spatial modeling the impact of livestock grazing, fire management and wood cutting on the structure...
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Spatial modeling the impact of livestock grazing, Fire management and wood cutting on the
structure of savana woodland vegetation
Dr Didier Zida
Post-doc
16 August 2011
Thesis objectives
1. Examine the dynamics of sapling populations in response to annual early fire, livestockgrazing and selective tree cutting by analyzing changes in species richness andsapling population density over a ten year period
2. Examine the effects of fire, livestock grazing and selective cutting on seedlingrecruitment in the mid- and long-term by analyzing changes in seedling populationdensity and species richness five and ten years after post treatment
3. Identify the seed germination requirements of selected savanna woodlandSpecies
4. Identify seedling morphological attributes that ensure better field performanceof two savanna woodland species
Fuel wood and non-wood forest products from African savanna woodlands are essential for
livelihood of the rural people.
The challenge is to manage these disturbances to sustain livelihood and environment
In Burkina Faso, Livestock grazing, wood cutting, and fire are common anthropogenic disturbances shaping
savanna woodland vegetation structure and functions
Study sites
Experimental design in Laba et Tiogo since 1992
Mean annual rainfall Laba (1992-2008): 886 mm
Mean annual rainfall Tiogo (1992-2008): 845 mm
Silviculture Treatements applied to each experimental siteGrazing Fire Selective cutting Number of plots of
2500 m2
Grazing
No Grazing
No Fire
Annual early fire
3 year fire exclusion
No fire
Annual early fire
3 year fire exclusion
No CuttingSelective cuttingCutting + Direct seeding
No CuttingSelective cuttingCutting + Direct seeding
No CuttingSelective cuttingCutting + Direct seeding
No CuttingSelective cuttingCutting + Direct seeding
No CuttingSelective cuttingCutting + Direct seeding
No CuttingSelective cuttingCutting + Direct seeding
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STUDIES CONDUCTED
Many studies conducted on the influence of livestock grazing, annual early fire and selective tree cutting on : production and regeneration of woody vegetation ;Production and diversity of herbaceous vegetation;Soil physico-chemical charactersitics
Doctoral thesis
Peer reviewed papers (2002-2010) : more than 25
No Auteurs Titres thèses Années
1 Louis Sawadogo Evaluation des potentialités pastorales d'une forêt classée soudanienne du Burkina Faso. (Cas de la forêt classée de Tiogo).
1996
2 Robert Nygard Productivity of woody vegetation in savanna woodlands in Burkina Faso.
2000
3 Patrice Savadogo Dynamics of Sudanian savanna-woodland ecosystem in response to disturbances.
2007
4 Didier Zida Impact of forest management regimes on ligneous regeneration in the Sudanian savanna of Burkina Faso.
2007
5 Saran Traoré Impact des termitières épigées sur la régénération et la dynamique des écosystèmes de savanes : Cas de la forêt classée de Tiogo, Burkina Faso.
2008
6 Djibril S. Dayamba
Fire, plant-derived smoke and grazing effects on woody and herbaceous regeneration in the Sudanian savanna-woodlands: implications for productivity and diversity
2010
Cohabitation of two strata : woody et herbaceous ;Huge number of species with different behaviors ;Spatial heterogeneity (soil, vegetation)Root system not studied yet ;Rainfall highly variable ;Annual herbaceous highly variable ;Spatial and inter-annual variablity of fire, cutting, grazing effects.System highly resilient…
Need of long term studies to be able to draw sound conclusion that could be extrapolate beyond the few ha of the experimental plots.
COMPLEXITY OF THE SYSTEM:
Need of Extrapolation of the existing insight in factors influencing carbon stores beyond the few ha of the
experimental plots.
Aim of the post-doc:- Develop a rule based model and
- Proto-type a GIS based system allowing simulating the effects of grazing, fuel-wood collection and fire management on the vegetation physiognomy of the two state forests
This extrapolation require
spatially explicit models which allow to predict the state of the vegetation from its history of grazing by
livestock, the intensity and frequency of fire and fuelwood collection .
6 month post-doc:
