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Abstract. Water plays a significant role in wetlands. Floodwater utilisation in wetlands brings a wide range of wetland services, from goods production and water regulation to animal protection and aesthetics related to water supply in wetlands. In this study, the floodwater utilisation values of wetland services were estimated within the Momoge wetland and Xianghai wetland in western Jilin province of northeastern China. From 2003 to 2008, the floodwater diverted from the Nenjiang and Tao'er River is 381 million m3, which translates into a monetary value of approximately 1.35 billion RMB in 2008 (RMB: Chinese Currency, RMB 6.80 = US$ 1), and the ratio of economic value, eco-environmental value, and social value is 1:12:2. Besides the monetary value of the water itself, excessive floodwater utilisation may bring losses to wetlands; the threshold floodwater utilisation volumes in wetlands are discussed. Floodwater utilisation can alleviate water shortages in wetlands, and the evaluation of floodwater utilisation in wetland services in monetary terms is a guide for the effective use of the floodwater resources and for the conservation of wetlands.

Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S.Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC). ; Our nearest neighbor, Proxima Centauri, hosts a temperate terrestrial planet. We detected in radial velocities evidence of a possible second planet with minimum mass mc sin ic = 5.8 ± 1.9M⊕ and orbital period Pc = 5.21–0.22 +0.26 years. The analysis of photometric data and spectro-scopic activity diagnostics does not explain the signal in terms of a stellar activity cycle, but follow-up is required in the coming years for confirming its planetary origin. We show that the existence of the planet can be ascertained, and its true mass can be determined with high accuracy, by combining Gaia astrometry and radial velocities. Proxima c could become a prime target for follow-up and characterization with next-generation direct imaging instrumentation due to the large maximum angular separation of ~1 arc second from the parent star. The candidate planet represents a challenge for the models of super-Earth formation and evolution. Copyright © 2020 The Authors, some rights reserved. ; M.D. acknowledges financial support from Progetto Premiale 2015 FRONTIERA funding scheme of the Italian Ministry of Education, University, and Research. P.G. acknowledges financial support from the Italian Space Agency (ASI) under contract 2014-025-R.1.2015 to INAF. D.B. acknowledges financial support from INAF and Agenzia Spaziale Italiana (ASI grant no. 2014-025-R.1.2015) for the 2016 PhD fellowship programme of INAF. H.R.A.J. is supported by UK STFC grant ST/R006598/1. J.S.S. and P.A.P.R. acknowledge support by FONDECYT grant 1161218 and partial support from CONICYT project Basal AFB-170002. M.J.L.-G., N.M., C.R.-L., E.R., G.A., and J.F.G. acknowledge financial support from Spanish MINECO AYA2016-79425-C3-3-P, AYA2017-84390-C2-1-R (co-funded by FEDER), ESP2017-87143R, and ESP2017-87676-C05-02-R and the State Agency for Research of the Spanish MCIU through the "Center of Excellence Severo Ochoa" award for the Instituto de Astrofisica de Andalucia (SEV-2017-0709). G.A.-E. research is funded via grant ST/P000592/1 "Astronomy Research at Queen Mary"granted by the Science and Technology Facilities Council/United Kingdom. ; Peer reviewed

The closet exoplanets to the Sun provide opportunities for detailed characterization of planets outside the Solar System. We report the discovery, using radial velocity measurements, of a compact multiplanet system of super-Earth exoplanets orbiting the nearby red dwarf star GJ 887. The two planets have orbital periods of 9.3 and 21.8 days. Assuming an Earth-like albedo, the equilibrium temperature of the 21.8-day planet is similar to 350 kelvin. The planets are interior to, but close to the inner edge of, the liquid-water habitable zone. We also detect an unconfirmed signal with a period of similar to 50 days, which could correspond to a third super-Earth in a more temperate orbit. Our observations show that GJ 887 has photometric variability below 500 parts per million, which is unusually quiet for a red dwarf. ; German Research Foundation (DFG) FOR2544 JE 701/3-1 German Research Foundation (DFG) SPP 1992 JE 701/5-1 Science & Technology Facilities Council (STFC) ST/P000584/1 ST/T000295/1 ST/P000592/1 Spanish Agencia Estatal de Investigacion AYA2017-89637R AYA2016-79425-C3-3-S ESP2017-87676-C5-2-R ESP2017-87143R PGC2018-098153-B-C31 ESP2016-80435-C2-2-R Centre of Excellence "Severo Ochoa" Instituto de Astrofisica de Andalucia SEV-2017-0709 Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT) CONICYT FONDECYT 3180405 Swiss National Science Foundation (SNSF) CONICYT/PFCHA-Doctorado Nacional, Chile 21140646 Spanish Government ESP2016-80435-C2-1-R PGC2018-098153-B-C33 European Union (EU) ESP2016-80435-C2-1-R PGC2018-098153-B-C33 Generalitat de Catalunya/CERCA program Science & Technology Facilities Council (STFC) ST/M001008/1 Australian Research Council DP0774000 DP130102695 DP170103491 NASA through Hubble Fellowship - Space Telescope Science Institute HST-HF2-51399.001 Ministerio de Ciencia, Innovacion y Universidades Ramon y Cajal fellowship RYC-2017-22489 Science & Technology Facilities Council (STFC) ST/P000592/1 National Aeronautics & Space Administration (NASA) NAS5-26555

