ALBERT

Description: Data underlying figures 1, 2, 3 and 5. Figure 1: Monthly mass changes of the Greenland Ice Sheet from GRACE/GRACE-FO and SMB-D (2003-2019) Figure 2: Biennial mass balance and its components from GRACE/GRACE-FO and SMB-D (2003-2018) for the Greenland Ice Sheet, along with regional estimates for 2017-2018 for East and West. Figure 3: Rate of mass change for year 2019 from GRACE/GRACE-FO and SMB-D Figure 5: Annual mass balance and its main components from SMB-D (1948-2019) and GRACE/GRACE-FO (2003-2019)

Description: Here, we provide the raw pollen data archived in three Siberian lake sediment cores spanning the mid-Holocene to the present (7.6-0 cal ka BP), from northern typical tundra to southern open larch forest in the Omoloy region. There are three cores: 1. 14-OM-20B, Lat. / °: 70.53, Lon. / °: 132.91, Ele. / m a.s.l.: 52, Modern vegetation: open larch forest, Lake area / km2: 0.26, Maximal depth / m: 3.4 2. 14-OM-02B, Lat. / °: 70.72, Lon. / °: 132.67, Ele. / m a.s.l.: 58, Modern vegetation: forest tundra, Lake area / km2: 0.08, Maximal depth / m: 3.5 3. 14-OM-12A, Lat. / °: 70.96, Lon. / °: 132.57, Ele. / m a.s.l.: 60, Modern vegetation: tundra, Lake area / km2: 0.09, Maximal depth / m: 4.5 Three lake sediment cores, 14OM12A (33 cm long), 14OM02B (49.5 cm long) and 14OM20B (86 cm long), were recovered from three sites using a UWITEC gravity corer (6 cm internal diameter) equipped with a hammer tool in July 2014. From the three cores, 16 bulk organic carbon samples were selected because of the lack of macrofossil remains and radiocarbon dated using accelerator mass spectrometry (AMS) at Poznań radiocarbon laboratory of Adam Mickiewicz University, Poland. In addition, 30 freeze-dried samples per core at 0.25 or 0.5 cm intervals between 0 and 15 cm were analysed for 210Pb/137Cs at the Liverpool University Environmental Radioactivity Laboratory. In this project, we analyse pollen and sedaDNA (Liu et al., 2020; doi:10.5061/dryad.69p8cz900) from three lake sediment cores from the Omoloy region in north-eastern Siberia (northern Yakutia), which are currently surrounded by different vegetation types ranging from typical tundra to open larch forest. First, our aim is to compare sedaDNA with the pollen data to see whether both methods track the same pattern with respect to compositional changes and diversity changes across the northern Russian treeline zone or are complementary to each other. Second, we reconstruct the mid- to late-Holocene changes of vegetation composition along a north–south transect. Third, we use the sedaDNA data to reconstruct variations in species richness and relate this to vegetation and climate change.

Description: Understanding the resilience of African savannas to global change requires quantitative information on long-term vegetation dynamics. Here we present a reconstruction of past vegetation cover of the northern Namibian savanna obtained after applying the REVEALS model to fossil pollen data from Lake Otjikoto. We also present modern pollen and vegetation data used to calculate pollen productivity estimates for the major Namibian savanna taxa Acacia (Senegalia, Vachellia), Combretaceae, Dichrostachys, Grewia and Poaceae. Data were collected at 10 sites along a rainfall gradient in north central Namibia. Modern pollen was extracted from soil samples collected from plots at the different sites. Vegetation data were extracted from satellite images covering a 1.5 km radius from the plots where pollen was collected. The mean cover of the studied taxa was calculated by 100 m rings.

Description: The Late Holocene is a substantial cultural and economic transition in the eastern Eurasian Steppe and Altai Region, but paleoclimate conditions during this time remain unclear. Therefore, we established a high-resolution paleoclimate record from Lake Khar Nuur in the Mongolian Altai, spanning the last 4200 years. Lake Khar Nuur is a high-altitude lake with a small catchment located at 2,486 m a.s.l. (48°37'22.9"N, 88°56'42.5"E). We recovered the sediment core (that we abbreviate KN18) from the deepest part of the lake (49.4 m) in July 2018 using an Uwitec gravity corer. Within the sediment core KN18, a wide array of lake sediment proxies was measured. While total organic carbon (TOC), total nitrogen, bulk δ^13^C~TOC~, δ^15^N and biogenic silica were measured in 2 cm resolution, the elemental composition (log (Ca/Ti) ratio) was measured in 0.5 cm resolution. Additionally, compound-specific hydrogen isotopic composition of _n_-alkanes was measured in 1 cm resolution.

Description: A shallow subtidal area in the northern Wadden Sea was monitored over 17 years for sediment parameters and macrobenthic fauna using stratified random sampling of a grid of 50 sampling positions. Samples were collected with a Reineck-type box-corer of 0.02 m² surface area, always during preceeded high tide. Granulometric sediment composition was analysed from a sub-sample of each box-core using a diffraction laser particle-size analyser. Macrobenthos (sieved through 1 mm square meshes and fixed in buffered formalin solution) was counted, identified to species level, and the size of hard-shelled individuals measured. The amount of shell detritus was quantified as wet-weight in the benthos samples. From 2003 to 2007 sampling was approximatively monthly and from 2008 to 2013 seasonally. When a new ship with larger drought was put into operation, the number of sampling sites needed to be reduced to 33 from 2014 onwards and sampling frequency was only once per year in autumn.

Description: The data set contains the results of laboratory examination of 13 soil samples taken at the ground truthing reference sites during the flight campaign.

Description: Here we present soil characteristics from Alpine European larch and Swiss pine forests, as well as mixed forests. The forests are located in the LTSER area "Val Mazia/Matschertal" in the Vinschgau Valley, South Tyrol, Italy. Each three replicates from each forest type (larch, pine, and mixed) were sampled in late summer 2017.