The International Tundra Experiment (ITEX) is a long-term international collaboration of researchers examining the responses of arctic and alpine plants and ecosystems to climate change. Researchers measure plant responses to standardized, small-scale passive warming, snow manipulations, and nutrient additions. Researchers use small open-top chambers (OTCs) to passively increase mean air temperature by 1-2 °C. The ITEX approach has been validated by tundra responses at the plot level. The network has published meta-analyses on plant phenology, growth, and reproduction, composition and abundance, and carbon flux. The ITEX network consists of more than 50 sites in polar and alpine locations around the world. [[File:OTC at Alexandra Fiord, Ellesmere Island.jpg|thumb| ]]

Canadian sites

Alexandra Fiord, Ellesmere Island

Name of site leader(s): Greg Henry University: University of British Columbia Site elevation: 0-100m Latitude (WGS84 decimal degrees): 78.8833° N Longitude (WGS84 decimal degrees): 75.8000° W Date site was established: 1987 Does your site have OTC's? Yes Number of plots at your site (include OTCs control plots, etc.) 90 OTCs 99 controls When were they established? 1993 '''Have they been closed? If so, when?''' No Is there grazing at your site? No Climate data: Air temperature, Soil temperature, Snow depth, Precipitation, Cloud cover, Wind, global radiation etc. Current or past data collection : Phenology, Point framing, Above ground plant traits, Flower counts, Fertilizer plots, Snowmelt dates, Snow addition and removal, GIS data, Drones (https**:**//arcticdrones.org/), Phenocams (GoPros etc.), Transplant experiments, Plot photos, Soil moisture, Soil sampling, Succession studies Main genera in OTC plots: Dryas, Salix, Cassiope, Vaccinium, Sedges, Grasses, Rushes, Saxifraga, Equisetum, Poppy, Oxyria, Draba, Mosses/Lichens, Fungi Other nearby related study sites on Ellesmere: Sverdrup Pass, Princess Marie Bay, Hot Weather Creek,

Sverdrup Pass, Ellesmere Island, Nunavut

Name of site leader(s): Esther Lévesque,  Josef Svoboda (1986-1994) University: Université du Québec à Trois-Rivières (UQTR) Site elevation: 180 m Latitude (WGS84 decimal degrees): 79.14 Longitude (WGS84 decimal degrees):  -79.7 Date site was established: 1990 Does your site have OTC's?  No Number of plots at your site (include OTCs control plots, etc.) 13 in total along altitudinal gradients (300m to ca. 700m) on two substrates (granite and dolomite)    D1-D6 and G1-G7 When were they established? 1990 '''Have they been closed? If so, when?''' Yes, 1994 Is there grazing at your site? Insects, Ungulates, Hares (Lagomorphs) Climate data: Air temperature >1m, Soil temperature, Precipitation    Soil temperature    year round (1986-1994) Current or past data collection: Individual plant phenology, Above ground plant traits, Flower counts (total), Flower counts (per stage) Main genera in plots: Papaver Citation: Lévesque, E., Henry, G.H.R., Svoboda, J., 1997. Phenological and growth responses of Papaver radicatum along altitudinal gradients in the Canadian High Arctic. Global Change Biology 3, 125–145. https://doi.org/10.1111/j.1365-2486.1997.gcb145.x

Bylot Island, Nunavut

Name of site leader(s): Esther Lévesque University: Université du Québec à Trois-Rivières Latitude (WGS84 decimal degrees): 73.3652 Longitude (WGS84 decimal degrees): -79.0153

Nunatsiavut (Nain and Torr Bay)

Name of site leader(s): Laura Siegwart Collier, Luise Hermanutz University: Memorial University Latitude (WGS84 decimal degrees): 58.4774° N Longitude (WGS84 decimal degrees): 62.8295° W **Date site was established:**2009

Nain

Does your site have OTC's?  Yes Number of plots at your site (include OTCs control plots, etc.) 18 When were they established? 2009 '''Have they been closed? If so, when?''' Yes, the subsite is closed Is there grazing at your site?  No **Climate data:**Air temperature >1m, Soil temperature, PAR, Soil moisture probe **Current or past data collection:**Point framing, Flower counts (total), Plot photos, Fruit production **Main genera in OTC plots:**Betula, Vaccinium, Empetrum, Rhododendron, Carex, Bryophytes, Lichen

Torr Bay

Does your site have OTC's? Yes Number of plots at your site (include OTCs control plots, etc.) 60 When were they established? 2009 '''Have they been closed? If so, when?''' No but visited infrequently (once 3–5 years) Is there grazing at your site? Climate data: Air temperature >1m    Soil temperature, PAR, Soil moisture probe Current or past data collection: Point framing, Flower counts (total), Fruit production Main genera in OTC plots: Salix, Betula, Vaccinium, Empetrum, Rhododendron, Carex, Eriophorum, Poa, Juncus, Bryophytes, Lichen, Oxytropis

Tundra Ecosystem Research Station, Daring Lake

Name of site leader(s): Karin Clark University: Government of the Northwest Territories Latitude (WGS84 decimal degrees): 65 degrees 52 min N Longitude (WGS84 decimal degrees): 111 degrees 32 min W Date site was established: 1995 Does your site have OTC's? Currently have Number of plots at your site (include OTCs control plots, etc.) 9 When were they established? Plots established 1995; OTCs in 2000 '''Have they been closed? If so, when?''' No Is there grazing at your site? Yes Climate data: Air temperature, Soil temperature, Snow depth, Precipitation, radiation, wind speed and direction Current or past data collection: Phenology, Point framing, Above ground plant traits, Flower counts, Snowmelt dates Main genera in OTC plots: Salix, Betula, Vaccinium, Sedges, Saxifraga, Oxytropis

Qikiqtaruk (Herschel Island), Yukon

Name of site leader(s): Isla Myers-Smith University: University of Edinburgh, Yukon Parks Site elevation: 70m Latitude (WGS84 decimal degrees): 69.6 N Longitude (WGS84 decimal degrees): 138.9 W Date site was established: 1999 Does your site have OTC's? Never had Number of plots at your site (include OTCs control plots, etc.) 12 When were they established? 1999 '''Have they been closed? If so, when? ''' No Is there grazing at your site? Yes Climate data: Air temperature, Soil temperature, Snow depth, Precipitation Current or past data collection: Phenology, Point framing, Above ground plant traits, Herbivory, Flower counts, Plot photos, Snowmelt dates, GIS data, Drones (https://arcticdrones.org/), Phenocams (GoPros etc.), Soil sampling, Shrub common garden Main genera in OTC plots: Dryas, Salix, Betula, Sedges, Grasses, Mosses/Lichens

Garibaldi Park, BC, Canada

Name of site leader(s): Cassandra Elphinstone, Courtney Collins, Nathalie Chardon University: University of British Columbia Site elevation: 1470m Latitude (WGS84 decimal degrees): 49.927275 Longitude (WGS84 decimal degrees): -122.992919 Date site was established: 2022 Does your site have OTC's? Yes Number of plots at your site (include OTCs control plots, etc.) 24 When were they established? 2022 '''Have they been closed? If so, when?''' No Is there grazing at your site? Yes Climate data: Plot level Air temperature, Soil temperature, radiation Current or past data collection: Phenology, Point framing, Above ground plant traits, Flower counts, Phenocams (GoPros etc.), Plot photos, Soil moisture, Soil sampling Main genera in OTC plots: Salix, Cassiope, Phyllodoce, Kalmia, Triantha, Pinguicula, Equisetum, Carex

Greenlandic sites

Disko, Greenland

**Name of site leader(s): ** Per Molgaard University: Copenhagen Site elevation: 10-100m Latitude (WGS84 decimal degrees): 69.63N Longitude (WGS84 decimal degrees): 42.17W Date site was established: 1989 (last visit 2013) Does your site have OTC's? No Number of plots at your site (include OTCs control plots, etc.) 4 When were they established? 1992 '''Have they been closed? If so, when?''' Yes 1994 Is there grazing at your site? No Climate data: Air temperature, Soil temperature, Snow depth, Precipitation Current or past data collection: Phenology, Point framing, Above ground plant traits, Herbivory, Flower counts Main genera in OTC plots: Salix, Papaver, Caterpillars on willow

