1
|
Li F, Xiao J, Chen J, Ballantyne A, Jin K, Li B, Abraha M, John R. Global water use efficiency saturation due to increased vapor pressure deficit. Science 2023; 381:672-677. [PMID: 37561856 DOI: 10.1126/science.adf5041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 07/06/2023] [Indexed: 08/12/2023]
Abstract
The ratio of carbon assimilation to water evapotranspiration (ET) of an ecosystem, referred to as ecosystem water use efficiency (WUEeco), is widely expected to increase because of the rising atmospheric carbon dioxide concentration (Ca). However, little is known about the interactive effects of rising Ca and climate change on WUEeco. On the basis of upscaled estimates from machine learning methods and global FLUXNET observations, we show that global WUEeco has not risen since 2001 because of the asymmetric effects of an increased vapor pressure deficit (VPD), which depressed photosynthesis and enhanced ET. An undiminished ET trend indicates that rising temperature and VPD may play a more important role in regulating ET than declining stomatal conductance. Projected increases in VPD are predicted to affect the future coupling of the terrestrial carbon and water cycles.
Collapse
Affiliation(s)
- Fei Li
- Grassland Research Institute, Chinese Academy of Agricultural Sciences, Hohhot 010010, China
- Center for Global Change and Earth Observations, Michigan State University, East Lansing, MI 48823, USA
| | - Jingfeng Xiao
- Earth Systems Research Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH 03824, USA
| | - Jiquan Chen
- Center for Global Change and Earth Observations, Michigan State University, East Lansing, MI 48823, USA
| | - Ashley Ballantyne
- Department of Ecosystem and Conservation Science, University of Montana, Missoula, MT 59801, USA
- Laboratoire des Sciences du Climat et de l'Environnement, CEA-CNRS-UVSQ, 91190 Gif-sur-Yvette, France
| | - Ke Jin
- Grassland Research Institute, Chinese Academy of Agricultural Sciences, Hohhot 010010, China
| | - Bing Li
- Grassland Research Institute, Chinese Academy of Agricultural Sciences, Hohhot 010010, China
| | - Michael Abraha
- Center for Global Change and Earth Observations, Michigan State University, East Lansing, MI 48823, USA
| | - Ranjeet John
- Department of Biology and Department of Sustainability, University of South Dakota, Vermillion, SD 57069, USA
| |
Collapse
|
2
|
Tejera-Nieves M, Abraha M, Chen J, Hamilton SK, Robertson GP, Walker BJ. Corrigendum: Seasonal decline in leaf photosynthesis in perennial switchgrass explained by sink limitations and water deficit. Front Plant Sci 2023; 14:1204150. [PMID: 37152143 PMCID: PMC10157273 DOI: 10.3389/fpls.2023.1204150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 04/12/2023] [Indexed: 05/09/2023]
Abstract
[This corrects the article DOI: 10.3389/fpls.2022.1023571.].
Collapse
Affiliation(s)
- Mauricio Tejera-Nieves
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, United States
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI, United States
| | - Michael Abraha
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI, United States
- W. K. Kellogg Biological Station, Michigan State University, Hickory Corners, MI, United States
- Center for Global Change and Earth Observations, Michigan State University, East Lansing, MI, United States
| | - Jiquan Chen
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI, United States
- Center for Global Change and Earth Observations, Michigan State University, East Lansing, MI, United States
- Department of Geography, Environment, and Spatial Sciences, Michigan State University, East Lansing, MI, United States
| | - Stephen K. Hamilton
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI, United States
- W. K. Kellogg Biological Station, Michigan State University, Hickory Corners, MI, United States
- Department of Integrative Biology, Michigan State University, East Lansing, MI, United States
| | - G. Philip Robertson
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI, United States
- W. K. Kellogg Biological Station, Michigan State University, Hickory Corners, MI, United States
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI, United States
| | - Berkley James Walker
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, United States
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI, United States
- Department of Plant Biology, Michigan State University, East Lansing, MI, United States
- *Correspondence: Berkley James Walker,
| |
Collapse
|
3
|
Pan D, Gelfand I, Tao L, Abraha M, Sun K, Guo X, Chen J, Robertson GP, Zondlo MA. A new open-path eddy covariance method for nitrous oxide and other trace gases that minimizes temperature corrections. Glob Chang Biol 2022; 28:1446-1457. [PMID: 34758177 DOI: 10.1111/gcb.15986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 10/19/2021] [Accepted: 10/19/2021] [Indexed: 06/13/2023]
Abstract
