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    Optimization of subsampling, decontamination, and DNA extraction of difficult peat and silt permafrost samples

    1.
    Willerslev, E. et al. Diverse plant and animal genetic records from Holocene and Pleistocene sediments. Science 300, 791–795 (2003).
    ADS  CAS  PubMed  Google Scholar 
    2.
    Birks, H. J. B. & Birks, H. H. How have studies of ancient DNA from sediments contributed to the reconstruction of Quaternary floras?. New Phytol. 209, 499–506 (2016).
    CAS  PubMed  Google Scholar 

    3.
    Froese, D., Westgate, J., Preece, S. & Storer, J. Age and significance of the late Pleistocene Dawson tephra in eastern Beringia. Quatern. Sci. Rev. 21, 2137–2142 (2002).
    ADS  Google Scholar 

    4.
    Orlando, L. et al. Recalibrating Equus evolution using the genome sequence of an early Middle Pleistocene horse. Nature 499, 74 (2013).
    ADS  CAS  PubMed  Google Scholar 

    5.
    Poinar, H. N. et al. Metagenomics to paleogenomics: large-scale sequencing of mammoth DNA. Science 311, 392–394 (2006).
    ADS  CAS  PubMed  Google Scholar 

    6.
    Waters, M. R. & Stafford, T. W. Redefining the age of Clovis: implications for the peopling of the Americas. Science 315, 1122–1126 (2007).
    ADS  CAS  PubMed  Google Scholar 

    7.
    Davidson, E. A. & Janssens, I. A. Temperature sensitivity of soil carbon decomposition and feedbacks to climate change. Nature 440, 165 (2006).
    ADS  CAS  PubMed  Google Scholar 

    8.
    Mackelprang, R. et al. Metagenomic analysis of a permafrost microbial community reveals a rapid response to thaw. Nature 480, 368 (2011).
    ADS  CAS  PubMed  PubMed Central  Google Scholar 

    9.
    Nikrad, M. P., Kerkhof, L. J. & Häggblom, M. M. The subzero microbiome: microbial activity in frozen and thawing soils. FEMS Microbiol. Ecol. 92, fiw81 (2016).
    Google Scholar 

    10.
    Schuur, E. A. et al. Vulnerability of permafrost carbon to climate change: implications for the global carbon cycle. Bioscience 58, 701–714 (2008).
    Google Scholar 

    11.
    Shendure, J. et al. DNA sequencing at 40: past, present and future. Nature 550, 345 (2017).
    ADS  CAS  PubMed  Google Scholar 

    12.
    Weyrich, L. S. et al. Laboratory contamination over time during low-biomass sample analysis. Mol. Ecol. Resour. 19, 982–996 (2019).
    CAS  PubMed  PubMed Central  Google Scholar 

    13.
    Skoglund, P. et al. Separating endogenous ancient DNA from modern day contamination in a Siberian Neandertal. Proc. Natl. Acad. Sci. 111, 2229–2234 (2014).
    ADS  CAS  PubMed  Google Scholar 

    14.
    Bang-Andreasen, T., Schostag, M., Priemé, A., Elberling, B. & Jacobsen, C. S. Potential microbial contamination during sampling of permafrost soil assessed by tracers. Sci. Rep. 7, 43338 (2017).
    ADS  CAS  PubMed  PubMed Central  Google Scholar 

    15.
    Salter, S. J. et al. Reagent and laboratory contamination can critically impact sequence-based microbiome analyses. BMC Biol. 12, 87 (2014).
    PubMed  PubMed Central  Google Scholar 

    16.
    Willerslev, E., Hansen, A. J. & Poinar, H. N. Isolation of nucleic acids and cultures from fossil ice and permafrost. Trends Ecol. Evol. 19, 141–147 (2004).
    PubMed  Google Scholar 

    17.
    Barbato, R. A. et al. Removal of exogenous materials from the outer portion of frozen cores to investigate the ancient biological communities harbored inside. JoVE 3, e54091 (2016).
    Google Scholar 

    18.
    D’Costa, V. M. et al. Antibiotic resistance is ancient. Nature 477, 457 (2011).
    ADS  PubMed  Google Scholar 

    19.
    Rivkina, E., Petrovskaya, L., Vishnivetskaya, T., Krivushin, K., Shmakova, L., Tutukina, M., Meyers, A., & Kondrashov, F. Metagenomic analyses of the late Pleistocene permafrost—Additional tools for reconstruction of environmental conditions. Biogeosciences 13 (2016).

    20.
    Kallmeyer, J. Contamination Control for Scientific Drilling Operations Vol. 98, 61–91 (Academic Press, London, 2017).
    Google Scholar 

    21.
    Kallmeyer, J., Mangelsdorf, K., Cragg, B. & Horsfield, B. Techniques for contamination assessment during drilling for terrestrial subsurface sediments. Geomicrobiol. J. 23, 227–239 (2006).
    CAS  Google Scholar 

    22.
    Korlević, P. et al. Reducing microbial and human contamination in DNA extractions from ancient bones and teeth. Biotechniques 59, 87–93 (2015).
    PubMed  Google Scholar 

    23.
    Llamas, B. et al. From the field to the laboratory: controlling DNA contamination in human ancient DNA research in the high-throughput sequencing era. STAR: Sci. Technol. Archaeol. Res. 3, 1–14 (2017).
    Google Scholar 

    24.
    Yanagawa, K., Nunoura, T., McAllister, S., Hirai, M., Breuker, A., Brandt, L., House, C., Moyer, C., Birrien, J.-L., Aoike, K., Sunamura, M., Urabe, T., Mottl, M., & Takai, K. The first microbiological contamination assessment by deep-sea drilling and coring by the D/V Chikyu at the Iheya North hydrothermal field in the Mid-Okinawa Trough (IODP Expedition 331). Front. Microbiol. 4 (2013).

    25.
    Yang, D. Y. & Watt, K. Contamination controls when preparing archaeological remains for ancient DNA analysis. J. Archaeol. Sci. 32, 331–336 (2005).
    Google Scholar 

    26.
    Bollongino, R., Tresset, A. & Vigne, J.-D. Environment and excavation: pre-lab impacts on ancient DNA analyses. C. R. Palevol 7, 91–98 (2008).
    Google Scholar 

    27.
    Smith, D. C. Ajsmrfsahhs. Tracer-based estimates of drilling-induced microbial contamination of Deep Sea Crust. Geomicrobiol. J. 17, 207–219 (2000).
    CAS  Google Scholar 

    28.
    Krivushin, K. et al. Two metagenomes from late pleistocene Northeast Siberian Permafrost. Genome Announc. 3, e01380-e1414 (2015).
    PubMed  PubMed Central  Google Scholar 

    29.
    Vishnivetskaya, T. A. et al. Bacterial community in ancient Siberian permafrost as characterized by culture and culture-independent methods. Astrobiology 6, 400–414 (2006).
    ADS  CAS  PubMed  Google Scholar 

    30.
    Wright, G. D. & Poinar, H. Antibiotic resistance is ancient: implications for drug discovery. Trends Microbiol. 20, 157–159 (2012).
    CAS  PubMed  Google Scholar 

    31.
    Kalmár, T., Bachrati, C. Z., Marcsik, A. & Raskó, I. A simple and efficient method for PCR amplifiable DNA extraction from ancient bones. Nucl. Acids Res. 28, e67–e67 (2000).
    PubMed  Google Scholar 

    32.
    Palmirotta, R. et al. Use of a multiplex polymerase chain reaction assay in the sex typing of DNA extracted from archaeological bone. Int. J. Osteoarchaeol. 7, 605–609 (1997).
    Google Scholar 

    33.
    González-Oliver, A., Márquez-Morfín, L., Jiménez, J. C. & Torre-Blanco, A. Founding Amerindian mitochondrial DNA lineages in ancient Maya from Xcaret, Quintana Roo. Am. J. Phys. Anthropol. 116, 230–235 (2001).
    PubMed  Google Scholar 

    34.
    Kemp, B. M. & Smith, D. G. Use of bleach to eliminate contaminating DNA from the surface of bones and teeth. Forens. Sci. Int. 154, 53–61 (2005).
    CAS  Google Scholar 