Arctic Station, Disko, Greenland

Name of site leader(s): Anders Michelsen, Bo Elberling University: University of Copenhagen

Mesic-dry heath tundra

Site elevation: 95m Latitude (WGS84 decimal degrees): 69 16 N Longitude (WGS84 decimal degrees): 53 27 W Date site was established: 20Does your site have OTC's? Only snow fences Number of plots at your site (include OTCs control plots, etc.) 48 When were they established? 2012 '''Have they been closed? If so, when?''' still running Is there grazing at your site? Yes Climate data: Air temperature, Soil temperature, Snow depth, Precipitation, Cloud cover Current or past data collection: Point framing, Above ground plant traits, Below ground traits, Snow fences, Soil moisture, Drones, Soil sampling Main genera in OTC plots: Dryas, Salix, Betula, Cassiope, Vaccinium, Sedges, Grasses, Mosses/Lichens

Wet sedge tundra

Site elevation: 85m Latitude (WGS84 decimal degrees): 69 26 N Longitude (WGS84 decimal degrees): 53 47 W Date site was established: 2013 Does your site have OTC's? Only snow fences Number of plots at your site (include OTCs control plots, etc.) 48 When were they established? 2013 '''Have they been closed? If so, when?''' still running Is there grazing at your site? Yes Climate data: Air temperature, Soil temperature, Snow depth, Precipitation, Cloud cover Current or past data collection: Point framing, Above ground plant traits, Below ground traits, Snow fences, Snowmelt dates, Soil moisture, Drones, Soil sampling Main genera in OTC plots: Salix, Sedges, Rushes, Equisetum, Mosses/Lichens

Zackenberg, Greenland

Name of site leader(s): Niels Martin Schmidt University: Aarhus University Site elevation: App. 55 m Latitude (WGS84 decimal degrees): 74.47427 Longitude (WGS84 decimal degrees): -20.52895 Date site was established: 1996 Does your site have OTC's? Currently have Number of plots at your site (include OTCs control plots, etc.) 20 When were they established? 2007 '''Have they been closed? If so, when?''' No Is there grazing at your site? Yes Climate data: Air temperature, Soil temperature, Snow depth, Precipitation, Cloud cover Current or past data collection: Phenology, Point framing, Flower counts, Plot photos, Snowmelt dates, Soil moisture, Soil sampling Main genera in OTC plots: Salix, Cassiope, Vaccinium, Grasses, Mosses/Lichens

Zackenberg, Greenland

Name of site leader(s): Anders Michelsen University: University of Copenhagen Site elevation: 35m Latitude (WGS84 decimal degrees): 74 30 N Longitude (WGS84 decimal degrees): 21 00 W Date site was established: 2004 Does your site have OTC's? Yes Number of plots at your site (include OTCs control plots, etc.) 20 When were they established? 2004 '''Have they been closed? If so, when?''' Is there grazing at your site? Yes Climate data: Air temperature, Soil temperature, Snow depth, Precipitation Current or past data collection: Point framing, Snowmelt dates, Soil moisture Main genera in OTC plots: Dryas, Salix, Cassiope, Vaccinium, Grasses, Mosses/Lichens

Kobbefjord (Nuuk), Greenland

Name of site leader(s): Katrine Raundrup University: Greenland Institute of Natural Resources Site elevation: 27 m Latitude (WGS84 decimal degrees): 64.137147 Longitude (WGS84 decimal degrees): -51.379999 Date site was established: 2008 Does your site have OTC's? Yes Number of plots at your site (include OTCs control plots, etc.) 30 When were they established? 2008 '''Have they been closed? If so, when? ''' No Is there grazing at your site? No Climate data: Air temperature, Soil temperature, Snow depth, Precipitation, Cloud cover Current or past data collection: Phenology, Above ground plant traits, Flower counts, Plot photos, Snowmelt dates, Soil moisture, GIS data, Soil sampling Main genera in OTC plots: Salix, Sedges, Grasses, Mosses/Lichens, Empetrum

Kangerlussuaq, Greenland

Name of site leader(s): Eric Post University: University of California, Davis Site elevation: 200m Latitude (WGS84 decimal degrees): 67.017 Longitude (WGS84 decimal degrees): -50.717 Date site was established: 2003 Does your site have OTC's? Yes Subsites: KANGER.DOC, KANGER.DOPEY, KANGER.BASHFUL

European sites

Auðkúluheiði, Iceland

Name of site leader(s): Ingibjörg S. Jónsdóttir University: University of Iceland and University Centre in Svalbard Site elevation: 450m **Latitude (WGS84 decimal degrees): **65°12'0" N **Longitude (WGS84 decimal degrees): **19°42'0" W Date site was established: 1996 Does your site have OTC's? Yes Number of plots at your site (include OTCs control plots, etc.) 30 When were they established? 1996 '''Have they been closed? If so, when?'''  No Is there grazing at your site? Yes Climate data: Air temperature, Soil temperature, Precipitation, Total radiation, PAR Current or past data collection: Phenology, Point framing, Above ground plant traits, Herbivory, Flower counts, Plot photos, Snowmelt dates, Soil moisture, Soil sampling Main genera in OTC plots: Dryas, Salix, Betula, Vaccinium, Sedges, Grasses, Rushes, Equisetum, Silene, Cerastium, Mosses/Lichens, Empetrum

Landmannahellir/Löðmundarvatn at Fjallabak, Iceland

Name of site leader(s): Ólafur S. Andrésson 2017–present,  Alejandro Salazar 2017-2019 University: University of Iceland, Faculty of Life and Environmental Sciences Site elevation: 600m Latitude (WGS84 decimal degrees): 64.0364 Longitude (WGS84 decimal degrees): 19.219017 Date site was established:  2017 Does your site have OTC's? Yes Number of plots at your site (include OTCs control plots, etc.) 16 When were they established? 2018 '''Have they been closed? If so, when?''' No Is there grazing at your site? Ungulates, Birds Climate data: Soil temperature, Snowmelt date, Current or past data collection:  Soil moisture probe, Vegetation cover, microbial composition, soil respiration, N fixation, Plot photos, Below ground microbe surveys, Flux, Lichen cover, Bryophyte cover, Litter bags, Soil (chemical nutrient composition), N fixation (ARA), cyanobacteria cover on biocrust, soil respiration Main genera in OTC plots: Salix, Empetrum, Carex, Bryophytes, Lichen, Liverwort (Anthelia) biocrust is the primary research subject and main ground cover (followed by moss).

