More stories

  • in

    Spatio-temporal distribution and acoustic characterization of haddock (Melanogrammus aeglefinus, Gadidae) calls in the Arctic fjord Kongsfjorden (Svalbard Islands)

    1.
    Olsen, E. et al. Cod, haddock, saithe, herring, and capelin in the Barents Sea and adjacent waters: A review of the biological value of the area. J. Mar. Sci. 67, 87–101 (2010).
    MathSciNet  Google Scholar 
    2.
    Hislop, J. A comparison of the reproductive tacticsand strategies of cod, haddock, whiting and Norwaypout in the North Sea. In Fish Reproduction: Strategies and Tactics 311–329 (Academic Press, New York, 1984).
    Google Scholar 

    3.
    Bergstad, O., Jorgensen, T. & Dragesund, O. Life history and ecology of the Gadoid resources of the Barents Sea. Fish. Res. 5, 119–161 (1987).
    Article  Google Scholar 

    4.
    Boudreau, P. R. Acoustic observations of patterns of aggregation in haddock (Melanogrammus aeglefinus) and their significance to production and catch. Can. J. Fish. Aquat. Sci. 49, 23–31 (1992).
    Article  Google Scholar 

    5.
    Solemdal, P., Knutsen, T., Bjørke, H., Fossum, P. & Mukhina, N. Maturation, spawning and egg drift of Arcto-Norwegian haddock (Melanogrammus aeglefinus). in Ichthyoplankton Ecology (1997).

    6.
    Casaretto, L., Picciulin, M., Olsen, K. & Hawkins, A. D. Locating spawning haddock (Melanogrammus aeglefinus, Linnaeus, 1758) at sea by means of sound. Fish. Res. 154, 127–134 (2014).
    Article  Google Scholar 

    7.
    Hawkins, A. D. & Picciulin, M. The importance of underwater sounds to gadoid fishes. J. Acoust. Soc. Am. 145, 3536–3551 (2019).
    ADS  Article  Google Scholar 

    8.
    Hawkins, A. D. & Amorim, M. C. P. Spawning sounds of the male haddock, Melanogrammus aeglefinus. Environ. Biol. Fishes 59, 29–41 (2000).
    Article  Google Scholar 

    9.
    Casaretto, L., Picciulin, M. & Hawkins, A. D. Seasonal patterns and individual differences in the calls of male haddock Melanogrammus aeglefinus: melanogrammus aeglefinus sounds. J. Fish Biol. 87, 579–603 (2015).
    CAS  PubMed  Article  Google Scholar 

    10.
    Bremner, A. A., Trippel, E. A. & Terhune, J. M. Sound production by adult haddock, Melanogrammus aeglefinus, in isolation, Pairs and Trios. Environ. Biol. Fishes 65, 359–362 (2002).
    Article  Google Scholar 

    11.
    Casaretto, L., Picciulin, M. & Hawkins, A. D. Mating behaviour by the haddock (Melanogrammus aeglefinus). Environ. Biol. Fishes 98, 913–923 (2015).
    Article  Google Scholar 

    12.
    Casaretto, L., Picciulin, M. & Hawkins, A. D. Differences between male, female and juvenile haddock (Melanogrammus aeglefinus L.) sounds. Bioacoustics 25, 111–125 (2016).
    Article  Google Scholar 

    13.
    Templeman, W. & Hodder, V. M. Variation with fish length, sex, stage of sexual maturity and season, in the appearance and volume of the drumming muscles of the swimbladder in the haddock, Melanogrammus aeglefinus L. J. Fish Res. Board Can. 2, 355–390 (1958).
    Article  Google Scholar 

    14.
    Buscaino, G. et al. Temporal patterns in the soundscape of the shallow waters of a Mediterranean marine protected area. Sci. Rep. 6, 34230 (2016).
    ADS  CAS  PubMed  PubMed Central  Article  Google Scholar 

    15.
    Ceraulo, M. et al. Acoustic comparison of a patchy Mediterranean shallow water seascape: Posidonia oceanica meadow and sandy bottom habitats. Ecol. Indic. 85, 1030–1043 (2018).
    Article  Google Scholar 

    16.
    Rice, A. N., Morano, J. L., Hodge, K. B. & Muirhead, C. A. Spatial and temporal patterns of toadfish and black drum chorusing activity in the South Atlantic Bight. Environ. Biol. Fishes 99, 705–716 (2016).
    Article  Google Scholar 

    17.
    Connaughton, M. A. & Taylor, M. H. Seasonal and daily cycles in sound production associated with spawning in the weakfish, Cynoscion regalis. Environ. Biol. Fishes 42, 233–240 (1995).
    Article  Google Scholar 

    18.
    Locascio, J. V. & Mann, D. A. Diel and seasonal timing of sound production by black drum (Pogonias cromis). Fish. Bull. 109, 327–338 (2011).
    Google Scholar 

    19.
    McCauley, R. Fish choruses from the Kimberley, seasonal and lunar links as determined by long term sea noise monitoring. Proc. Acoust. Soc. Aust. (2012).

    20.
    Ceraulo, M. et al. Spatial and temporal variability of the soundscape in a Southwestern Atlantic coastal lagoon. Hydrobiologia 847, 2255–2277 (2020).
    Article  Google Scholar 

    21.
    Tellechea, J. S., Bouvier, D. & Norbis, W. Spawining sound in whitemouth croaker (Scienidae): Seasonal and daily cycles. Bioacoustics 20, 159–168 (2011).
    Article  Google Scholar 

    22.
    Stelzer, R. J. & Chittka, L. Research article Bumblebee foraging rhythms under the midnight sun measured with radiofrequency identification. (2010).

    23.
    Steiger, S. S. et al. When the sun never sets: Diverse activity rhythms under continuous daylight in free-living arctic-breeding birds. Proc. R. Soc. B Biol. Sci. 280, 20131016 (2013).
    Article  Google Scholar 

    24.
    Benoit, D., Simard, Y., Gagné, J., Geoffroy, M. & Fortier, L. From polar night to midnight sun: Photoperiod, seal predation, and the diel vertical migrations of polar cod (Boreogadus saida) under landfast ice in the Arctic Ocean. Polar Biol. 33, 1505–1520 (2010).
    Article  Google Scholar 

    25.
    Bruce Martin, S. & Cott, P. A. The under-ice soundscape in Great Slave Lake near the city of Yellowknife, Northwest Territories, Canada. J. Gt. Lakes Res. 42, 248–255 (2016).
    Article  Google Scholar 

    26.
    Müller, S. Seasonal phase shift and the duration of activity time in the Burbot, Lota lota (L.) (Pisces, Gadidae). J. Comparat. Physiol. 84, 357–359 (1973).
    Article  Google Scholar 

    27.
    Berge, J. et al. First records of atlantic mackerel (Scomber scombrus) from the Svalbard Archipelago, Norway, with possible explanations for the extension of its distribution. Arctic 68, 54 (2015).
    Article  Google Scholar 

    28.
    Renaud, P. E. et al. Is the poleward expansion by Atlantic cod and haddock threatening native polar cod, Boreogadus saida?. Polar Biol. 35, 401–412 (2012).
    Article  Google Scholar 

    29.
    Misund, O. A. et al. Norwegian fisheries in the Svalbard zone since 1980. Regulations, profitability and warming waters affect landings. Polar Sci. 10, 312–322 (2016).
    ADS  Article  Google Scholar 

    30.
    Vihtakari, M. et al. Black-legged kittiwakes as messengers of Atlantification in the Arctic. Sci. Rep. 8, 2 (2018).
    Article  CAS  Google Scholar 

    31.
    Brand, M. & Fischer, P. Species composition and abundance of the shallow water fish community of Kongsfjorden, Svalbard. Polar Biol. 39, 2155–2167 (2016).
    Article  Google Scholar 

    32.
    Connaughton, M. A. & Taylor, M. H. Effects of photoperiod and temperature on sexual recrudescence in the male weakfish, Cynoscion regalis. Environ. Biol. Fishes 45, 273–281 (1996).
    Article  Google Scholar 

    33.
    Ladich, F. Acoustic communication in fishes: Temperature plays a role. Fish Fish. 19, 598–612 (2018).
    Article  Google Scholar 

    34.
    Papes, S. & Ladich, F. Effects of temperature on sound production and auditory abilities in the striped raphael Catfish Platydoras armatulus (Family Doradidae). PLoS ONE 6, e26479 (2011).
    ADS  CAS  PubMed  PubMed Central  Article  Google Scholar 

    35.
    Stanley, J. A., Van Parijs, S. M. & Hatch, L. T. Underwater sound from vessel traffic reduces the effective communication range in Atlantic cod and haddock. Sci. Rep. 7, 2 (2017).
    Article  CAS  Google Scholar 

    36.
    Last, K. S., Hobbs, L., Berge, J., Brierley, A. S. & Cottier, F. Moonlight drives ocean-scale mass vertical migration of Zooplankton during the arctic winter. Curr. Biol. 26, 244–251 (2016).
    CAS  PubMed  Article  Google Scholar 

    37.
    de Vincenzi, G. et al. Influence of environmental parameters on the use and spatiotemporal distribution of the vocalizations of bearded seals (Erignathus barbatus) in Kongsfjorden, Spitsbergen. Polar Biol. 42, 1241–1254 (2019).
    Article  Google Scholar 

    38.
    Svendenson, et al. kongsfiorden gradient arctic atlantic.pdf. Polar Res. 21, 133–166 (2002).
    Google Scholar 

    39.
    Hop, H. et al. The marine ecosystem of Kongsfjorden, Svalbard. Polar Res. 21, 167–208 (2002).
    Article  Google Scholar 

    40.
    Dalpadado, P., Bogstad, B., Eriksen, E. & Rey, L. Distribution and diet of 0-group cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) in the Barents Sea in relation to food availability and temperature. Polar Biol. 32, 1583–1596 (2009).
    Article  Google Scholar 

    41.
    Akamatsu, T., Okumura, T., Novarini, N. & Yan, H. Y. Empirical refinements applicable to the recording of fish sounds in small tanks. J. Acoust. Soc. Am. 112, 3073–3082 (2002).
    ADS  PubMed  Article  Google Scholar 