    35.
    Rogers, S. O. et al. Comparisons of protocols for decontamination of environmental ice samples for biological and molecular examinations. Appl. Environ. Microbiol. 70, 2540–2544 (2004).
    CAS  PubMed  PubMed Central  Google Scholar 

    36.
    Salamon, M., Tuross, N., Arensburg, B. & Weiner, S. Relatively well preserved DNA is present in the crystal aggregates of fossil bones. Proc. Natl. Acad. Sci. USA 102, 13783–13788 (2005).
    ADS  CAS  PubMed  Google Scholar 

    37.
    Mackelprang, R. et al. Microbial survival strategies in ancient permafrost: insights from metagenomics. ISME 11, 2305 (2017).
    CAS  Google Scholar 

    38.
    Vishnivetskaya, T., Kathariou, S., McGrath, J., Gilichinsky, D. & Tiedje, J. M. Low-temperature recovery strategies for the isolation of bacteria from ancient permafrost sediments. Extremophiles 4, 165–173 (2000).
    CAS  PubMed  Google Scholar 

    39.
    Yergeau, E., Hogues, H., Whyte, L. G. & Greer, C. W. The functional potential of high Arctic permafrost revealed by metagenomic sequencing, qPCR and microarray analyses. ISME 4, 1206 (2010).
    CAS  Google Scholar 

    40.
    Vishnivetskaya, T. A. et al. Commercial DNA extraction kits impact observed microbial community composition in permafrost samples. FEMS Microbiol. Ecol. 87, 217–230 (2014).
    CAS  PubMed  Google Scholar 

    41.
    Braid, M. D., Daniels, L. M. & Kitts, C. L. Removal of PCR inhibitors from soil DNA by chemical flocculation. J. Microbiol. Methods 52, 389–393 (2003).
    CAS  PubMed  Google Scholar 

    42.
    Griffiths, R. I., Whiteley, A. S., O’Donnell, A. G. & Bailey, M. J. Rapid method for coextraction of DNA and RNA from natural environments for analysis of ribosomal DNA- and rRNA-based microbial community composition. Appl. Environ. Microbiol. 66, 5488–5491 (2000).
    CAS  PubMed  PubMed Central  Google Scholar 

    43.
    Porter, T. M. et al. Amplicon pyrosequencing late Pleistocene permafrost: the removal of putative contaminant sequences and small-scale reproducibility. Mol. Ecol. Resour. 13, 798–810 (2013).
    CAS  PubMed  Google Scholar 

    44.
    Porter, T. J. et al. Recent summer warming in northwestern Canada exceeds the Holocene thermal maximum. Nat. Commun. 10, 1631 (2019).
    ADS  PubMed  PubMed Central  Google Scholar 

    45.
    Durfee, T. et al. The complete genome sequence of Escherichia coli DH10B: insights into the biology of a laboratory workhorse. J. Bacteriol. 190, 2597–2606 (2008).
    CAS  PubMed  PubMed Central  Google Scholar 

    46.
    Guzman, L. M., Belin, D., Carson, M. J. & Beckwith, J. Tight regulation, modulation, and high-level expression by vectors containing the arabinose PBAD promoter. J. Bacteriol. 177, 4121–4130 (1995).
    CAS  PubMed  PubMed Central  Google Scholar 

    47.
    Shaner, N. C. et al. A bright monomeric green fluorescent protein derived from Branchiostoma lanceolatum. Nat. Methods 10, 407 (2013).
    CAS  PubMed  PubMed Central  Google Scholar 

    48.
    Cooper, A. & Poinar, H. N. Ancient DNA: do it right or not at all. Science 289, 1139–1139 (2000).
    CAS  PubMed  Google Scholar 

    49.
    Bottos, E. M., Kennedy, D. W., Romero, E. B., Fansler, S. J., Brown, J. M., Bramer, L. M., Chu, R. K., Tfaily, M. M., Jansson, J. K. & Stegen, J. C. Dispersal limitation and thermodynamic constraints govern spatial structure of permafrost microbial communities. FEMS Microbiol. Ecol. 94 (2018).

    50.
    Hultman, J. et al. Multi-omics of permafrost, active layer and thermokarst bog soil microbiomes. Nature 521, 208 (2015).
    ADS  CAS  PubMed  Google Scholar 

    51.
    Smith, D. C., Spivack, A. J., Fisk, M. R., Haveman, S. A. & Staudigel, H. Tracer-based estimates of drilling-induced microbial contamination of deep sea crust. Geomicrobiol J. 17, 207–219 (2000).
    CAS  Google Scholar 

    52.
    Kallmeyer, J., Pockalny, R., Adhikari, R. R., Smith, D. C. & D’Hondt, S. Global distribution of microbial abundance and biomass in subseafloor sediment. Proc. Natl. Acad. Sci. 109, 16213–16216 (2012).
    ADS  CAS  PubMed  Google Scholar 

    53.
    Juck, D. F. et al. Utilization of fluorescent microspheres and a green fluorescent protein-marked strain for assessment of microbiological contamination of permafrost and ground ice core samples from the Canadian High Arctic. Appl. Environ. Microbiol. 71, 1035–1041 (2005).
    CAS  PubMed  PubMed Central  Google Scholar 

    54.
    Colwell, F. S., Pryfogle, P. A., Lee, B. D. & Bishop, C. L. Use of a cyanobacterium as a particulate tracer for terrestrial subsurface applications. J. Microbiol. Methods 20, 93–101 (1994).
    Google Scholar 

    55.
    Friese, A. et al. (2017) A simple and inexpensive technique for assessing contamination during drilling operations. Limnol. Oceanogr. Methods 15, 200–211 (2017).
    CAS  Google Scholar 

    56.
    Knapp, M., Clarke, A. C., Horsburgh, K. A. & Matisoo-Smith, E. A. Setting the stage—Building and working in an ancient DNA laboratory. Ann. Anat. Anatomischer Anzeiger 194, 3–6 (2012).
    CAS  PubMed  Google Scholar 

    57.
    Eisenhofer, R. et al. Contamination in low microbial biomass microbiome studies: issues and recommendations. Trends Microbiol. 27, 105–117 (2019).
    CAS  PubMed  Google Scholar  More

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    Reconciling yield gains in agronomic trials with returns under African smallholder conditions