Billefjorden, Svalbard

Name of site leader(s): Petr Macek University: University of South Bohemia Site elevation: 70m Latitude (WGS84 decimal degrees): 78.5304 **Longitude (WGS84 decimal degrees): ** 16.3070 Date site was established: 2014 Does your site have OTC's? Yes Number of plots at your site (include OTCs control plots, etc.) 30 When were they established? 2015 '''Have they been closed? If so, when? ''' Is there grazing at your site? Yes Climate data: Air temperature, Soil temperature, Precipitation, leaf temperatures Current or past data collection: Plant cover (%), Above ground plant traits, Herbivory, Flower counts, Plot photos, Snowmelt dates, Soil moisture, Soil sampling Main genera in OTC plots: Dryas, Salix, Cassiope, Sedges, Grasses, Rushes, Saxifraga, Equisetum, Silene, Cerastium, Oxyria, Mosses/Lichens

AWS1, Svalbard

**Name of site leader(s):**Petr Macek **University:**University of South Bohemia **Site elevation:**50 **Latitude (WGS84 decimal degrees):**78.717 **Longitude (WGS84 decimal degrees):**16.445 Date site was established: 2014 **Does your site have OTC's?**OTCs, Herbivory exclosure, Seeding experiments Number of plots at your site (include OTCs control plots, etc.) 50 When were they established? 2015 '''Have they been closed? If so, when?''' No **Is there grazing at your site?**Ungulates, Birds **Climate data:**Air temperature >1m, Soil temperature Current or past data collection: Individual plant phenology, Snapshot phenology, Above ground plant traits, Flower counts (total), Plot photos, Transplant experiments, Plant abundance measure (other than point framing), Lichen cover, Bryophyte cover, Plant tissue nutrient composition, Litter bags    Reciprocal transplant experiment, Dark diversity (species richness) **Main genera in OTC plots:**Dryas, Salix, Carex, Saxifraga, Silene, Cerastium, Oxyria, Draba, Equisetum, Bryophytes

Adventdalen Wet and Mesic, Svalbard

Name of site leader(s): Elisabeth J Cooper University: UiT The Arctic University of Norway Site elevation: 50 **Latitude (WGS84 decimal degrees):**78.16 Longitude (WGS84 decimal degrees): 16.1 Date site was established: 2003 Does your site have OTC's? OTCs, Goose grazing When were they established? 2003 '''Have they been closed? If so, when?''' Yes, 2015

SAdvent, Svalbard

Name of site leader(s): Elisabeth J Cooper University: UiT The Arctic University of Norway Site elevation: 50 **Latitude (WGS84 decimal degrees):**78.16 Longitude (WGS84 decimal degrees): 16.1 Date site was established: 2006 Does your site have OTC's? OTCs (occasionally), Snow fences, Snow removal When were they established? 2006 '''Have they been closed? If so, when?''' No

Endalen, Svalbard

Name of site leader(s): Ingibjorg Jonsdottir University: University of Iceland and University Centre in Svalbard Site elevation:   100  m Latitude (WGS84 decimal degrees): 78.187445 Longitude (WGS84 decimal degrees): 15.75835 Date site was established: 2002 Does your site have OTC's?  Yes    OTCs Sub-sites: Dryas Heath, Cassiope Low, Cassiope High,  Fellfield, Snowbed Low, Snowbed High

Faroe Islands

Name of site leader(s): Magnus Gaard, Anna Maria Fosaa University: University of the Faroe Islands Site elevation: 600 m Latitude (WGS84 decimal degrees): 62.0667 Longitude (WGS84 decimal degrees): -6.95 Date site was established:   2001 Does your site have OTC's?     Yes

Knutshø, Dovre, Norway

Name of site leader(s): Annika Hofgaard University: Norwegian Institute for Nature Research (NINA) Site elevation: 1050-1150m Latitude (WGS84 decimal degrees): 62 18' N Longitude (WGS84 decimal degrees): 09 37' E Date site was established: 1998 Does your site have OTC's? Yes Number of plots at your site (include OTCs control plots, etc.) 3 When were they established? 1998 '''Have they been closed? If so, when? ''' Is there grazing at your site? Yes Climate data: No, two year of air and soil temperature data (ambient and OTC) at the start of site use Current or past data collection: Above ground plant traits, Herbivory, Plot photos, plant cover (%) Main genera in OTC plots: Salix, Betula, Vaccinium, Sedges, Grasses, Rushes, Equisetum, Mosses/Lichens, Empetrum, Astragalus and a number of other dwarf shrubs and herbs

Finse, Norway

Name of site leader(s): Kari Klanderud University: Norwegian University of Life Sciences Site elevation: 1500 m asl Latitude (WGS84 decimal degrees): 60.6051° N Longitude (WGS84 decimal degrees): 7.5046° E Date site was established: June 2000 Does your site have OTC's? Yes Number of plots at your site (include OTCs control plots, etc.) 40 OTCs 40 controls When were they established? 2000 '''Have they been closed? If so, when?''' No Is there grazing at your site? Yes Climate data: Air temperature, Precipitation, Done by climate station at Finse (1200 m asl) Current or past data collection: Above ground plant traits, Flower counts, Plot photos, Soil moisture, Soil sampling, Vegetation analyses by sub plot frequencies and % cover Main genera in OTC plots: Dryas, Sedges, Grasses, Silene, Mosses/Lichens

Kilpisjärvi Finland

Name of site leader(s): Anne Tolvanen University: Natural Resources Institute Finland Site elevation: 670 m a.s.l. Latitude (WGS84 decimal degrees): 69.4N Longitude (WGS84 decimal degrees): 20.490E Date site was established: 01.06.1994 Does your site have OTC's? Currently have Number of plots at your site (include OTCs control plots, etc.) 20 When were they established? 1994 '''Have they been closed? If so, when?''' running experiment Is there grazing at your site? Yes, factorial simulated herbivory treatment. Climate data: Air temperature, Soil temperature Current or past data collection: Point framing, Herbivory, Soil sampling, GHG fluxes, plant C/N concentrations, soil microbial communities Main genera in OTC plots: Salix, Betula, Vaccinium, Rushes, Mosses/Lichens

Kilpisjärvi Finland II

Name of site leader(s): Friederike Gehrmann University: University of Helsinki Site elevation: 700m Latitude (WGS84 decimal degrees): 69.0443 Longitude (WGS84 decimal degrees): 20.8033 Date site was established: 2014 Does your site have OTC's? Never had Number of plots at your site (include OTCs control plots, etc.) 24 When were they established? 2014 '''Have they been closed? If so, when? '''No Is there grazing at your site? Yes Climate data: Air temperature, Soil temperature Current or past data collection: Phenology, Snowmelt dates, Soil moisture, ecophysiology Main genera in OTC plots: Salix, Betula, Cassiope, Vaccinium, Saxifraga, Silene

Latnjajaure, Sweden

Name of site leader(s): Robert Bjork and Mats Bjorkman University: Göteborg University Site elevation: 981 m Latitude (WGS84 decimal degrees): 68.21N Longitude (WGS84 decimal degrees): 18.31E Date site was established: 1990 (First full ITEX year 1993) Does your site have OTC's? Yes Number of plots at your site (include OTCs control plots, etc.) 50 plots (in 5 plant communities) When were they established? 1993, 1994, 1996 '''Have they been closed? If so, when?''' Is there grazing at your site? Yes Climate data: Air temperature, Soil temperature, Snow depth, Precipitation, Cloud cover, Wind, global radiation etc. Current or past data collection: Phenology, Point framing, Above ground plant traits, Herbivory, Flower counts, Plot photos, Fertilizer plots, Snowmelt dates, Soil moisture, Soil sampling, soil fauna, soil parameters Main genera in OTC plots: Dryas, Salix, Betula, Cassiope, Vaccinium, Sedges, Grasses, Rushes, Saxifraga, Equisetum, Silene, Cerastium, Oxyria, Draba, Mosses/Lichens, many mosses and lichens determined to species of genera level

Paddus, Abisko, Sweden

Name of site leader(s): Anders Michelsen University: University of Copenhagen

(mesic tree-line heath)

Site elevation: 550m Latitude (WGS84 decimal degrees): 68 19 N Longitude (WGS84 decimal degrees): 18 51 E Date site was established: 1989 Does your site have OTC's? Yes Number of plots at your site (include OTCs control plots, etc.) 48 When were they established? 1989 '''Have they been closed? If so, when?''' Is there grazing at your site? No Climate data: Air temperature, Soil temperature Current or past data collection: Phenology, Point framing, Above ground plant traits, Below ground traits, Herbivory, Flower counts, Fertilizer plots, Soil moisture, Soil sampling Main genera in OTC plots: Dryas, Salix, Betula, Cassiope, Vaccinium, Sedges, Grasses, Equisetum, Silene, Mosses/Lichens

Substrate (graminoid-rich heath)