    42.
    Cottier, F. et al. Water mass modification in an Arctic fjord through cross-shelf exchange: The seasonal hydrography of Kongsfjorden, Svalbard. J. Geophys. Res. 110, 2 (2005).
    Google Scholar 

    43.
    Lydersen, C. et al. The importance of tidewater glaciers for marine mammals and seabirds in Svalbard, Norway. J. Mar. Syst. 129, 452–471 (2014).
    Article  Google Scholar 

    44.
    Nuth, C., Schuler, T. V., Kohler, J., Altena, B. & Hagen, J. O. Estimating the long-term calving flux of Kronebreen, Svalbard, from geodetic elevation changes and mass-balance modeling. J. Glaciol. 58, 119–133 (2012).
    ADS  Article  Google Scholar 

    45.
    Pethon, P. & Nyström, B. O. Aschehougs store fiskebok Norges fisker i farger. (Aschehoug, 2005).

    46.
    Kaiser, J. F. On a simple algorithm to calculate the energy of a signal. Proc. IEEE Int. Conf. Acoust. 2, 381–384 (1990).
    Google Scholar 

    47.
    Wood, S. N. Generalized Additive Models: An Introduction with R (Chapman and Hall/CRC, Boca Raton, 2017).
    Google Scholar 

    48.
    R Core Team. R: A language and environment for statistical computing. (R Foundation for Statistical Computing, 2017). More

  • in

    Earliest fossils of giant-sized bony-toothed birds (Aves: Pelagornithidae) from the Eocene of Seymour Island, Antarctica

    1.
    Harrison, C. J. O. A bony-toothed bird (Odontopterygiformes) from the Palaeocene of England. Tert. Res. 7, 23–25 (1985).
    ADS  Google Scholar 
    2.
    Averianov, A. O., Panteleyev, O. R., Potapova, O. R. & Nessov, L. A. Bony-toothed birds (Aves: Pelecaniformes: Odontopterygia) of the late Paleocene and Eocene of the western margin of ancient Asia. Tr. Zool. Inst. 239, 3–12 (1991).
    Google Scholar 

    3.
    Boessenecker, R. W. & Smith, N. A. Latest Pacific Basin record of a bony-toothed bird (Aves, Pelagornithidae) from the Pliocene Purisima Formation of California, U.S.A.. J. Vertebr. Paleontol. 31, 652–657 (2011).
    Article  Google Scholar 

    4.
    Fitzgerald, E. M. G., Park, T. & Worthy, T. H. First giant bony-toothed bird (Pelagornithidae) from Australia. J. Vertebr. Paleontol. 32, 971–974 (2012).
    Article  Google Scholar 

    5.
    Louchart, A. et al. Structure and growth pattern of pseudoteeth in Pelagornis mauretanicus (Aves, Odontopterygiformes, Pelagornithidae). PLoS ONE https://doi.org/10.1371/journal.pone.0080372 (2013).
    Article  PubMed  PubMed Central  Google Scholar 

    6.
    Louchart, A. et al. Bony pseudoteeth of extinct pelagic birds (Aves, Odontopterygiformes) formed through a response of bone cells to tooth-specific epithelial signals under unique conditions. Sci. Rep. 8, 1–9 (2018).
    CAS  Article  Google Scholar 

    7.
    Olson, S. L. The fossil record of birds. In Avian Biology vol. Vlll (eds Famer, D. S. & King, J. R.) 79–252 (Academic Press, Cambridge, 1985).
    Google Scholar 

    8.
    Zusi, R. L. & Warheit, K. I. On the evolution of intraramal mandibular joints in pseudodontorns (Aves: Odontopterygia). In Papers in Avian Paleontology Honoring Pierce Brodkorb (ed. Campbell, K. E.) 351–360 (Natural History Museum of Los Angeles County, Los Angeles, 1992).
    Google Scholar 

    9.
    Cenizo, M., Hospitaleche, C. A. & Reguero, M. Diversity of pseudo-toothed birds (Pelagornithidae) from the Eocene of Antarctica. J. Paleontol. 89, 870–881 (2015).
    Article  Google Scholar 

    10.
    Rubilar-Rogers, D., Yury-Yáñez, R., Mayr, G., Gutstein, C. & Otero, R. A humerus of a giant late Eocene pseudo-toothed bird from Antarctica. J. Vertebr. Paleontol. 2, 182A (2011).
    Google Scholar 

    11.
    Dingle, R. V. & Lavelle, M. Late Cretaceous–Cenozoic climatic variations of the northern Antarctic Peninsula: new geochemical evidence and review. Palaeogeogr. Palaeoclimatol. Palaeoecol. 141, 215–232 (1998).
    Article  Google Scholar 

    12.
    Ivany, L. C. et al. Eocene climate record of a high southern latitude continental shelf: Seymour Island, Antarctica. Bull. Geol. Soc. Am. 120, 659–678 (2008).
    CAS  Article  Google Scholar 

    13.
    Montes, M., Nozal, F., Santillana, S., Marenssi, S. & Olivero, E. Mapa geológico de Isla Marambio (Seymour) Antártida; escala 1:20,000. Serie Cartográfica Geocientífica Antártica Geológico y Minero de Espana (Instituto Antártico Argentino, Villa Lynch, 2013).
    Google Scholar 

    14.
    Elliot, D. H. & Trautman, T. A. Lower Tertiary strata on Seymour Island, Antarctic Peninsula. In Antarctic Geoscience (ed. Craddock, C.) 287–297 (University of Winsconsin Press, Madison, 1982).
    Google Scholar 

    15.
    Marenssi, S. A., Net, L. I. & Santillana, S. N. Provenance, environmental and paleogeographic controls on sandstone composition in an incised-valley system: the Eocene La Meseta Formation, Seymour Island, Antarctica. Sediment. Geol. 150, 301–321 (2002).
    ADS  CAS  Article  Google Scholar 

    16.
    Sadler, P. M. Geometry and stratification of uppermost Cretaceous and Paleogene units on Seymour Island, northern Antarctic Peninsula. Geol. Soc. Am. Mem. 169, 303–320 (1988).
    Google Scholar 

    17.
    Marenssi, S. A., Santillana, S. N. & Rinaldi, C. A. Stratigraphy of the La Meseta Formation (Eocene), Marambio (Seymour) Island, Antarctica. Asoc. Paleontol. Argent. Publ. Espec. 5, 137–146 (1998).
    Google Scholar 

    18.
    Beamud, E., Montes, M. J., Santillana, S., Nozal, F. & Marenssi, S. A. Magnetostratigraphic dating of Paleogene sediments in the Seymour Island (Antarctic Peninsula): a preliminary chronostratigraphy. In AGU Fall Meeting Abstracts (2015).

    19.
    Montes, M. et al. Geología y geomorfología de la isla Marambio (Seymour). Serie Cartográfica Geocientífica Antártica; 1:20.000 (Instituto Geologico y Minero de España Instituto Antártico Argentino, Villa Lynch, 2019).
    Google Scholar 

    20.
    Douglas, P. M. J. et al. Pronounced zonal heterogeneity in Eocene southern high-latitude sea surface temperatures. Proc. Natl. Acad. Sci. U.S.A. 111, 6582–6587 (2014).
    ADS  CAS  PubMed  PubMed Central  Article  Google Scholar 

    21.
    Amenábar, C. R., Montes, M., Nozal, F. & Santillana, S. Dinoflagellate cysts of the La Meseta Formation (middle to late Eocene), Antarctic Peninsula: implications for biostratigraphy, palaeoceanography and palaeoenvironment. Geol. Mag. 157, 351–366 (2020).
    ADS  Article  CAS  Google Scholar 

    22.
    Acosta Hospitaleche, C., Jadwiszczak, P., Clarke, J. A. & Cenizo, M. The fossil record of birds from the James Ross Basin, West Antarctica. Adv. Polar Sci. 30, 251–273 (2019).
    Google Scholar 

    23.
    Tambussi, C. P. & Degrange, F. J. South American and Antarctic continental Cenozoic Birds: Paleobiogeographic Affinities and Disparities (Springer, Berlin, 2013).
    Google Scholar 

    24.
    Acosta Hospitaleche, C. & Jadwiszczak, P. Enigmatic morphological disparity in tarsometatarsi of giant penguins from the Eocene of Antarctica. Pol. Polar Res. 32, 175–180 (2011).
    Article  Google Scholar 

    25.
    Acosta Hospitaleche, C. New crania from Seymour Island (Antarctica) shed light on anatomy of Eocene penguins. Pol. Polar Res. 34, 397–412 (2013).
    Article  Google Scholar 

    26.
    Acosta Hospitaleche, C., Hagström, J., Reguero, M. & Mörs, T. Historical perspective of Otto Nordenskjöld’s Antarctic penguin fossil collection and Carl Wiman’s contribution. Polar Rec. (Gr. Brit) 53, 364–375 (2017).
    Article  Google Scholar 

    27.
    Tonni, E. P. & Cione, A. L. Una nueva colección de vertebrados del Terciaria inferior de la Isla Vicecomodoro Marambio (Seymour Island) Antártida. Obra Centen. del Mus. La Plata 5, 73–79 (1978).
    Google Scholar 

    28.
    Tonni, E. P. Un pseudodontornítido (Pelecaniformes, Odontopterygia) de gran tamaño, del Terciario temprano de Antártida. Ameghiniana 17, 273–276 (1980).
    Google Scholar 

    29.
    Bargo, M. S. & Reguero, M. A. Annotated catalogue of the fossil vertebrates from Antarctica housed in the Museo de La Plata, Argentina. I. Birds and land mammals from La Meseta Formation (Eocene-?Early Oligocene). Assoc. Paleontol. Argent. Publ. Espec. 5, 211–221 (1998).
    Google Scholar 

    30.
    Vizcaino, S. F., Reguero, M. A., Marenssi, S. A. & Santillana, S. N. New land mammal-bearing localities from the Eocene La Meseta Formation, Seymour Island, Antarctica. In The Antarctic Region: Geological Evolution and Processes (ed. Ricci, C. A.) 997–1000 (Terra Antarctica Publication, Siena, 1997).
    Google Scholar 