    Experimental design
    The trials were conducted in five regions (Boro, Ugunja, Ukwala, Wagai and Yala) of Siaya County in western Kenya. Siaya County is located at 00°08.468′ N, 34°25.378′ E, and at an altitude of 1,336 m above sea level. The experimental sites were in lower midland 1(LM1) and lower midlands 2 (LM2) agro-ecological zones, which experience bimodal rainfall with long rains (LR) starting in March to July and short Rains (SR) starting in Late August to December41 and receive average annual rainfall of 1,500 mm42. The soils are mainly Ferralsols and Acrisols in the higher areas and Vertisols in the low areas.
    Trials were conducted in 48 randomly selected villages, using stratification at the sub-county level. Half of them (randomly selected) participated in the trials in the long and short rain of 2014 and the long rain of 2015. The other half started in the short rain of 2014 and continued throughout the long and short rain of 2015. In each village 10 farmers participated in the trial. Half of them were specifically selected for participation in a community meeting. In those meetings, the researchers explained the objectives of the trials and asked the community members to nominate 5 farmers (as well as 5 potential substitutes), including two women, thought to be good farmers and interested in participating in the trials. Such non-random selection of farmers is common practice in research trials (Supplementary Table S1 online). The other half was selected randomly from the list of all the farmers in the village. All selected farmers were visited to obtain consent for the trials and identify the potential trial parcel (chosen by the farmer, conditional on fitting with some criteria for suitability to the research trials). A small number of replacements was done (but always keeping 5 selected by the community and 5 random). In each village 4 random farmers (2 random and 2 selected) were assigned to participate in the maize trial, while 3 random farmers (at least 1 random and 1 selected) were assigned to participate in the soybean trial. The other 3 farmers participated in a maize-soybean intercrop trial. During implementation, the assignment of inputs for the intercrop trial was, however, contaminated. As a result none of the plots in the intercrop trial received a best-bet input package, making the agronomic findings from that trial hard to interpret, and therefore not necessarily of interest for the decomposition proposed in this paper. Nevertheless, for completeness, results for these intercrop trials are shown in Supplementary Table S14 online.
    Researcher-designed and farmer-managed trials
    The trials would qualify as researcher-designed and farmer-managed (under the supervision of the researchers). The research team had full control over the design of the trials, from the choice of inputs to spacing and other management practices. All inputs were provided by the research team, with the exception of the local maize seed tested in two out of the six plots. A researcher (local expert agronomist) was present and led planting, gapping and thinning, all fertilizer applications, and harvesting. In these activities, labor was typically provided by the farmer. Planting dates were mostly decided by the researchers to best target the onset of rains, also responding to the farmers’ feedback on beginning of rains and availability to schedule the visit for planting. The farmer was in charge of land preparation, weeding and other management, with the researchers providing guidelines on those practices. In each village, a contact person (typically one of the ten farmers) visited the trials weekly to verify that the farmers fulfilled their responsibilities. Farmers were also asked to inform the contact person in case of any pest or disease, in which case the researcher provided the required pesticide or fungicide.
    Treatment structure and application
    Supplementary Table S2 online presents the full factorial designs of the multi-locational trials for maize and soybean, including details on crop varieties and quantity of inputs. The plot sizes were 4.5 × 5 m and the treatments were completely randomized between the six plots on each parcel. Plot sizes are of a similar order of magnitude as those found in other recently published work. A 1 m inter-plot spacing was planted with sweet potatoes to act as a buffer between plots to prevent inter-plot contamination. The sweet potatoes were planted at 50 cm from each plot, and border rows of the maize and soya plots were excluded for yield estimations to limit any edge effect. Hence the area harvested was 12.9 m2 for maize and 13.5 m2 for soybean. The experiments were repeated for three seasons, and plot layout and treatments were maintained for three seasons.
    For the soybean trials, a soybean rhizobia inoculant was tested alone, with Minjingu hyper phosphate (0-30-0 + 38CaO) or Sympal (0:23:15 + 10CaO + 4S + 1MgO + 0.1Zn) in a full factorial design. Phosphorus rate of 30 kg P ha−1 was used to determine the quantity of Sympal and Minjingu hyper phosphate to be applied. On each farm only one replicate was used; hence, 6 plots were installed on each farm. Inoculation was done at planting as a seed coating using the directions for use in the respective product labels. Each plot had 6 soybean lines of 5 m in length each spaced at 5 cm from plant to plant within row and 50 cm from row to row. Inoculation was done on all the rows. Soybean variety TGx1740-2F with medium maturity (95–100 days)43 was used as the test crop. The spatial variability of the soybean response is studied in44. The soybean trials demonstrated that the combination of rhizobia inoculant and P-source led to important yield gains44.
    The choice of inputs resulted from prior research conducted as part of the Compro project. Soybean was chosen as test crop mainly because in the prior phase of the project it had shown good response to rhizobia inoculation45 and was agro-ecologically suitable to the region. Kenya is an importer of soybean and multiple efforts are geared towards raising local production. In Compro I, the two rhizobia inoculants were tested and shown to be effective in increasing nodulation, nitrogen fixation and yield when inoculated on the tested soybean variety. Minjingu and Sympal were chosen based on their formulation with respect to the chemical characteristics of the soils in the test sites and results of earlier research46. The soils generally lack phosphorus and are acidic. A mapping study47 specifically identified Western Kenya as a potential K deficient area, and soil acidity has long been identified as a constraining factor in Western Kenya48 hence the importance of CaO. Results from soil sampling of the trial plots confirmed that more than 56.87% of soils were acidic (pH  More

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    Two potential equilibrium states in long-term soil respiration activity of dry grasslands are maintained by local topographic features

    Spatial patterns of stability proxies and background variables
    Figure 2 a, b show the spatial distribution of our two proxy variables, the average rank of Rs per position (rankRs) and of the range of the ranks per position (rangeRs) in kriged maps. The middle to southern areas were found to have the largest, whilst the north-eastern areas the smallest rankRs values, whereas a slightly different pattern was characteristic for rangeRs with some additional north-western large values. Similarly, larger average soil organic carbon content (meanSOC) and average soil water content (meanSWC) (Fig. 2 c, d) were detected at the western-middle-southern regions and smaller at the north-eastern part of the study site.
    Figure 2

    Kriged patterns of stability proxies, rankRs (a) and rangeRs (b), as well as of background factors, meanSOC (%, c) and meanSWC (%, d).

    Full size image

    Correlations between stability proxies and background variables along DEMs: entire dataset
    We investigated the potential direct effects of the different terrain attributes (local mean elevation (mALT), standard deviation of elevation (SD), topographic position index (TPI), slope (Sl), Easterness and Northness (East, North)) on the spatial distributions of our proxy variables by using the terrain attributes originating from differently smoothed DEM rasters. DEM1 was the original, 0.2 m resolution model, while DEMs 2–6 were progressively smoothed by a factor of two resulting in different resolution DEM rasters (DEM2: 0.4 m, DEM3: 0.8 m, DEM4: 1.6 m, DEM5: 3.2 m, DEM6: 6.4 m, respectively), and finally DEM7 met the resolution of the field measuring campaigns (10 m). The terrain attributes were filtered out from the rasters for the 78 measuring positions of the sampling grid.
    On the basis of the correlation analysis we found an important difference in terrain attribute features between DEM 5 and 6, especially in SD, Sl, North and East. All subsequent results are then based on DEMs 1–5, which were found to be more similar to each other and to the original DEM1. The maps of terrain attributes with the box blur kernel from DEM1-5 can be found in the Supplementary Information (SI) together with the descriptions and calculations. As we couldn’t find any of the blur kernels superior to the other when considering correlations, the results hereafter are only presented for the box blur kernel calculations for simplicity.
    When we considered the entire dataset (named hereafter: “A” dataset), we could only find significant correlation between rangeRs and TPI at less smoothed DEMs but the correlation was very weak (black symbols and line in Fig. 3).
    Figure 3

    Direct correlation between TPI and stability proxy, rangeRs at less smoothed DEMs, DEM1-2 for datasets A (black symbols and line) and S (blue symbols and line, see the information later on). The correlations were significant at p = 0.0076 and p  = 0.0172 levels, although they were weak, r2 = 0.09, r2 = 0.42 for A and S (see the information later on), respectively.

    Full size image

    Any other correlation between the proxies and the terrain attributes could only be deduced indirectly from the positive correlations between rankRs and meanSOC, meanSWC (cf. Table 1b). These correlations were scale-independent, i.e., we detected them at every DEMs. In general, the larger the soil carbon content and soil moisture at a position (cf. Figure 2c,d, showing quite similar patterns to the proxy patterns in the figure upper row), the larger the Rs activity detected and the opposite was true for lower carbon content and soil moisture positions.
    Table 1 (a) Statistically significant (p  More

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    Structures spread across our seas

    1.
    Duarte, C. M. et al. Front. Ecol. Environ. 11, 91–97 (2012).
    Article  Google Scholar 
    2.
    Firth, L. B. et al. in Oceanography and Marine Biology: An Annual Review Vol. 54 (eds Hughes, R. N. et al.) 193–269 (Taylor & Francis, 2016).

    3.
    Bugnot, A. B. et al. Nat. Sustain. https://doi.org/10.1038/s41893-020-00595-1 (2020).

    4.
    Bishop, M. J. et al. J. Exp. Mar. Biol. Ecol. 492, 7–30 (2017).
    Article  Google Scholar 

    5.
    Dong, Y., Huang, X., Wang, W., Li, Y. & Wang, J. et al. Divers. Distrib. 22, 731–744 (2016).
    Article  Google Scholar 

    6.
    Nagelkerken, I., Doney, S. C. & Munday, P. L. Oceanography and Marine Biology: An Annual Review Vol. 57 (eds Hawkins, S. J. et al.) 229–264 (Taylor & Francis, 2019).

