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
| Name | Data type | Temporal extent | Geographical extent | Strengths | Example key findings |
| Observation networks | |||||
| LTER Network, USA | Field site network | Since 1980 | 25 sites; USA | Monitoring; 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 network | Future (construction began 2010) | 20 core land sites; USA | Stratified by ecoregions; all vegetation types; ground and airborne instruments; organisms, biogeochemical fluxes, climate | Designed to monitor and forecast ecosystem response to changing climate, land use, invasive species (146) |
| CTFS-ForestGEO | Repeated tree censuses in large forest plots | Since 1981 | 59 sites; tropical, temperate and boreal forest; global | Tree 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) |
| FLUXNET | Eddy covariance towers; Carbon, water, energy fluxes | Since 1980s | 200 sites; global | Common instrumentation supports intersite comparisons across vegetation types | Droughts cause decreased carbon flux, net decline in terrestrial carbon sink (28) |
| PhenoCam (147) | Ground-based digital cameras sensing plant canopy phenology | Global network of sites, most in North America | Often colocated with eddy covariance towers; compliments satellite-based remote sensing | Track 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 Survey | Surveyors used bearing trees as witness to survey corner | Established 1787 | Portions of USA | Extensive 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 Service | Decadal sampling of forest plots | Since 1928 | National Forests and other forested lands; USA | Probability designed sample; repeated inventory estimates demographic rates for trees | Positive effect CO2 fertilization on tree growth (151); drought-induced forest die off (152); nitrogen deposition increased tree growth for some species (153) |
| European forest inventories | Repeated sampling of forest plots | Varies; Spain since 1965 (154) | National forested lands | Probability designed sample; repeated inventory estimates tree demographic rates | Regeneration reflects succession following disturbance, management; succession mediates forest response to climate change; tree mortality attributed to climate-change drought |
| Coordinated experiments | |||||
| FACE | Research coordination network; Elevated open-air CO2 | Established 1990s | Field experiments, standard protocols and measurements; across vegetation types | Trees more responsive than herbs; nitrogen limitations less than anticipated (80) | |
| Drought-Net www.drought-net.org | Research coordination network; manipulating water input | Under development; incorporates established experiments | Global | Field experiments, standard protocols and measurements; across vegetation types | Objective to identify mechanisms of sensitivity to drought across ecosystem types to predict drought responses |