Diécké Classified Forest
West Africa > Republic of Guinea > Diécké Classified Forest
Summary
- Western chimpanzees (Pan troglodytes verus) are present in Diécké Classified Forest.
- It has been estimated that 80 (CI: 25-253) individuals occur in the forest.
- The chimpanzee population trend is unknown.
- This site has a total size of 640 km².
- Key threats to chimpanzees are poaching and habitat destruction.
- The following conservation activities were conducted by the Centre Forestier de N'Zérékoré: land-use planning, reforestation and monitoring of illegal hunting.
- Diécké Classified Forest is one of the last biodiversity rich forest blocks remaining in southern Guinea.
Site characteristics
Diécké is a forest in southern Guinea close to the border with Liberia (7°39'N - 7°21'N and 9°06'W - 8°47'W) and was designated as a Classified Forest in 1945 (IUCN category not reported, UNEP-WCMC and IUCN 2018). The forest is located in Guinée forestière, one of four Guinean natural regions, and is part of the region N'Zérékoré. It is about 100km west of Bossou and 950 km from the Guinean capital Conakry (Carvalho 2011). The forest has a size of 640 km², 70% of which are dense forest and the remainder being sparsely forested areas, fallows, and open land (WCF 2012). Diécké forest has a rich biodiversity with hippopotamus (Hippopotamus amphibius), duikers, and several primate species, including chimpanzees (WCF 2012). It is also listed as an Important Bird Area and harbors several species of plants and amphibians. Together with Ziama forest, this is one of the last remaining large forest blocks in southern Guinea. The terrain is partly hilly and ranges in altitude from 50-800m (Carvalho 2012).
Table 1: Basic site information for Diécké Classified Forest
| Area | 640 km² |
| Coordinates | 8.94 W, 7.54 N |
| Designation | Classified Forest |
| Habitat types | Subtropical/tropical moist lowland forest |
IUCN habitat categories Site designations
Ape status
Based on a nation-wide questionnaire survey, the presence of western chimpanzee was confirmed by Sugiyama & Soumah (1988). In a nationwide survey Rebecca Kormos identified Ziama Biosphere Reserve as the second most important priority area for western chimpanzee conservation in Guinea due to high chimpanzee densities encountered during reconnaissance surveys (Ham 1998). A nationwide survey by the Wild Chimpanzee Foundation estimated the chimpanzee population size at around 80 individuals (WCF 2012).
Table 2: Great ape population estimates in Diécké Classified Forest
| Species | Year | Abundance estimate (95% confidence interval) | Density estimate (per km²) | Encounter rate (nests/km) | Area | Method | Source | Comments | A.P.E.S. database ID |
|---|---|---|---|---|---|---|---|---|---|
| Pan troglodytes verus | 1988 | 50 | Diécké forest | Interview method | Sugiyama & Soumah 1988 | Questionnaire survey | |||
| Pan troglodytes verus | 1997 | 209-307 | 0.17 | 2.6 | Diécké forest | Line transects (Distance) | Ham 1998 | Total survey effort: 5.2 km | |
| Pan troglodytes verus | 2012 | 80 (25-253) | 0.14 | 0.3 | Diécké forest | Line transects (Distance) | WCF 2012 | Total survey effort:144.8km |
Threats
Illegal poaching represents the major threat to the chimpanzee population in the park (WCF 2012, Ham 1998). More than 500,000 immigrants migrated to this area beginning in 1989 from Sierra Leone and Liberia resulting in a strong increase in illegal logging (Carvalho 2011). There was also an increase in plantations of oil palm, rubber, and crops (Carvalho 2011).
Table 3: Threats to great apes in Diécké Classified Forest
| Category | Specific threats | Threat level | Quantified severity | Description | Year of threat |
|---|---|---|---|---|---|
| 1. Residential & commercial development | Absent | ||||
| 2. Agriculture & aquaculture | 2.1. Annual & Perennial Non-Timber Crops | High | 0.30 signs of agriculture/km (43 signs of agriculture, survey effort: 144.853 km, WCF 2012) | Plantations for oil palm and rubber, and other crops (Carvalho 2011, UNEP-WCMC and IUCN 2018) | Ongoing (2011, 2018) |
| 3. Energy production & mining | Absent | ||||
| 4. Transportation & service corridors | 4.1. Roads & railroads | Medium | 1.26 roads/km (182 roads, survey effort: 144.853 km, WCF 2012) | Second highest encounter rate of all anthropogenic signs (WCF 2012) | Ongoing (2012) |
| 5. Biological resource use | 5.1. Hunting & collecting terrestrial animals | High | 1.45 signs of hunting/km (210 signs of hunting, survey effort: 144.853 km, WCF 2012) | Illegal poaching is consistently mentioned as the most prevalent threat across reports (Carvalho 2011, UNEP-WCMC and IUCN 2018) | Ongoing (2011, 2018) |
| 5.3. Logging & wood harvesting | Present | 0.05 signs of wood extraction/km (7 signs of wood extraction, survey effort: 144.853 km, WCF 2012) | Logging increased strongly when migrants arrived from Sierra Leone and Liberia in 1989 (Carvalho 2011). Signs of logging and charcoal production were found in a survey in 2011 (WCF 2012) | Ongoing (2011, 2012) | |
| 6. Human intrusions & disturbance | Absent | ||||
| 7. Natural system modifications | Absent | ||||
| 8. Invasive & other problematic species, genes, diseases | Unknown | ||||
| 9. Pollution | Absent | ||||
| 10. Geological Events | Absent | ||||
| 11. Climate change & severe weather | Unknown | ||||
| 12. Other options | Absent |
Conservation activities
The Centre Forestier de N'Zérékoré is responsible for Diécké Classified Forest. In the 1990’s the forest was divided into three land-use zones, the outer two allowing for different degrees of human activities, while the core of the forest was designated a ‘integrally protected area’ (WCF 2012). After 2000 Progerfor (the Projet de Gestion des Ressources Forestières), a cooperation between Centre Forestier de N'Zérékoré and German partners, conducted conservation activities, including reforestation and monitoring of illegal hunting (Carvalho 2011).