    7.
    Hawkins, S. J. et al. Mar. Pollut. Bull. 156, 111150 (2020).
    CAS  Article  Google Scholar 

    8.
    Bayraktarov, E. et al. Ecol. Appl. 26, 1055–1074 (2016).
    Article  Google Scholar 

    9.
    Jones, P. J. S., Lieberknecht, L. M. & Qiu, W. Mar. Policy 71, 256–264 (2016).
    Article  Google Scholar 

    10.
    Bracewell, S. A., Spencer, M., Marrs, R. H., Iles, M. & Robinson, L. A. PLoS ONE 7, e48863 (2012).
    CAS  Article  Google Scholar 

    11.
    Evans, A. J. et al. Environ. Sci. Policy 91, 60–69 (2019).
    Article  Google Scholar 

    12.
    Firth, L. B. et al. J. Appl. Ecol. https://doi.org/10.1111/1365-2664.13683 (2020). More

  • in

    Coupled Southern Ocean cooling and Antarctic ice sheet expansion during the middle Miocene

    1.
    Ji, S. C. et al. A symmetrical CO2 peak and asymmetrical climate change during the middle Miocene. Earth Planet. Sci. Lett. 499, 134–144 (2018).
    Google Scholar 
    2.
    Sosdian, S. M. et al. Constraining the evolution of Neogene ocean carbonate chemistry using the boron isotope pH proxy. Earth Planet. Sci. Lett. 498, 362–376 (2018).
    Google Scholar 

    3.
    Super, J. R. et al. North Atlantic temperature and pCO2 coupling in the early–middle Miocene. Geology 46, 519–522 (2018).
    Google Scholar 

    4.
    Flower, B. P. & Kennett, J. P. Middle Miocene ocean-climate transition—high-resolution oxygen and carbon isotopic records from Deep-Sea Drilling Project Site 588A, Southwest Pacific. Paleoceanography 8, 811–843 (1993).
    Google Scholar 

    5.
    Zachos, J. C., Pagani, M., Sloan, L., Thomas, E. & Billups, K. Trends, rhythms, and aberrations in global climate 65 Ma to present. Science 292, 686–693 (2001).
    Google Scholar 

    6.
    de Boer, B., van de Wal, R. S. W., Bintanja, R., Lourens, L. J. & Tuenter, E. Cenozoic global ice-volume and temperature simulations with 1-D ice-sheet models forced by benthic δ18O records. Ann. Glaciol. 51, 23–33 (2010).
    Google Scholar 

    7.
    Lear, C. H., Mawbey, E. M. & Rosenthal, Y. Cenozoic benthic foraminiferal Mg/Ca and Li/Ca records: toward unlocking temperatures and saturation states. Paleoceanography 25, PA4215 (2010).

    8.
    Frigola, A., Prange, M. & Schulz, M. Boundary conditions for the middle Miocene climate transition (MMCT v1.0). Geosci. Model Dev. 11, 1607–1626 (2018).
    Google Scholar 

    9.
    Shevenell, A. E., Kennett, J. P. & Lea, D. W. Middle Miocene Southern Ocean cooling and Antarctic cryosphere expansion. Science 305, 1766–1770 (2004).
    Google Scholar 

    10.
    Kuhnert, H., Bickert, T. & Paulsen, H. Southern Ocean frontal system changes precede Antarctic ice sheet growth during the middle Miocene. Earth Planet. Sci. Lett. 284, 630–638 (2009).
    Google Scholar 

    11.
    Holbourn, A., Kuhnt, W., Schulz, M. & Erlenkeuser, H. Impacts of orbital forcing and atmospheric carbon dioxide on Miocene ice-sheet expansion. Nature 438, 483–487 (2005).
    Google Scholar 

    12.
    Gray, W. R. & Evans, D. Nonthermal influences on Mg/Ca in planktonic foraminifera: a review of culture studies and application to the Last Glacial Maximum. Paleoceanogr. Paleoclimatol. 34, 306–315 (2019).
    Google Scholar 

    13.
    Holland, K. et al. Constraining multiple controls on planktic foraminifera Mg/Ca. Geochim. Cosmochim. Acta 273, 116–136 (2020).
    Google Scholar 

    14.
    Exon, N. F. et al. in Proc. Ocean Drilling Program Initial Reports Vol. 189, Ch. 6 (ODP, 2001).

    15.
    Ghosh, P. et al. 13C–18O bonds in carbonate minerals: a new kind of paleothermometer. Geochim. Cosmochim. Acta 70, 1439–1456 (2006).
    Google Scholar 

    16.
    Peral, M. et al. Updated calibration of the clumped isotope thermometer in planktonic and benthic foraminifera. Geochim. Cosmochim. Acta 239, 1–16 (2018).
    Google Scholar 

    17.
    Leutert, T. J. et al. Sensitivity of clumped isotope temperatures in fossil benthic and planktic foraminifera to diagenetic alteration. Geochim. Cosmochim. Acta 257, 354–372 (2019).
    Google Scholar 

    18.
    Meinicke, N. et al. A robust calibration of the clumped isotopes to temperature relationship for foraminifers. Geochim. Cosmochim. Acta 270, 160–183 (2020).
    Google Scholar 

    19.
    Schouten, S., Hopmans, E. C., Schefuss, E. & Damsté, J. S. S. Distributional variations in marine crenarchaeotal membrane lipids: a new tool for reconstructing ancient sea water temperatures? Earth Planet. Sci. Lett. 204, 265–274 (2002).
    Google Scholar 

    20.
    Schouten, S., Hopmans, E. C. & Damsté, J. S. S. The organic geochemistry of glycerol dialkyl glycerol tetraether lipids: a review. Org. Geochem. 54, 19–61 (2013).
    Google Scholar 

    21.
    Elling, F. J., Konneke, M., Mussmann, M., Greve, A. & Hinrichs, K. U. Influence of temperature, pH, and salinity on membrane lipid composition and TEX86 of marine planktonic Thaumarchaeal isolates. Geochim. Cosmochim. Acta 171, 238–255 (2015).
    Google Scholar 

    22.
    Heath, R. A. et al. A review of the physical oceanography of the seas around New Zealand—1982. N. Z. J. Mar. Freshwater Res. 19, 79–124 (1985).
    Google Scholar 

    23.
    Torsvik, T. H. et al. Phanerozoic polar wander, palaeogeography and dynamics. Earth Sci. Rev. 114, 325–368 (2012).
    Google Scholar 

    24.
    van Hinsbergen, D. J. J. et al. A paleolatitude calculator for paleoclimate studies. PLoS ONE 10, e0126946 (2015).
    Google Scholar 

    25.
    King, A. L. & Howard, W. R. Seasonality of foraminiferal flux in sediment traps at Chatham Rise, SW Pacific: implications for paleotemperature estimates. Deep-Sea Res. I 48, 1687–1708 (2001).
    Google Scholar 

    26.
    Pahnke, K., Zahn, R., Elderfield, H. & Schulz, M. 340,000-year centennial-scale marine record of Southern Hemisphere climatic oscillation. Science 301, 948–952 (2003).
    Google Scholar 

    27.
    Vázquez Riveiros, N. et al. Mg/Ca thermometry in planktic foraminifera: improving paleotemperature estimations for G. bulloides and N. pachyderma left. Geochem. Geophys. Geosyst. 17, 1249–1264 (2016).
    Google Scholar 

    28.
    Sangiorgi, F. et al. Southern Ocean warming and Wilkes Land ice sheet retreat during the mid-Miocene. Nat. Commun. 9, 317 (2018).
    Google Scholar 

    29.
    Knorr, G. & Lohmann, G. Climate warming during Antarctic ice sheet expansion at the middle Miocene transition. Nat. Geosci. 7, 376–381 (2014).
    Google Scholar 

    30.
    Ho, S. L. & Laepple, T. Flat meridional temperature gradient in the early Eocene in the subsurface rather than surface ocean. Nat. Geosci. 9, 606–610 (2016).
    Google Scholar 

    31.
    Evans, D. & Müller, W. Deep time foraminifera Mg/Ca paleothermometry: nonlinear correction for secular change in seawater Mg/Ca. Paleoceanography 27, PA4205 (2012).
    Google Scholar 

    32.
    Lear, C. H. et al. Neogene ice volume and ocean temperatures: insights from infaunal foraminiferal Mg/Ca paleothermometry. Paleoceanography 30, 1437–1454 (2015).
    Google Scholar 

    33.
    Shevenell, A. E., Kennett, J. P. & Lea, D. W. Southern Ocean Middle Miocene ODP1171 Foraminifer Stable Isotope and Mg/Ca Data IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series no. 2006-061 (NOAA/NCDC, 2006).

