48 hours, and 20 days after a cyclonic storm, Biporjoy, which hit the region in June, 2023. Statistical analyses (Shapiro-Wilk normality and Kruskalwallis H test) were performed on the data to assess the differences in phosphorus concentrations among the phases. To examine the long-range transport of dust-borne phosphorus and its subsequent deposition in the target grassland, we employed an interdisciplinary approach that integrated satellite imagery and ground-based measurements. Spatial and temporal variations in dust emissions were assessed using satellite remote sensing data, while ground truthing was done for phosphorus content analysis using standard protocols. The aerosol data from MERRA-2 for the past 40 years were used to examine the relationship between aerosol concentrations and wind direction and speed. Our findings reveal that the Middle East, North Africa, and Thar Deserts significantly contribute to the phosphorus deposition in the target grassland during specific seasons. The SW cyclone ‘Biporjoy’ that followed the same track of aerosols loading (MENA) had a landfall on this zone (June 16, 2023) affected the P depositional patterns. The pre cyclone, post cyclone and 20 DAC (Days after Cyclone), had AP values 20.15, 20.54 and 24.06 respectively. However, TP values were 45.81 ± SE = 1.73, 60.95 ± SE = 1.39 and 61.98 ± SE = 1.40 respectively. The highest TP values was in phase 3 (20 DAC phase) 61.89 ± SE = 1.40. Dust storms and other atmospheric circulation patterns were found to play a pivotal role in facilitating the long-range transport of phosphorus-laden dust particles from these source regions to the target grassland. Ultimately, our research contributes to the broader understanding of global nutrient cycling and land-air interactions, enabling informed decision-making for the conservation and sustainable management of terrestrial ecosystems.