OBSERVER: CLMS monitors the heartbeat of our vegetation
Copernicus Land Monitoring Service (CLMS) data plays an important role in the monitoring and management of land and ecosystems. This makes it is an important component to contribute to the restoration goals of the European Green Deal and to the EU digital strategy. As part of the latter, Destination Earth aims to develop a high precision digital model of the Earth, i.e. digital twins, to model, monitor and simulate natural phenomena and related human activities. Such models require continuous high quality data streams with high spatial and temporal resolution to monitor the health of our planet. The Copernicus biophysical parameters monitor the condition of land surface vegetation daily and thereby provide information on the health of our ecosystems at European and Global scale. Therefore, these parameters contribute important components to this digital model and also provide actionable data directly to policy makers and land managers.
Monitoring ecosystems
Plants follow periodic life-cycle events called phenology, such as emergence, flowering and bud-burst (in spring), maturation and leaf coloration and fall (in autumn). Also, despite their foliage year-round, evergreen vegetation has a more and a less productive phase. In the tropics, anthropogenic impacts (e.g. deforestation) can also disturb the condition and productivity of vegetation. Human land use, like soil sealing when building for example new settlements, completely removes vegetation from the surface impeding flood and heat protection, hampering climate change adaptation, carbon sequestration while destroying and fragmenting habitats.
Extreme weather events and climatic change are other factors that can change or disturb vegetation condition and productivity. Gathering field-level information on the status of the vegetation and the observable impact of disruptive land use or natural events is expensive and difficult over large areas. Earth Observation is a very cost efficient alternative and it allows precise and repeatable observations in a harmonised manner, whilst utilising continental and global coverage.
Monitoring vegetation from space
The Copernicus Sentinel satellites provide a continuous stream of Earth Observation data and information at different levels of details; 300 meters for Sentinel-3 and 10 meters for Sentinel-2. These data enable us to derive indices that represent the presence and vigour of green biomass and allow to detect differences in the intensity of photosynthetic activity. These indices can then be used to monitor the vegetation phenology, productivity and their dynamics and allow the assessment of anthropogenic or climatic impacts on our ecosystems.
CLMS routinely generates several indices at different details to monitor the dynamics of vegetation. These routinely generated products are fit for purpose for different applications and suitable for various levels of expertise and needs. They include:
- Normalised Difference Vegetation Index (NDVI): a generic indicator of the greenness of the land;
- Fraction of Absorbed Photosynthetically Active Radiation (fAPAR): information on the radiation absorbed by leaves for their photosynthetic activity, which is a good proxy for biomass production;
- Leaf Area Index (LAI): quantifies the thickness of vegetation cover, which is important to monitor the health of forests; and
- Plant Phenology Index (PPI): an index optimised to detect the main events in the vegetation phenological cycle (e.g. in spring and autumn).
The vegetation indices are provided at 300 meters spatial resolution over the entire globe and at 10 meters spatial resolution over continental Europe. The information is provided at three time intervals:
- Daily, the raw information;
- 10-daily, a cleaned signal with a frequency useful for anomaly analysis; and
- Yearly to track the major annual plant evolution events (start of season, end of season, etc.) and estimate the total annual biomass production.
Free information helps tracking our planet’s health
Information on vegetation dynamics is important for various policies, but it is also directly relevant for our daily life. For example, early flowering can pose health issues to people dealing with allergies, and farmers and gardeners need to know the schedule of plant development to decide when to apply fertilizers and pesticides etc., and commercial companies may use the information to forecast sales and related production intensity of appliances, such as grass mowers.
The Copernicus Earth Observation products are freely available and can be accessed and used by anybody in support of policy design and implementation and in support of monitoring for land management decision making related, e.g. deforestation, carbon accounting, ecosystem functioning, land degradation, biodiversity and assessing climate impacts, such as drought, and other disasters.
Deforestation
Forests play an important role in maintaining biodiversity and providing ecosystem services, which include nutrient cycling, preventing soil erosion, flooding while providing food and water. Carbon emissions from tropical deforestation and forest degradation are estimated to contribute 6-17% to man-made carbon emissions at global scale. The main driver of forest loss in the tropics is the conversion to agriculture lands, particularly cash crop plantations. Time series analyses of the CLMS vegetation indices, covering as period as long as from 1999 till now, allow the identification of the changes in the extent of tree cover and, up to a certain extent, also degradation. The CLMS land cover maps, at global scale with 300 meters details and at European scale with 20 meters, are good references supporting such dynamic temporal analysis. Further to the detailed forest cover products generated over Europe, this year CLMS will introduce specific forest products over the tropics, such as tree cover presence, density and change.
The operationally generated and quality checked vegetation indices are the main source data for compiling these advanced products. These CLMS products support in particular the REDD+ activities under the UNFCCC, i.e. Reducing Emissions from Deforestation and forest Degradation, and will contribute to the implementation of the proposed EU Regulation on deforestation-free products.
