GCRI · Biodiversity Nexus
Species and genetic diversity
Species populations and the genetic variation within them are the raw material of every ecosystem and of its capacity to adapt. Extinction is the last step of a long decline, and much of the loss happens earlier, as populations shrink, fragment and lose genetic diversity. This page sets out how populations and extinction risk are observed, how genetic diversity is monitored, and how uneven evidence across species and regions shapes what can be concluded.
Species and genetic diversity on the record.
Species and genetic diversity: how the risk develops.
Species populations and genetic diversity. The dossier below sets out how the risk develops, what is measured, where the data come from, how it is modelled and who decides.
Several drivers at once
IPBES identifies five direct drivers of loss: change in land and sea use, direct exploitation, climate change, pollution and invasive alien species. Their weight differs by group and region, and most declining species face several at the same time.
Small populations spiral
As a population shrinks, inbreeding, loss of genetic variation and demographic chance raise its extinction risk further. A population can persist for decades below a viable size, leaving an extinction debt that is paid later.
Genetic erosion
Fragmentation isolates populations and cuts gene flow. Genetic diversity can fall faster than numbers, reducing the capacity to adapt to disease and a changing climate, including in crop wild relatives and traditional livestock breeds.
Losses cascade through food webs
Removing top predators, pollinators, seed dispersers or habitat-forming species changes the abundance of many others. Hunting out large seed dispersers alters tree composition and carbon storage; overfishing of grazers lets algae smother reefs.
Habitat condition in the Amazon Basin.
Land cover, vegetation and population density over the Amazon Basin, from NASA GIBS. Each layer carries its own date.
The interactive map needs JavaScript; the layer list and sources are below.
Layers 3
Habitat condition, for this page
About this layer
- Evidence
- Modelled (latest year GIBS publishes)
- Source
- MODIS Terra and Aqua land cover (MCD12Q1) (NASA LP DAAC)
- Provider
- NASA LP DAAC
- Licence
- NASA open data
- Vintage
- yearly; Satellite classification; latest year GIBS publishes
- Newest at build
- 2024-01-01
- Resolution
- about 500 m grid
- Uncertainty
- Satellite land cover classes for the year shown, including croplands; a classification with known errors, not a farm register.
- Reached through
- gibs.earthdata.nasa.gov, only after you allow the live map
About this layer
- Evidence
- Observed (clouds leave gaps)
- Source
- MODIS Terra EVI (NASA LANCE)
- Provider
- NASA LANCE
- Licence
- NASA open data
- Vintage
- daily; Satellite index; clouds leave gaps
- Newest at build
- 2026-10-13
- Resolution
- about 250 m grid
- Uncertainty
- Satellite vegetation index for the 8 days to the date shown, a habitat condition indicator; not a measure of species or biodiversity.
- Reached through
- gibs.earthdata.nasa.gov, only after you allow the live map
About this layer
- Evidence
- Estimated
- Source
- Gridded Population of the World v4.11 (NASA SEDAC (CIESIN, Columbia University))
- Provider
- NASA SEDAC (CIESIN, Columbia University)
- Licence
- CC BY 4.0
- Vintage
- null; Census-based estimate, static (2020)
- Resolution
- about 1 km grid
- Uncertainty
- Census-based estimate of people per square kilometre in 2020, shown as exposure context; not a count of people affected by any hazard.
- Reached through
- gibs.earthdata.nasa.gov, only after you allow the live map
About this layer
- Evidence
- Observed
- Source
- VIIRS NOAA-20 corrected reflectance (NASA LANCE)
- Provider
- NASA LANCE
- Licence
- NASA open data
- Vintage
- daily; Satellite image
- Newest at build
- 2026-10-14
- Resolution
- about 250 m grid
- Uncertainty
- Satellite image. Satellite or model raster as the provider publishes it. Clouds, swath gaps and retrieval error leave gaps and noise; values are indicators, not measurements at a place.
- Reached through
- gibs.earthdata.nasa.gov, only after you allow the live map
About this layer
- Evidence
- Modelled (latest 8-day period GIBS publishes)
- Source
- MODIS Aqua GPP (MYD17) (NASA LP DAAC)
- Provider
- NASA LP DAAC
- Licence
- NASA open data
- Vintage
- 8-day; Satellite-driven model; latest 8-day period GIBS publishes
- Newest at build
- 2026-09-30
- Resolution
- about 500 m grid
- Uncertainty
- Model estimate of carbon taken up by plants over the 8-day period shown; an indicator of growth, not harvest or production.