    34.
    Gray, W. R. et al. The effects of temperature, salinity, and the carbonate system on Mg/Ca in Globigerinoides ruber (white): a global sediment trap calibration. Earth Planet. Sci. Lett. 482, 607–620 (2018).
    Google Scholar 

    35.
    Toggweiler, J. R., Russell, J. L. & Carson, S. R. Midlatitude westerlies, atmospheric CO2, and climate change during the ice ages. Paleoceanography 21, PA2005 (2006).
    Google Scholar 

    36.
    Anderson, R. F. et al. Wind-driven upwelling in the Southern Ocean and the deglacial rise in atmospheric CO2. Science 323, 1443–1448 (2009).
    Google Scholar 

    37.
    Sigman, D. M., Hain, M. P. & Haug, G. H. The polar ocean and glacial cycles in atmospheric CO2 concentration. Nature 466, 47–55 (2010).
    Google Scholar 

    38.
    Studer, A. S. et al. Antarctic Zone nutrient conditions during the last two glacial cycles. Paleoceanography 30, 845–862 (2015).
    Google Scholar 

    39.
    Müller, R. D. et al. GPlates: building a virtual Earth through deep time. Geochem. Geophys. Geosyst. 19, 2243–2261 (2018).
    Google Scholar 

    40.
    Matthews, K. J. et al. Global plate boundary evolution and kinematics since the late Paleozoic. Glob. Planet. Change 146, 226–250 (2016).
    Google Scholar 

    41.
    Bernasconi, S. M. et al. Reducing uncertainties in carbonate clumped isotope analysis through consistent carbonate-based standardization. Geochem. Geophys. Geosyst. 19, 2895–2914 (2018).
    Google Scholar 

    42.
    Kele, S. et al. Temperature dependence of oxygen- and clumped isotope fractionation in carbonates: a study of travertines and tufas in the 6–95 °C temperature range. Geochim. Cosmochim. Acta 168, 172–192 (2015).
    Google Scholar 

    43.
    Kim, J. H. et al. New indices and calibrations derived from the distribution of crenarchaeal isoprenoid tetraether lipids: implications for past sea surface temperature reconstructions. Geochim. Cosmochim. Acta 74, 4639–4654 (2010).
    Google Scholar 

    44.
    Greenop, R. et al. A record of Neogene seawater δ11B reconstructed from paired δ11B analyses on benthic and planktic foraminifera. Clim. Past 13, 149–170 (2017).
    Google Scholar 

    45.
    Shevenell, A. E. & Kennett, J. P. in The Cenozoic Southern Ocean: Tectonics, Sedimentation, and Climate Change Between Australia and Antarctica Vol. 151 (eds Exon, N. et al.) 235–252 (AGU, 2004).

    46.
    Shevenell, A. E., Kennett, J. P. & Lea, D. W. Middle Miocene ice sheet dynamics, deep-sea temperatures, and carbon cycling: a Southern Ocean perspective. Geochem. Geophys. Geosyst. 9, Q02006 (2008).
    Google Scholar 

    47.
    Schmid, T. W., Radke, J. & Bernasconi, S. M. Clumped-Isotope Measurements on Small Carbonate Samples with a Kiel IV Carbonate Device and a MAT 253 Mass Spectrometer Application Note 30233 (ThermoFisher, 2012).

    48.
    Hu, B. et al. A modified procedure for gas-source isotope ratio mass spectrometry: the long-integration dual-inlet (LIDI) methodology and implications for clumped isotope measurements. Rapid Commun. Mass Spectrom. 28, 1413–1425 (2014).
    Google Scholar 

    49.
    Meckler, A. N., Ziegler, M., Millan, M. I., Breitenbach, S. F. M. & Bernasconi, S. M. Long-term performance of the Kiel carbonate device with a new correction scheme for clumped isotope measurements. Rapid Commun. Mass Spectrom. 28, 1705–1715 (2014).
    Google Scholar 

    50.
    Grauel, A. L. et al. Calibration and application of the ‘clumped isotope’ thermometer to foraminifera for high resolution climate reconstructions. Geochim. Cosmochim. Acta 108, 125–140 (2013).
    Google Scholar 

    51.
    Rodríguez-Sanz, L. et al. Penultimate deglacial warming across the Mediterranean Sea revealed by clumped isotopes in foraminifera. Sci. Rep. 7, 16572 (2017).
    Google Scholar 

    52.
    Schmid, T. W. & Bernasconi, S. M. An automated method for ‘clumped-isotope’ measurements on small carbonate samples. Rapid Commun. Mass Spectrom. 24, 1955–1963 (2010).
    Google Scholar 

    53.
    Piasecki, A. et al. Application of clumped isotope thermometry to benthic foraminifera. Geochem. Geophys. Geosyst. 20, 2082–2090 (2019).
    Google Scholar 

    54.
    Huntington, K. W. et al. Methods and limitations of ‘clumped’ CO2 isotope (Δ47) analysis by gas-source isotope ratio mass spectrometry. J. Mass Spectrom. 44, 1318–1329 (2009).
    Google Scholar 

    55.
    Auderset, A., Schmitt, M. & Martínez-García, A. Simultaneous extraction and chromatographic separation of n-alkanes and alkenones from glycerol dialkyl glycerol tetraethers via selective accelerated solvent extraction. Org. Geochem. 143, 103979 (2020).
    Google Scholar 

    56.
    Hopmans, E. C., Schouten, S. & Damsté, J. S. S. The effect of improved chromatography on GDGT-based palaeoproxies. Org. Geochem. 93, 1–6 (2016).
    Google Scholar 

    57.
    Huguet, C. et al. An improved method to determine the absolute abundance of glycerol dibiphytanyl glycerol tetraether lipids. Org. Geochem. 37, 1036–1041 (2006).
    Google Scholar 

    58.
    Evans, D., Brierley, C., Raymo, M. E., Erez, J. & Müller, W. Planktic foraminifera shell chemistry response to seawater chemistry: Pliocene–Pleistocene seawater Mg/Ca, temperature and sea level change. Earth Planet. Sci. Lett. 438, 139–148 (2016).
    Google Scholar 

    59.
    Cramwinckel, M. J. et al. Synchronous tropical and polar temperature evolution in the Eocene. Nature 559, 382–386 (2018).
    Google Scholar 

    60.
    Shackleton, N. J. Attainment of isotopic equilibrium between ocean water and the benthonic foraminifera genus Uvigerina: isotopic changes in the ocean during the last glacial. Colloq. Int. C.N.R.S. 219, 203–209 (1974).
    Google Scholar 

    61.
    Bemis, B. E., Spero, H. J., Bijma, J. & Lea, D. W. Reevaluation of the oxygen isotopic composition of planktonic foraminifera: experimental results and revised paleotemperature equations. Paleoceanography 13, 150–160 (1998).
    Google Scholar 

    62.
    Schmidt, G. A., Bigg, G. R. & Rohling, E. J. Global Seawater Oxygen-18 Database Version 1.22 (GISS, 1999); https://data.giss.nasa.gov/o18data/ More

  • in

    Ecological restoration impact on total terrestrial water storage

    1.
    Bryan, B. A. et al. China’s response to a national land-system sustainability emergency. Nature 559, 193–204 (2018).
    CAS  Google Scholar 
    2.
    Ouyang, Z. et al. Improvements in ecosystem services from investments in natural capital. Science 352, 1455–1459 (2016).
    CAS  Google Scholar 

    3.
    Chen, C. et al. China and India lead in greening of the world through land-use management. Nat. Sustain. 2, 122–129 (2019).
    Google Scholar 

    4.
    Tong, X. et al. Increased vegetation growth and carbon stock in China karst via ecological engineering. Nat. Sustain. 1, 44–50 (2018).
    Google Scholar 

    5.
    Lu, F. et al. Effects of national ecological restoration projects on carbon sequestration in China from 2001 to 2010. Proc. Natl Acad. Sci. USA 115, 4039 (2018).
    CAS  Google Scholar 

    6.
    Feng, X. et al. Revegetation in China’s Loess Plateau is approaching sustainable water resource limits. Nat. Clim. Change 6, 1019 (2016).
    Google Scholar 