Carbon accounting
Increasing carbon dioxide emissions are one of the reasons for the greenhouse effect which results in increasing global temperatures, i.e. global warming. The impacts of global warming are manifold. It changes migration patterns of animals and changes plant phenology with a phenological mismatch between preys and predators, as one of the negative consequences. Global warming causes ice to melt, making see level rise with forced dislocation of coastal populations and causes climatic extremes such as severe floods, heavy storms, prolonged droughts and frequent fires. Vegetation can counteract carbon dioxide emissions by converting it into biomass through active photosynthesis. Increase and decrease in vegetation biomass can be calculated per specific land covers using the Copernicus trend information on vegetation phenology related with accumulated productivity estimates. These data derived from the CLMS vegetation products are a required input for carbon flux modelling used for the annual or even intra-annual accounting of carbon dioxide emissions and removals. This is the backbone support for the monitoring of climate policy effectiveness. One such policy is the EU’s land use, land-use change and forestry (LULUCF) Regulation ((EU) 2018/841) that covers the greenhouse gas (GHG) emissions and removals resulting from the management of land, forests and biomass.
Land degradation
Intensive human land use that has been unremittingly optimized for producing food and fiber is very often at the limits of over-exploitation. This creates substantial stress on the land resources, including soil and water. The resulting impacts can cause irreversible loss of ecosystem services leading to land degradation. Fertiliser dependent intensive agriculture, nitrification of water resources, overgrazing, land take, conversion of semi-natural lands to urban areas and soil sealing can bring about irreversible land degradation. Although land degradation results from a combination of natural and socio-economic drivers, it is generally perceptible from long lasting loss of vegetation cover and biomass productivity. Whilst the expression of land degradation is occurring at local scales, it is nonetheless affecting planetary biogeochemical cycles – a global phenomenon.
The status and change of the vegetation cover is indeed a good proxy that reflects well the degree at which the land is used or consumed. The CLMS routine global vegetation products that are derived from Sentinel-3 data have ensured a continuation of the long standing SPOT and Proba-V series since 1999 and with that provide an excellent means for analyzing the past trends in perspective to the current situation. Constant downward trends of vegetation productivity are a principal indicator within the wider scheme of land degradation assessment. Currently some 36% of the global land surface shows stressed productivity levels, and 9% undergoes a persistent decline (period 2014 to 2019). CLMS also supports the United Nations Convention to Combat Desertification with tailored data needed for reaching the land degradation neutrality goal and the default dataset on vegetation productivity (Rotllan-Puig, Ivits and Cherlet, 2021) needed for the ongoing SDG 15.3 reporting on restoring degraded land and soil.
Climate impact assessment
Climate change increases the frequency and intensity of extreme events, such as droughts. Long lasting, severe and frequent droughts distresses, and on a longer term can modify, the vegetation cover causing habitat loss, migration of local species and the spread of invasive alien species and consequently biodiversity loss. Droughts have an impact on water resources and agriculture production, cause soil erosion, reduce carbon sequestration and overall contribute to land degradation. Monitoring drought impact is a precondition for effective measures to adapt or increase the resilience of ecosystems. Droughts affect several targets of the EU Biodiversity strategy to 2030 related to protecting and restoring nature. As droughts hamper nature's ability to deliver a wide range of environmental, social, climate change adaptation and mitigation, and biodiversity benefits, they impact the implementation of the EU Strategy on Green Infrastructure. Viable food production, sustainable management of natural resources, climate action and balanced territorial development, long-term objectives of the EU Common Agriculture Policy, are also affected by droughts.
By calculating negative anomalies of vegetation productivity derived from time series of vegetation indices in areas that are pressured, for example, by droughts or wildfires, remote sensing observed vegetation phenology and productivity can quantify impacts of climatic extremes on biomass conditions. Such analysis is performed by the European Drought Observatory[1] by combining various data sources such as precipitation measurements, soil moisture models and vegetation indices. The European Environment Agency maintains an indicator[2] and a dashboard[3] addressing drought impact on the ecosystems using the biophysical variables service of the Copernicus Land Monitoring Service. Both applications will largely benefit from the High Resolution Vegetation Phenology and Productivity Service in addressing drought impact on the local scale and distinguishing areas where policy measures need to be implemented to support nature restoration goals.
Biodiversity
Biodiversity is deteriorating due to severe ecosystem fragmentation and high environmental pressures. Many species, habitats and ecosystems are threatened by urban sprawl, unsustainable farming and forestry, and pollution. In Europe, 36% of the habitat area has a bad and 45% a poor quality. Conservation of habitats and biodiversity is important for the maintenance of ecosystem functions and the provision of ecosystem services. Much more effort is needed to reverse current trends and to ensure a resilient and healthy nature. The Biodiversity Information System for Europe and the European Nature Information System (EUNIS) provide information habitat types and species in Europe, while the Digital Observatory for Protected Areas provides such information for protected areas across the globe. The Copernicus vegetation phenology data at high resolution in combination with new Artificial Intelligence techniques can improve the mapping and distribution of habitats, at a higher spatial detail, faster and with less efforts. The Copernicus vegetation datasets contribute directly to several Essential Biodiversity Variables to monitor biodiversity and restore ecosystems.
Further reading and data access
Are you interested to read more about Copernicus Vegetation products? Then head over to the Copernicus Land Monitoring Service web site or have a direct look at the data through the WEKEO Viewing Portal.
[1] https://edo.jrc.ec.europa.eu/edov2/php/index.php?id=1000
[2] https://www.eea.europa.eu/ims/drought-impact-on-ecosystems-in-europe
[3] https://www.eea.europa.eu/data-and-maps/data/data-viewers/drought-impac…