Additionality of carbon offset projects
Fundamental to the integrity of carbon offsets is the principle of additionality. Any emission reduction generated by carbon offset projects should be additional, meaning the emission reduction would not have occurred without revenue from the sale of carbon offsets. In high quality REDD+, additionality is demonstrated not only by ensuring that revenue from carbon offset sales is channeled towards protecting forests from degradation and deforestation, but also by creating social and conservation benefits – such as by building basic infrastructure like schools, hospitals, and roads for communities, and setting up monitoring and protection programs for wildlife. This ensures that deforestation drivers – including agriculture and logging – are addressed and transformed into durable incentives for forest and wildlife protection.
Additionality in terms of community or biodiversity benefits can be subjective and intangible, and hence challenging to quantify or measure. The Keo Seima Wildlife Sanctuary REDD+ Project (KSWS), developed and managed by the Wildlife Conservation Society (WCS) Cambodia in partnership with the Royal Government of Cambodia, exemplifies how REDD+ projects can bring about evidenced-based improvements in biodiversity outcomes.
Quantifying biodiversity additionality
The biodiversity benefits that KSWS has brought to local wildlife and communities can be assessed using indicators, which are standardized, evidence-based measures of biodiversity quality. Biodiversity indicators are used to assess KSWS’s baseline biodiversity value, the quality of their biodiversity monitoring program, and the reach and impact of their biodiversity protection activities.
KSWS’s rich baseline biodiversity value
A high baseline biodiversity value indicates that there is high potential for generating biodiversity benefits within a project area. Three indicators help us assess KSWS’s baseline biodiversity – whether the project is located in an area expected to be highly biodiverse, the quality of the area’s existing habitats, and whether wildlife species found in the area are under significant threat (e.g. IUCN Red List).
KSWS is located within the Eastern Plains Landscape, which is situated at the intersection of two important ecoregions — the Annamite Mountains and the lower Mekong dry forests. Hence the Eastern Plains Landscape contains a mosaic of habitat types that support a diverse range of species, including rare birds and globally significant populations of endangered wildlife, many of whom are endemic to the area. Furthermore, large parts of these habitats remain relatively undisturbed, and are home to populations of megafauna like the endangered Asian elephant (Elephas maximus) and banteng (Bos javanicus), whose populations have faced severe decline in Southeast Asia in recent decades. Significant threats to biodiversity exist in the area due to hunting, which has dramatically reduced the populations of key wildlife species; habitat destruction and fragmentation from deforestation, illegal logging, and over-harvesting also threaten wildlife in the area.
Table 1: Assessment of KSWS’s baseline biodiversity value
| Indicators | Assessment | Rationale |
| Location in an area of high biodiversity value | High value | KSWS is located within the Eastern Plains Landscape at the intersection of two important ecoregions (Annamite Mountains and lower Mekong dry forests), which supports high biodiversity and local endemism |
| Habitat quality | High value | Large parts of the habitat remain intact and are relatively undisturbed |
| Anthropogenic threats faced | High value | Biodiversity in the area is threatened by habitat destruction and fragmentation, logging and deforestation, and hunting |
KSWS’s world class biodiversity monitoring program
Monitoring the population trend and distribution of key wildlife species within a project area helps the local biodiversity team identify species at risk of further decline and shapes the conservation strategies adopted by the project. Any changes in populations of key wildlife species may indicate broader shifts in the ecological health and balance of the area, such as a change in the amount of anthropogenic threat (for e.g. poaching activity) faced by the species. Hence, the implementation of a biodiversity monitoring program is crucial to the assessment and measurement of changes in biodiversity within the project area across time. The robustness of KSWS’s biodiversity monitoring program is assessed through four indicators – whether key wildlife species to be monitored, their baseline conditions and threats faced have been identified, and the frequency of biodiversity monitoring and reporting.
KSWS has a world-class biodiversity monitoring program that has been running for over a decade. Core to the program are regular line transect monitoring assessments, which monitor the distribution and population of 13 key species found within the project area. The results of this monitoring program are updated and made publicly available every two years, with the latest monitoring cycle completed in 2022. In addition to monitoring these key species, Keo Seima’s project team and academic collaborators also keep a record of all wildlife species found at the site, and have to date identified more than 10 species newly described by science within the project area.