Low-power, open-path gas sensors enable eddy covariance (EC) flux measurements in remote areas without line power. However, open-path flux measurements are sensitive to fluctuations in air temperature, pressure, and humidity. Laser-based, open-path sensors with the needed sensitivity for trace gases like methane (CH4 ) and nitrous oxide (N2 O) are impacted by additional spectroscopic effects. Corrections for these effects, especially those related to temperature fluctuations, often exceed the flux of gases, leading to large uncertainties in the associated fluxes. For example, the density and spectroscopic corrections arising from temperature fluctuations can be one or two orders of magnitude greater than background N2 O fluxes. Consequently, measuring background fluxes with laser-based, open-path sensors is extremely challenging, particularly for N2 O and gases with similar high-precision requirements. We demonstrate a new laser-based, open-path N2 O sensor and a general approach applicable to other gases that minimizes temperature-related corrections for EC flux measurements. The method identifies absorption lines with spectroscopic effects in the opposite direction of density effects from temperature and, thus, density and spectroscopic effects nearly cancel one another. The new open-path N2 O sensor was tested at a corn (Zea mays L.) field in Southwestern Michigan, United States. The sensor had an optimal precision of 0.1 ppbv at 10 Hz and power consumption of 50 W. Field trials showed that temperature-related corrections were 6% of density corrections, reducing EC random errors by 20-fold compared to previously examined lines. Measured open-path N2 O EC fluxes showed excellent agreement with those made with static chambers (m = 1.0 ± 0.3; r2 = .96). More generally, we identified absorption lines for CO2 and CH4 flux measurements that can reduce the temperature-related corrections by 10-100 times compared to existing open-path sensors. The proposed method provides a new direction for future open-path sensors, facilitating the expansion of accurate EC flux measurements.
Collapse
Affiliation(s)
- Da Pan
- Department of Civil and Environmental Engineering, Princeton University, Princeton, New Jersey, USA
- Center for Mid-Infrared Technologies for Health and the Environmental, NSF-ERC, Princeton, New Jersey, USA
| | - Ilya Gelfand
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, Michigan, USA
- W.K. Kellogg Biological Station, Michigan State University, Hickory Corners, Michigan, USA
- The French Associates Institute for Agriculture and Biotechnology of Drylands, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Lei Tao
- Department of Civil and Environmental Engineering, Princeton University, Princeton, New Jersey, USA
- Center for Mid-Infrared Technologies for Health and the Environmental, NSF-ERC, Princeton, New Jersey, USA
| | - Michael Abraha
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, Michigan, USA
- W.K. Kellogg Biological Station, Michigan State University, Hickory Corners, Michigan, USA
- Center for Global Change and Earth Observations, Michigan State University, East Lansing, Michigan, USA
| | - Kang Sun
- Department of Civil, Structural and Environmental Engineering, University at Buffalo, Buffalo, New York, USA
- Research and Education in eNergy, Environment and Water (RENEW) Institute, University at Buffalo, Buffalo, New York, USA
| | - Xuehui Guo
- Department of Civil and Environmental Engineering, Princeton University, Princeton, New Jersey, USA
- Center for Mid-Infrared Technologies for Health and the Environmental, NSF-ERC, Princeton, New Jersey, USA
| | - Jiquan Chen
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, Michigan, USA
- Center for Global Change and Earth Observations, Michigan State University, East Lansing, Michigan, USA
| | - G Philip Robertson
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, Michigan, USA
- W.K. Kellogg Biological Station, Michigan State University, Hickory Corners, Michigan, USA
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, Michigan, USA
| | - Mark A Zondlo
- Department of Civil and Environmental Engineering, Princeton University, Princeton, New Jersey, USA
- Center for Mid-Infrared Technologies for Health and the Environmental, NSF-ERC, Princeton, New Jersey, USA
| |
Collapse
|
4
|
Tejera-Nieves M, Abraha M, Chen J, Hamilton SK, Robertson GP, Walker James B. Seasonal decline in leaf photosynthesis in perennial switchgrass explained by sink limitations and water deficit. Front Plant Sci 2022; 13:1023571. [PMID: 36684783 PMCID: PMC9846045 DOI: 10.3389/fpls.2022.1023571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 12/07/2022] [Indexed: 05/05/2023]
Abstract