    31.
    Marenssi, S. A., Reguero, M. A., Santillana, S. N. & Vizcaino, S. F. Eocene land mammals from Seymour Island, Antarctica: palaeobiogeographical implications. Antarct. Sci. 6, 3–15 (1994).
    ADS  Article  Google Scholar 

    32.
    de la Fuente, M. S., Santillana, S. N. & Marenssi, S. A. An Eocene leatherback turtle (Cryptodira: Dermochelyidae) from Seymour Island, Antarctica. Stud. Geol. Salmant. 31, 21–34 (1995).
    Google Scholar 

    33.
    Cione, A. L., Reguero, M. A. & Acosta Hospitaleche, C. Did the continent and sea have different temperatures in the northern Antarctic Peninsula during the middle Eocene?. Rev. la Asoc. Geol. Argent. 62, 586–596 (2007).
    Google Scholar 

    34.
    Acosta Hospitaleche, C. & Reguero, M. Additional Pelagornithidae remains from Seymour Island, Antarctica. J. South Am. Earth Sci. 99, 102504 (2020).
    Article  Google Scholar 

    35.
    Chávez Hoffmeister, M. & Oyanadel Urbina, P. Reply to C. Acosta Hospitaleche and M. Reguero (2020) additional Pelagornithidae remains from Seymour Island, Antarctica. J. South Am. Earth Sci. https://doi.org/10.1016/j.jsames.2020.102643 (2020).
    Article  Google Scholar 

    36.
    Stilwell, J. D., Jones, C. M., Levy, R. H. & Harwood, D. M. First fossil bird from East Antarctica. Antarct. J. U.S. 33, 12–16 (1998).
    Google Scholar 

    37.
    Jones, C. M. The first record of a fossil bird from East Antarctica. Am. Geophys. Union Antarct. Res. Ser. 76, 359–364 (2000).
    Article  Google Scholar 

    38.
    Stilwell, J. D. Eocene mollusca (Bivalvia, Gastropoda and Scaphopoda) from McMurdo sound: systematics and paleoecologic significance. Am. Geophys. Union Antarct. Res. Ser. 76, 261–320 (2000).
    Article  Google Scholar 

    39.
    Askin, R. A. Spores and pollen from the McMurdo sound erratics, Antarctica. Am. Geophys. Union Antarct. Res. Ser. 76, 161–181 (2000).
    Article  Google Scholar 

    40.
    Levy, R. H. & Harwood, D. M. Tertiary marine palynomorphs from the McMurdo sound, East Antarctica. Am. Geophys. Union Antarct. Res. Ser. 76, 183–242 (2000).
    Article  Google Scholar 

    41.
    Harwood, D. M. & Bohaty, S. M. Marine diatom assemblages from Eocene and younger erratics, McMurdo sound, Antarctica. Am. Geophys. Union Antarct. Res. Ser. 76, 73–98 (2000).
    Article  Google Scholar 

    42.
    Bohaty, S. M. & Harwood, D. M. Ebridian and silicoflagellate biostratigraphy from Eocene McMurdo erratics and the southern ocean. Am. Geophys. Union Antarct. Res. Ser. 76, 99–159 (2000).
    Article  Google Scholar 

    43.
    Case, J., Reguero, M., Martin, J. & Cordes-Person, A. A cursorial bird from the Maastrictian of Antarctica. J. Vertebr. Paleontol. 3(Supplem), 48A-48A (2006).
    Google Scholar 

    44.
    Tambussi, C. & Acosta Hospitaleche, C. Antarctic birds (Neornithes) during the Cretaceous-Eocene times. Rev. Asoc. Geol. Argent. 62, 604–617 (2007).
    Google Scholar 

    45.
    Cenizo, M. M. Review of the putative Phorusrhacidae from the Cretaceous and Paleogene of Antarctica: new records of ratites and pelagornithid birds. Pol. Polar Res. 33, 239–258 (2012).
    Article  Google Scholar 

    46.
    Cione, A. L., de van Mercedes Azpelicueta, M. & Bellwood, D. R. An oplegnathid fish from the Eocene of Antarctica. Palaeontology 37, 931–940 (1994).
    Google Scholar 

    47.
    Reguero, M. A. & Gasparini, Z. Late Cretaceous–Early Tertiary marine and terrestrial vertebrates from James Ross Basin, Antarctic Peninsula: a review. In Antarct. Penins. Tierra del Fuego Proceedings of the “Otto Nordensjold’s Antarctic Expedition of 1901–1903 and Swedish Scientists in Patagonia: A Symposium”. 55–76 (2006).

    48.
    Bourdon, E., Amaghzaz, M. & Bouya, B. Pseudotoothed birds (Aves, Odontopterygiformes) from the Early Tertiary of Morocco. Am. Museum Novit. 3704, 1–71 (2010).
    Article  Google Scholar 

    49.
    Mayr, G., Goedert, J. L. & McLeod, S. A. Partial skeleton of a bony-toothed bird from the late Oligocene/early Miocene of Oregon (USA) and the systematics of Neogene Pelagornithidae. J. Paleontol. 87, 922–929 (2013).
    Article  Google Scholar 

    50.
    Harrison, C. J. O. & Walker, C. A. A review of the bony-toothed birds (Odontopterygiformes): with descriptions of some new species. Tert. Res. Spec. Pap. 2, 1–72 (1976).
    Google Scholar 

    51.
    Stidham, T. A. New skull material of Osteodontornis orri (Aves: Pelagornithidae) from the Miocene of California. PaleoBios 24, 7–12 (2004).
    Google Scholar 

    52.
    Mayr, G. & Rubilar-Rogers, D. Osteology of a new giant bony-toothed bird from the Miocene of Chile, with a revision of the taxonomy of Neogene Pelagornithidae. J. Vertebr. Paleontol. 30, 1313–1330 (2010).
    Article  Google Scholar 

    53.
    Mayr, G., De Pietri, V. L., Love, L., Mannering, A. & Scofield, R. P. Oldest, smallest and phylogenetically most basal pelagornithid, from the early Paleocene of New Zealand, sheds light on the evolutionary history of the largest flying birds. Pap. Palaeontol. 1–17 (2019). https://doi.org/10.1002/spp2.1284.

    54.
    Ksepka, D. T. Flight performance of the largest volant bird. Proc. Natl. Acad. Sci. U.S.A. 111, 10624–10629 (2014).
    ADS  CAS  PubMed  PubMed Central  Article  Google Scholar 

    55.
    Acosta Hospitaleche, C., Márquez, G., Pérez, L. M., Rosato, V. & Cione, A. L. Lichen bioerosion on fossil vertebrates from the Cenozoic of Patagonia and Antarctica. Ichnos 18, 1–8 (2011).
    Article  Google Scholar 

    56.
    Mikuláš, R. Modern and fossil traces in terrestrial lithic substrates. Ichnos 8, 177–184 (2001).
    Article  Google Scholar 

    57.
    Mourer-Chauviré, C. & Geraads, D. The Struthionidae and Pelagornithidae (Aves: Struthioniformes, Odontopterygiformes) from the late Pliocene of Ahl Al Oughlam, Morocco. Oryctos 7, 169–194 (2008).
    Google Scholar 

    58.
    Owen, R. Description of the skull of a dentigerous bird (Odontopteryx toliapicus) from the London Clay of Sheppey. Q. J. Geol. Soc. 29, 511–521 (1873).
    Article  Google Scholar 

    59.
    Howard, H. A gigantic ‘toothed’ marine bird from the Miocene of California. Sta. Barbar. Museum Nat. Hist. Dep. Geol. Bull. 1, 1–23 (1957).
    Google Scholar 

    60.
    Mayr, G. & Zvonok, E. Middle Eocene Pelagornithidae and Gaviiformes (Aves) from the Ukrainian Paratethys. Palaeontology 54, 1347–1359 (2011).
    Article  Google Scholar 

    61.
    Hara, U., Mörs, T., Hagström, J. & Reguero, M. A. Eocene bryozoan assemblages from the La Meseta Formation of Seymour Island, Antarctica. Geol. Q. 62, 705–728 (2018).
    Google Scholar 

    62.
    Gelfo, J. N., Goin, F. J., Bauza, N. & Reguero, M. A. The fossil record of Antarctic land mammals : commented review and hypotheses for future research. Adv. Polar Sci. 30, 274–292 (2019).
    Google Scholar 

    63.
    Acosta Hospitaleche, C. & Gelfo, J. N. Procellariiform remains and a new species from the latest Eocene of Antarctica. Hist. Biol. 29, 755–769 (2017).
    Article  Google Scholar 

    64.
    Baumel, J. J. & Witmer, L. M. Osteologia. In Handbook of Avian Anatomy (eds Baumel, J. J. et al.) (Publications of the Nuttall Ornithological Club, Cambridge, 1993).
    Google Scholar  More

  • in

    Invasion front dynamics in disordered environments

    Effective medium approximation
    For a linearized version of Fisher , we first obtain the effect of disorder on invasion velocity using Effective Medium Approximation (EMA). Using the EMA approach, we can replace the spatially irregular diffusion constant with a uniform one in which the effective diffusivity is everywhere equal to (D_{e}) and can replace (D_0(1+xi f(x))) in Eq. (2)44. To obtain (D_{e}), one needs to discretize Eq. (2) using a finite-difference method, which leads to the following equation for the population density39:

    $$begin{aligned} frac{partial C_i(t)}{partial t}=sum _{jin {i}}W_{ij}[C_j(t)-C_i(t)]+RC_i(t) ;, end{aligned}$$
    (4)

    where j belongs to nearest neighbors of i and (W_{ij}=D_{ij}/delta ^2) stands for the density flow rate between units i and j with distance of (delta). Due to spatially irregular diffusion constant we have (W_{ij}=W_0(1+xi f_{ij})). Following44, one has

    $$begin{aligned} D_e=bigg ( int _{0}^{infty } frac{g(w) dw}{w} bigg )^{-1} end{aligned}$$
    (5)

    where g(w) is probability density function for (W_{ij}). Applying this approach to our case leads to

    $$begin{aligned} D_{e}=D_0(1-|xi |^2/3) end{aligned}$$
    (6)

    where (|xi |) stands for dimensionless magnitude of (xi) ((xi ^2) has a physical dimension of length, meter).
    Perturbation analysis for invasion front fluctuations
    The first step towards the study of dynamics of a propagating front is linearizing (3) by neglecting the (C^2) term in an environment with effect diffusion constant, (D_e), as:

    $$begin{aligned} frac{partial C}{partial t}=RC+frac{partial }{partial x} big ((D_e + xi f(x)) frac{partial }{partial x} Cbig ) end{aligned}$$
    (7)

