Related Experiment Video
Updated: Jun 12, 2026
10:28
Investigating the Relationship between Sea Surface Chlorophyll and Major Features of the South China Sea with Satellite Information
Published on: June 13, 2020
Jet-induced rainfall seasonality and C4 migration over East Asia
Jiawei Da1,2,3, Chijun Sun4, Lily Serach5
1Department of Earth and Planetary Sciences, Jackson School of Geosciences, The University of Texas at Austin, Austin, TX, USA. jiawei@psu.edu.
Nature Communications
|June 10, 2026
Summary
Rainfall seasonality, not just amount, drove the spread of C4 grasslands in East Asia during the Plio-Pleistocene. These shifts influenced ecosystems and early human evolution by altering vegetation patterns.
Area of Science:
- Paleoclimatology
- Paleoecology
- Paleoanthropology
Background:
- The Neogene expansion of C4 grasslands significantly impacted terrestrial ecosystems and mammalian evolution, including hominins.
- Identifying environmental drivers of C4 expansion is challenging due to asynchronous continental spread, especially at higher latitudes.
Purpose of the Study:
- To investigate the environmental drivers of extratropical C4 grassland distribution in East Asia during the Plio-Pleistocene.
- To understand the relationship between rainfall seasonality, paleoclimate, and vegetation shifts.
Main Methods:
- Analysis of rainfall oxygen isotope ratios and clumped isotope soil temperatures on the Chinese Loess Plateau (CLP) from 7 to 2.5 million years ago.
- Interpretation of organic carbon d13C records to identify C4-rich ecosystems.
- Paleoclimate modeling to refine the East Asian paleomonsoon concept.
Main Results:
- Coupled variations in rainfall isotopes and soil temperatures indicate shifts in rainfall seasonality, linked to the position of the subtropical westerly jet.
- More spring rain occurred during warmer periods, while concentrated summer rain prevailed under cooler climates.
- C4-rich ecosystems tracked the poleward and equatorward shifts of the summer rain band, eventually dominating cooler regions.
Conclusions:
- Rainfall seasonality, driven by meridional shifts of a summer rain band, governed extratropical C4 distributions in East Asia.
- The study refines the understanding of the East Asian paleomonsoon and its influence on vegetation.
- Highlights the tight coupling between regional rainfall seasonality and the migration of C4 ecosystems, impacting hominin environments.
Related Concept Videos
01:12Precipitation Processes
The experimental conditions in a gravimetric analysis should be optimized to maximize the particle size and purity of the obtained precipitate. Ideally, the concentration of the precipitating reagent should be low with effective stirring to maintain low relative supersaturation for the growth of large crystals. In homogeneous precipitation, the precipitant is slowly generated by a chemical reaction in the solution to avoid local reagent excesses. For example, urea decomposes gradually to...
01:17Precipitation and Co-precipitation
Precipitation and coprecipitation methods can be used to separate a mixture of ions in a solution. In qualitative inorganic analysis, ions that form sparingly soluble precipitates with the same reagent are separated based on the differences in solubility products. For example, consider the separation of Cu(II) and Fe(II) ions by precipitation as insoluble sulfides. First, copper(II) sulfide is precipitated by the addition of acidic H2S, where the dissociation of H2S is suppressed. Adding H2S...
00:53Migration
Migration is long-range, seasonal movement from one region or habitat to another. This common strategy, carried out by many different organisms around the world, is an adaptive response that typically corresponds to changes in an organism’s environment, like resource availability or climate. Migrations can involve huge groups of thousands of animals as well as single individuals traveling alone and can range from thousands of kilometers to just a few hundred meters.
01:03Precipitation Gravimetry
Precipitation gravimetry is based on converting an analyte into a sparingly soluble precipitate, which is separated by filtration and weighed. An ideal precipitate should be pure, insoluble, of known composition, and easily filtered from the reaction mixture.
In determining nickel by gravimetric analysis, a precipitant of ethanolic dimethylglyoxime is added to a hot nickel salt solution. This is quickly followed by the dropwise addition of dilute ammonia solution until precipitation occurs. A...
In determining nickel by gravimetric analysis, a precipitant of ethanolic dimethylglyoxime is added to a hot nickel salt solution. This is quickly followed by the dropwise addition of dilute ammonia solution until precipitation occurs. A...
02:41Responses to Drought and Flooding
Water plays a significant role in the life cycle of plants. However, insufficient or excess of water can be detrimental and pose a serious threat to plants.
01:50Global Climate Change
Throughout its ~4.5 billion year history, the Earth has experienced periods of warming and cooling. However, the current drastic increase in global temperatures is well outside of the Earth’s cyclic norms, and evidence for human-caused global climate change is compelling. Paleoclimatology, the study of ancient climate conditions, provides ample evidence for human-caused global climate change by comparing recent conditions with those in the past.