    7.
    Jia, X., Shao, M. A., Zhu, Y. & Luo, Y. Soil moisture decline due to afforestation across the Loess Plateau, China. J. Hydrol. 546, 113–122 (2017).
    Google Scholar 

    8.
    Chen, Y. et al. Balancing green and grain trade. Nat. Geosci. 8, 739–741 (2015).
    Google Scholar 

    9.
    Tong, X. et al. Forest management in southern China generates short term extensive carbon sequestration. Nat. Commun. 11, 129 (2020).
    CAS  Google Scholar 

    10.
    Jackson, R. B. et al. Trading water for carbon with biological carbon sequestration. Science 310, 1944–1947 (2005).
    CAS  Google Scholar 

    11.
    Li, Y. et al. Divergent hydrological response to large-scale afforestation and vegetation greening in China. Sci. Adv. 4, eaar4182 (2018).
    Google Scholar 

    12.
    Green, J. K. et al. Regionally strong feedbacks between the atmosphere and terrestrial biosphere. Nat. Geosci. 10, 410–414 (2017).
    CAS  Google Scholar 

    13.
    Branch, O. & Wulfmeyer, V. Deliberate enhancement of rainfall using desert plantations. Proc. Natl Acad. Sci. USA 116, 18841–18847 (2019).
    CAS  Google Scholar 

    14.
    Ellison, D. et al. Trees, forests and water: cool insights for a hot world. Glob. Environ. Change 43, 51–61 (2017).
    Google Scholar 

    15.
    McDonnell, J. J. et al. Water sustainability and watershed storage. Nat. Sustain. 1, 378–379 (2018).
    Google Scholar 

    16.
    Rodell, M. et al. Emerging trends in global freshwater availability. Nature 557, 651–659 (2018).
    CAS  Google Scholar 

    17.
    Mirzabaev, A. et al. in IPCC Special Report on Climate Change and Land (eds Akhtar-Schuster, M., Driouech, F. & Sankaran, M.) Ch. 3 (IPCC, Cambridge Univ. Press, 2019).

    18.
    Rodell, M., Velicogna, I. & Famiglietti, J. S. Satellite-based estimates of groundwater depletion in India. Nature 460, 999–1002 (2009).
    CAS  Google Scholar 

    19.
    Scanlon, B. R. et al. Global models underestimate large decadal declining and rising water storage trends relative to GRACE satellite data. Proc. Natl Acad. Sci. USA 115, E1080 (2018).
    CAS  Google Scholar 

    20.
    Tapley, B. D., Bettadpur, S., Ries, J. C., Thompson, P. F. & Watkins, M. M. GRACE Measurements of Mass Variability in the Earth System. Science 305, 503–505 (2004).
    CAS  Google Scholar 

    21.
    Tapley, B. D. et al. Contributions of GRACE to understanding climate change. Nat. Clim. Change 9, 358–369 (2019).
    Google Scholar 

    22.
    Tian, H. et al. Response of vegetation activity dynamic to climatic change and ecological restoration programs in Inner Mongolia from 2000 to 2012. Ecol. Eng. 82, 276–289 (2015).
    Google Scholar 

    23.
    Zhang, Z. & Huisingh, D. Combating desertification in China: monitoring, control, management and revegetation. J. Clean. Prod. 182, 765–775 (2018).
    Google Scholar 

    24.
    Huang, Y., Wang, N.-a, He, T., Chen, H. & Zhao, L. Historical desertification of the Mu Us Desert, Northern China: A multidisciplinary study. Geomorphology 110, 108–117 (2009).
    Google Scholar 

    25.
    Xu, D. Y., Kang, X. W., Zhuang, D. F. & Pan, J. J. Multi-scale quantitative assessment of the relative roles of climate change and human activities in desertification–a case study of the Ordos Plateau, China. J. Arid Environ. 74, 498–507 (2010).
    Google Scholar 

    26.
    Yan, F., Wu, B. & Wang, Y. Estimating spatiotemporal patterns of aboveground biomass using Landsat TM and MODIS images in the Mu Us Sandy Land, China. Agric. For. Meteorol. 200, 119–128 (2015).
    Google Scholar 

    27.
    Li, S. et al. Vegetation changes in recent large-scale ecological restoration projects and subsequent impact on water resources in China’s Loess Plateau. Sci. Total Environ. 569–570, 1032–1039 (2016).
    Google Scholar 

    28.
    Xu, Z. et al. Recent greening (1981–2013) in the Mu Us dune field, north-central China, and its potential causes. Land Degrad. Dev. 29, 1509–1520 (2018).
    Google Scholar 

    29.
    Poulter, B. et al. Plant functional type classification for earth system models: results from the European Space Agency’s Land Cover Climate Change Initiative. Geosci. Model Dev. 8, 2315–2328 (2015).
    Google Scholar 

    30.
    Xu, Z., Mason, J. A. & Lu, H. Vegetated dune morphodynamics during recent stabilization of the Mu Us dune field, north-central China. Geomorphology 228, 486–503 (2015).
    Google Scholar 

    31.
    Review of the Kubuqi Ecological Restoration Project: A Desert Green Economy Pilot Initiative (United Nations Environment Programme, 2015).

    32.
    Cheng, D.-h et al. Estimation of groundwater evaportranspiration using diurnal water table fluctuations in the Mu Us Desert, northern China. J. Hydrol. 490, 106–113 (2013).
    Google Scholar 

    33.
    Yu, X., Huang, Y., Li, E., Li, X. & Guo, W. Effects of rainfall and vegetation to soil water input and output processes in the Mu Us Sandy Land, northwest China. CATENA 161, 96–103 (2018).
    Google Scholar 

    34.
    Li, Q. et al. Feasibility of the combination of CO2 Geological storage and saline water development in sedimentary basins of China. Energy Proc. 37, 4511–4517 (2013).
    CAS  Google Scholar 

    35.
    Xie, X., Xu, C., Wen, Y. & Li, W. Monitoring groundwater storage changes in the Loess Plateau using GRACE satellite gravity data, hydrological models and coal mining data. Remote Sens. 10, 605 (2018).
    Google Scholar 

    36.
    Griffin-Nolan, R. J. et al. Legacy effects of a regional drought on aboveground net primary production in six central US grasslands. Plant Ecol. 219, 505–515 (2018).
    Google Scholar 

    37.
    Poulter, B. et al. Contribution of semi-arid ecosystems to interannual variability of the global carbon cycle. Nature 509, 600–603 (2014).
    CAS  Google Scholar 

    38.
    Ahlström, A. et al. The dominant role of semi-arid ecosystems in the trend and variability of the land CO2 sink. Science 348, 895–899 (2015).
    Google Scholar 

    39.
    Cho, S., Ser-Oddamba, B., Batkhuu, N.-O. & Seok Kim, H. Comparison of water use efficiency and biomass production in 10-year-old Populus sibirica and Ulmus pumila plantations in Lun soum, Mongolia. For. Sci. Technol. 15, 147–158 (2019).
    Google Scholar 

    40.
    Swenson, S. C. & Lawrence, D. M. A GRACE-based assessment of interannual groundwater dynamics in the Community Land Model. Water Resour. Res. 51, 8817–8833 (2015).
    Google Scholar 

    41.
    Guo, J., Huang, G., Wang, X., Li, Y. & Lin, Q. Investigating future precipitation changes over China through a high-resolution regional climate model ensemble. Earth’s Future 5, 285–303 (2017).
    Google Scholar 

    42.
    Gong, T., Lei, H., Yang, D., Jiao, Y. & Yang, H. Monitoring the variations of evapotranspiration due to land use/cover change in a semiarid shrubland. Hydrol. Earth Syst. Sci. 21, 863–877 (2017).
    Google Scholar 

    43.
    Feng, W. et al. Evaluation of groundwater depletion in North China using the Gravity Recovery and Climate Experiment (GRACE) data and ground-based measurements. Water Resour. Res. 49, 2110–2118 (2013).
    Google Scholar 

    44.
    Famiglietti, J. S. Satellites measure recent rates of groundwater depletion in California’s Central Valley. Geophys. Res. Lett. 38, L03403 (2011).
    Google Scholar 

    45.
    Wang, J. et al. Recent global decline in endorheic basin water storages. Nat. Geosci. 11, 926–932 (2018).
    CAS  Google Scholar 