    This is based on the fact that near the front, the cell density is (C ll 1). In other words, focusing on the dynamics of the front position, automatically grants us the possibility of linearizing (3).
    The construction of the solution can be proceeded according to a valuable insight given in the classic paper43, where the particle density is written as follows

    $$begin{aligned} C(zeta ,t) approx C_0(zeta +eta (t),t)+ delta C_1(zeta ,t) end{aligned}$$
    (8)

    where C is written in the comoving frame and (zeta = x-vt). It is assumed that (delta C_1 ll 1) and in the same order as the perturbing function. So that terms containing f(x) and (delta C_1) can be neglected. Furthermore, (C_0) is assumed to satisfy the linearized Eq. (3) with (xi =0), i.e.

    $$begin{aligned} frac{partial C_0(zeta ,t)}{partial t}-hat{Gamma } C_0(zeta )=,& {} frac{partial C_0(zeta ,t)}{partial t} nonumber \&-bigg (D_e frac{d^2}{dzeta ^2} + vfrac{d}{dzeta } + Rbigg )C_0(zeta ,t) = 0 end{aligned}$$
    (9)

    Which has the following solution

    $$begin{aligned} C_0(zeta ,t) = frac{1}{sqrt{4pi D_e t}}e^{-frac{1}{2}sqrt{frac{R}{D_e}}zeta }e^{-frac{zeta ^2}{4D_e t}} end{aligned}$$
    (10)

    The first term in (8) describes the effects of the perturbing function f(x) on the position of the propagating front, while the second term shows the change in the shape of the front. This approach has also been employed and well explained in a recent paper17. As shown in17,43, to determine the effective diffusion coefficient for the fluctuating front, it is sufficient to solve (3) using (8) for (eta (t)). Note also that since we are interested in the dynamics of the system in long times ((t gg frac{1}{R})), (v_e) can be assumed to be equal to (2sqrt{R D_e})45. Plugging (8) in Eq. (9) expressed in comoving coordinates and considering (xi =bar{xi }/D_e) yields

    $$begin{aligned} frac{partial delta C_1}{partial t} – hat{Gamma }delta C_1 + dot{eta (t)} C_0(zeta ,t) = bar{xi } bigg (f(zeta ) C’_0(zeta ,t)bigg )’ end{aligned}$$
    (11)

    Noting that the operator (hat{Gamma }) is not self-adjoint (The adjoint of (hat{Gamma }) is: (hat{Gamma ^dagger }=D_e dfrac{d^2}{dzeta ^2} – v_e dfrac{d}{dzeta } + R)) and following43, we multiply Eq. (11) from the left in the eigenfunction of (hat{Gamma ^dagger }) with 0 eigenvalue (which is (e^{sqrt{frac{R}{D_e}}zeta })) and integrate. Thus,

    $$begin{aligned} {,} & int _{-infty }^{infty } e^{sqrt{frac{R}{D_e}}zeta }frac{partial delta C_1(zeta ,t)}{partial t} dzeta + dot{eta (t)}int _{-infty }^{infty }e^{sqrt{frac{R}{D_e}}zeta }C’_0(zeta ,t) dzeta nonumber \&quad = bar{xi } int _{-infty }^{infty } e^{sqrt{frac{R}{D_e}}zeta }bigg (f(zeta ) C’_0(zeta ,t)bigg )’dzeta end{aligned}$$
    (12)

    Which yields

    $$begin{aligned} dot{eta }(t) =bar{xi } dfrac{int _{-infty }^{infty } e^{sqrt{frac{R}{D_e}}zeta }bigg (f(zeta ) C’_0(zeta ,t)bigg )’ dzeta }{int _{-infty }^{infty }e^{sqrt{frac{R}{D_e}}zeta }C’_0(zeta ,t) dzeta } end{aligned}$$
    (13)

    Which can further be simplified into

    $$begin{aligned} dot{eta }(t)=,& {} bar{xi }dfrac{int _{-infty }^{infty } e^{sqrt{frac{R}{D_e}}zeta }f(zeta ) C’_0(zeta ,t) dzeta }{int _{-infty }^{infty }e^{sqrt{frac{R}{D_e}}zeta }C_0(zeta ,t) dzeta } nonumber \=,& {} bar{xi } e^{-frac{R t}{4}}int _{-infty }^{infty } e^{sqrt{frac{R}{D_e}}zeta }f(zeta ) C’_0(zeta ,t) dzeta end{aligned}$$
    (14)

    Or equivalently,

    $$begin{aligned} eta (t) =bar{xi } int _{0}^{t} dtau e^{-frac{Rtau }{4}} int _{-infty }^{infty } dzeta e^{sqrt{frac{R}{D_e}}zeta }f(zeta ) C’_0(zeta ,tau ) end{aligned}$$
    (15)

    According to17, the effective diffusion would be given by

    $$begin{aligned} D_{C} = dfrac{langle eta ^2(t) rangle }{2t} end{aligned}$$
    (16)

    Or

    $$begin{aligned} D_{C}=,& {} frac{bar{xi }^2}{2t}int _{0}^{t}d{T_1}int _{0}^{t}d{T_2}int _{-infty }^{infty } C’_0(zeta ,T_1)C’_0(zeta ,T_2) nonumber \&times e^{-frac{R T_1}{4}}e^{-frac{R T_2}{4}}e^{2sqrt{frac{R}{D_e}}zeta } dzeta end{aligned}$$
    (17)

    where we have performed an ensemble average over (eta ^2(t)) using the fact that (langle f(x)f(y) rangle = delta (x-y)). A numerical calculation of (16) can be readily computed using any mathematical software. However, valuable insight can still be obtained from (17), if we use dimensionless parameters (tau _i=frac{T_i}{t}) and (sigma =sqrt{frac{R}{D_0}}zeta). In other words

    $$begin{aligned} D_{C}=,& {} bar{xi }^2 dfrac{sqrt{R}}{32pi D^{3/2}_0}int _{0}^{1}dtau _1int _{0}^{1}dtau _2int _{-infty }^{infty }dsigma nonumber \&times dfrac{left( 1+dfrac{sigma }{Rttau _1}right) left( 1+dfrac{sigma }{Rttau _2}right) }{sqrt{tau _1tau _2}}e^{-frac{sigma ^2}{4Rttau _1}}e^{-frac{sigma ^2}{4Rttau _2}}e^{sigma }e^{-R tfrac{(tau _1+tau _2)}{4}} end{aligned}$$
    (18)

    Equation (18) gives the effective diffusion coefficient for the stochastic behavior of the front. For a diffusive behavior, we would expect this effective diffusion coefficient to tend to a constant at large times. At large times, we can approximate the integral as follows,

    $$begin{aligned} D_{C} approx bar{xi }^2 dfrac{sqrt{R}}{32pi D^{3/2}_e}int _{0}^{1}dtau _1int _{0}^{1}dtau _2int _{-infty }^{infty }dsigma dfrac{1}{sqrt{tau _1tau _2}}e^{-frac{sigma ^2}{4Rttau _1}} e^{-frac{sigma ^2}{4Rttau _2}}e^{sigma }e^{-R tfrac{(tau _1+tau _2)}{4}} end{aligned}$$
    (19)

    Luckily, Eq. (19) can be evaluated exactly to yield

    $$begin{aligned} D_{C}&approx bar{xi }^2 dfrac{sqrt{R}}{32pi D^{3/2}_e} nonumber \&quad frac{2 pi (2 R t-1) text {Erf}left( frac{sqrt{R t}}{2}right) -2 pi e^{2 R t} text {Erf}left( frac{3 sqrt{R t}}{2}right) +2 pi e^{2 R t} text {Erf}left( sqrt{2} sqrt{R t}right) +8 sqrt{pi } e^{-frac{1}{4} (R t)} sqrt{R t}-4 sqrt{2 pi } sqrt{R t}}{R t} end{aligned}$$
    (20)

    Where Erf(x) is the error function. As (trightarrow infty) this gives the following simple relation for the diffusion constant for the wave front

    $$begin{aligned} D_{C}(trightarrow infty ) = bar{xi }^2 dfrac{sqrt{R}}{8 D^{3/2}_e} end{aligned}$$
    (21)

    Substituting (xi =bar{xi }/D_e) and (D_e=D_0(1-|xi |^2/3)), we will get the following beautiful equation for the effective diffusion constant of the front at large times:

    $$begin{aligned} D_{C}(trightarrow infty ) =dfrac{1}{8} xi ^2 sqrt{R D_0(1- |xi |^2/3)}. end{aligned}$$
    (22) More

  • in

    The impact of social ties and SARS memory on the public awareness of 2019 novel coronavirus (SARS-CoV-2) outbreak

    The early warnings of the outbreak
    As early as Dec 31st, 2019, when Wuhan Municipal Health Commission first informed the public about the emerging pneumonia cases21, most of the cities (326 out of 346) exhibited at least some awareness of the emerging SARS-CoV-2 outbreak (Fig. 2b). However, awareness then decreased until Jan 19th, 2020, one day before the Chinese Centre for Disease Control and Prevention confirmed human-to-human transmissions of the novel coronavirus9. Since Jan 20th, 2020, overall awareness increased by a magnitude of at least five, demonstrating significant awareness across all cities (Fig. 2b). Awareness remained low as the epidemic spread, falling close to its lowest point on the starting day of Chunyun (Jan 10th, 2020). Considering cities that showed initial novel coronavirus awareness levels at least 1.5 times that of the search term “common cold”, we found a total of 166 alert cities as early as Dec 31st, 2019 (48 cities at a tighter threshold of (C = 3.0) times, illustrated in Fig. 2a). However, awareness decreased significantly during Chunyun.
    Figure 2