- Reached through
- gibs.earthdata.nasa.gov, only after you allow the live map
About this layer
- Evidence
- Observed (clouds and overpass timing leave gaps)
- Source
- VIIRS NOAA-20 375 m (FIRMS) (NASA LANCE FIRMS)
- Provider
- NASA LANCE FIRMS
- Licence
- NASA open data
- Vintage
- daily; Satellite detection; clouds and overpass timing leave gaps
- Newest at build
- 2026-10-13
- Resolution
- about 500 m grid
- Uncertainty
- Satellite hot-spot detections for the day shown, including gas flares and industrial heat; not a confirmed fire, an incident report or a warning.
- Reached through
- gibs.earthdata.nasa.gov, only after you allow the live map
Keyboard, with the map focused
Hold Ctrl or ⌘ and scroll to zoom
Latest available
NASA GIBS / EOSDIS · ASTER GDEM (METI, NASA) · Blue Marble (NASA) · © OpenStreetMap contributors (ODbL) · Natural Earth
Loading the latest NASA imagery.
Drag to move. Ctrl or ⌘ and scroll, pinch or the buttons to zoom; hover for the values under the pointer; reset returns to the region.
Habitat condition, framed on the Amazon Basin.Satellite and model products as NASA publishes them, each with its own date. They are indicators, not assessments of any place.
Data: NASA GIBS · ASTER GDEM · Blue Marble · © OpenStreetMap contributors · Natural Earth · NASA EONET · NASA JPL OPERA DIST-ALERTSources and licences
- We acknowledge the use of imagery provided by services from NASA’s Global Imagery Browse Services (GIBS), part of NASA’s Earth Science Data and Information System (ESDIS). Colours redrawn from the published colour map; values averaged into hexagonal cells where shown (modified). NASA open data
- We acknowledge the use of imagery provided by services from NASA’s Global Imagery Browse Services (GIBS), part of NASA’s Earth Science Data and Information System (ESDIS). Colours redrawn from the published colour map; values averaged into hexagonal cells where shown (modified). NASA open data
- MODIS land products (vegetation indices, gross primary production, land cover), NASA LP DAAC and LANCE; imagery via NASA GIBS. Colours redrawn from the published colour map; values averaged into hexagonal cells where shown (modified). NASA open data
- Center for International Earth Science Information Network (CIESIN), Columbia University. 2018. Gridded Population of the World, Version 4 (GPWv4): Population Density, Revision 11. NASA Socioeconomic Data and Applications Center (SEDAC). Licensed under CC BY 4.0. Colours redrawn from the published colour map; values averaged into hexagonal cells where shown (modified). doi:10.7927/H49C6VHW. CC BY 4.0
- VIIRS near-real-time products (flood, land surface temperature, snow cover, corrected reflectance), NASA LANCE; imagery via NASA GIBS. Colours redrawn from the published colour map; values averaged into hexagonal cells where shown (modified). NASA open data
- NASA Fire Information for Resource Management System (FIRMS), VIIRS 375 m active fire product, NASA LANCE; vector tiles via NASA GIBS. Colours redrawn from the published colour map; values averaged into hexagonal cells where shown (modified). NASA open data
- ASTER GDEM is a product of METI and NASA (ASTER Global Digital Elevation Model V003, NASA LP DAAC); imagery via NASA GIBS. Colours redrawn from the published colour map; values averaged into hexagonal cells where shown (modified). Cite as: NASA/METI/AIST/Japan Spacesystems and U.S./Japan ASTER Science Team (2019). ASTER Global Digital Elevation Model V003. doi:10.5067/ASTER/ASTGTM.003. NASA open data
- Made with Natural Earth. Free vector and raster map data @ naturalearthdata.com. Public domain
- © OpenStreetMap contributors (ODbL), via NASA GIBS (coastlines, boundaries, roads and place names). Colours redrawn from the published colour map; values averaged into hexagonal cells where shown (modified). ODbL
- Blue Marble, NASA Earth Observatory; imagery via NASA GIBS. Colours redrawn from the published colour map; values averaged into hexagonal cells where shown (modified). NASA open data
- Context on the globe and flat map: coastlines, boundaries, roads and place names from NASA GIBS reference layers (OpenStreetMap data, ODbL, © OpenStreetMap contributors); Blue Marble imagery as an optional base; 3D terrain and the elevation read-out from the ASTER GDEM elevation colour index (5 m to 200 m classes, exaggerated for legibility). Boundaries are drawn as published and imply no position on any territory.