Barnard's star is a red dwarf, and has the largest proper motion (apparent motion across the sky) of all known stars. At a distance of 1.8 parsecs, it is the closest single star to the Sun; only the three stars in the α Centauri system are closer. Barnard's star is also among the least magnetically active red dwarfs known and has an estimated age older than the Solar System. Its properties make it a prime target for planetary searches; various techniques with different sensitivity limits have been used previously, including radial-velocity imaging, astrometry and direct imaging, but all ultimately led to negative or null results. Here we combine numerous measurements from high-precision radial-velocity instruments, revealing the presence of a low-amplitude periodic signal with a period of 233 days. Independent photometric and spectroscopic monitoring, as well as an analysis of instrumental systematic effects, suggest that this signal is best explained as arising from a planetary companion. The candidate planet around Barnard's star is a cold super-Earth, with a minimum mass of 3.2 times that of Earth, orbiting near its snow line (the minimum distance from the star at which volatile compounds could condense). The combination of all radial-velocity datasets spanning 20 years of measurements additionally reveals a long-term modulation that could arise from a stellar magnetic-activity cycle or from a more distant planetary object. Because of its proximity to the Sun, the candidate planet has a maximum angular separation of 220 milliarcseconds from Barnard's star, making it an excellent target for direct imaging and astrometric observations in the future. © 2018, Springer Nature Limited. ; The results are based on observations made with the CARMENES instrument at the 3.5-m telescope of the Centro Astronomico Hispano-Aleman de Calar Alto (CAHA, Almeria, Spain), funded by the German Max-Planck-Gesellschaft (MPG), the Spanish Consejo Superior de Investigaciones Cientificas (CSIC), the European Union and the CARMENES Consortium members; the 90-cm telescope at the Sierra Nevada Observatory (Granada, Spain) and the 40-cm robotic telescope at the SPACEOBS observatory (San Pedro de Atacama, Chile), both operated by the Instituto de Astrofisica de Andalucia (IAA); and the 80-cm Joan Oro Telescope (TJO) of the Montsec Astronomical Observatory (OAdM), owned by the Generalitat de Catalunya and operated by the Institute of Space Studies of Catalonia (IEEC). This research was supported by the following institutions, grants and fellowships: Spanish MINECO ESP2016-80435-C2-1-R, ESP2016-80435-C2-2-R, AYA2016-79425-C3-1-P, AYA2016-79245-C3-2-P, AYA2016-79425-C3-3-P, AYA2015-69350-C3-2-P, ESP2014-54362-P, AYA2014-56359-P, RYC-2013-14875; Generalitat de Catalunya/CERCA programme; Fondo Europeo de Desarrollo Regional (FEDER); German Science Foundation (DFG) Research Unit FOR2544, project JE 701/3-1; STFC Consolidated Grants ST/P000584/1, ST/P000592/1, ST/M001008/1; NSF AST-0307493; Queen Mary University of London Scholarship; Perren foundation grant; CONICYT-FONDECYT 1161218, 3180405; Swiss National Science Foundation (SNSF); Koshland Foundation and McDonald-Leapman grant; and NASA Hubble Fellowship grant HST-HF2-51399.001. J.T. is a Hubble Fellow.