    46.
    Chen, X. et al. Detecting significant decreasing trends of land surface soil moisture in eastern China during the past three decades (1979–2010). J. Geophys. Res. Atmos. 121, 5177–5192 (2016).
    Google Scholar 

    47.
    Peng, D. & Zhou, T. Why was the arid and semiarid northwest China getting wetter in the recent decades? J. Geophys. Res. Atmos. 122, 9060–9075 (2017).
    Google Scholar 

    48.
    Grassi, G. et al. The key role of forests in meeting climate targets requires science for credible mitigation. Nat. Clim. Change 7, 220–226 (2017).
    Google Scholar 

    49.
    Griscom, B. W. et al. Natural climate solutions. Proc. Natl Acad. Sci. USA 114, 11645 (2017).
    CAS  Google Scholar 

    50.
    Bastin, J.-F. et al. The global tree restoration potential. Science 365, 76–79 (2019).
    CAS  Google Scholar 

    51.
    Watkins, M. M., Wiese, D. N., Yuan, D.-N., Boening, C. & Landerer, F. W. Improved methods for observing Earth’s time variable mass distribution with GRACE using spherical cap mascons. J. Geophys. Res. Solid Earth 120, 2648–2671 (2015).
    Google Scholar 

    52.
    Wiese, D. N., Landerer, F. W. & Watkins, M. M. Quantifying and reducing leakage errors in the JPL RL05M GRACE mascon solution. Water Resour. Res. 52, 7490–7502 (2016).
    Google Scholar 

    53.
    Myneni, R. B., Hall, F. G., Sellers, P. J. & Marshak, A. L. The interpretation of spectral vegetation indexes. IEEE Trans. Geosci. Remote Sens. 33, 481–486 (1995).
    Google Scholar 

    54.
    Glenn, E. P., Huete, A. R., Nagler, P. L., Hirschboeck, K. K. & Brown, P. Integrating remote sensing and ground methods to estimate evapotranspiration. Crit. Rev. Plant Sci. 26, 139–168 (2007).
    Google Scholar 

    55.
    Pinzon, J. & Tucker, C. A non-stationary 1981–2012 AVHRR NDVI3g time series. Remote Sens. 6, 6929–6960 (2014).
    Google Scholar 

    56.
    Fan, X. & Liu, Y. Multisensor normalized difference vegetation index intercalibration: A comprehensive overview of the causes of and solutions for multisensor differences. IEEE Geosci. Remote Sens. Mag. 6, 23–45 (2018).
    Google Scholar 

    57.
    Huffman, G. J. et al. The TRMM multisatellite precipitation analysis (TMPA): Quasi-global, multiyear, combined-sensor precipitation estimates at fine scales. J. Hydrometeorol. 8, 38–55 (2007).
    Google Scholar 

    58.
    Harris, I., Osborn, T. J., Jones, P. & Lister, D. Version 4 of the CRU TS monthly high-resolution gridded multivariate climate dataset. Sci. Data 7, 109 (2020).
    Google Scholar 

    59.
    Zhou, Y., Shi, C., Du, J. & Fan, X. Characteristics and causes of changes in annual runoff of the Wuding River in 1956–2009. Environ. Earth Sci. 69, 225–234 (2013).
    Google Scholar 

    60.
    Rodell, M. Basin scale estimates of evapotranspiration using GRACE and other observations. Geophys. Res. Lett. 31, L20504 (2004).
    Google Scholar 

    61.
    Gerten, D., Schaphoff, S., Haberlandt, U., Lucht, W. & Sitch, S. Terrestrial vegetation and water balance—hydrological evaluation of a dynamic global vegetation model. J. Hydrol. 286, 249–270 (2004).
    CAS  Google Scholar 

    62.
    Smith, B. et al. Implications of incorporating N cycling and N limitations on primary production in an individual-based dynamic vegetation model. Biogeosciences 11, 2027–2054 (2014).
    Google Scholar 

    63.
    Haxeltine, A. & Prentice, I. C. BIOME3: An equilibrium terrestrial biosphere model based on ecophysiological constraints, resource availability, and competition among plant functional types. Glob. Biogeochem. Cycles 10, 693–709 (1996).
    CAS  Google Scholar 

    64.
    Prestele, R. et al. Current challenges of implementing anthropogenic land-use and land-cover change in models contributing to climate change assessments. Earth Syst. Dyn. 8, 369–386 (2017).
    Google Scholar 

    65.
    Piao, S. et al. Lower land-use emissions responsible for increased net land carbon sink during the slow warming period. Nat. Geosci. 11, 739–743 (2018).
    CAS  Google Scholar 

    66.
    Tian, H. et al. The Global N2O Model Intercomparison Project. Bull. Am. Meteorol. Soc. 99, 1231–1251 (2018).
    Google Scholar 

    67.
    Etheridge, D. M. et al. Natural and anthropogenic changes in atmospheric CO2 over the last 1000 years from air in Antarctic ice and firn. J. Geophys. Res. Atmos. 101, 4115–4128 (1996).
    CAS  Google Scholar 

    68.
    Keeling, C. D., Whorf, T. P., Wahlen, M. & van der Plichtt, J. Interannual extremes in the rate of rise of atmospheric carbon dioxide since 1980. Nature 375, 666–670 (1995).
    CAS  Google Scholar  More

  • in

    Context-aware dimensionality reduction deconvolutes gut microbial community dynamics

    1.
    Gibson, T. E. & Gerber, G. K. Robust and scalable models of microbiome dynamics. In Proceedings of the 35th International Conference on Machine Learning 80 (eds Dy, J. et al.) 1763–1772 (PMLR, 2018).
    2.
    Shenhav, L. et al. Modeling the temporal dynamics of the gut microbial community in adults and infants. PLoS Comput. Biol. 15, e1006960 (2019).
    CAS  Article  Google Scholar 

    3.
    Äijö, T., Müller, C. L. & Bonneau, R. Temporal probabilistic modeling of bacterial compositions derived from 16S rRNA sequencing. Bioinformatics 34, 372–380 (2018).
    Article  Google Scholar 

    4.
    Silverman, J. D., Durand, H. K., Bloom, R. J., Mukherjee, S. & David, L. A. Dynamic linear models guide design and analysis of microbiota studies within artificial human guts. Microbiome 6, 202 (2018).
    Article  Google Scholar 

    5.
    Martino, C. et al. A novel sparse compositional technique reveals microbial perturbations. mSystems 4, e00016–e00019 (2019).
    Article  Google Scholar 

    6.
    Gloor, G. B., Macklaim, J. M., Pawlowsky-Glahn, V. & Egozcue, J. J. Microbiome datasets are compositional: and this is not optional. Front. Microbiol. 8, 2224 (2017).
    Article  Google Scholar 

    7.
    Morton, J. T. et al. Establishing microbial composition measurement standards with reference frames. Nat. Commun. 10, 2719 (2019).
    Article  Google Scholar 

    8.
    Halfvarson, J. et al. Dynamics of the human gut microbiome in inflammatory bowel disease. Nat. Microbiol. 2, 17004 (2017).
    CAS  Article  Google Scholar 

    9.
    Jaccard, P. The distribution of the flora in the alpine zone. 1. New Phytol. 11, 37–50 (1912).
    Article  Google Scholar 

    10.
    Bray, J. R. & Curtis, J. T. An ordination of the upland forest communities of Southern Wisconsin. Ecol. Monogr. 27, 325–349 (1957).
    Article  Google Scholar 

    11.
    Aitchison, J. Principal component analysis of compositional data. Biometrika 70, 57–65 (1983).
    Article  Google Scholar 

    12.
    Lozupone, C. & Knight, R. UniFrac: a new phylogenetic method for comparing microbial communities. Appl. Environ. Microbiol. 71, 8228–8235 (2005).
    CAS  Article  Google Scholar 

    13.
    McDonald, D. et al. Striped UniFrac: enabling microbiome analysis at unprecedented scale. Nat. Methods 15, 847–848 (2018).
    CAS  Article  Google Scholar 

    14.
    Bokulich, N. A. et al. Antibiotics, birth mode, and diet shape microbiome maturation during early life. Sci. Transl. Med. 8, 343ra82–343ra82 (2016).
    Article  Google Scholar 

    15.
    Yassour, M. et al. Natural history of the infant gut microbiome and impact of antibiotic treatment on bacterial strain diversity and stability. Sci. Transl. Med. 8, 343ra81 (2016).
    Article  Google Scholar 

    16.
    McDonald, D. et al. American Gut: an open platform for citizen science microbiome research. mSystems 3, e00031–18 (2018).
    CAS  Article  Google Scholar 

    17.
    Lauber, C. L., Hamady, M., Knight, R. & Fierer, N. Pyrosequencing-based assessment of soil pH as a predictor of soil bacterial community structure at the continental scale. Appl. Environ. Microbiol. 75, 5111–5120 (2009).
    CAS  Article  Google Scholar 

    18.
    Keshavan, R. H., Montanari, A. & Oh, S. Low-rank matrix completion with noisy observations: a quantitative comparison. In Proc. 2009 47th Annual Allerton Conference on Communication, Control, and Computing 1216–1222 (Curran Associates, 2009).

