资源环境科技发展态势分析平台

Periodic shifts in Earth's orbit alter incoming solar radiation and drive Quaternary climate cycles. However, unambiguous detection of these orbitally driven climatic changes in records of terrestrial sedimentation and pedogenesis remains poorly defined, limiting our understanding of climate change-landscape feedbacks, impairing our interpretation of terrestrial paleoclimate proxies, and limiting linkages among pedogenesis, sedimentation, and paleoclimatic change. Using a meta-analysis, we show that Quaternary soil ages preserved in the modern record have periodicities of 41 and 98 kyr, consistent with orbital cycles. Further, soil ages predominantly date to periods of low rates of climatic change following rapid climate shifts associated with glacial-to-interglacial transitions. Soil age appears linked to orbital cycles via climate-modulated sediment deposition, which may largely constrain soil formation to distinct climate periods. These data demonstrate a record of widespread orbital cyclicity in sediment deposition and subsequent pedogenesis, providing a key insight into soil-landscape evolution and terrestrial paleo-environment changes.

Plain Language Summary Over the past 2.6 million years, the Earth's climate has cycled at regular intervals in concert with orbital variations. Climate variations have driven changes in the rates of erosion and deposition of new sediment, but detection of these orbitally driven climate cycles has remained elusive in soil systems. We demonstrated that soils were preserved to the present at the same intervals as known orbital climate cycles using a meta-analysis of soil chronosequences. We further tied dominant periods of soil formation to periods of relatively low rates of past climate change or periods of relatively stable, unchanging climate that enable soil formation. Our results provide a better understanding of how climate change impacts landscapes, which could greatly enhance our understanding of the impact of future climate change on soil resources and new insights into past environmental changes.