enclosure-exclosure : management tools of forest-ungulates©sentation.pdf · 12 in 2008...
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Enclosure-exclosure : management tools of forest-ungulates
Journée d’étude
« Gestion rationnelle et conservation de la grande faune »
François LEHAIRE
4 octobre 2012
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In temperate forest, ungulates feeding activity can lead to :
� Overgrazing (vegetation)
Context Objectives Methods Results Discussion
Ligot G.
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In temperate forest, ungulates feeding activity can lead to :
� Overgrazing (vegetation)
� Browsing (regeneration)
Context Objectives Methods Results Discussion
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In temperate forest, ungulates feeding activity can lead to :
� Overgrazing (vegetation)
� Browsing (regeneration)
� Bark Stripping (trees)
Context Objectives Methods Results Discussion
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In temperate forest, ungulates feeding activity can lead to :
� Overgrazing (vegetation)
� Browsing (regeneration)
� Bark Stripping (trees)
� Timber production
� Conservation
Conflicts with other forest functions :
Context Objectives Methods Results Discussion
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Context Objectives Methods Results Discussion
Identify the functional traits of vegetation that changes with ungulate pressions
Indicators of ecological changes (habitat impacts)
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Context Objectives Methods Results Discussion
Calculating indicators of habitat changes :
� Systematic inventory
� Enclosure-exclosure device
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Context Objectives Methods Results Discussion
Calculating indicators of habitat changes :
� High accuracy
� Requires considerable investment of time, people and money
� Systematic inventory
� Enclosure-exclosure device � Visual approach
� Compare natural density with controlled density
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Enclosure-exclosure device� Compare
• Enclosure: controlled density (for this study 0 ungulates)
• Exclosure: natural density
EXCLOSURE
ENCLOSURE
fenced
unfenced
Context Objectives Methods Results Discussion
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Enclosure-exclosure device� Compare
• Enclosure: controlled density (for this study 0 ungulates)
• Exclosure: natural density
� Dimension• 4.5 x 4.5 m• Fence 2 m• Remote 10 – 25 m
Context Objectives Methods Results Discussion
2 m
4.5 m
10 - 25 m
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Study area� Temperate deciduous forest
� Ardenne Region (southern Belgium, Florenville)
� Forest gaps (area with ground vegetation and regeneration)
� Comparison of 2 areas
Chiny
2.5 deer/km²
Low density
5 enclo-exclo
Sainte-Cécile
7.5 deer/km²
High density
12 enclo-exclo
Context Objectives Methods Results Discussion
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Enclosure-exclosure device
� Ungulates� Cervus elaphus L.
� Capreolus capreolus L.
� Ovis aries musimon Schreber
� Sus scrofa L.
Context Objectives Methods Results Discussion
Ligot G.
Ligot G.
Ligot G.
Ligot G.
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Data acquisition
� 2 m radius plot
� April to June
Context Objectives Methods Results Discussion
EXCLOSURE
ENCLOSURE
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Data acquisition
Measurements of ground vegetation and regeneration
� Presence/absence of species
Context Objectives Methods Results Discussion
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Data acquisition
Measurements of ground vegetation and regeneration
� Presence/absence of species
� Continuous variable :
Context Objectives Methods Results Discussion
� Richness (number of species)
� Total cover
� Gramineae cover
� Cover and height• Rubus fruticosus L.• Rubus idaeus L.• Vaccinium myrtillus L.
Ground vegetation
� Richness (number of species)
� Total cover
� Seedling density
� Average height
Regeneration
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Monitoring 2006 � 2012
2006 2007 2008 2010 2012
Set up
Context Objectives Methods Results Discussion
Ligot G.
Ligot G.
Ligot G.
(Bi-)Annual indicators
Multiannual indicators
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Presence of species
� Rubus idaeus L.
� Sorbus aucuparia L.
� Chamerion angustifolium (L.) Holub
Context Objectives Methods Results Discussion
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Presence/absence of species (Chameriom)
Context Objectives Methods Results Discussion
LOW
DENSITy
ENCLOSURE EXCLOSURE
HIGH
DENSITy
ENCLOSURE EXCLOSURE
2006
2007 -
2008
2010 -
2012
GAPS
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Continuous variable
Context Objectives Methods Results Discussion
LOW
DENSITy
ENCLOSURE EXCLOSURE
HIGH
DENSITy
ENCLOSURE EXCLOSURE
2006
no difference
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Annual indicators
� Ground vegetation richness
� Regeneration richness
� Height Rubus fruticosus L.
� Height Rubus idaeus L.
� Seedling density
Context Objectives Methods Results Discussion
2006
2007 -
2008
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Multiannual indicators
� Ground vegetation richness
� Regeneration richness
� Height Rubus fruticosus L.
� Height Rubus idaeus L.
� Seedling density
� Total cover
� Height Betulus sp.
� Height Fagus sylvatica L.
Context Objectives Methods Results Discussion
2006
2007 -
2008
2010 -
2012
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Context Objectives Methods Results Discussion
Seedling density difference between enclosure and exclosure
-29
14
50
3 7 4
-30
-15
0
15
30
45
60
2006 2008 2010 2012
Years
Diff
eren
ce (n
b of
see
dlin
gs)
Low density
High density
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� Visual approach – didactic
� Monitoring annual and multiannual
� Objective dialogue between the different actors involved in the management of forest-ungulates
Context Objectives Methods Results Conclusion
Ligot G.
Ligot G.
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� Visual approach – didactic
� Monitoring annual and multiannual
� Objective dialogue between the different actors involved in the management of forest-ungulates
� Annual indicators depends on extreme weather conditions>< Multiannual indicators
Context Objectives Methods Results Conclusion
Ligot G.
� Enclosures-exclosures could be an important tool in the context of forest certification theyprovide information to meet PEFC and FSC commitments
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Perspectives
� Establishing long-term indicators (10, 15, 20 years) ?
� Installing new devices � Validating indicators
� 12 in 2008 (Florenville)
� 15 in 2010 (Beauraing)
� 65 in 2012 (Florenville, Neufchâteau)
� Automatic gap detection with LIDAR data
� Mapping gaps in order to objectively scatter enclo-exclo devices
Context Objectives Methods Results Conclusion
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Thank You
for your attention