Site elevation: 560m Latitude (WGS84 decimal degrees): 68 19 N Longitude (WGS84 decimal degrees): 18 50 E Date site was established: 2012 Does your site have OTC's? Yes Number of plots at your site (include OTCs control plots, etc.) 30 When were they established? 2012 '''Have they been closed? If so, when?''' Is there grazing at your site? Yes Climate data: Air temperature, Soil temperature Current or past data collection: Phenology, Point framing, Above ground plant traits, Below ground traits, Fertilizer plots, Soil moisture, Soil sampling Main genera in OTC plots: Salix, Betula, Vaccinium, Sedges, Grasses, Rushes, Equisetum, Mosses/Lichens

Multe (wet heath)

Site elevation: 430m Latitude (WGS84 decimal degrees): 68 20 N Longitude (WGS84 decimal degrees): 18 49 E Date site was established: 1999 Does your site have OTC's? Yes Number of plots at your site (include OTCs control plots, etc.) 30 When were they established? 1999 '''Have they been closed? If so, when? ''' Is there grazing at your site? No Climate data: Air temperature, Soil temperature Current or past data collection: Phenology, Point framing, Above ground plant traits, Below ground traits, Fertilizer plots, Soil moisture, Soil sampling Main genera in OTC plots: Salix, Betula, Vaccinium, Sedges, Grasses, Rushes, Equisetum, Mosses/Lichens

Forest (understory in open birch forest)

Site elevation: 430m Latitude (WGS84 decimal degrees): 68 20 N Longitude (WGS84 decimal degrees): 18 50 E Date site was established: 2009 Does your site have OTC's? Yes Number of plots at your site (include OTCs control plots, etc.) 10 When were they established? 2009 '''Have they been closed? If so, when?''' Is there grazing at your site? No Climate data: Air temperature, Soil temperature Current or past data collection: Point framing, Above ground plant traits, Below ground traits, Soil moisture, Soil sampling Main genera in OTC plots: Vaccinium, Grasses, Mosses/Lichens

Abisko Torneträsk treeline, Sweden

Name of site leader(s): Ellen Dorrepaal University: Umeå University Site elevation: 570-775 masl Latitude (WGS84 decimal degrees): N68°18'-N68°31 Longitude (WGS84 decimal degrees): E18°12'-E18°54' Date site was established: 2011 Does your site have OTC's? Currently have Number of plots at your site (include OTCs control plots, etc.) 96 When were they established? 2011 '''Have they been closed? If so, when?''' NA Is there grazing at your site? Yes Climate data: Air temperature, Soil temperature, Snow depth, Precipitation, Soil moisture Current or past data collection: Point framing, Above ground plant traits, Soil moisture, Transplant experiments, Nutrients; (Transplanted) seedling survival; Experiment includes OTCs and moss removal treatments for vegetation dominated by three different moss species, across 8 sites along a precipitation gradient Main genera in OTC plots: Salix, Betula, Vaccinium, Sedges, Grasses, Mosses/Lichens, Empetrum; In general very variable, since the experiment includes 8 sites (one replicate per site) and 3 dominant moss species per site

Arvidsjaur, Sweden - forest fire chronosequence

Name of site leader(s): Ellen Dorrepaal University: Umeå University Site elevation: 424-522 masl Latitude (WGS84 decimal degrees): N65°35'-N66°07' Longitude (WGS84 decimal degrees): E17°15'-E19°26' Date site was established: 2010 Does your site have OTC's? Currently have Number of plots at your site (include OTCs control plots, etc.) 80 When were they established? 2010 '''Have they been closed? If so, when?''' NA Is there grazing at your site? Yes Climate data: Air temperature, Soil temperature, Soil moisture Current or past data collection: Point framing, Above ground plant traits, Below ground traits, Soil moisture, Soil sampling, Transplant experiments, Soil nutrients; Nematodes; Microbial community (PLFA); (Transplanted) seedling survival; Litter decomposition; Experiment consists of OTC x moss removal x shrub removal (full factorial) across 10 sites with varying fire history in the northern boreal forest (Pine/Spruce/Birch), with one treatment replicate per site Main genera in OTC plots: Vaccinium, Mosses/Lichens, Empetrum

Gavia Pass I, Italy

Name of site leader(s): Michele Carbognani University: Parma (Italy) Site elevation: 2700 m Latitude (WGS84 decimal degrees): 46.3404 Longitude (WGS84 decimal degrees): 10.4986 Date site was established: 2008 Does your site have OTC's? Currently have Number of plots at your site (include OTCs control plots, etc.) 20 When were they established? 2008 '''Have they been closed? If so, when?''' No Is there grazing at your site? No Climate data: Air temperature, Soil temperature Current or past data collection: Phenology, Point framing, Above ground plant traits, Flower counts, Plot photos, Snowmelt dates, Soil moisture, litter decomposition Main genera in OTC plots: Salix, Cerastium, Mosses/Lichens, Veronica, Cardamine, Poa, Leucanthemopsis

Gavia Pass II, Italy

Name of site leader(s): Alessandro Petraglia University: Parma (Italy) Site elevation: 2700 m Latitude (WGS84 decimal degrees): 46.3404 Longitude (WGS84 decimal degrees): 10.4986 Date site was established: 2012 Does your site have OTC's? Currently have Number of plots at your site (include OTCs control plots, etc.) 18 When were they established? 2012 '''Have they been closed? If so, when?''' No Is there grazing at your site? No Climate data: Air temperature, Soil temperature, Precipitation, PAR Current or past data collection: Phenology, Point framing, Flower counts, Snow addition and removal, Snowmelt dates, Soil moisture Main genera in OTC plots: Salix, Cerastium, Mosses/Lichens, Veronica, Cardamine, Poa, Leucathemopsis

Foscagno Pass, Italy

Name of site leader(s): Nicoletta Cannone University: Università dell'Insubria Site elevation: 2250-2550m Latitude (WGS84 decimal degrees): 46.04 N Longitude (WGS84 decimal degrees): 10.02 Date site was established: 2007 Does your site have OTC's? Never had Number of plots at your site (include OTCs control plots, etc.) 100 When were they established? 2007 '''Have they been closed? If so, when?''' running experiment Is there grazing at your site? No Climate data: Air temperature, Soil temperature, Precipitation, Snow depth and snow melting Current or past data collection: Phenology, Above ground plant traits, Flower counts, Plot photos, Fertilizer plots, Snowmelt dates, GIS data, Vegetation data (composition and % coverage) Main genera in OTC plots: Salix, Vaccinium, Sedges, Grasses, Saxifraga, Silene, Cerastium, Oxyria, Mosses/Lichens

Stelvio Pass, Italy

Name of site leader(s): Nicoletta Cannone University: Università dell'Insubria Site elevation: 2700m Latitude (WGS84 decimal degrees): 46.31 N Longitude (WGS84 decimal degrees): 10.25 E Date site was established: 2014 Does your site have OTC's? Currently have Number of plots at your site (include OTCs control plots, etc.) 120 When were they established? 2014 '''Have they been closed? If so, when?''' running experiment Is there grazing at your site? No Climate data: Air temperature, Soil temperature, Snow depth, Precipitation, Snow melting dates Current or past data collection: Phenology, Above ground plant traits, Flower counts, Plot photos, Snow fences, Fertilizer plots, Snowmelt dates, Soil moisture, GIS data, Soil sampling, Vegetation analyses (composition and % cover) Main genera in OTC plots: Salix, Sedges, Grasses, Mosses/Lichens

Val Bercla, Switzerland

Name of site leader(s): Christian Rixen **University *** WSL Institute for Snow and Avalanche Research SLF Site elevation 2500m Latitude (WGS84 decimal degrees) 46.47 Longitude (WGS84 decimal degrees) 9.58 Date site was established 1994 Does your site have OTC's? Currently have Number of plots at your site (include OTC's control plots, etc.) 9 When were they established? 1994 '''Have they been closed? If so, when?''' No OTCs from 1987 to 2008 Is there grazing at your site? Yes '''Does your site collect climate data? If yes, what type?''' No climate station directly at site but in the general area. Air temperature, Soil temperature, Snow depth, Precipitation, Cloud cover **Current or past data collection at your site:**Phenology, Above ground plant traits, Herbivory, Plot photos, Abundance estimates Main genera in OTC plots: Salix, Sedges, Grasses, Saxifraga, Silene, Mosses/Lichens