Leaf photosynthesis of perennial grasses usually decreases markedly from early to late summer, even when the canopy remains green and environmental conditions are favorable for photosynthesis. Understanding the physiological basis of this photosynthetic decline reveals the potential for yield improvement. We tested the association of seasonal photosynthetic decline in switchgrass (Panicum virgatum L.) with water availability by comparing plants experiencing ambient rainfall with plants in a rainfall exclusion experiment in Michigan, USA. For switchgrass exposed to ambient rainfall, daily net CO2 assimilation ( A n e t ' ) declined from 0.9 mol CO2 m-2 day-1 in early summer to 0.43 mol CO2 m-2 day-1 in late summer (53% reduction; P<0.0001). Under rainfall exclusion shelters, soil water content was 73% lower and A n e t ' was 12% and 26% lower in July and September, respectively, compared to those of the rainfed plants. Despite these differences, the seasonal photosynthetic decline was similar in the season-long rainfall exclusion compared to the rainfed plants; A n e t ' in switchgrass under the shelters declined from 0.85 mol CO2 m-2 day-1 in early summer to 0.39 mol CO2 m-2 day-1 (54% reduction; P<0.0001) in late summer. These results suggest that while water deficit limited A n e t ' late in the season, abundant late-season rainfalls were not enough to restore A n e t ' in the rainfed plants to early-summer values suggesting water deficit was not the sole driver of the decline. Alongside change in photosynthesis, starch in the rhizomes increased 4-fold (P<0.0001) and stabilized when leaf photosynthesis reached constant low values. Additionally, water limitation under shelters had no negative effects on the timing of rhizome starch accumulation, and rhizome starch content increased ~ 6-fold. These results showed that rhizomes also affect leaf photosynthesis during the growing season. Towards the end of the growing season, when vegetative growth is completed and rhizome reserves are filled, diminishing rhizome sink activity likely explained the observed photosynthetic declines in plants under both ambient and reduced water availability.
Collapse
Affiliation(s)
- Mauricio Tejera-Nieves
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, United States
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI, United States
| | - Michael Abraha
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI, United States
- W. K. Kellogg Biological Station, Michigan State University, Hickory Corners, MI, United States
- Center for Global Change and Earth Observations, Michigan State University, East Lansing, MI, United States
| | - Jiquan Chen
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI, United States
- Center for Global Change and Earth Observations, Michigan State University, East Lansing, MI, United States
- Department of Geography, Environment, and Spatial Sciences, Michigan State University, East Lansing, MI, United States
| | - Stephen K. Hamilton
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI, United States
- W. K. Kellogg Biological Station, Michigan State University, Hickory Corners, MI, United States
- Department of Integrative Biology, Michigan State University, East Lansing, MI, United States
| | - G. Philip Robertson
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI, United States
- W. K. Kellogg Biological Station, Michigan State University, Hickory Corners, MI, United States
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI, United States
| | - Berkley Walker James
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, United States
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI, United States
- Department of Plant Biology, Michigan State University, East Lansing, MI, United States
- *Correspondence: Berkley Walker James,
| |
Collapse
|
5
|
Abraha M, Gelfand I, Hamilton SK, Chen J, Robertson GP. Legacy effects of land use on soil nitrous oxide emissions in annual crop and perennial grassland ecosystems. Ecol Appl 2018; 28:1362-1369. [PMID: 29856901 DOI: 10.1002/eap.1745] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 01/20/2018] [Accepted: 04/09/2018] [Indexed: 05/12/2023]
Abstract
Land use conversions into and out of agriculture may influence soil-atmosphere greenhouse gas fluxes for many years. We tested the legacy effects of land use on cumulative soil nitrous oxide (N2 O) fluxes for 5 yr following conversion of 22-yr-old Conservation Reserve Program (CRP) grasslands and conventionally tilled agricultural fields (AGR) to continuous no-till corn, switchgrass, and restored prairie. An unconverted CRP field served as a reference. We assessed the labile soil C pool of the upper 10 cm in 2009 (the conversion year) and in 2014 using short-term soil incubations. We also measured in situ soil N2 O fluxes biweekly from 2009 through 2014 using static chambers except when soils were frozen. The labile C pool was approximately twofold higher in soils previously in CRP than in those formerly in tilled cropland. Five-year cumulative soil N2 O emissions were approximately threefold higher in the corn system on former CRP than on former cropland despite similar fertilization rates (~184 kg N·ha-1 ·yr-1 ). The lower cumulative emissions from corn on former cropland were similar to emissions from switchgrass that was fertilized less (~57 kg N·ha-1 ·yr-1 ), regardless of former land use, and lowest emissions were observed from the unfertilized restored prairie and reference systems. Findings support the hypothesis that soil labile carbon levels modulate the response of soil N2 O emissions to nitrogen inputs, with soils higher in labile carbon but otherwise similar, in this case reflecting land use history, responding more strongly to added nitrogen.