    19.
    Lek-Heng Lim. Singular values and eigenvalues of tensors: a variational approach. In Proc. 1st IEEE International Workshop on Computational Advances in Multi-Sensor Adaptive Processing 129–132 (Curran Associates, 2005).

    20.
    Anandkumar, A., Ge, R. & Janzamin, M. Guaranteed non-orthogonal tensor decomposition via alternating rank-1 updates. Preprint at arXiv http://arxiv.org/abs/1402.5180 (2014).

    21.
    Jain, P. & Oh, S. Provable tensor factorization with missing data. Adv. Neural Inf. Process. Syst. 27 (eds Ghahramani, Z. et al.) 1431–1439 (Curran Associates, 2014).

    22.
    Aitchison, J. & Ho, C. H. The multivariate Poisson-log normal distribution. Biometrika 76, 643–653 (1989).
    Article  Google Scholar 

    23.
    Amir, A. et al. Deblur rapidly resolves single-nucleotide community sequence patterns. mSystems 2, e00191–16 (2017).
    PubMed  PubMed Central  Google Scholar 

    24.
    Bolyen, E. et al. Reproducible, interactive, scalable and extensible microbiome data science using QIIME 2. Nat. Biotechnol. 37, 852–857 (2019).
    CAS  Article  Google Scholar 

    25.
    Janssen, S. et al. Phylogenetic placement of exact amplicon sequences improves associations with clinical information. mSystems 3, e00021–18 (2018).
    CAS  Article  Google Scholar 

    26.
    McDonald, D. et al. An improved Greengenes taxonomy with explicit ranks for ecological and evolutionary analyses of bacteria and archaea. ISME J. 6, 610–618 (2012).
    CAS  Article  Google Scholar 

    27.
    Gonzalez, A. et al. Qiita: rapid, web-enabled microbiome meta-analysis. Nat. Methods 551, 457 (2018).
    Google Scholar  More

  • in

    Decoupling livestock and crop production at the household level in China

    1.
    Griggs, D. et al. Sustainable development goals for people and planet. Nature 495, 305–307 (2013).
    CAS  Article  Google Scholar 
    2.
    FAOSTAT: FAO Statistical Databases (FAO, 2020).

    3.
    Bai, Z. et al. China’s livestock transition: driving forces, impacts, and consequences. Sci. Adv. 4, r8534 (2018).
    Article  Google Scholar 

    4.
    Oenema, O. Nitrogen budgets and losses in livestock systems. Int. Congr. Ser. 1293, 262–271 (2006).
    Article  Google Scholar 

    5.
    Sutton, M. A. et al. Our Nutrient World: The Challenge to Produce More Food and Energy with Less Pollution (Centre for Ecology and Hydrology, 2013).

    6.
    van Grinsven, H. J. M. et al. Reducing external costs of nitrogen pollution by relocation of pig production between regions in the European Union. Reg. Environ. Change 18, 2403–2415 (2018).
    Article  Google Scholar 

    7.
    Sutton, M. A. et al. Too much of a good thing. Nature 472, 159–161 (2011).
    CAS  Article  Google Scholar 

    8.
    Gu, B., Zhang, X., Bai, X., Fu, B. & Chen, D. Four steps to food security for swelling cities. Nature 566, 31–33 (2019).
    CAS  Article  Google Scholar 

    9.
    Zhang, C. et al. Rebuilding the linkage between livestock and cropland to mitigate agricultural pollution in China. Resour. Conserv Recycl. 144, 65–73 (2019).
    Article  Google Scholar 

    10.
    Gu, B., Ju, X., Chang, S. X., Ge, Y. & Chang, J. Nitrogen use efficiencies in Chinese agricultural systems and implications for food security and environmental protection. Reg. Environ. Change 17, 1217–1227 (2017).
    Article  Google Scholar 

    11.
    Gu, B., Ju, X., Chang, J., Ge, Y. & Vitousek, P. M. Integrated reactive nitrogen budgets and future trends in China. Proc. Natl Acad. Sci. USA 112, 8792–8797 (2015).
    CAS  Article  Google Scholar 

    12.
    Ma, L. et al. Exploring future food provision scenarios for China. Environ. Sci. Technol. 53, 1385–1393 (2018).
    Article  Google Scholar 

    13.
    Wu, Y. et al. Policy distortions, farm size, and the overuse of agricultural chemicals in China. Proc. Natl Acad. Sci. USA 115, 7010–7015 (2018).
    CAS  Article  Google Scholar 

    14.
    Ju, X., Gu, B., Wu, Y. & Galloway, J. N. Reducing China’s fertilizer use by increasing farm size. Glob. Environ. Change 41, 26–32 (2016).
    Article  Google Scholar 

    15.
    Fan, L. et al. Decreasing farm number benefits the mitigation of agricultural non-point source pollution in China. Environ. Sci. Pollut. Res. Int. 26, 464–472 (2019).
    Article  Google Scholar 

    16.
    Naylor, R. Losing the links between livestock and land. Science 310, 1621–1622 (2005).
    CAS  Article  Google Scholar 

    17.
    Willems, J. et al. Why Danish pig farms have far more land and pigs than Dutch farms? Implications for feed supply, manure recycling and production costs. Agric. Syst. 144, 122–132 (2016).
    Article  Google Scholar 

    18.
    Garnier, J. et al. Reconnecting crop and cattle farming to reduce nitrogen losses to river water of an intensive agricultural catchment (Seine basin, France): past, present and future. Environ. Sci. Policy 63, 76–90 (2016).
    CAS  Article  Google Scholar 

    19.
    National Data (National Bureau of China, 2019).

    20.
    Bai, X., Shi, P. & Liu, Y. Society: realizing China’s urban dream. Nature 509, 158–160 (2014).
    Article  Google Scholar 

    21.
    Zheng, C., Liu, Y., Bluemling, B., Mol, A. P. J. & Chen, J. Environmental potentials of policy instruments to mitigate nutrient emissions in Chinese livestock production. Sci. Total Environ. 502, 149–156 (2015).
    CAS  Article  Google Scholar 

    22.
    Cui, Z. et al. Pursuing sustainable productivity with millions of smallholder farmers. Nature 555, 363–366 (2018).
    CAS  Article  Google Scholar 

    23.
    Bai, Z. et al. China’s pig relocation in balance. Nat. Sustain. 2, 888 (2019).
    Article  Google Scholar 

    24.
    Zhang, X. et al. Managing nitrogen for sustainable development. Nature 528, 51–59 (2015).
    CAS  Article  Google Scholar 

    25.
    van Grinsven, H. J. M. et al. Costs and benefits of nitrogen for Europe and implications for mitigation. Environ. Sci. Technol. 47, 3571–3579 (2013).
    Article  Google Scholar 

    26.
    Oenema, O. et al. in The European Nitrogen Assessment: Sources, Effects and Policy Perspectives (eds M. A. Sutton et al.) 62–81 (Cambridge Univ. Press, 2011).

    27.
    The Technical Guidelines for Measuring the Bearing Capacity of Soil Contaminated by Livestock and Poultry Manure (Ministry of Agriculture and Rural Affairs of the People’s Republic of China, 2018).

    28.
    Gu, B. et al. Toward a generic analytical framework for sustainable nitrogen management: application for China. Environ. Sci. Technol. 53, 1109–1118 (2019).
    CAS  Article  Google Scholar  More