Stillberg snow manipulation experiment, Switzerland

Name of site leader(s): Sonja Wipf and Christian Rixen University: WSL-Institute for Snow and Avalanche Research SLF Site elevation: 2220 m Latitude (WGS84 decimal degrees): 46.77224 Longitude (WGS84 decimal degrees):  9.86569 Date site was established: 2003 Does your site have OTC's?  No  Snow removal Number of plots at your site (include OTCs control plots, etc.) 21 When were they established? 2004 '''Have they been closed? If so, when?''' No but since 2006 maintained with minimal effort (snow manipulation done, not many measurements). Vegetation does not show much response. Is there grazing at your site?  No Climate data: Air temperature >1m, Soil temperature, Snow depth, Snowmelt date, Precipitation, PAR, Wind speed, Wind direction, Solar radiation, Weather station <500m away Current or past data collection:  Individual plant phenology, Plot photos, Plant abundance measure (other than point framing), Lichen cover, Bryophyte cover, Litter bags, Individual growth Main genera in OTC plots: Vaccinium, Empetrum, Rhododendron, Carex, Loiseleuria, Helictotrichum

Jakobshorn, Davos, Switzerland

Name of site leader(s): Janet Prevey University: Pacific Northwest Research Station Site elevation: 2320 m Latitude (WGS84 decimal degrees): 46.77 Longitude (WGS84 decimal degrees): 9.86 Date site was established: 2014

Pyrenees, Spain

Name of site leader(s): Estela Illa Bachs, Benjamin Komak, Olivier Argagnon and Ludovic Olicard **University:**Universitat de Barcelona

Ulldeter

Site elevation: 2400 m Latitude (WGS84 decimal degrees): 42.41926 Longitude (WGS84 decimal degrees): 2.24756 Date site was established: 2018 **Does your site have OTC's?**Yes Number of plots at your site (include OTCs control plots, etc.) 8 **When were they established?**2019 '''Have they been closed? If so, when?''' Is there grazing at your site? No **Climate data:**Air temperature >1m, Snow depth, Precipitation, Wind speed, Solar radiation, Air temperature (near ground, ~10 cm), Snowmelt date Current or past data collection:  Snapshot phenology, Point framing, Above ground plant traits, Plot photos, Plant tissue nutrient composition, Soil (physical texture), Soil (chemical nutrient composition), Species Abundance and Phenology Main genera in OTC plots: Salix, Poa, Agrostis, Gentiana, Nardus, Trifolium

Ratera

Site elevation: 2560 m Latitude (WGS84 decimal degrees): 42.6053 Longitude (WGS84 decimal degrees):  0.96021 Date site was established:   2016 Does your site have OTC's? Yes Number of plots at your site (include OTCs control plots, etc.) 8 When were they established? 2017 '''Have they been closed? If so, when?'''  No Is there grazing at your site? Ungulates Climate data: Air temperature (near ground, ~10 cm), Snowmelt date Current or past data collection: Point framing, Above ground plant traits, Plot photos, Plant tissue nutrient composition, Soil (physical texture), Soil (chemical nutrient composition)    Species Abundance and Phenology Main genera in OTC plots: Salix, Carex, Poa, Bryophytes, Agrostis, Nardus

Envalira

Site elevation: 2500 m Latitude (WGS84 decimal degrees): 42.52372 Longitude (WGS84 decimal degrees): 1.73507 Date site was established: 2017 **Does your site have OTC's?**Yes Number of plots at your site (include OTCs control plots, etc.) 8 When were they established? 2017 '''Have they been closed? If so, when?''' No Is there grazing at your site? No Climate data: Air temperature (near ground, ~10 cm) Current or past data collection: Point framing, Above ground plant traits, Plot photos, Plant tissue nutrient composition, Soil (physical texture), Soil (chemical nutrient composition)    Species Abundance and Phenology Main genera in OTC plots:  Salix, Carex, Poa, Agrostis, Gentiana, Nardus, Sibbaldia

Arrious

Site elevation: 2370 m Latitude (WGS84 decimal degrees): 42.84143 Longitude (WGS84 decimal degrees): -0.33682 Date site was established: 2017 Does your site have OTC's? Yes Number of plots at your site (include OTCs control plots, etc.) 8 When were they established? 2017 '''Have they been closed? If so, when?''' No Is there grazing at your site? Unknown Climate data: Air temperature (near ground, ~10 cm), Snowmelt date Current or past data collection: Point framing, Above ground plant traits, Plant tissue nutrient composition, Soil (physical texture), Soil (chemical nutrient composition)    Species Abundance and Phenology Main genera in OTC plots: Salix, Festuca, Gentiana, Trifolium

Cataperdís (Andorra), Spain

Name of site leader(s): Estela Illa Bachs, Benjamin Komak, Empar Carrillo Ortuño, Josep Maria Ninot Sugrañes, Alba Anadon Rosell, Aaron Pérez Haase, and Oriol Grau Fernández University: Universitat de Barcelona Site elevation: 2535 m Latitude (WGS84 decimal degrees):  42.61678 Longitude (WGS84 decimal degrees): 1.48186 Date site was established: 2017 Does your site have OTC's? Yes Number of plots at your site (include OTCs control plots, etc.) 16 When were they established?  2019 '''Have they been closed? If so, when?'''  No Is there grazing at your site? No Climate data: Air temperature (near ground, ~10 cm), Snowmelt date Current or past data collection: Point framing, Above ground plant traits, Plot photos, Below ground microbe surveys, Plant tissue nutrient composition, Litter bags, Soil (physical texture), Soil (chemical nutrient composition), Species Abundance and Phenology, OTCs, Snow removal Main genera in OTC plots: Salix, Poa, Bryophytes, Lichen, Sibbaldia, Leontodon (= Scorzoneroides)

Asian sites

Alpine tundra of the Changbai Mountains, Northeast China

**Name of site leader(s):**Shengwei Zong, Hongshi He; 2015-ongoing, Zhengfang Wu; 2009-ongoing, Haibo Du; 2009-ongoing, and Xu Jiawei; 2008-ongoing University: Northeast Normal University Site elevation: 2300 m Latitude (WGS84 decimal degrees): 72 Longitude (WGS84 decimal degrees): 42 Date site was established: 2009 Does your site have OTC's? Yes OTCs and Fertilizer (2013), Snow removal (2019), Vegetation removal (2018) **Number of plots at your site (include OTCs control plots, etc.)**128 When were they established? 2011 '''Have they been closed? If so, when?''' No Is there grazing at your site? No Climate data: Air temperature >1m, Soil temperature, Precipitation, Solar radiation, Wind speed, Wind direction, Soil moisture probe Current or past data collection: Above ground plant traits, Plot photos, Plant abundance measure (other than point framing), Above ground biomass harvest, Below ground biomass harvest, Soil (physical texture), Soil (chemical nutrient composition)    Fine-scale geospatial data (GPS points for each plot), Drone images, Phenocams of site (GoPros etc.), Reciprocal transplant experiment Main genera in OTC plots: Dryas, Salix, Vaccinium, Rhododendron, Carex, Festuca, Poa, Juncus, Oxyria, Lycopodium, Bryophytes, Lichen, Oxytropis

American sites

Barrow/Utqiagvik & Atqasuk

Name of site leader(s): Christian Bay 1994–1995, Patrick Webber 1995–2007, Robert Hollister 2007-current University: Grand Valley State University