Collapse
Affiliation(s)
- Michael Abraha
- Center for Global Change and Earth Observations, Michigan State University, East Lansing, Michigan, 48823, USA
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, Michigan, 48824, USA
- W.K. Kellogg Biological Station, Michigan State University, Hickory Corners, Michigan, 49060, USA
| | - Ilya Gelfand
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, Michigan, 48824, USA
- W.K. Kellogg Biological Station, Michigan State University, Hickory Corners, Michigan, 49060, USA
| | - Stephen K Hamilton
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, Michigan, 48824, USA
- W.K. Kellogg Biological Station, Michigan State University, Hickory Corners, Michigan, 49060, USA
- Department of Integrative Biology, Michigan State University, East Lansing, Michigan, 48824, USA
| | - Jiquan Chen
- Center for Global Change and Earth Observations, Michigan State University, East Lansing, Michigan, 48823, USA
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, Michigan, 48824, USA
- Department of Geography, Environment, and Spatial Sciences, Michigan State University, East Lansing, Michigan, 48824, USA
| | - G Philip Robertson
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, Michigan, 48824, USA
- W.K. Kellogg Biological Station, Michigan State University, Hickory Corners, Michigan, 49060, USA
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, Michigan, 48824, USA
| |
Collapse
|
6
|
Shao C, Chen J, Chu H, Lafortezza R, Dong G, Abraha M, Batkhishig O, John R, Ouyang Z, Zhang Y, Qi J. Grassland productivity and carbon sequestration in Mongolian grasslands: The underlying mechanisms and nomadic implications. Environ Res 2017; 159:124-134. [PMID: 28797887 DOI: 10.1016/j.envres.2017.08.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 07/29/2017] [Accepted: 08/01/2017] [Indexed: 06/07/2023]
Abstract
BACKGROUND Quantifying carbon (C) dioxide exchanges between ecosystems and the atmosphere and the underlying mechanism of biophysical regulations under similar environmental conditions is critical for an accurate understanding of C budgets and ecosystem functions. METHODS For the first time, a cluster of four eddy covariance towers were set up to answer how C fluxes shift among four dominant ecosystems in Mongolia - meadow steppe (MDW), typical steppe (TPL), dry typical steppe (DRT) and shrubland (SHB) during two growing seasons (2014 and 2015). RESULTS Large variations were observed for the annual net ecosystem exchange (NEE) from 59 to 193gCm-2, though all four sites acted as a C source. During the two growing seasons, MDW acted as a C sink, TPL and DRT were C neutral, while SHB acted as a C source. MDW to SHB and TPL conversions resulted in a 2.6- and 2.2-fold increase in C release, respectively, whereas the TPL to SHB conversion resulted in a 1.1-fold increase at the annual scale. C assimilation was higher at MDW than those at the other three ecosystems due to its greater C assimilation ability and longer C assimilation times during the day and growing period. On the other hand, C release was highest at SHB due to significantly lower photosynthetic production and relatively higher ecosystem respiration (ER). A stepwise multiple regression analysis showed that the seasonal variations in NEE, ER and gross ecosystem production (GEP) were controlled by air temperature at MDW, while they were controlled mainly by soil moisture at TPL, DRT and SHB. When air temperature increased, the NEE at MDW and TPL changed more dramatically than at DRT and SHB, suggesting not only a stronger C release ability but also a higher temperature sensitivity at MDW and TPL. CONCLUSIONS The ongoing and predicted global changes in Mongolia likely impact the C exchange at MDW and TPL more than at DRT and SHB in Mongolia. Our results suggest that, with increasing drought and vegetation type succession, a clear trend for greater CO2 emissions may result in further global warming in the future. This study implies that diverse grassland ecosystems will respond differently to climate change in the future and can be seen as nature-based solutions (NBS) supporting climate change adaptation and mitigation strategies.
