中国科学院西双版纳热带植物园机构知识库

Dust emission and accumulation have been continually increasing over the past several decades in South Asia. Dust storms, originating in western regions, regularly move across the Indian subcontinent and may reach parts of the Himalayas, including the Tibetan Plateau (TP). Their frequency has risen rapidly on the Indo-Gangetic Plains. Dust storms impact processes associated with atmospheric composition, radiative balance, precipitation, nutrient cycling, and vegetation sustainability. However, these effects have not yet been synthesized in the context of South Asia, which this study addresses. We investigate dust sources and the causes of dust storms in South Asia, their implications for the TP ecosystem, and how they impact vegetation health and sustainability. Indian dust storms originate from both, the local Thar Desert and distant deserts in the Middle East and Northeast Africa. Long-range dust transport has synergistic as well as antagonistic effects on vegetation health and ecosystem sustainability, while vegetation also acts as a trap for atmospheric dust, purifying polluted air. Soils in forest ecosystems may derive 4%-30% of their nutrient inputs, mainly phosphorus (P), from long-range transported dust. Dust-bound P can also be absorbed through foliar uptake of dust deposited on leaves. In simulation experiments, plants were able to increase their P content by 30%-37% through foliar uptake. However, dust deposition on leaves and its subsequent uptake can impair plant growth and biomass production by clogging stomata, modifying the leaf microenvironment, hindering transpiration and gas exchange, degrading chlorophyll, limiting photosynthesis, and reprogramming cellular metabolism. It is hypothesized that plant responses to dust may have an evolutionary basis. We conclude that dust can have mixed impacts on ecosystem functioning and highlight the urgent need for systematic and detailed investigations into its effects in a regional context.