Table 2: Assessment of KSWS’s biodiversity monitoring program
| Indicators | Assessment | Rationale |
| Wildlife species identified for monitoring | High value | 13 key species identified for monitoring in the project area |
| Baseline conditions for wildlife | High value | 12 out of 13 of the wildlife species monitored have declining global populations |
| Threats to wildlife | High value | 11 out of 13 of the monitored species are classified as globally threatened by IUCN Red List, and face threats of habitat loss, hunting, and poaching |
| Frequency of biodiversity monitoring and reporting | High value | Results from the monitoring program are updated and made publicly available every two years, with the latest monitoring cycle completed in 2022. Additionally, all wildlife species found in the project area are recorded and compiled into a species checklist |
KSWS’s robust biodiversity protection measures
Assessing the design and implementation of KSWS’s biodiversity protection measures tells us the extent to which the project is protecting the biodiversity value of the environment. Indicators that help us assess the reach of KSWS’s biodiversity protection measures look at whether the project has implemented patrol activities, community outreach programs, and human-wildlife conflict mediation to combat direct threats to wildlife.
Beyond biodiversity monitoring, the project has also built a robust enforcement program aimed at reducing anthropogenic threats to local wildlife, which includes: conducting regular anti-snaring patrols to locate and remove snares from wildlife and poaching hotspots; human-wildlife conflict mitigation through community engagement and other strategies to minimize crop raiding by elephants; and implementing a nest protection program for threatened bird species, which provides financial incentives to local communities for protecting these nests from poaching. These activities build on data gathered from the biodiversity monitoring program to actively combat threats to wildlife – for example, anti-snaring patrols are conducted more frequently in locations identified as key biodiversity hotspots from transect surveys, and have yielded the removal of 1247 snares from the project area throughout the lifetime of the project. The results from KSWS’s various biodiversity monitoring and protection activities are also conveyed to government officials and local communities via outreach programs to build biodiversity awareness and support for ongoing and future biodiversity-related activities within the community.
Table 3: Assessment of KSWS’s biodiversity protection measures
| Indicators | Assessment | Rationale |
| Presence of patrol activities | High value | Anti-snare patrols implemented to collect snares and prevent wildlife crime |
| Presence of human-wildlife conflict mediation activities | High value | Human-wildlife conflict management programs implemented to manage crop raiding by elephants without the use of snaring |
| Presence of community outreach activities | High value | Community and governmental outreach programs implemented to educate the public on the significance of and gain buy-in for biodiversity conservation programs |
The impact of KSWS’s biodiversity protection measures
Lastly, it is also important to assess whether the biodiversity protection measures implemented at Keo Seima have yielded any biodiversity benefits. To measure the results of KSWS’s biodiversity protection programs, two indicators are identified – the population trends of key wildlife species in the project area, and the overall species richness of Keo Seima.
Ten out of the 13 key species monitored at Keo Seima had improved population trends (stable or slower decline) compared to global estimates (see: above graphic). Given their severe global population decline, the stable populations of four primate species – black-shanked douc, Indochinese silvered langur, southern yellow-cheeked crested gibbon, and the northern pig-tailed macaque – are especially encouraging and represent KSWS’s conservation success. The slowed rate of decline of other faunal species – sambar, Eld’s deer, gaur, and banteng – compared to their populations outside of Keo Seima Wildlife Sanctuary also highlights KSWS’s success in mitigating threats against wildlife.
To date, data collected over a 10-year period shows that KSWS is home to more than 1,000 species of birds, mammals, reptiles, amphibians, fish, molluscs and plants. Over 100 of these species are globally threatened, with 41 species classified as Endangered or Critically Endangered by the IUCN Red List, such as the black-shanked douc langur, Sunda pangolin (Manis javanica; Critically Endangered), Asian elephant (Elephas maximus; Endangered), and the giant ibis (Thaumatibis gigantea; Critically Endangered), which is the focus of KSWS’s nest protection program. This is the highest species richness recorded in any protected area in Cambodia, highlighting the biodiversity richness of the landscape, as well as the rigor of KSWS’s biodiversity monitoring program.
Table 3: Assessment of the impact of KSWS’s biodiversity protection measures
| Indicators | Assessment | Rationale |
| Population trend of key species in KSWS | High value | Improved population trends for 10 out of 13 key wildlife species monitored in comparison to their global population estimates |
| KSWS species richness | High value | Highest number of species found in any protected area in Cambodia with more than 1000 species of birds, mammals, reptiles, amphibians, fish, molluscs and plants, 41 of which are classified as Endangered or Critically Endangered by IUCN Red List |
The biodiversity benefits of REDD+
Overall, KSWS’s biodiversity monitoring program and protection measures have yielded strong results in protecting the local wildlife. Given the severe population decline of some of these species outside of Keo Seima, KSWS’s work in conserving Southeast Asian faunal biodiversity holds regional and global significance, and highlights how forest protection activities funded by carbon revenue can create evidence-based improvements in biodiversity. Beyond keeping tropical forests intact, investments in REDD+ can help to realize the true value of standing forests by creating conditions for a thriving wildlife population and a stable and resilient forest ecosystem.