    Public awareness over time. (a) The frequency distributions of cities that exhibit the first significant signal of awareness over time. The number of cities for which searches for the combined term “Wuhan” and “pneumonia” exceed (user2{ C} = 3) times the search term “common cold” is reported every day. (b) Public awareness on the topic of “pneumonia” over time. All 346 cities exhibit at least some searches of the term “pneumonia” during the initial outbreak period. Of these, 326 cities recorded searches about it as early as Dec 31st, 2019. Cities are divided into two groups according to whether or not they had reported SARS cases in 2003–04. The mean values of awareness magnitude were computed on a daily basis for two groups of cities respectively. Accordingly, a paired t-test was performed on those two time-series, and we found the cities that had reported SARS cases had greater of awareness (t-statistic: 3.56; degrees of freedom: 23; p  More

  • in

    Effect of bentonite as a soil amendment on field water-holding capacity, and millet photosynthesis and grain quality

    1.
    Waggoner, P. E. Agriculture and a climate changed by more carbon dioxide. In Changing Climate: Report of the Carbon Dioxide Assessment Committee (ed. National Research Council (NRC)) 383–418 (National Academy Press, Washington, DC, 1983). https://doi.org/10.1038/s41598-020-75350-9.
    Google Scholar 
    2.
    Shinozaki, K., Yamaguchi-Shinozaki, K. & Seki, M. Regulatory network of gene expression in the drought and cold stress responses. J. Curr. Opin. Plant Biol. 6, 410–417 (2003).
    CAS  Google Scholar 

    3.
    Deng, X. et al. Improving agricultural water use efficiency in arid and semiarid areas of China. J. Agric. Water Manag. 80, 23–40 (2006).
    Google Scholar 

    4.
    Hussain, M. et al. Improving drought tolerance by exogenous application of glycinebetaine and salicylic acid in sunflower. J. Agron. Crop Sci. 194, 193–199 (2008).
    CAS  Google Scholar 

    5.
    Wang, W., Vinocur, B. & Altman, A. Plant responses to drought, salinity and extreme temperatures: Towards genetic engineering for stress tolerance. J. Planta. 218, 1–14 (2003).
    CAS  Google Scholar 

    6.
    Bartels, D. & Sunkar, R. Drought and salt tolerance in plants. J. Crit. Rev. Plant Sci. 24, 23–58 (2005).
    CAS  Google Scholar 

    7.
    Rost, S. et al. Global potential to increase crop production through water management in rainfed agriculture. J. Environ. Res. Lett. 4, 1–9 (2009).
    Google Scholar 

    8.
    Miflin, B. Crop improvement in the 21st century. J Exp Bot. 51, 1–8 (2000).
    CAS  PubMed  Google Scholar 

    9.
    Islam, M. R. et al. Impact of water-saving superabsorbent polymer on oat (Avena spp.) yield and quality in an arid sandy soil. J. Sci. Res. Essays. 6, 720–728 (2011).
    CAS  Google Scholar 

    10.
    Lu, H. et al. Earliest domestication of common millet (Panicum miliaceum) in East Asia extended to 10000 years ago. J. Proc. Natl. Acad. Sci. 106, 7367–7372 (2009).
    ADS  CAS  Google Scholar 

    11.
    Anonymous. Plant area of millet in China in 2017. Available from: https://data.chinabaogao.com/nonglinmuyu/2019/0R43PA2019.html (2019).

    12.
    Tolk, J., Howell, T. & Evett, S. Effect of mulch, irrigation, and soil type on water use and yield of maize. J. Soil Tilll Res. 50, 137–147 (1999).
    Google Scholar 

    13.
    Panda, R., Behera, S. & Kashyap, P. Effective management of irrigation water for maize under stressed conditions. J. Agric. Water Manag. 66, 181–203 (2004).
    Google Scholar 

    14.
    Cattivelli, L. et al. Drought tolerance improvement in crop plants: An integrated view from breeding to genomics. J. Field Crop Res. 105, 1–14 (2008).
    Google Scholar 

    15.
    Chaves, M. M. et al. How plants cope with water stress in the field? Photosynthesis and growth. J. Ann. Bot.-Lond. 89, 907–916 (2002).
    CAS  Google Scholar 

    16.
    Xu, C. et al. Effect of biochar amendment on yield and photosynthesis of peanut on two types of soils. J. Environ. Sci. Pollut. R. 22, 6112–6125 (2015).
    CAS  Google Scholar 

    17.
    Shah, N. & Paulsen, G. Interaction of drought and high temperature on photosynthesis and grain-filling of wheat. J. Plant Soil. 257, 219–226 (2003).
    CAS  Google Scholar 

    18.
    Soda, W. et al. Co-composting of acid waste bentonites and their effects on soil properties and crop biomass. J. Environ. Qual. 35, 2293–2301 (2006).
    CAS  PubMed  Google Scholar 

    19.
    Guiwei, Q., De Varennes, A. & Cunha-Queda, C. Remediation of a mine soil with insoluble polyacrylate polymers enhances soil quality and plant growth. J. Soil Use Manag. 24, 350–356 (2008).
    Google Scholar 

    20.
    Hüttermann, A., Orikiriza, L. J. B. & Agaba, H. Application of superabsorbent polymers for improving the ecological chemistry of degraded or polluted lands. J. Clean Soil. Air. Water. 37, 517–526 (2009).
    Google Scholar 

    21.
    Narjary, B. et al. Water availability in different soils in relation to hydrogel application. J. Geoderma 187, 94–101 (2012).
    ADS  Google Scholar 

    22.
    Arbona, V. et al. Hydrogel substrate amendment alleviates drought effects on young citrus plants. J. Plant Soil. 270, 73–82 (2005).
    CAS  Google Scholar 

    23.
    Wang, Y. et al. Influences of Millet–Peanut intercropping on photosynthetic characteristics and yield of Millet. J. Agric. Sci. Technol. 22, 153–165 (2020).
    Google Scholar 

    24.
    Gao, H. et al. Diurnal change of photosynthetic characteristics and response tonight intensity of seven ornamental grasses. J. Acta Prataculturae Sinica 19, 87–93 (2010).
    Google Scholar 

    25.
    Yordanov, I., Velikova, V. & Tsonev, T. Plant responses to drought, acclimation, and stress tolerance. J. Photosynthetica 38, 171–186 (2000).
    CAS  Google Scholar 

    26.
    Yangwei, P. & Yan, S. Resources characteristics and market situation of bentonites at home and Abroad. J. Metal Mine. 95–99, 105 (2012).
    Google Scholar 

    27.
    Fraenkel-Conrat, H., Singer, B. & Tsugita, A. Purification of viral RNA by means of bentonite. J. Virol. 14, 54–58 (1961).
    CAS  Google Scholar 

    28.
    Lopez-Fernandez M, et al. Microbial community changes induced by uranyl nitrate in bentonite clay microcosms. In 16th International Clay Conference (ICC). Granada, Spain (2017).

    29.
    Bentahar, S. et al. Removal of a cationic dye from aqueous solution by natural clay. J. Groundw. Sustain. Devel. 6, 255–262 (2018).
    Google Scholar 

    30.
    De Castro, M. L. F. A. et al. Adsorption of Methylene Blue dye and Cu(II) ions on EDTA-modified bentonite: Isotherm, kinetic and thermodynamic studies. J. Sustain. Environ. Res. 28, 197–205 (2018).
    Google Scholar 

    31.
    Mi, J. et al. Effect of bentonite amendment on soil hydraulic parameters and millet crop performance in a semi-arid region. J. Field Crop Res. 212, 107–114 (2017).
    Google Scholar 

    32.
    Hall, D. J. M. et al. Claying and deep ripping can increase crop yields and profits on water repellent sands with marginal fertility in southern Western Australia. J. Aust. J. Soil Res. 48, 178–187 (2010).
    Google Scholar 

    33.
    Shi, Y., Chen, X. & Shen, S. Mechanisms of organic cementing soil aggregate formation and its theoretical models. J. Chin. J. Appl. Ecol. 13, 1495–1498 (2002).
    Google Scholar 

    34.
    Mi, J. et al. Effect of sandy soil amendment on Dry-farmland water-conserving characteristic and millet seeding growth. J. Irrigat. Drain. 23, 92–96 (2015).
    Google Scholar 

    35.
    Mi, J. et al. Effects of sandy soil amendment on soil moisture and growth status of millet with rainfed sandy soil in a semi-arid region. J. Adv. Mater. Res. 1092–1093, 1234–1242 (2015).
    Google Scholar 

    36.
    Jiang, P. et al. Principles and experimental verification of capillary suction method for fast measurement of field capacity. J. Trans. CSAE. 22, 1–5 (2006).
    CAS  Google Scholar 

    37.
    Andrenelli, M. et al. Field application of pelletized biochar: Short term effect on the hydrological properties of a silty clay loam soil. J. Agric. Water Manag. 163, 190–196 (2016).
    Google Scholar 

    38.
    Jones, J. Jr. Kjeldahl Method for Nitrogen Determination (Micro-Macro Publishing, Athens, 1991).
    Google Scholar 

    39.
    Nielsen, S. S. Food Analysis (Aspen Publishers Inc, New York, 1998).
    Google Scholar 

    40.
    Ganzler, K., Salgo, A. & Valkó, K. Microwave extraction: A novel sample preparation method for chromatography. J. Chromatogr. A 371, 299–306 (1986).
    CAS  Google Scholar 

    41.
    Min D B, Steenson D, Crude fat analysis. In Food Analysis. Vol. 2. New York: Kluwer Academic/Plenum Publishers. 113–131 (1998).