- Live events: NASA Earth Observatory Natural Event Tracker (EONET); events are indicative and keep their original source links.
- Live: NASA EONET Events are indicative, not authority warnings.
- Observed (EO): NASA JPL OPERA DIST-ALERT (contains modified Copernicus Sentinel data 2026). We acknowledge the use of imagery provided by services from NASA’s Global Imagery Browse Services (GIBS), part of NASA’s Earth Science Data and Information System (ESDIS).
- NASA GIBS: We acknowledge the use of imagery provided by services from NASA’s Global Imagery Browse Services (GIBS), part of NASA’s Earth Science Data and Information System (ESDIS).
- Optional layers (6 sources in the layer list: live, forecast, observed and context) print their provider credit on the map and here when switched on; forecasts are model output and derived indices are estimates.
Layers and dates
- Land cover type (IGBP), yearly: MODIS Terra and Aqua land cover (MCD12Q1), NASA LP DAAC · 2024
- Enhanced vegetation index, rolling 8 days: MODIS Terra EVI, NASA LANCE · 13 Oct 2026
- Population density, 2020: Population: CIESIN, Columbia University, Gridded Population of the World v4.11 (2018), NASA SEDAC, CC BY 4.0 · static
- True colour: VIIRS NOAA-20 corrected reflectance, NASA LANCE · 13 Oct 2026
- Gross primary production, 8-day total: MODIS Aqua GPP (MYD17), NASA LP DAAC · 30 Sep 2026
- Active fires and thermal anomalies: VIIRS NOAA-20 375 m (FIRMS), NASA LANCE FIRMS · 13 Oct 2026
Species and genes are the raw material of food and medicine.
| Domain | How it couples here | What to watch |
|---|---|---|
| Food | Crop wild relatives and livestock breeds hold traits for future breeding. See agritech and innovation. | Conservation status of crop wild relatives |
| Health | Many medicines derive from natural compounds; biodiversity loss narrows options. | Use of natural products in drug discovery |
| Water | Freshwater species are among the fastest declining groups. | Freshwater species trends |
| Energy | Wind and hydropower siting affects birds, bats and migratory fish. | Collision and passage monitoring |
Essential Biodiversity Variables (Pereira and others, 2013) define what to measure: genetic composition, species populations, species traits, community composition, ecosystem structure and ecosystem function. The Red List Index measures change in extinction risk; GBIF aggregates occurrence records, with known biases toward accessible places and well-studied groups.
Ecosystem condition account.
The screen a team would use to follow this subject: its measures, states and decisions. Names are examples and values are illustrative.
Ecosystem condition account
Species and genetic diversity · Wetland complex · Accounting year 3
- Extent change▼ 1pct of openingWatch
- Condition index0.710 to 10.02Watch
- Species of concern9recorded
- Restoration under management463haNormal
Condition indicators
| Water level regime | 0.7 | 0.6 | 1.0 |
| Native vegetation cover | 0.5 | 0.4 | 1.0 |
| Invasive species pressure | 0.3 | 0.4 | 0.0 |
| Connectivity | 0.5 | 0.6 | 1.0 |
Condition index
Species evidence and contributions.
Species and genetic diversity analyses are designed for the Global Systems Risk and Resilience series, following the indicators of the Global Biodiversity Framework monitoring framework (decision 15/5). Occurrence data contributed through GBIF, survey data with methods, and genetic monitoring results are the contributions that help.
Model species and genetic diversity as a system. Run the cascade.
Assembled from the Nexus Standards area profile Biodiversity and nature risk standards: the hazards it names, the systems and sectors that carry the loss, the controls that dampen it and the data that observe it. Choose the components, pick an initiating hazard and step through the cascade. The Map view places the run on an example geography with open data. Every coupling weight is a stated assumption you can change. A teaching model, not a forecast, an assessment or a certification. To model a place of your own choosing, open the full System Builder.