Table 4: Conservation activities in Diécké Classified Forest
| Category | Specific activity | Description | Year of activity |
|---|---|---|---|
| 1. Residential & commercial development | Not reported | ||
| 2. Agriculture & aquaculture | Not reported | ||
| 3. Energy production & mining | Not reported | ||
| 4. Transportation & service corridors | Not reported | ||
| 5. Biological resource use | 5.15. Implement monitoring surveillance strategies | Monitoring of illegal hunting was conducted (Carvalho 2011), but it is not clear whether these activities are still on-going | After 2000 |
| 6. Human intrusions & disturbance | Not reported | ||
| 7. Natural system modifications | Not reported | ||
| 8. Invasive & other problematic species, genes, diseases | Not reported | ||
| 9. Pollution | Not reported | ||
| 10. Education & Awareness | Not reported | ||
| 11. Habitat Protection | 11.1. Create buffer zones around protected primate habitat | Forest was divided into three land-use zones, with the core of the forest being (25% of total areas) designated as an ‘integrally protected area’ (Carvalho 2011) | After 2000 |
| 11.2. Legally protect primate habitat | Designated as Classified Forest since 1945 (UNEP-WCMC and IUCN 2018) | Ongoing (2018) | |
| 11.8. Plant indigenous trees to re-establish natural tree communities in clear-cut areas | Reforestation activities by Progerfor (Carvalho 2011) | After 2000 | |
| 12. Species Management | Not reported | ||
| 13. Livelihood; Economic & Other Incentives | Not reported |
Conservation activities list (Junker et al. 2017)
Impediments
Table 5: Impediments reported for Diécké Classified Forest
| Impediment | Source |
|---|---|
| Not reported |
Research activities
From 1996 to 1997 Rebecca Kormos (née Ham) did a nationwide surveys on chimpanzees across Guinea (Ham 1998). She identified Diécké Classified Forest as a priority site. In 1999 Tetsuro Matsuzawa did a preliminary survey in Diécké to scope for a possible future research site (Matsuzawa et al. 1999) and discovered that the chimpanzees crack panda nuts. To inform the extension of the protected area network Brugiere and Kormos (2009) identified 16 Key Biodiversity Areas across Guinea based on the occurrence of globally threatened large and medium-sized mammals, among which Diécké Classified Forest ranked second. From 2006 to 2008 Sousa and Carvalho conducted research in Diécké to study the nut-cracking behavior of chimpanzees (Carvalho 2011). The Wild Chimpanzee Foundation did a nationwide inventory of chimpanzee populations in Guinea between 2009 and 2011. The WCF monitoring team covered a total of 10 sites, including Diécké Classified Forest, using transect surveys (WCF 2012).
Documented behaviours
Table 6: Great ape behaviors reported for Diécké Classified Forest
| Behavior | Source |
|---|---|
| Nut cracking | Matsuzawa et al. 1999, Carvalho 2011 |
Relevant datasets
References
Brugiere D, Kormos R. 2009. Review of the protected area network in Guinea, West Africa, and recommendations for new sites for biodiversity conservation, Biodiversity and Conservation, 18:847
Carvalho S. 2011. Diécké forest, Guinea: delving into chimpanzee behavior using Stone tool surveys, in Matsuzawa T, Humle T and Sugiyama Y, ed. The chimpanzees of Bossou and Nimba. Springer. Tokyo
Ham R. 1998. Nationwide chimpanzee census and large mammal survey Republic of Guinea. Unpublished report for the European Communion, Guinea-Conakry.
Matsuzawa T et al. 1999. Diecke Forest Guinea. Report. Primate Research Institute, Kyoto University, Japan
Sugiyama, Y. & Soumah, A.G. (1988) Preliminary Survey of the Distribution and Population of Chimpanzees in the Republic of Guinea. Primates, 29(4):569-574
UNEP-WCMC, IUCN. 2018. Protected Planet: The World Database on Protected Areas (WDPA), Cambridge, UK: UNEP-WCMC and IUCN Online: diecke-classified-forest www.protectedplanet.net
WCF. 2012. Etat de la faune et des menaces dans les aires protégées terrestres et principales zones de forte biodiversité de Rep. de Guinée. Report. Wild Chimpanzee Foundation, Sangaredi, Republic of Guinea. Online: www.wildchimps.org
Page completed by: A.P.E.S. Wiki Team Date: 15/11/2018