Intense chemical weathering in tropical regions produces soils characterized by silicon(Si)depletion and iron and aluminum oxide accumulation,leading to soil degradation.Consequently,Si cycling is of paramount importa...Intense chemical weathering in tropical regions produces soils characterized by silicon(Si)depletion and iron and aluminum oxide accumulation,leading to soil degradation.Consequently,Si cycling is of paramount importance in tropical regions.This review summarizes the key processes of the terrestrial Si biogeochemical cycle in tropical areas and underscores its biogeochemical significance in ecosystems.Runoff outputs constitute the dominant mechanism of Si depletion in tropical soils.However,the combined effects of dissolved Si(DSi)retention by highly weathered soil and Si uptake by vegetation attenuate desilication rates in these ecosystems.Tropical soils exhibit limited quantities of weatherable minerals,resulting in soil solution with low concentrations of DSi.Consequently,the primary sources of available Si are atmospheric dust inputs from distant sources and biogenic silica originating from plants.Irrigation,application of Si fertilizers,crop harvesting,and corresponding Si exports significantly impact soil Si cycling within agroecosystems.Therefore,soil Si cycling in tropical regions is different from that in other climatic zones.However,there are still many knowledge gaps within contemporary research.We propose to delve into several perspectives,including the exploration of the processes,fluxes,rates,related factors,and mechanisms associated with Si cycling in tropical regions.Comprehensive research from these perspectives would significantly enhance the understanding of pedogenesis and soil evolution and provide valuable insights for guiding the sustainable management of tropical soils.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.42277312 and 41877010)。
文摘Intense chemical weathering in tropical regions produces soils characterized by silicon(Si)depletion and iron and aluminum oxide accumulation,leading to soil degradation.Consequently,Si cycling is of paramount importance in tropical regions.This review summarizes the key processes of the terrestrial Si biogeochemical cycle in tropical areas and underscores its biogeochemical significance in ecosystems.Runoff outputs constitute the dominant mechanism of Si depletion in tropical soils.However,the combined effects of dissolved Si(DSi)retention by highly weathered soil and Si uptake by vegetation attenuate desilication rates in these ecosystems.Tropical soils exhibit limited quantities of weatherable minerals,resulting in soil solution with low concentrations of DSi.Consequently,the primary sources of available Si are atmospheric dust inputs from distant sources and biogenic silica originating from plants.Irrigation,application of Si fertilizers,crop harvesting,and corresponding Si exports significantly impact soil Si cycling within agroecosystems.Therefore,soil Si cycling in tropical regions is different from that in other climatic zones.However,there are still many knowledge gaps within contemporary research.We propose to delve into several perspectives,including the exploration of the processes,fluxes,rates,related factors,and mechanisms associated with Si cycling in tropical regions.Comprehensive research from these perspectives would significantly enhance the understanding of pedogenesis and soil evolution and provide valuable insights for guiding the sustainable management of tropical soils.