Barrow/Utqiagvik Dry Site

Site elevation: 5m Latitude (WGS84 decimal degrees): 71.31502696 Longitude (WGS84 decimal degrees): -156.6010247 Date site was established:  1994 Does your site have OTC's?    Yes    OTCs Number of plots at your site (include OTCs control plots, etc.) 48 When were they established?  1994 '''Have they been closed? If so, when?''' No Is there grazing at your site? Insects, Rodents, Birds Climate data: Air temperature 10 cm, Air temperature >1m, Soil temperature, Snowmelt date, Precipitation, PAR, Wind speed, Wind direction, Soil moisture probe, Active layer depth Current or past data collection: Plot level phenology, Individual plant phenology, Snapshot phenology, Point framing, Above ground plant traits, Below ground plant traits, Flower counts (total), Flower counts (per stage), Plot photos, Phenocams (GoPros etc.), Transplant experiments, Multispectral data, Flux, Methane Flux, Plant abundance measure (other than point framing), Lichen cover, Bryophyte cover, Plant tissue nutrient composition, Above ground biomass harvest, Below ground biomass harvest, Litter bags    Fine-scale geospatial data (GPS points for each plot), Drone images, Multispectral data, Phenocams of site (GoPros etc.), Reciprocal transplant experiment, Dark diversity (species richness), Taxonomic classification of bryophytes Main genera in OTC plots: Salix, Cassiope, Carex, Eriophorum, Poa, Saxifraga, Cerastium, Stellaria, Papaver, Draba, Bryophytes, Lichen

Barrow/Utqiagvik Wet Site

Site elevation: 3 m Latitude (WGS84 decimal degrees): 71.31051842 Longitude (WGS84 decimal degrees):  -156.5978987 Date site was established:  1995 Does your site have OTC's? Yes    OTCs Number of plots at your site (include OTCs control plots, etc.)   48 When were they established?   1995 '''Have they been closed? If so, when?''' No Is there grazing at your site? Insects, Rodents, Birds Climate data: Air temperature 10 cm, Soil temperature, Snowmelt date, Soil moisture probe, Active layer depth Current or past data collection: Plot level phenology, Individual plant phenology, Snapshot phenology, Point framing, Above ground plant traits, Flower counts (total), Flower counts (per stage), Plot photos, Phenocams (GoPros etc.), Multispectral data, Flux, Plant abundance measure (other than point framing), Lichen cover, Bryophyte cover, Litter bags    Fine-scale geospatial data (GPS points for each plot), Drone images, Multispectral data, Phenocams of site (GoPros etc.), Dark diversity (species richness), Taxonomic classification of bryophytes Main genera in OTC plots: Salix, Carex, Eriophorum, Poa, Saxifraga, Cerastium, Stellaria, Draba, Cardamine, Bryophytes

Atqasuk Dry Site

Site elevation: 22 m Latitude (WGS84 decimal degrees):  70.45373011 Longitude (WGS84 decimal degrees):  -157.4073879 Date site was established:  1996 Does your site have OTC's? Yes Number of plots at your site (include OTCs control plots, etc.)  48 When were they established?   1996 '''Have they been closed? If so, when?''' Is there grazing at your site?  Insects, Ungulates, Rodents, Birds Climate data: Air temperature 10 cm, Air temperature >1m, Soil temperature, Snowmelt date, Precipitation, PAR, Wind speed, Wind direction, Soil moisture probe, Active layer depth **Current or past data collection:**Plot level phenology, Individual plant phenology, Snapshot phenology, Point framing, Above ground plant traits, Flower counts (total), Flower counts (per stage), Plot photos, Phenocams (GoPros etc.), Multispectral data, Flux, Plant abundance measure (other than point framing), Lichen cover, Bryophyte cover, Plant tissue nutrient composition, Above ground biomass harvest, Litter bags    Fine-scale geospatial data (GPS points for each plot), Drone images, Multispectral data, Phenocams of site (GoPros etc.), Dark diversity (species richness), Taxonomic classification of bryophytes Main genera in OTC plots: Salix, Cassiope, Vaccinium, Carex, Poa, Bryophytes, Lichen

Atqasuk Wet Site

Site elevation: 17 m Latitude (WGS84 decimal degrees): 70.45303348 Longitude (WGS84 decimal degrees):  -157.4003018 Date site was established:   1996 Does your site have OTC's? Yes Number of plots at your site (include OTCs control plots, etc.)  48 When were they established?  1996 '''Have they been closed? If so, when?''' No Is there grazing at your site? Insects, Ungulates, Rodents Climate data: Air temperature 10 cm, Soil temperature, Snowmelt date, Soil moisture probe, Active layer depth    Air temperature (near ground, ~10 cm), Soil temperature, Snowmelt date, Soil moisture probe, Active layer depth Current or past data collection:  Plot level phenology, Individual plant phenology, Snapshot phenology, Point framing, Above ground plant traits, Flower counts (total), Flower counts (per stage), Plot photos, Phenocams (GoPros etc.), Multispectral data, Flux, Lichen cover, Bryophyte cover, Litter bags    Fine-scale geospatial data (GPS points for each plot), Drone images, Multispectral data, Phenocams of site (GoPros etc.), Dark diversity (species richness), Taxonomic classification of bryophytes Main genera in OTC plots: Salix, Betula, Carex, Eriophorum, Bryophytes, Lichen

Toolik and surrounding area (Shaver)

Name of site leader(s): GR Shaver University:  Ecosystems Center, MBL Subsites: Toolik Historic Site, Imnavait Sites, ARC LTER sites - many local sites and experiments, all within about 25 km of Toolik Lake. We break these down by vegetation type, including Moist acidic tussock tundra, Moist nonacidic tussock tundra, moist nonacidic nontussock tundra, dry heath tundra, wet sedge tundra, and deciduous shrub tundra. Much of the data on these sites is available at the ARC LTER web site at:  http://ecosystems.mbl.edu/arc/ Date site was established: 1976 Does your site have OTC's? Yes  OTCs (1982) and Fertilizer (1982), Herbivory exclosure (1996), Vegetation removal (1995), Shade treatments When were they established?  Dates above are dates of first expt, new experiments with same treatments established at various dates in the 1980s-2000s **                                                                                   ** '''Have they been closed? If so, when?''' No Is there grazing at your site?  Insects, Ungulates, Rodents, Birds **Climate data:**Air temperature >1m, Soil temperature, Snow depth, Snowmelt date, Precipitation, Cloud cover, PAR, Wind speed, Wind direction, Soil moisture probe, Soil moisture (% water by weight), Active layer depth, Solar radiation, UV Current or past data collection:  Plot level phenology, Individual plant phenology, Point framing, Above ground plant traits, Below ground plant traits, Flower counts (total), Flower counts (per stage), Plot photos, Transplant experiments, Below ground microbe surveys, Multispectral data, Above ground invertebrates, Below ground invertebrates, Flux, Methane Flux, Plant abundance measure (other than point framing), Lichen cover, Bryophyte cover, Plant tissue nutrient composition, Above ground biomass harvest, Below ground biomass harvest, Litter bags, Soil (physical texture), Soil (chemical nutrient composition), Lots of soil chemistry, plant allometry and vegetative and sexual demography    Fine-scale geospatial data (GPS points for each plot), Multispectral data, Common garden experiment, Reciprocal transplant experiment Note: Many protocols established before ITEX; some ITEX protocols developed from ours **Main genera in OTC plots:  **Dryas, Salix, Betula, Cassiope, Vaccinium, Empetrum, Rhododendron, Carex, Eriophorum, Festuca, Poa, Juncus, Saxifraga, Silene, Cerastium, Stellaria, Papaver, Oxyria, Draba, Cardamine, Equisetum, Lycopodium, Ferns, Bryophytes, Lichen, Astragalus, Oxytropis, Rubus, Above checked spp occur at >50% occurrence at at least one local site but none at every site

Toolik Lake, Alaska (Gough)

