Mare volcanics on the Moon are the key record of thermo-chemical evolution throughout most of lunar history1–3. Young mare basalts—mainly distributed in a region rich in potassium, rare-earth elements and phosphorus (KREEP) in Oceanus Procellarum, called the Procellarum KREEP Terrane (PKT)4—were thought to be formed from KREEP-rich sources at depth5–7. However, this hypothesis has not been tested with young basalts from the PKT. Here we present a petrological and geochemical study of the basalt clasts from the PKT returned by the Chang’e-5 mission8. These two-billion-year-old basalts are the youngest lunar samples reported so far9. Bulk rock compositions have moderate titanium and high iron contents with KREEP-like rare-earth-element and high thorium concentrations. However, strontium–neodymium isotopes indicate that these basalts were derived from a non-KREEP mantle source. To produce the high abundances of rare-earth elements and thorium, low-degree partial melting and extensive fractional crystallization are required. Our results indicate that the KREEP association may not be a prerequisite for young mare volcanism. Absolving the need to invoke heat-producing elements in their source implies a more sustained cooling history of the lunar interior to generate the Moon’s youngest melts.
Although deep carbon recycling plays an important role in the atmospheric CO2 budget and climate changes through geological time, the precise mechanisms remain poorly understood. Since recycled sedimentary carbonate through plate subduction is the main light-δ26Mg reservoir within deep-Earth, Mg isotope variation in mantle-derived melts provides a novel perspective when investigating deep carbon cycling. Here, we show that the Late Cretaceous and Cenozoic continental basalts from 13 regions covering the whole of eastern China have low δ26Mg isotopic compositions, while the Early Cretaceous basalts from the same area and the island arc basalts from circum-Pacific subduction zones have mantle-like or heavy Mg isotopic characteristics. Thus, a large-scale mantle low δ26Mg anomaly in eastern China has been delineated, suggesting the contribution of sedimentary carbonates recycled into the upper mantle, but limited into the lower mantle. This large-scale spatial and temporal variation of Mg isotopes in the mantle places severe constraints on deep carbon recycling via oceanic subduction.
It is becoming increasingly clear that global warming is taking place; however, its long-term effects on biological populations are largely unknown due to lack of long-term data. Here, we reconstructed a 1,910-y-long time series of outbreaks of Oriental migratory locusts ( Locusta migratoria manilensis ) in China, on the basis of information extracted from >8,000 historical documents. First by analyzing the most recent period with the best data quality using generalized additive models, we found statistically significant associations between the reconstructed locust abundance and indexes of precipitation and temperature at both annual (A.D. 1512–1911) and decadal (A.D. 1000–1900) scales: There were more locusts under dry and cold conditions and when locust abundance was high in the preceding year or decade. Second, by exploring locust–environment correlations using a 200-y moving window, we tested whether these associations also hold further back in time. The locust–precipitation correlation was found to hold at least as far back as to A.D. 500, supporting the robustness of this link as well as the quality of both reconstructions. The locust–temperature correlation was weaker and less consistent, which may reflect this link being indirect and thus more easily moderated by other factors. We anticipate that further analysis of this unique time series now available to the scientific community will continue to provide insights into biological consequences of climate change in the years to come.
Many species have experienced dramatic declines over the past millennia due to the accelerated impact of human activity and climate change, but compelling evidence over such long‐term time scales is rare. China has a unique system archiving historical records of important social, meteorological, agricultural and biological events over the last three millennia. We derived historical species occurrences (0–2000 AD) based on a comprehensive review of literature. To detect the driving forces of range contraction, we used correlation and multiple regression to quantify the linear association between species range indices and climate variables (five temperature series and three precipitation series), as well as a human population size series. We also used a machine learning technique, random forest, to quantify the nonlinear effects of the climate variables and human population size. The southward retreat of the Asian elephant Elephas maximus and the rhinoceroses (Dicerorhinus sumatrensis, Rhinoceros unicornis, R. sondaicus) was closely associated with climate cooling and intensified human impact (represented by high population size), and the westward retreat of the giant panda Ailuropoda melanoleuca was associated with intensified human impact. One temperature series and human population size showed interactive effect on range shift of the Asian elephant and the rhinoceroses; the effect of temperature was positive at low population size, but negative at high population size. Our results imply that a higher temperature caused the northward or eastward range shift of the Asian elephant, the rhinoceroses and the giant panda, and currently this trend is impeded by human activities. We also illustrate how human activity and climate act synergistically to cause range contraction.
