Table S1.

Observations and experiments that have revealed effects of large scale drivers, climate and land use, on vegetation, and tested for effects of global change factors on plant and vegetation response

NameData typeTemporal extentGeographical extentStrengthsExample key findings
Observation networks
 LTER Network, USAField site networkSince 198025 sites; USAMonitoring; experiments; cross-site and international comparison (144); socio-ecological systems (145)Drier ecosystems more efficient than wetter ones at converting available energy into NPP (24)
 National Environmental Observatory Network (NEON)Monitoring site networkFuture (construction began 2010)20 core land sites; USAStratified by ecoregions; all vegetation types; ground and airborne instruments; organisms, biogeochemical fluxes, climateDesigned to monitor and forecast ecosystem response to changing climate, land use, invasive species (146)
 CTFS-ForestGEORepeated tree censuses in large forest plotsSince 198159 sites; tropical, temperate and boreal forest; globalTree demographic data; common measurement protocols support intersite comparisons“Undisturbed” tropical forest shows signs of past disturbance; effects of warming at high latitudes; cascading effects via changes in landscape matrix (29)
 FLUXNETEddy covariance towers; Carbon, water, energy fluxesSince 1980s200 sites; globalCommon instrumentation supports intersite comparisons across vegetation typesDroughts cause decreased carbon flux, net decline in terrestrial carbon sink (28)
 PhenoCam (147)Ground-based digital cameras sensing plant canopy phenologyGlobal network of sites, most in North AmericaOften colocated with eddy covariance towers; compliments satellite-based remote sensingTrack advanced spring green-up and other climate-driven changes in vegetation growing season, a sensitive indicator of climate change (148)
Vegetation surveys
 US Public Lands SurveySurveyors used bearing trees as witness to survey cornerEstablished 1787Portions of USAExtensive and systematic; resurvey techniques account for biases; records century scale change (149, 150)Deforestation in past centuries followed by forest regrowth leads to north temperate carbon sink with long lasting effects on composition, structure
 US Forest Inventory and Analysis (FIA), US Dept. Agriculture Forest ServiceDecadal sampling of forest plotsSince 1928National Forests and other forested lands; USAProbability designed sample; repeated inventory estimates demographic rates for treesPositive effect CO2 fertilization on tree growth (151); drought-induced forest die off (152); nitrogen deposition increased tree growth for some species (153)
 European forest inventoriesRepeated sampling of forest plotsVaries; Spain since 1965 (154)National forested landsProbability designed sample; repeated inventory estimates tree demographic ratesRegeneration reflects succession following disturbance, management; succession mediates forest response to climate change; tree mortality attributed to climate-change drought
Coordinated experiments
 FACEResearch coordination network; Elevated open-air CO2Established 1990sField experiments, standard protocols and measurements; across vegetation typesTrees more responsive than herbs; nitrogen limitations less than anticipated (80)
 Drought-Net www.drought-net.orgResearch coordination network; manipulating water inputUnder development; incorporates established experimentsGlobalField experiments, standard protocols and measurements; across vegetation typesObjective to identify mechanisms of sensitivity to drought across ecosystem types to predict drought responses