Hazards
- Deforestation
- Biodiversity loss (set off downstream)
- Soil erosion (set off downstream)
- Land-system change boundary transgression (set off downstream)
- Amazon rainforest dieback (set off downstream)
- Slope slide (set off downstream)
- Flash flood (set off downstream)
- Zoonotic spillover event (set off downstream)
- Wildfire (set off downstream)
- Emerging arbovirus outbreak (set off downstream)
- Malaria resurgence (set off downstream)
Systems and couplings
- Biodiversity and nature risk standards
- Climate risk standards Feedback
- Health risk standards Cascade
- Food and agriculture risk standards Dependency
- Environmental degradation hazard standards Shared hazard records
Controls
NS-0Constitution and principlesNS-1The UNI and the artefact catalogue (grammar v0.2: domain, sector, region and environment segments)NS-3Risk record UNIs (grammar, legacy crosswalk, allocation authority)NS-3bDataset and product metadata profile (STAC, DCAT, PROV-O)NS-5Figure, map and visualisation standard (with the UI/UX kit)NS-9Contextual UNIs (deployments, instances, programme instances)NS-11Verification and monitoring (evidence, attestations, zero-trust conformance observation)NRS-N5Biodiversity and nature risk and resilienceNRS-H65Hazard family: Planetary boundary transgressions (NHS-1 planet.boundary)NRS-H27Hazard family: Biodiversity and species stress (NHS-1 eco.species)NRS-H26Hazard family: Land and wetland degradation (NHS-1 eco.land)NRS-H28Hazard family: Climate-state shifts (NHS-1 eco.climate-state)NRS-H64Hazard family: Ecosystem regime shifts (NHS-1 eco.regime-shift)
Observation
- GBIF occurrence API and downloads (listed for reference)
- World Database on Protected and Conserved Areas (listed for reference)
- Global Forest Watch tree cover loss (Hansen/UMD) and alerts (listed for reference)
- ESA WorldCover 10 m land cover (listed for reference)
- Copernicus Land Monitoring Service products (listed for reference)
- Red List Index
- Forest area as a proportion of total land area
- Proportion of important sites for terrestrial and freshwater biodiversity covered by protected areas
Example geography
- Pacific Island states: 150 hexagonal cells
- Vegetation disturbance alerts, 30 m (OPERA DIST-ALERT), NASA GIBS
- Surface soil moisture (SMAP), NASA GIBS
- Night lights tonight, outages (VIIRS Day/Night Band), NASA GIBS
- Rain rate, last half hour (IMERG), NASA GIBS
What is measured, and how well.
Each indicator carries its unit, its cadence, the kind of source behind it and the evidence label a value would carry. No values are shown: a programme supplies them under its own authority.
| Indicator | Unit | Cadence | Source type | Label |
|---|---|---|---|---|
| Red List Index | dimensionless index of aggregate extinction risk | per reassessment cycle | IUCN Red List assessments | Published statistics |
| Living Planet Index | index relative to a baseline year | biennial | Compiled vertebrate population time series | ESTIMATED |
| Species Habitat Index | percent of suitable habitat retained relative to baseline | annual | Remote sensing with species range models | MODELLED |
| Populations above the effective size threshold | percent of populations assessed | per assessment | Census and genetic estimates of effective population size | ESTIMATED |
| Georeferenced occurrence records | count of records per taxon and grid cell | continuous | Natural history collections and observation networks | OBSERVED |
| Threatened species in a site or range | count of species by Red List category | per assessment | IUCN range maps intersected with sites | ESTIMATED |
| Abundance trend of monitored populations | percent change per year | annual | Standardised surveys such as breeding bird counts | OBSERVED |
How species and genetic diversity is modelled, measured and tested.
The model, its assumptions, its data and its uncertainty, in the form a scientist or engineer would check. Structures follow published methods. The values drawn are illustrative, not findings.
Earth observation chain
How a satellite or sensor record becomes evidence on species and genetic diversity, and where each step adds uncertainty.
- 01 · Acquireorbit, sensor and revisitUncertainty: gaps from cloud and orbit
- 02 · Calibrateradiometric and geometricUncertainty: sensor drift
- 03 · Correctatmosphere and terrainUncertainty: aerosol and slope assumptions
- 04 · Retrieve or classifythe variable or the classUncertainty: model and training error
- 05 · Validateagainst ground truthUncertainty: sample design and size
- 06 · Publishwith error bars and lineageUncertainty: stated, never hidden
Where the evidence comes from.