Global warming is currently of great concern. Yet the ecological effects of low-frequency climate variations remain largely unknown. Recent analyses of interdecadal variability in population abundance of the Oriental migratory locust (Locusta migratoria manilensis) in China have revealed negative associations with temperature and positive associations with Yangtze drought and flood frequencies during the past millennium (AD 957-1956). In order to shed new light on the causal relationships between locust abundance, floods, droughts and temperature in ancient China, we used wavelet analysis to explore how the coherencies between the different variables at different frequencies have been changed during the past millennium. We find consistent in-phase coherencies between locusts and drought/flood frequencies, and out-of-phase coherencies between locusts and temperature and between drought/flood and temperature at period components of 160-170 years. Similar results are obtained when historical data of drought/flood frequencies of the Yangtze Delta region are used, despite flood data showing a weak and somewhat inconsistent association with other factors. We suggest that previously unreported periodic cooling of 160-170-year intervals dominate climatic variability in China through the past millennium, the cooling events promoting locust plagues by enhancing temperature-associated drought/flood events. Our results signify a rare example of possible benign effects of global warming on the regional risk of natural disasters such as flood/drought events and outbreaks of pest insects.
Recent studies have linked climatic and social instabilities in ancient China; the underlying causal mechanisms have, however, often not been quantitatively assessed. Here, using historical records and palaeoclimatic reconstructions during AD 10 -1900, we demonstrate that war frequency, price of rice, locust plague, drought frequency, flood frequency and temperature in China show two predominant periodic bands around 160 and 320 years where they interact significantly with each other. Temperature cooling shows direct positive association with the frequency of external aggression war to the Chinese dynasties mostly from the northern pastoral nomadic societies, and indirect positive association with the frequency of internal war within the Chinese dynasties through drought and locust plagues. The collapses of the agricultural dynasties of the Han, Tang, Song and Ming are more closely associated with low temperature. Our study suggests that food production during the last two millennia has been more unstable during cooler periods, resulting in more social conflicts owing to rebellions within the dynasties or/and southward aggressions from northern pastoral nomadic societies in ancient China.
A wide range of climate change-induced effects have been implicated in the prevalence of infectious diseases. Disentangling causes and consequences, however, remains particularly challenging at historical time scales, for which the quality and quantity of most of the available natural proxy archives and written documentary sources often decline. Here, we reconstruct the spatiotemporal occurrence patterns of human epidemics for large parts of China and most of the last two millennia. Cold and dry climate conditions indirectly increased the prevalence of epidemics through the influences of locusts and famines. Our results further reveal that low-frequency, long-term temperature trends mainly contributed to negative associations with epidemics, while positive associations of epidemics with droughts, floods, locusts, and famines mainly coincided with both higher and lower frequency temperature variations. Nevertheless, unstable relationships between human epidemics and temperature changes were observed on relatively smaller time scales. Our study suggests that an intertwined, direct, and indirect array of biological, ecological, and societal responses to different aspects of past climatic changes strongly depended on the frequency domain and study period chosen.
The crested ibis (Nipponia nippon) had declined severely from a common species to only two pairs in last century. To analyze the declining process, we established a GIS database with historical occurrences of the crested ibis based on published literatures, and layers of environmental factors such as elevation, wetland, and human activities. We compared the environmental factors at the occurrence sites in diVerent periods to quantify the changes of habitat use across time. To address the spatial deviation of the occurrences and check the eVect of measuring scale on habitat use, we calculated the environmental factors in a serial measuring scales from 1 to 161 £ 161 km 2 . Our results indicated that the crested ibis traditionally lives in habitat with higher wetland density and higher human impact, then it gradually moved to areas with higher elevation and lower human impact in last century. In 1980-2000 the crested ibis stayed at a very high elevation, lower wetland density and lower human impact as possible consequences of human activities such as using fertilizer and pesticide, drying the over wintering rice paddies, and direct hunting. Our quantitative analysis of the habitat use matched well the previous published statements (which have no numerical evidences) on the declination of the crested ibis. We suggest to reestablish the habitat with traditional farming practice that the bird has adapted as a major solution for applications such as conservation planning and reintroduction.
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