0
Taking stock of smallholders and community forestry
                   Session 13
 Impact of local forestry practices on l...
Let’s go to Central Cameroon
Fairly recent introgression
             of forest onto savannah

Humans are hardly responsible for past
  bioclimatic eve...
Multidisciplinary evidence of
           this extensive phenomenon

•    Phytogeography
•    Botany
•    Phytosociology
• ...
Forest-savannah ecotone

               •  Rich ecosystem
               - Diversified mosaic
               - Forest plan...
Ecological heterogeneity
               of the ecotone

forest/savannah ecotone in the   forest/savannah ecotone in the
  ...
Tikar… and Bedzan

           •  Warlike and conquering stratified
                 society

           •  Originally cere...
Forest swiddeners
             and savannah cultivators
Intercropped swidden under forest




                            ...
Non agricultural activities

hunting                  fishing




                                   gathering
Afforestation between
     1950 and 1989



                        Sectors of faster
                        afforestatio...
Accelerated afforestation
   near residential sites
   Villages were built right up against the forest edge
Accelerated afforestation
   near residential sites
                    Temporary swidden camps
Accelerated afforestation
   near residential sites
                    Seasonal fishing camps
Accelerated afforestation
   near residential sites




                            In 35 years
Local strategies to
         control afforestation




Fragmented swidden area           Single swidden area
   fast affor...
Local strategies to
control afforestation
            Selective tree cutting by forest swiddeners
Local strategies to
               control afforestation
Seed rain and nucleation
Local strategies to
          control afforestation
1970s: Permanent agroforest belt as a fence against afforestation


  ...
Local strategies to
                       control afforestation
                             Agroforest trees as safety n...
Local strategies to
                 control afforestation
     1980s: invasion by Chromolaena odorata (Asteraceae)
      ...
Local strategies to
           control afforestation
                  Early burning of savannahs
       Chromolaena facil...
Local strategies to
       control afforestation
             Delayed burning of fallows

Exhausting clearing of young fal...
Local strategies to
    control afforestation
         Delayed burning of fallows
Chromolaena compromises afforestation

 ...
Local strategies to
           control afforestation
Effect of Chromolaena on
  the fallowing rotation

•  No more forest ...
Local strategies to
              control afforestation
Community farming activities and mutual aid
Increased man-days per...
In brief


               1980s
            Invasion by
           Chromolaena
              odorata
Where do we go from here…
            … well, let’s go back to there!
•  Coupled human-nature shaping of ecosystems

•  An...
Thank you for your attention!
Upcoming SlideShare
Loading in...5
×

Land use change and local forest dynamics in the forest-savannah boundary in central cameroon

1,237

Published on

Edmond Dounias

Presentation for the conference on
Taking stock of smallholders and community forestry
Montpellier France
March 24-26, 2010

Published in: Education
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total Views
1,237
On Slideshare
0
From Embeds
0
Number of Embeds
1
Actions
Shares
0
Downloads
10
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Transcript of "Land use change and local forest dynamics in the forest-savannah boundary in central cameroon"