Name of site leader(s): Laura Gough, Ed Rastetter, Donie Bret-Harte University: MBL Woods Hole, University of Alaska, Towson University Site elevation: 730 m Latitude (WGS84 decimal degrees): 68 deg 38 min N Longitude (WGS84 decimal degrees): 149 deg 34 min W Date site was established: 1976 Does your site have OTC's? No Number of plots at your site (include OTCs control plots, etc.) hundreds When were they established? 1976-2006 '''Have they been closed? If so, when?''' Is there grazing at your site? Yes Climate data: Air temperature, Soil temperature, Snow depth, Precipitation, Cloud cover, PAR, radiation balance, uv Current or past data collection: Phenology, Point framing, Above ground plant traits, Below ground traits, Herbivory, Flower counts, Plot photos, Snow fences, Snow addition and removal, Fertilizer plots, Snowmelt dates, Soil moisture, GIS data, Soil sampling, NPP GPP, bulk CNP stocks and turnover Main genera in OTC plots: Salix, Betula, Cassiope, Vaccinium, Sedges, Grasses, Rushes, Mosses/Lichens, NO OTCs—plastic greenhouses. 5 contrasting veg types

Alaska Ecotypes/Alaska Eriophorum vaginatum Transplant Garden

Name of site leader(s): Ned Fetcher 2014–present, Jim Tang 2014-present, Michael Moody 2014–present University: Wilkes University, Marine Biological Laboratory, University of Texas - El Paso This is a reciprocal transplant experiment using three populations, Sagwon, Toolik, Lake, and Coldfoot. Each plot contains three tussocks of Eriophorum vaginatum that were transplanted in August 2014. At Sagwon and Toolik Lake, half of the plots had OTC's beginning in July 2015.

Toolik Lake

Site elevation: 763 m Latitude (WGS84 decimal degrees):  68.62886 Longitude (WGS84 decimal degrees): -149.576521 Date site was established: 2011, 2014 Does your site have OTC's? Currently have Number of plots at your site (include OTCs control plots, etc.) 72 When were they established? 24 in 2011, 48 in 2014 '''Have they been closed? If so, when?''' Is there grazing at your site? No Climate data: Air temperature 10 cm, Air temperature >1m, Soil temperature, Snow depth, Snowmelt date, Precipitation, Cloud cover, PAR, Wind speed, Wind direction, Active layer depth, Solar radiation, Data available from Toolik Field Station website Current or past data collection:  Individual plant phenology, Snapshot phenology, Above ground plant traits, Below ground plant traits, Flower counts (total), Plot photos, Phenocams (GoPros etc.), Transplant experiments, Flux, Litter bags    Fine-scale geospatial data (GPS points for each plot), Drone images, Phenocams of site (GoPros etc.), Common garden experiment, Reciprocal transplant experiment Main genera in OTC plots:  Salix, Betula, Cassiope, Vaccinium, Empetrum, Rhododendron, Carex, Eriophorum, Bryophytes, Lichen, Rubus

Sagwon

Site elevation: 297m Latitude (WGS84 decimal degrees): 69.4239 Longitude (WGS84 decimal degrees): -148.7008 Date site was established: 2014 Does your site have OTC's? Currently have Number of plots at your site (include OTCs control plots, etc.) 48 When were they established? 2015 '''Have they been closed? If so, when?''' Is there grazing at your site? No Climate data:  Air temperature >1m, Soil temperature, Snow depth, Snowmelt date, Precipitation, Wind speed, Wind direction, Solar radiation, Data is available from USDA SNOTEL website Current or past data collection:  Individual plant phenology, Above ground plant traits, Below ground plant traits, Plot photos, Transplant experiments, Litter bags    Fine-scale geospatial data (GPS points for each plot), Common garden experiment, Reciprocal transplant experiment Main genera in OTC plots: Salix, Betula, Vaccinium, Rhododendron, Carex, Eriophorum, Bryophytes, Lichen, Rubus

Coldfoot

Site elevation: 320 m Latitude (WGS84 decimal degrees): 67.2586 Longitude (WGS84 decimal degrees): -150.1698 Date site was established: 2014 Does your site have OTC's? Never had Number of plots at your site (include OTCs control plots, etc.) 24 When were they established? 2014 '''Have they been closed? If so, when?''' NA Is there grazing at your site? No Climate data: Air temperature >1m, Soil temperature, Snow depth, Snowmelt date, Precipitation, Wind speed, Wind direction, Solar radiation, Data are available from the USDA-SNOTEL website. Current or past data collection: Individual plant phenology, Above ground plant traits, Plot photos, Litter bags    Fine-scale geospatial data (GPS points for each plot), Common garden experiment, Reciprocal transplant experiment Main genera in OTC plots: Salix, Betula, Vaccinium, Rhododendron, Carex, Eriophorum, Bryophytes, Lichen, Rubus

Toolik Lake (Welker and Oberbauer)

Name of site leader(s): Jeffrey M Welker and Steven F Oberbauer University: Florida International University

Toolik Moist

Site elevation:  720 m Latitude (WGS84 decimal degrees):   68.62 Longitude (WGS84 decimal degrees): -149.603 Date site was established:  1994 Does your site have OTC's?   Yes    OTCs, Snow fences When were they established? 1994

Toolik Dry

Site elevation:   720 m Latitude (WGS84 decimal degrees):  68.62 Longitude (WGS84 decimal degrees):  -149.598 Date site was established: 1994 Does your site have OTC's? Yes    OTCs, Snow fences When were they established? 1994

Toolik Snowfield

Latitude (WGS84 decimal degrees):  68.62 Longitude (WGS84 decimal degrees):   -149.601 Does your site have OTC's? Yes  OTCs

Imnaviat Creek, Alaska

Name of site leader(s): Jeremy May and Steven Oberbauer University: Florida International University

Dry Heath

Site elevation: 927m asl Latitude (WGS84 decimal degrees): 68 37' N Longitude (WGS84 decimal degrees): 149 18' W Date site was established: 2016 Does your site have OTC's? Currently have Number of plots at your site (include OTCs control plots, etc.) 16 When were they established? June 2016 '''Have they been closed? If so, when?''' No Is there grazing at your site? No Climate data: No Current or past data collection: Point framing, Plot photos, NDVI Main genera in OTC plots: Dryas, Salix, Betula, Cassiope, Vaccinium, Sedges, Grasses, Saxifraga, Mosses/Lichens

Wet Acidic

Site elevation: 927 m asl Latitude (WGS84 decimal degrees): 68 37' N Longitude (WGS84 decimal degrees): 149 18' W Date site was established: 2016 Does your site have OTC's? Currently have Number of plots at your site (include OTCs control plots, etc.) 16 When were they established? June 2016 '''Have they been closed? If so, when?''' No Is there grazing at your site? No Climate data: No Current or past data collection: Point framing, Plot photos, NDVI Main genera in OTC plots: Salix, Betula, Cassiope, Vaccinium, Sedges, Grasses, Saxifraga, Mosses/Lichens

Alaska Ice Cut

Name of site leader(s): Ellen Dorrepaal University: Umeå University Site elevation: 385 m asl Latitude (WGS84 decimal degrees): N69°048' Longitude (WGS84 decimal degrees): W148°836' Date site was established: 2014 Does your site have OTC's? Currently have Number of plots at your site (include OTCs control plots, etc.) 24 When were they established? 2014 (snow fences), 2016 (OTCs) '''Have they been closed? If so, when?''' NA Is there grazing at your site? No Climate data: Air temperature, Soil temperature, Snow depth, Thaw depth; Soil moisture Current or past data collection: Point framing, Above ground plant traits, Snow fences, Soil moisture, Drones, NDVI; Ecosystem Respiration; GPP Main genera in OTC plots: Salix, Betula, Vaccinium, Sedges, Mosses/Lichens, Ledum,  Rubus

White Mountains

**Name of site leader(s):**Christopher Kopp **University:**University of British Columbia

Fellfield

Site elevation:  3100 m Latitude (WGS84 decimal degrees):  37.5 Longitude (WGS84 decimal degrees): -118.17 Date site was established: 2013 Does your site have OTC's? No

Shrubland

Site elevation: 3700 m Latitude (WGS84 decimal degrees):    37.5 Longitude (WGS84 decimal degrees): -118.17 Date site was established:   2013 Does your site have OTC's?  No