Named public datasets and institutional records, each with its licence class. Sources by agreement are used only under their terms and never republished.
| Source | What it gives | Licence class |
|---|---|---|
| IUCN Red List of Threatened Species | Extinction-risk assessments, range maps, threats and conservation actions | Free for non-commercial use, terms of use |
| Global Biodiversity Information Facility (GBIF) | Species occurrence records from collections, surveys and citizen science | CC0, CC BY or CC BY-NC per dataset |
| Living Planet Index database | Vertebrate population time series compiled from published sources | Free for non-commercial use, terms of use |
| BioTIME | Assemblage time series of species abundance at fixed locations | Terms per study, mostly open with attribution |
| INSDC sequence archives and the Barcode of Life Data System | Genetic sequences and DNA barcodes for identification and diversity estimates | Public, no restrictions on INSDC; open with attribution on BOLD |
| eBird Basic Dataset (Cornell Lab of Ornithology) | Checklist-based bird observations with effort information | Free for non-commercial use, terms of use |
| National biodiversity monitoring schemes | Standardised counts such as breeding bird and butterfly monitoring | Public records, terms per scheme |
Who decides, and what the evidence serves.
Biodiversity Nexus prepares evidence. The decisions below are taken by the authorities named, under their own rules, and never by the platform.
| Who decides | The question | Evidence this page serves |
|---|---|---|
| Environment ministries and CBD national focal points | Which species and populations need recovery action, and how genetic diversity is reported in the national strategy | Red List status, population trends, effective size estimates where they exist |
| Wildlife and protected-area agencies | Where to survey, protect or translocate, and which threats to address first | Distribution models, threat maps, record gaps |
| CITES management and scientific authorities | Whether trade in a species is non-detrimental to its survival in the wild | Population status and trend, harvest and trade records, the uncertainty in each |
| Infrastructure developers and their lenders | Whether a site holds critical habitat for threatened or range-restricted species | Red List ranges, Key Biodiversity Areas and occurrence records at the site, with gaps stated |
Outputs this topic produces
- Species evidence notes with record coverage and gaps mapped
- Distribution models with range and uncertainty stated
- Population trend summaries that separate data-rich and data-poor groups
- Genetic diversity monitoring guides aligned to the Kunming-Montreal indicators
What experts ask.
Experts studying species and genetic diversity return to a common set of questions.
- Which populations are declining, how fast, and what is driving the decline?
- Which species are at risk of extinction, and how reliable is the evidence behind that assessment?
- How much genetic diversity remains in wild populations and in the crops and livestock societies depend on?
- Which species play outsized roles, such as pollinators, predators or habitat builders, whose loss would cascade?
- How will species ranges shift as climate changes, and can populations move or adapt fast enough?
How populations shrink and lose their capacity to adapt.
Populations decline when habitat is lost or fragmented, when individuals are harvested faster than they reproduce, when invasive species or diseases arrive, or when the climate moves outside their tolerance. Small, isolated populations then face further risks of their own: random fluctuations in births and deaths, inbreeding, and the loss of rare genetic variants through drift. These processes can carry a population towards extinction even after the original pressure has eased, a pattern often described as an extinction debt.
Genetic diversity matters because it sets the range of responses available to a population when conditions change. Domesticated species face the same issue: narrowing the genetic base of crops and livestock can raise productivity while increasing vulnerability to a single pest or disease. Loss of a functionally important species, such as a dominant grazer or a pollinator, can change an entire ecosystem.
How the evidence is built, and where it stops.
- 01
Population monitoring
Repeated counts, transects, camera traps and citizen science records reveal trends. Coverage is uneven, biased towards well-studied groups and accessible places.
- 02
Extinction risk assessment
Standard criteria combine population size, decline and range. Many species lack the data to be assessed at all.
- 03
Environmental DNA
DNA fragments in water or soil can detect species without seeing them. Detection is not abundance, and reference libraries are incomplete.
- 04
Population genetics
Genetic sampling estimates effective population size and connectivity. It is still rare outside a few species, and its analysis draws on spatial statistics.
How it is studied, and what the methods cannot say.
- 01Ecology and biodiversity scienceSpecies distribution modelling · Population trend and viability analysisApplied here
- 02Spatial statistics and geostatisticsBias-corrected distribution surfaces · Hotspots of change and threatApplied here
- 03Earth observation and remote sensingForest loss and disturbance alerts · Wetland and mangrove dynamicsApplied here
- 04Causal inference and impact evaluationProtected area effectiveness · Restoration and payment programme evaluationApplied here
- 05Geospatial information systemsOverlap with sensitive biodiversity · Connectivity and corridor analysisApplied here
Where this page’s references lead.
The bodies and documents this page is read against. Status and editions change; each link goes to the issuing body.
Questions and answers.
Why do different biodiversity indices show different trends?
Does a species record mean the species is still there?
Why monitor genetic diversity and not only species?
Why care about genetic diversity if a species is still common?
Are extinction risk lists complete?
Can environmental DNA replace field surveys?
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