  1. 1. Taking stock of smallholders and community forestry Session 13 Impact of local forestry practices on landscapes Land-use change and local forest dynamics in the forest-savannah boundary in Central Cameroon
  2. 2. Let’s go to Central Cameroon
  3. 3. Fairly recent introgression of forest onto savannah Humans are hardly responsible for past bioclimatic events… … But they have co-influenced the impact of such events on the environment… … Humans are becoming a major driving force in the dynamics of ecosystems Ongoing afforestation on African forest margins Attested throughout Western and Central Africa Bioclimatic origin of this phenomenon that started 1,000 years BP Local perceptions and attitudes vis-à-vis spontaneous afforestation are poorly documented
  4. 4. Multidisciplinary evidence of this extensive phenomenon •  Phytogeography •  Botany •  Phytosociology •  Remote sensing •  Pedology •  Dendrochronology •  Isotopic biochemistry •  Sedimentology •  Phytolites •  Palynology •  Ecology •  Archeology •  Anthropology
  5. 5. Forest-savannah ecotone •  Rich ecosystem - Diversified mosaic - Forest plants and animals meet with savannah plants and animals - Life forms specific to the ecotone •  Dynamic ecosystem - Afforestation: 1 to 3 meters per year - Changes perceptible in just a few years - Ideal conditions to question adaptation to change
  6. 6. Ecological heterogeneity of the ecotone forest/savannah ecotone in the forest/savannah ecotone in the southern area northern area
  7. 7. Tikar… and Bedzan •  Warlike and conquering stratified society •  Originally cereal cultivators •  Brought their ecology with them •  Sorghum progressively replaced by maize •  “Absorption” of populations met along migration •  Initiated into forest by Bedzan Pygmies
  8. 8. Forest swiddeners and savannah cultivators Intercropped swidden under forest Monocultural (cassava) field in the savannah
  9. 9. Non agricultural activities hunting fishing gathering
  10. 10. Afforestation between 1950 and 1989 Sectors of faster afforestation: former village settlements
  11. 11. Accelerated afforestation near residential sites Villages were built right up against the forest edge
  12. 12. Accelerated afforestation near residential sites Temporary swidden camps
  13. 13. Accelerated afforestation near residential sites Seasonal fishing camps
  14. 14. Accelerated afforestation near residential sites In 35 years
  15. 15. Local strategies to control afforestation Fragmented swidden area Single swidden area fast afforestation slowed afforestation
  16. 16. Local strategies to control afforestation Selective tree cutting by forest swiddeners
  17. 17. Local strategies to control afforestation Seed rain and nucleation
  18. 18. Local strategies to control afforestation 1970s: Permanent agroforest belt as a fence against afforestation Coffee agroforest
  19. 19. Local strategies to control afforestation Agroforest trees as safety net Ictyotoxic bark of Albizia coriaria Medicinal bark of Enantia chloranta Storage of cola nuts in termites’ nests
  20. 20. Local strategies to control afforestation 1980s: invasion by Chromolaena odorata (Asteraceae) Pan-tropical invasive shrub Good for agronomy •  Voluntarily introduced as a cover crop •  Improves soil structure (stops the leaching of mineral elements, increases the depth of the humus stratum, reduces soil acidity) •  Green manure •  Nematicide properties Bad for ecology •  Compromises forest regeneration •  The African variegated grasshopper (Zonocerus variegatus, Orthoptera, Pyrgomorphidae)
  21. 21. Local strategies to control afforestation Early burning of savannahs Chromolaena facilitates afforestation Suffrutescent plant: architecture smothers fire and protects tree seedlings of the forest edge Abundant faunal circulation underneath (rodents) Early burned savannahs
  22. 22. Local strategies to control afforestation Delayed burning of fallows Exhausting clearing of young fallows invaded by Chromolaena
  23. 23. Local strategies to control afforestation Delayed burning of fallows Chromolaena compromises afforestation High caloric return of Chromolaena burning
  24. 24. Local strategies to control afforestation Effect of Chromolaena on the fallowing rotation •  No more forest regrowth •  Fallowing period reduced to 5 years
  25. 25. Local strategies to control afforestation Community farming activities and mutual aid Increased man-days per hectare Socio-political system of savannah farmers more adapted to Chromolaena
  26. 26. In brief 1980s Invasion by Chromolaena odorata
  27. 27. Where do we go from here… … well, let’s go back to there! •  Coupled human-nature shaping of ecosystems •  Analysis of biocultural interactions needed to catch local understanding and influence of ecosystem dynamics (socioecological systems) •  Local rationality differs from the scientific and conservationist views •  Indigenous peoples are not de facto “conservationists”, but may elaborate adaptive responses that are environmental-friendly •  “Conservationist” does not mean “conservative”. Adaptive responses may be stimulated by external factors (cash crop plantations ; invasive shrub) •  Innovative adoptions depend on socio-political features of the considered community
  28. 28. Thank you for your attention!
  1. A particular slide catching your eye?

    Clipping is a handy way to collect important slides you want to go back to later.

×