    42.
    Möller, J. Comparing Methods for Fibre Determination in Food and Feed, Vol. 1026712 (The Association of American Feed Control Officials, West Lafayette, 2014).
    Google Scholar 

    43.
    Bakass, M., Mokhlisse, A. & Lallemant, M. Absorption and desorption of liquid water by a superabsorbent polyelectrolyte: Role of polymer on the capacity for absorption of a ground. J Appl Polym. Sci. 82, 1541–1548 (2001).
    CAS  Google Scholar 

    44.
    Yu, J. et al. Superabsorbents and semiarid soil properties affecting water absorption. J. Soil. Sci. Soc. Am. J. 75, 2305–2313 (2011).
    ADS  CAS  Google Scholar 

    45.
    Sun, Z. et al. Effect of ion-type and concentration on water-retention capacity of bentonite used in geosynthetic clay liner. J. Chin. Ceram. Soc. 38, 1826–1831 (2010).
    Google Scholar 

    46.
    Suzuki, S. et al. Improvement in water-holding capacity and structural stability of a sandy soil in Northeast Thailand. J. Arid Land Res. Manag. 21, 37–49 (2007).
    Google Scholar 

    47.
    Betti, G. et al. Size of subsoil clods affects soil–water availability in sand–clay mixtures. J. Soil Res. 54, 276–290 (2016).
    Google Scholar 

    48.
    Al-Omran, A. et al. Impact of natural deposits of Saudi Arabia on selected physical properties of calcareous sandy soil. J. Dirasa Agric Sci. 29, 285–294 (2002).
    Google Scholar 

    49.
    Tan, G. et al. Effect of super absorbent resin on the rate of maize emergence and soil moisture. J. Jilin Agric. Sci. 30, 26–27 (2004).
    Google Scholar 

    50.
    Zhou, L. et al. Effect of bentonite-humic acid application on the improvement of soil structure and maize yield in a sandy soil of a semi-arid region. J. Geoderma. 338, 269–280 (2019).
    ADS  CAS  Google Scholar 

    51.
    Fang, S. et al. Synthesis of chitosan derivative graft acrylic acid superabsorbent polymers and its application as water retaining agent. J. Int. J. Biol. Macromol. 115, 754–761 (2018).
    CAS  Google Scholar 

    52.
    Zhang, X. et al. Dry matter, harvest index, grain yield and water use efficiency as affected by water supply in winter wheat. J. Irrigation Sci. 27, 1–10 (2008).
    Google Scholar 

    53.
    Giri, G. S. & Schillinger, W. F. Seed priming winter wheat for germination, emergence, and yield. J. Crop Sci. 43, 2135–2141 (2003).
    Google Scholar 

    54.
    Jamnická, G. et al. The soil hydrogel improved photosynthetic performance of beech seedlings treated under drought. J. Plant Soil Environ. 59, 446–451 (2013).
    Google Scholar 

    55.
    Islam, M. R. et al. A lysimeter study of nitrate leaching, optimum fertilisation rate and growth responses of corn (Zea mays L.) following soil amendment with water-saving super-absorbent polymer. J. Sci/ Food Agric. 91, 1990–1997 (2011).
    CAS  Google Scholar 

    56.
    Tahir, S. & Marschner, P. Clay amendment to sandy soil—Effect of clay concentration and ped size on nutrient dynamics after residue addition. J. Soils Sediments 16, 2072–2080 (2016).
    CAS  Google Scholar 

    57.
    Croker, J. et al. Effects of recycled bentonite addition on soil properties, plant growth and nutrient uptake in a tropical sandy soil. J. Plant Soil. 267, 155–163 (2004).
    CAS  Google Scholar 

    58.
    Brix, H. The effect of water stress on the rates of photosynthesis and respiration in tomato plants and loblolly pine seedlings. J. Physiol. Plantarum. 15, 10–20 (1962).
    Google Scholar 

    59.
    Wang, L. et al. Progress in researches on effect of iron promoting accumulation of soil organic carbon. J. Acta Pedologica Sinica 55, 1041–1050 (2018).
    Google Scholar 

    60.
    Taylor, J. R. N. & Duodu, K. G. Sorghum and millets: Grain-quality characteristics and management of quality requirements. In Cereal Grains (2nd edn) (eds Batey, I. & Miskelly, D.) 317–351 (Woodhead Publishing, Wrigley, Colin, 2017).
    Google Scholar 

    61.
    Abbas, M. et al. Effect of some soil amendments on yield and quality traits of sugar beet (Beta vulgaris L.) under water stress in sandy soil. J. Egypt. J. Agron. 40, 75–88 (2018).
    Google Scholar 

    62.
    Leila, K., Hassan, F. & Pooran, G. Effects of different irrigation and superabsorbent levels on physio-morphological traits and forage yield of millet (Pennisetum americanum L.). J. Am. Euras. J. Agric. Environ. Sci. 13, 1043–1049 (2013).
    Google Scholar 

    63.
    Li, X. et al. Effects of super-absorbent polymers on a soil–wheat (Triticum aestivum L.) system in the field. J. Appl Soil Ecol. 73, 58–63 (2014).
    ADS  Google Scholar 

    64.
    Sojka, R. et al. Polyacrylamide in agriculture and environmental land management. J. Adv Agron. 92, 75–162 (2007).
    CAS  Google Scholar 

    65.
    Wang, A., Li, F. & Yang, S. Effect of polyacrylamide application on runoff, erosion, and soil nutrient loss under simulated rainfall. J. Pedosphere. 21, 628–638 (2011).
    CAS  Google Scholar  More

  • in

    Host genetic variation explains reduced protection of commercial vaccines against Piscirickettsia salmonis in Atlantic salmon

    Fish and vaccines
    Two pedigree populations of Atlantic salmon (Salmo salar) called Fanad and Lochy were used in this study18 (Table 1). The two populations were managed separately and had different origins. Fish were provided in 2016 by the salmon fish farming company Salmones Camanchaca and pit tagged in April 2016 at an average weight of 26.4 ± 3.9 g and 30.2 ± 4.2 g, for populations Fanad and Lochy, respectively. During the freshwater growth period, salmon were immunized twice using commercial vaccines, following the strict Salmones Camanchaca protocols. First, fish were vaccinated by intraperitoneal (IP) injection with a pentavalent vaccine against P. salmonis, Vibrio ordalii, A. salmonicida, IPNV (infectious pancreatic necrosis virus) and ISAV (infectious salmon anemia virus). Second, fish were immunized by IP injection against P. salmonis using a monovalent live attenuated vaccine at the same time as the first vaccination. Since 2016, this double vaccination strategy has been a common practice in the Chilean salmon industry17. Fish were transferred as smolts to the Aquadvice experimental station in Puerto Montt, Chile. Unvaccinated fish were injected with PBS (phosphate-buffered saline) and used as control (Table 1). Prior to transferring the fish, a health check by RT-PCR was performed to verify that the fish were free of viral (ISAV and IPNV) and bacterial pathogens (Vibrio sp., Flavobacterium sp., P. salmonis, and Renibacterium salmoninarum). At the experimental station, all fish underwent a 15 days acclimatization period in seawater (salinity of 32% and a temperature of 15 ± 1 °C). Fish were fed daily ad libitum with a commercial diet.
    Calculation of Piscirickettsia salmonis LD50
    The median lethal dose (LD50) of P. salmonis (EM-90 type) was determined as previously described18. Briefly, animals from both populations were distributed in eight tanks of 350 L (n = 60 fish per tank). The LD50 was calculated in fish infected by IP injection with 200 μL of a P. salmonis suspension. Three dilutions were assessed from stock with concentrations of 1 × 106.63 TCID/mL (TCID = median tissue culture infective dose): 1 × 10–3 TCID/mL, 1 × 10–4 TCID/mL, and 1 × 10–5 TCID/mL. Controls were injected with 200 μL of PBS. Fish were monitored daily for 30 days, and mortalities were recorded. The presence of bacteria was assessed by qRT-PCR. In both infection scenarios, a single infection and coinfection, the highest dose of P. salmonis was used (1 × 10–3 TCID/mL) as a conservative measure because the fish grow about 100 g between LD50 and the main challenge (50 days).
    Infection design, trait of resistance and protection added by vaccine
    Fish were treated with two different types of infection, a single infection with P. salmonis (PS) or coinfection with both C. rogercresseyi and P. salmonis (CAL + PS) as previously described18. In short, infections against P. salmonis occurred at 822 ATU (accumulated thermal units) within the immunization period described by the vaccine manufacturer. Vaccinated and unvaccinated fish from populations Fanad and Lochy were equally distributed in four tanks of 6 m3, with two replicates per type of infection. For the single infection with P. salmonis, fish were IP injected. For the coinfection, fish were exposed first to sea lice and then to P. salmonis. A coinfection procedure was established based on our previous experience with this study model45,55. Infections with sea lice were performed by adding 60 copepodites per fish to each tank of coinfection. Copepodites were collected from egg-bearing females reared in the laboratory and confirmed as “pathogen-free” (P. salmonis, R. salmoninarum, IPNV, and ISAV) by RT-PCR diagnostic. After the addition of parasites, water flow was stopped for a period of 8 h, and tanks were covered to decrease light intensity, which favors a successful settlement of sea lice on fish55. A placebo procedure was applied to single infection tanks, keeping them in darkness and controlling the volume of water, temperature, oxygen levels, and fish density equivalent to those that were measured in coinfected tanks18. The secondary infection was performed with P. salmonis after seven days of sea lice infestation, and the establishment of the parasites was confirmed and quantified on all fish. Therefore, our experimental design had two types of treatments: (1) single infection (PS) or coinfection (CAL + PS); and (2) vaccinated or unvaccinated fish. Vaccinated and unvaccinated fish with a single infection were distributed in tanks 1 and 2, and vaccinated and unvaccinated fish with a coinfection were distributed in tanks 3 and 4. Further, fish were fasted for one day prior to each procedure to minimize the detrimental effects of stress on water quality parameters. Finally, fish were sedated with AQUI-S (50% Isoeugenol, 17 mL/100 L water) to reduce stress during handling. Fish were monitored daily for 30 days, and resistance to P. salmonis was measured individually as days to death. Protection added by vaccination was calculated as the difference of resistance between vaccinated fish and their unvaccinated full-sibs and represented under a single Genetic and Environment model (GxE, G = full-sib family; E = Vaccination treatment).
    Comparison of moribund and survivor fish
    Bacterial load, growth, and macroscopic lesions were evaluated in survivors and moribund fish. Moribund fish were obtained as dying fish when 50% of mortality was reached in both a single infection and coinfection treatments. Moribund fish were recognized and collected by three behavioral traits: lethargy, no response to stimuli, and slow swimming close to the tank wall. Resistance to P. salmonis was measured by days to death and mortality (alive versus dead) and monitored for 30 days15,45, survivors fish comprised those that lived at the end of experiment15. Forty fish were collected from each group of moribund and survivors, and from each treatment (PS and CAL + PS) and comparisons were performed between unvaccinated and vaccinated fish, twenty fish each group. However, due to the low number of unvaccinated survivors fish coinfected with P. salmonis and sea lice, it was not possible to compare with the vaccinated survivors fish.
    Specific growth rate (SGR)
    SGR was evaluated for moribund and survivors fish. The specific growth rate was calculated previous to infection, and post-infection as SGR = ((lnw2 − lnw1)*t−1)*100, where w2 corresponds to final weight, w1 to the initial weight, and t corresponds to the number of days between infection and death of the fish or the end of the trial if they survived56.
    Piscirickettsia salmonis load
    Piscirickettsia salmonis load was evaluated for moribund and survivors fish. P. salmonis load was estimated based on the amount of specific ribosomal RNA from the bacteria in the head kidneys of the infected fish, as measured by qRT-PCR. Dead fish were not used to evaluate bacterial load. Threshold cycle (CT) values from bacterial RNA was used as an indication of the bacterial load as previously described18. Head kidney samples were extracted from 20 moribund and survivors fish per group and preserved in RNAlater at − 80 °C until RNA extraction. RNA was extracted from tissue samples with the TRIzol reagent (Thermo Fisher Scientific, MA, USA) following the instructions provided by the manufacturer. DNA was removed through an additional step using a DNase incubation for 60 min at 37 °C. The quality of the RNA extraction was checked by visualizing the 28S and 18S rRNA bands resolved in 1% of agarose gels stained with SYBR Safe DNA gel stain (Invitrogen, CA, USA), and the total concentration of the RNA was measured spectrophotometrically in a MaestroNano device (MAESTROGEN, Hsinchu, Taiwan). One hundred nanograms of purified total RNA was used for the qRT-PCR reactions. The qRT-PCR reaction was prepared using the Brilliant III SYBR master mix (Agilent Technologies, CA, USA) by adding the template RNA, probes, and primers as described previously57. qRT-PCR was performed in the Eco Real-Time PCR system (Illumina, CA, USA), whose results were expressed in terms of CT. All samples were tested in triplicates and were calibrated to a plate standard that contained a combination of samples from all groups tested. Primers used for 23S gene of S. salar were forward primer TCTGGGAAGTGTGGCGATAGA and reverse primer TCCCGACCTACTCTTGTTTCATC.
    Necropsy analysis
    Macroscopic lesions from 20 fish per treatment were analyzed on moribund and survivors fish13; almost all survivors sampled fish were vaccinated, except one unvaccinated fish that survived to P. salmonis infection (data not shown). Fresh samples were analyzed by two veterinarians who were blinded to the treatments. Macroscopic lesions evaluated in the tissues were peeling or undergoing desquamation, congestion, and ecchymosis in the skin, paleness, and melanomacrophages in the gills, white hepatic nodules, hepatomegaly, spleen paleness, and splenomegaly. Macroscopic lesions were indicated as present or absent.
    Statistical analysis
    Significance levels of resistant to P. salmonis were obtained using a two-way ANOVA followed by a Tukey post-hoc test and unpaired t-test. The effects of populations and sex of fish on SGR and P. salmonis load were analyzed using a non-parametric Kruskal–Wallis test followed by a Dunn post-hoc test. Additionally, differences in the clinical signs of the P. salmonis infection between different treatments were analyzed using a non-parametric Chi-square proportion. All statistical analyses were performed using R Core Team (RStudio, Vienna, Austria). Graphs were designed with GraphPad Prism 8.0 software (GraphPad Software, CA, USA).
    Quantitative genetic analysis
    Each population in this study has a different genetic origin and has been managed as closed populations during the domestication process. Thus, (co) variance components of days to death were estimated independently for each population from the data of its genealogy (Table 1) using VCE 6.0 software by Groeneveld et al.58.
    Heritability of days to death was estimated using the following univariate animal model:

    $$y = upsilon 1 , + X_{1} t + X_{2} i + X_{3} v + Za + e,,,,{text{Model}},1$$

    where y is the vector of the trait days to death, μ is the overall mean effect, t is the fixed effect of tank; i is the fixed effect of type of infection; v is the fixed effect of group of vaccination; a is the random effects vector of animal effects, with a ~ N(0, σa2A); and e is the random vector of errors, with e ~ N(0, σe2Ie). X1, X2, X3, and Z are incidence matrices, and A is the numerator relationship matrix obtained from pedigree information. The magnitude of estimated heritability was established following the classification of Cardellino and Rovira59: low (0.05–0.15), medium (0.20–0.40), and high (0.45–0.60) and very high ( > 0.65).
    Genotype–environment interactions (GxE) were estimated by means of genetic correlations between the trait days to death measured in one environment (i.e., unvaccinated and single infection with P. salmonis) and the same trait measured in the other environment (i.e., vaccinated and coinfection).
    Genetic correlations were estimated using the following bivariate animal model:

    $$y_{1} ,;y_{2} = X_{1} d + X_{2} t(d) + X_{3} i(d) + X_{4} v(d) + Za(d) + e,,,,{text{Model}},1$$

    where, y1 and y2 are the data vectors for the traits of interest (days to death in vaccinated and unvaccinated fish); d is the fixed vector of trait effects; t(d), i(d), v(d), are the fixed effects of tank, type of infection and group of vaccination effects within trait, respectively; a(d) is the random vector of animal effects within trait, with a(d) ~ N(0, A ⊗ G); and e is the random vector of errors, with e ~ N(0, I ⊗ R). The matrix G is a 2 × 2 variance–covariance matrix between traits defined by a genetic additive correlation term, rg, and a genetic variance (σgj2) for each trait. The matrix R is an unstructured 2 × 2 residual variance–covariance matrix with a different variance for each trait (σej2), and a covariance between traits (σeij). All other terms were previously defined. Correlations were classified as low (0–0.39), medium (0.40–0.59), high (0.60–0.79), and very high (0.80–1), regardless whether it was positive or negative. Significance testing of the estimates of heritability and genetic correlation were approximate as suggest by Åkesson et al.60. Thus, any genetic parameter value was considered significantly different from zero with P  More

  • in

    Evidence of unprecedented rise in growth synchrony from global tree ring records

    1.
    Thomas, C. D. et al. Extinction risk from climate change. Nature 427, 145–148 (2004).
    CAS  Google Scholar 
    2.
    Alexander, J. M., Diez, J. M. & Levine, J. M. Novel competitors shape species’ responses to climate change. Nature 525, 515–518 (2015).
    CAS  PubMed  Google Scholar 

    3.
    Seidl, R., Schelhaas, M.-J., Rammer, W. & Verkerk, P. J. Increasing forest disturbances in Europe and their impact on carbon storage. Nat. Clim. Change 4, 806–810 (2014).
    CAS  Google Scholar 

    4.
    Post, E. & Forchhammer, M. C. Synchronization of animal population dynamics by large-scale climate. Nature 420, 168–171 (2002).
    CAS  PubMed  Google Scholar 

    5.
    Koenig, W. D. & Liebhold, A. M. Temporally increasing spatial synchrony of North American temperature and bird populations. Nat. Clim. Change 6, 614–617 (2016).
    Google Scholar 

    6.
    Shestakova, T. et al. Forests synchronize their growth in contrasting Eurasian regions in response to climate warming. Proc. Natl Acad. Sci. USA 113, 662–667 (2016).
    CAS  PubMed  Google Scholar 

    7.
    Black, B. A. et al. Rising synchrony controls western North American ecosystems. Glob. Change Biol. 24, 2305–2314 (2018).
    Google Scholar 

    8.
    Heino, M. Noise colour, synchrony and extinctions in spatially structured populations. Oikos 83, 368–375 (1998).
    Google Scholar 

    9.
    Liebhold, A., Koenig, W. D. & Bjørnstad, O. N. Spatial synchrony in population dynamics. Annu. Rev. Ecol. Evol. Syst. 35, 467–490 (2004).
    Google Scholar 

    10.
    Gouhier, T. C., Guichard, F. & González, A. Synchrony and stability of food webs in metacommunities. Am. Nat. 175, E16–E34 (2010).
    PubMed  Google Scholar 

    11.
    Elton, C. S. Periodic fluctuations in the numbers of animals: their causes and effects. Br. J. Exp. Bot. 2, 119–163 (1924).
    Google Scholar 

    12.
    Moran, P. A. P. The statistical analysis of the Canadian lynx cycle. Aust. J. Zool. 1, 291–298 (1953).
    Google Scholar 

    13.
    Loreau, M. & de Mazancourt, C. Species synchrony and its drivers: neutral and nonneutral community dynamics in fluctuating environments. Am. Nat. 172, E48–E66 (2008).
    PubMed  Google Scholar 

    14.
    Buma, B. et al. The value of linking paleoecological and neoecological perspectives to understand spatially-explicit ecosystem resilience. Landsc. Ecol. 34, 17–33 (2018).
    Google Scholar 

    15.
    Hughes, B. B. et al. Long-term studies contribute disproportionately to ecology and policy. BioScience 67, 271–281 (2017).
    Google Scholar 

    16.
    Gajewski, K., Viau, A. E., Sawada, M., Atkinson, D. E. & Fines, P. Synchronicity in climate and vegetation transitions between Europe and North America during the Holocene. Clim. Change 78, 341–361 (2006).
    CAS  Google Scholar 

    17.
    Zhao, S. et al. The International Tree-Ring Data Bank (ITRDB) revisited: data availability and global ecological representativity. J. Biogeogr. https://doi.org/10.1111/jbi.13488 (2018).