Collapse
Affiliation(s)
- Changliang Shao
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Jiquan Chen
- Center for Global Change & Earth Observations (CGCEO), Michigan State University, East Lansing, MI 48823, USA.
| | - Housen Chu
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA 94720, USA
| | - Raffaele Lafortezza
- Center for Global Change & Earth Observations (CGCEO), Michigan State University, East Lansing, MI 48823, USA; Department of Agricultural and Environmental Sciences, University of Bari, Bari 70126, Italy
| | - Gang Dong
- School of Life Science, Shanxi University, Taiyuan 030006, China
| | - Michael Abraha
- Center for Global Change & Earth Observations (CGCEO), Michigan State University, East Lansing, MI 48823, USA
| | - Ochirbat Batkhishig
- Institute of Geography, Mongolian Academy of Sciences, Ulaanbarrtar 210620, Mongolia
| | - Ranjeet John
- Center for Global Change & Earth Observations (CGCEO), Michigan State University, East Lansing, MI 48823, USA
| | - Zutao Ouyang
- Center for Global Change & Earth Observations (CGCEO), Michigan State University, East Lansing, MI 48823, USA
| | - Yaoqi Zhang
- School of Forestry and Wildlife Sciences, Auburn University, Auburn, AL 36949, USA
| | - Jiaguo Qi
- Center for Global Change & Earth Observations (CGCEO), Michigan State University, East Lansing, MI 48823, USA
| |
Collapse
|
7
|
Shao C, Chen J, Li L, Dong G, Han J, Abraha M, John R. Grazing effects on surface energy fluxes in a desert steppe on the Mongolian Plateau. Ecol Appl 2017; 27:485-502. [PMID: 27761975 DOI: 10.1002/eap.1459] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Revised: 07/27/2016] [Accepted: 09/06/2016] [Indexed: 06/06/2023]
Abstract
Quantifying the surface energy fluxes of grazed and ungrazed steppes is essential to understand the roles of grasslands in local and global climate and in land use change. We used paired eddy-covariance towers to investigate the effects of grazing on energy balance (EB) components: net radiation (Rn ), latent heat (LE), sensible heat (H), and soil heat (G) fluxes on adjacent grazed and ungrazed areas in a desert steppe of the Mongolian Plateau for a two-year period (2010-2012). Near 95% of Rn was partitioned as LE and H, whereas the contributions of G and other components of the EB were 5% at an annual scale. H dominated the energy partitioning and shared ~50% of Rn . When comparing the grazed and the ungrazed desert steppe, there was remarkably lower Rn and a lower H, but higher G at the grazed site than at the ungrazed site. Both reduced available energy (Rn - G) and H indicated a "cooling effect" feedback onto the local climate through grazing. Grazing reduced the dry year LE but enhanced the wet year LE. Energy partitioning of LE/Rn was positively correlated with the canopy conductivity, leaf area index, and soil moisture. H/Rn was positively correlated with the vapor pressure deficit but negatively correlated with the soil moisture. Boosted regression tree results showed that LE/Rn was dominated by soil moisture in both years and at both sites, while grazing shifted the H/Rn domination from temperature to soil moisture in the wet year. Grazing not only caused an LE shift between the dry and the wet year, but also triggered a decrease in the H/Rn because of changes in vegetation and soil properties, indicating that the ungrazed area had a greater resistance while the grazed area had a greater sensitivity of EB components to the changing climate.