Niwot Ridge

**Name of site leader(s):**Sarah Elmendorf University:   University of Colorado, Boulder

Dry Fellfield

Site elevation:   3535 m Latitude (WGS84 decimal degrees):  40.0548849 Longitude (WGS84 decimal degrees):  -105.5880266 Does your site have OTC's?  No

Dry Meadow

Site elevation: 3529  m Latitude (WGS84 decimal degrees): 40.0554251 Longitude (WGS84 decimal degrees): -105.5888966 Does your site have OTC's? No

Moist Meadow

Site elevation:  3525 m Latitude (WGS84 decimal degrees):  40.05473969 Longitude (WGS84 decimal degrees):  -105.5901614 Does your site have OTC's? No

Moist Shrub Tundra

Site elevation: 3528 m Latitude (WGS84 decimal degrees): 40.05619788 Longitude (WGS84 decimal degrees):  -105.589602 Does your site have OTC's?     Yes

Snowbed

Site elevation: 3537 m Latitude (WGS84 decimal degrees): 40.0569184 Longitude (WGS84 decimal degrees): -105.5908668 Does your site have OTC's?  No

Snow Fence

Site elevation: 3524 m Latitude (WGS84 decimal degrees): 40.05659895 Longitude (WGS84 decimal degrees): -105.5895581 Does your site have OTC's?   No

Southern hemisphere sites

Antarctica

Name of site leader(s): Nicoletta Cannone University: Università dell'Insubria

Edmonson Point

Site elevation: 5–35 m Latitude (WGS84 decimal degrees): 74°19'S Longitude (WGS84 decimal degrees): 165°08'E Date site was established: 2014 Does your site have OTC's? No, but it does have precipitation shields, nutrient additions, and long-term monitoring without manipulations Number of plots at your site (include OTCs control plots, etc.) 88 When were they established? 2014 '''Have they been closed? If so, when? '''No Is there grazing at your site? No Climate data: Soil temperature Current or past data collection: Point framing, Plot photos, Snow fences, Fertilizer plots, Snowmelt dates, Soil sampling, Vegetation coverage and floristic composition Main genera in OTC plots: Mosses/Lichens

Finger Point

Site elevation: 50m **Latitude (WGS84 decimal degrees):  **77°00'S Longitude (WGS84 decimal degrees): 162°26'E Date site was established: **       ** 2014 Does your site have OTC's? No, but it does have precipitation shields, nutrient additions, and long-term monitoring without manipulations Number of plots at your site (include OTCs control plots, etc.) 36 When were they established? 2014 '''Have they been closed? If so, when? '''No ongoing experiment Is there grazing at your site? No **            ** Climate data: Air temperature, Soil temperature Current or past data collection: Point framing, Plot photos, Snow fences, Fertilizer plots, Snowmelt dates, Soil sampling, vegetation coverage and floristic composition Main genera in OTC plots: Mosses/Lichens

Apostrophe Island

Site elevation: 50m **Latitude (WGS84 decimal degrees):  **73°31'S Longitude (WGS84 decimal degrees): 167°25'E Date site was established: **       ** 2014 Does your site have OTC's? No, but it does have precipitation shields, nutrient additions, and long-term monitoring Number of plots at your site (include OTCs control plots, etc.) 36 When were they established? 2014 '''Have they been closed? If so, when? '''No, ongoing experiment Is there grazing at your site? No Climate data: Air temperature, Soil temperature Current or past data collection: Point framing, Plot photos, Snow fences, Fertilizer plots, Snowmelt dates, Soil sampling, vegetation coverage and floristic composition Main genera in OTC plots: Mosses/Lichens **       **

Tarn Flat

Site elevation: 20m **Latitude (WGS84 decimal degrees):  **74°59'S **    ** Longitude (WGS84 decimal degrees): 162°37'E Date site was established: **       ** 2014 Does your site have OTC's? No, but it does have precipitation shields, nutrient additions, and long-term monitoring Number of plots at your site (include OTCs control plots, etc.) 36 When were they established? 2014 '''Have they been closed? If so, when? '''No, ongoing experiment Is there grazing at your site? No **             ** Climate data: Soil temperature Current or past data collection: Point framing, Plot photos, Snow fences, Fertilizer plots, Snowmelt dates, Soil sampling, vegetation coverage and floristic composition Main genera in OTC plots: Mosses/Lichens

Boulder Clay

Site elevation: 150 m **               **     **Latitude (WGS84 decimal degrees):  **74°44'S Longitude (WGS84 decimal degrees): 164°01'E Date site was established: **       ** 2014 Does your site have OTC's? No, but it does have precipitation shields, nutrient additions, and long-term monitoring Number of plots at your site (include OTCs control plots, etc.) 36 When were they established? 2014 '''Have they been closed? If so, when? '''No, ongoing experiment Is there grazing at your site? No **             ** Climate data: Air temperature, Soil temperature, Snow depth Current or past data collection: Point framing, Plot photos, Snow fences, Fertilizer plots, Snowmelt dates, Soil sampling, vegetation coverage and floristic composition Main genera in OTC plots: Mosses/Lichens

Falkland Islands

Name of site leader(s): Stef Bokhorst (previously R. Aerts, P. Convey and A. Huiskes (all in 2003)) University:  VU Amsterdam Site elevation:  2 m Latitude (WGS84 decimal degrees):  -51.76 Longitude (WGS84 decimal degrees):  -59.03 Date site was established: 2003 Does your site have OTC's? Yes Number of plots at your site (include OTCs control plots, etc.) 24 When were they established?  2003 '''Have they been closed? If so, when?''' No Is there grazing at your site?  Birds Climate data: No    full monitoring only during 2003-2005 Current or past data collection:  Point framing, Plot photos, Litter bags, Soil (chemical nutrient composition) Main genera in OTC plots: Empetrum, Ferns, Bryophytes, Lichen

Anchorage Island

Name of site leader(s): Stef Bokhorst  (previously R. Aerts, P. Convey and A. Huiskes) University:  VU Amsterdam Site elevation: 30 m Latitude (WGS84 decimal degrees):  -67.61 Longitude (WGS84 decimal degrees):  -68.22 Date site was established: 2004 Does your site have OTC's? Yes OTCs and Fertilizer (2015) Number of plots at your site (include OTCs control plots, etc.) 12 When were they established?  2004 '''Have they been closed? If so, when?''' No Is there grazing at your site? No **Climate data:**Air temperature >1m, Wind speed, Wind direction, Solar radiation, Soil temperature, full soil temp, PAR and rel hum during 2004-2007 Current or past data collection: Point framing, Plot photos, Below ground microbe surveys, Multispectral data, Below ground invertebrates, Flux, Lichen cover, Bryophyte cover, Soil (chemical nutrient composition)    Taxonomic classification of lichens, Taxonomic classification of bryophytes Main genera in OTC plots:  Bryophytes, Lichen Yes     Yes, but infrequently (once 3–5 years)    No        Yes, year round

Reserva Ecológica Antisana

Name of site leader(s): Priscilla Muriel, Francisco Cuesta University: Pontificia Universidad Católica del Ecuador Site elevation: 4580 m Latitude (WGS84 decimal degrees): 0°28'1.50"S Longitude (WGS84 decimal degrees): 78° 9'43.00"W Date site was established: August 2013 Does your site have OTC's? Yes Number of plots at your site (include OTCs control plots, etc.) 25 control plots, 25 OTC plots (2013), 7 OTC+phenology plots and 7 corresponding control plots (2017) When were they established? August 2013 '''Have they been closed? If so, when? ''' No Is there grazing at your site? Yes Climate data: Air temperature, Soil temperature, This summer 2018 we will install a station with precipitation, radiation (PAR), soil water content Current or past data collection: Phenology, Above ground plant traits, Flower counts, Plot photos, Planned: soil sampling, herbivory Main genera in OTC plots: Páramo (tropical alpine vegetation) species