    18.
    Babst, F., Poulter, B., Bodesheim, P., Mahecha, M. D. & Frank, D. C. Improved tree-ring archives will support earth-system science. Nat. Ecol. Evol. 1, 0008 (2017).
    Google Scholar 

    19.
    Cook, E. R. & Peters, K. Calculating unbiased tree-ring indices for the study of climatic and environmental change. Holocene 7, 361–370 (1997).
    Google Scholar 

    20.
    Gedalof, Z. E. & Berg, A. A. Tree ring evidence for limited direct CO2 fertilization of forests over the 20th century. Glob. Biogeochem. Cycles 24, GB3027 (2010).
    Google Scholar 

    21.
    Gazol, A., Camarero, J. J., Anderegg, W. R. L. & Vicente-Serrano, S. M. Impacts of droughts on the growth resilience of Northern Hemisphere forests. Glob. Ecol. Biogeogr. 26, 166–176 (2016).
    Google Scholar 

    22.
    Pomara, L. Y. & Zuckerberg, B. Climate variability drives population cycling and synchrony. Divers. Distrib. 23, 421–434 (2017).
    Google Scholar 

    23.
    Briffa, M. et al. Trends in recent temperature and radial tree growth spanning 2000 years across northwest Eurasia. Phil. Trans. R. Soc. B 363, 2271–2284 (2008).
    PubMed  Google Scholar 

    24.
    Ponocná, T. et al. Deviations of treeline Norway spruce radial growth from summer temperatures in East-Central Europe. Agric. Meteorol. 253, 62–70 (2018).
    Google Scholar 

    25.
    Shestakova, T. A., Gutiérrez, E., Valeriano, C., Lapshina, E. & Voltas, J. Recent loss of sensitivity to summer temperature constrains tree growth synchrony among boreal Eurasian forests. Agric. Meteorol. 268, 318–330 (2019).
    Google Scholar 

    26.
    Schurman, J. S. et al. Large-scale disturbance legacies and the climate sensitivity of primary Picea abies forests. Glob. Change Biol. 24, 2169–2181 (2018).
    Google Scholar 

    27.
    Schweingruber, F. H. Tree Rings: Basics and Applications of Dendrochronology (Springer Science & Business Media, 1996).

    28.
    Speer, J. H. Fundamentals of Tree-Ring Research (Univ. of Arizona Press, 2010).

    29.
    Savolainen, O., Pyhäjärvi, T. & Knürr, T. Gene flow and local adaptation in trees. Annu. Rev. Ecol. Evol. Syst. 38, 595–619 (2007).
    Google Scholar 

    30.
    Ripa, J. Analysing the Moran effect and dispersal: their significance and interaction in synchronous population dynamics. Oikos 89, 175–187 (2000).
    Google Scholar 

    31.
    Hopson, J. & Fox, J. W. Occasional long distance dispersal increases spatial synchrony of population cycles. J. Anim. Ecol. 88, 154–163 (2019).
    PubMed  Google Scholar 

    32.
    Johnson, C. A. et al. Effects of temperature and resource variation on insect population dynamics: the bordered plant bug as a case study. Funct. Ecol. 30, 1122–1131 (2016).
    PubMed  Google Scholar 

    33.
    Parmesan, C. & Yohe, G. A globally coherent fingerprint of climate change impacts across natural systems. Nature 421, 37–42 (2003).
    CAS  PubMed  Google Scholar 

    34.
    St. George, S. The aberrant global synchrony of present-day warming. Nature 571, 483–484 (2019).
    CAS  PubMed  Google Scholar 

    35.
    Neukom, R. et al. Consistent multidecadal variability in global temperature reconstructions and simulations over the common era. Nat. Geosci. 12, 643–649 (2019).
    PubMed  PubMed Central  Google Scholar 

    36.
    Babst, F. et al. Twentieth century redistribution in climatic drivers of global tree growth. Sci. Adv. 5, eaat4313 (2019).
    PubMed  PubMed Central  Google Scholar 

    37.
    Giguère-Croteau, C. et al. North America’s oldest boreal trees are more efficient water users due to increased [CO2], but do not grow faster. Proc. Natl Acad. Sci. USA 116, 2749–2754 (2019).
    PubMed  Google Scholar 

    38.
    Duncan, A. B., Gonzalez, A. & Kaltz, O. Dispersal, environmental forcing, and parasites combine to affect metapopulation synchrony and stability. Ecology 96, 284–290 (2015).
    PubMed  Google Scholar 

    39.
    Girardin, M. P. et al. No growth stimulation of Canada’s boreal forest under half-century of combined warming and CO2 fertilization. Proc. Natl Acad. Sci. USA 113, E8406–E8414 (2016).
    CAS  PubMed  Google Scholar 

    40.
    Manzanedo, R. D. et al. Increase in CO2 concentration could alter the response of Hedera helix to climate change. Ecol. Evol. 8, 8598–8606 (2018).
    PubMed  PubMed Central  Google Scholar 

    41.
    Venter, O. et al. Sixteen years of change in the global terrestrial human footprint and implications for biodiversity conservation. Nat. Commun. 7, 12558 (2016).
    CAS  PubMed  PubMed Central  Google Scholar 

    42.
    Pederson, N. et al. Long-term drought sensitivity of trees in second-growth forests in a humid region. Can. J. Res. 42, 1837–1850 (2012).
    Google Scholar 

    43.
    Kug, J. S., An, S. I., Ham, Y. G. & Kang, I. S. Changes in El Niño and La Niña teleconnections over North Pacific–America in the global warming simulations. Theor. Appl. Clim. 100, 275–282 (2010).
    Google Scholar 

    44.
    Rahmstorf, S. & Coumou, D. Increase of extreme events in a warming world. Proc. Natl Acad. Sci. USA 108, 17905–17909 (2011).
    CAS  PubMed  Google Scholar 

    45.
    Cai, W. et al. Increasing frequency of extreme El Niño events due to greenhouse warming. Nat. Clim. Change 4, 111–116 (2014).
    CAS  Google Scholar 

    46.
    Fischer, E. M., Beyerle, U. & Knutti, R. Robust spatially aggregated projections of climate extremes. Nat. Clim. Change 3, 1033–1038 (2013).
    Google Scholar 

    47.
    Trenberth, K. E., Fasullo, J. T. & Shepherd, T. G. Attribution of climate extreme events. Nat. Clim. Change 5, 725–730 (2015).
    Google Scholar 

    48.
    Thurm, E. A. et al. Alternative tree species under climate warming in managed European forests. Ecol. Manage. 430, 485–497 (2018).
    Google Scholar 

    49.
    Manzanedo, R. D. & Pederson, N. Towards a more ecological dendroecology. Tree Ring Res. 75, 152–159 (2019).
    Google Scholar 

    50.
    Klesse, S. et al. Sampling bias overestimates climate change impacts on forest growth in the southwestern United States. Nat. Commun. 9, 5336 (2018).
    CAS  PubMed  PubMed Central  Google Scholar 

    51.
    Ettinger, A. K., Kevin, R. F. & HilleRisLambers, J. Climate determines upper, but not lower, altitudinal range limits of Pacific Northwest conifers. Ecology 92, 1323–1331 (2011).
    CAS  PubMed  Google Scholar 

    52.
    Grissino-Mayer, H. D. & Fritts, H. C. The International Tree-Ring Data Bank: an enhanced global database serving the global scientific community. Holocene 7, 235–238 (1997).
    Google Scholar 

    53.
    Wilson, R. et al. Last millennium Northern Hemisphere summer temperatures from tree rings. Part I: the long term context. Quat. Sci. Rev. 134, 1–18 (2016).
    Google Scholar 

    54.
    Cook, B. I., Anchukaitis, K. J., Touchan, R., Meko, D. M. & Cook, E. R. Spatiotemporal drought variability in the Mediterranean over the last 900 years. J. Geophys. Res. Atmos. 121, 2060–2074 (2016).
    PubMed  PubMed Central  Google Scholar 

    55.
    Charney, N. D. et al. Observed forest sensitivity to climate implies large changes in 21st century North American forest growth. Ecol. Lett. 19, 1119–1128 (2016).
    PubMed  Google Scholar 

    56.
    Bunn, A. G. A dendrochronology program library in R (dplR). Dendrochronologia 26, 115–124 (2008).
    Google Scholar 

    57.
    R: A Language and Environment for Statistical Computing Version 3.5.0 (R Core Team, 2017).

    58.
    Sheffield, J., Goteti, G. & Wood, E. F. Development of a 50-yr high-resolution global dataset of meteorological forcings for land surface modelling. J. Clim. 19, 3088–3111 (2006).
    Google Scholar 

    59.
    Lamarque, J.-F. et al. The Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP): overview and description of models, simulations and climate diagnostics. Geosci. Model Dev. 6, 179–206 (2013).
    CAS  Google Scholar 

    60.
    GISTEMP Team GISS Surface Temperature Analysis (GISTEMP) Version 4 (NASA Goddard Institute for Space Studies, accessed 2 July 2018); https://data.giss.nasa.gov/gistemp/ More

  • in

    Tree growth in sync

    1.
    Manzanedo, R. D., HilleRisLambers, J., Rademacher, T. T. & Pederson, N. Nat. Ecol. Evol. https://doi.org/10.1038/s41559-020-01306-x (2020).
    2.
    Shestakova, T. A. et al. Proc. Natl Acad. Sci. USA 113, 662–667 (2016).
    CAS  Article  Google Scholar 

    3.
    Pugh, T. A. M. et al. Proc. Natl Acad. Sci. USA 116, 4382–4387 (2019).
    CAS  Article  Google Scholar 

    4.
    Di Cecco, G. J. & Gouhier, T. C. Sci. Rep. 8, 14850 (2018).
    Article  Google Scholar 

    5.
    Shestakova, T. A., Gutiérrez, E., Valeriano, C., Lapshina, E. & Voltas, J. Agric. For. Meteorol. 268, 318–330 (2019).
    Article  Google Scholar 

    6.
    Hubau, W. et al. Nature 579, 80–87 (2020).
    CAS  Article  Google Scholar 

    7.
    Adams, M. A., Buckley, T. N. & Turnbull, T. L. Nat. Clim. Change 10, 466–471 (2020).
    CAS  Article  Google Scholar 

    8.
    Brienen R. J. W., Schöngart J. & Zuidema, P. A. in Tropical Tree Physiology Tree Physiology Vol. 6 (eds Goldstein, G. & Santiago L. S.) 439–461 (Springer, 2016).

    9.
    Hansen, B. B., Grøtan, V., Herfindal, I. & Lee, A. M. Ecography https://doi.org/10.1111/ecog.04962 (2020).

    10.
    Koenig, W. D. & Liebhold, A. M. Nat. Clim. Change 6, 614–617 (2016).
    Article  Google Scholar  More