Collapse
Affiliation(s)
- Changliang Shao
- Center for Global Change & Earth Observations, Michigan State University, East Lansing, Michigan, 48823, USA
| | - Jiquan Chen
- Center for Global Change & Earth Observations, Michigan State University, East Lansing, Michigan, 48823, USA
| | - Linghao Li
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, The Chinese Academy of Sciences, Beijing, 100093, China
| | - Gang Dong
- School of Life Science, Shanxi University, Taiyuan, 030006, China
| | - Juanjuan Han
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, The Chinese Academy of Sciences, Beijing, 100093, China
| | - Michael Abraha
- Center for Global Change & Earth Observations, Michigan State University, East Lansing, Michigan, 48823, USA
| | - Ranjeet John
- Center for Global Change & Earth Observations, Michigan State University, East Lansing, Michigan, 48823, USA
| |
Collapse
|
8
|
Abraha M, Kahsu TA, Godefay H, Konings E. P6.059 Vertical Transmission of HIV Less Than Half Among Mothers Belonging to Mother-Support Groups (MSG) Compared to Non-Member Mothers at Health Centres in Tigray, Ethiopia. Br J Vener Dis 2013. [DOI: 10.1136/sextrans-2013-051184.1212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
9
|
Kahsu TA, Abraha M, Tadesse F, Crandall B, Godefay H, Konings ELL. P6.063 Vertical Transmission of HIV by Age of Infant Testing and Type of Mother/Infant Prophylaxis in Tigray, Ethiopia. Br J Vener Dis 2013. [DOI: 10.1136/sextrans-2013-051184.1216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
10
|
Shoshani J, Walter RC, Abraha M, Berhe S, Tassy P, Sanders WJ, Marchant GH, Libsekal Y, Ghirmai T, Zinner D. A proboscidean from the late Oligocene of Eritrea, a "missing link" between early Elephantiformes and Elephantimorpha, and biogeographic implications. Proc Natl Acad Sci U S A 2006; 103:17296-301. [PMID: 17085582 PMCID: PMC1859925 DOI: 10.1073/pnas.0603689103] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2006] [Indexed: 11/18/2022] Open
Abstract
We report on a late Oligocene proboscidean species from Eritrea, dated to 26.8 +/- 1.5 Mya. This "missing link" between early elephantiformes and Elephantimorpha is the oldest known nongomphothere proboscidean to probably display horizontal tooth displacement, typical of elephants [Elephantimorpha consists of Mammutida (mastodons) and Elephantida, and Elephantida includes gomphotheres, stegodons, and elephants]. Together with the newly discovered late Oligocene gomphotheres from Chilga, Ethiopia, the Eritrean taxon points to the importance of East Africa as a major area for the knowledge of the early evolution of Elephantimorpha before the faunal exchange between Eurasia and Africa.
Collapse
Affiliation(s)
- Jeheskel Shoshani
- *Department of Biology, University of Asmara, P.O. Box 1220, Asmara, Eritrea
- Elephant Research Foundation, 106 East Hickory Grove Road, Bloomfield Hills, MI 48304
| | - Robert C. Walter
- Department of Earth and Environment, Franklin and Marshall College, Lancaster, PA 17604-3003
| | - Michael Abraha
- Eritrean Geological Survey, Department of Mines, Ministry of Mines and Energy, P.O. Box 272, Asmara, Eritrea
| | - Seife Berhe
- Global Resources, P.O. Box 4588, Asmara, Eritrea
| | - Pascal Tassy
- **USM203/Unité Mixte de Recherche 5143 Centre National de la Recherche Scientifique Paléobiodiversité, CP 38, Muséum National d'Histoire Naturelle, 57 Rue Cuvier, 75231 Paris Cedex 05, France
| | | | - Gary H. Marchant
- Elephant Research Foundation, 106 East Hickory Grove Road, Bloomfield Hills, MI 48304
| | - Yosief Libsekal
- Department of Archeology, National Museum of Eritrea, P.O. Box 1220, Asmara, Eritrea; and
| | | | - Dietmar Zinner
- Department of Cognitive Ethology, Deutsches Primatenzentrum, Kellnerweg 4, D-37077 Göttingen, Germany
| |
Collapse
|