Rapid assessment of plant invasions in natural and semi-natural … · 2019-07-29 · Rapid...
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Rapid assessment of plant invasions in natural and semi-natural forest habitat in Grande Comore Island Anziz AHMED ABDOU 1 , Mathieu ROUGET 1 , Olivier FLORES 2 , Vincent BOULLET 3 and Dominique STRASBERG 2 Introduction Comoros archipelago is a biodiversity hot spot characterized by a relatively dynamic land use change. Species introductions increased in the 1951s due to the massive development of agriculture by European settlers. These land use changes have direct consequences on the disturbance of natural habitats and indirectly on the proliferation of invasive alien species. Aims and objectives • Identify the most invasive plant species • Quantify the invasion levels of different habitat types in natural and semi-natural forest of Grande Comore island Classification of habitat Most invasive species Canopy and understory invasion Syzygium jambos Study area Vegetation survey •Exotic woody species •Vascular species whose height ≥ 1m •44 transects = 250 sections (30 x 10m) Habitat •Elevation, slope and dominant species •11 habitats vegetation and 5 land use types Methodology •Native vegetation •Less anthropogenics disturbances Natural •Forest invaded •Agriculture and tree logging Semi- natural •Exotic vegetation on canopy and understory Plantation 1: UMR PVBMT - CIRAD, 7, Chemin de l’IRAT, 97410 St-Pierre, La Réunion 2: UMR PVBMT - University of La Réunion, 15 avenue René Cassin CS92003, 97744 Saint-Denis, La Réunion 3: Retired person, self-employed, France - France •Grande Comore Island •La Grille (1087m) and Karthala (2361m) Land uses • Fo : Forest • B : Banana plantation • C : Cropland • D : Deforestation • Of : Old fields Habitats • LSDF : Leeward Submountain Dry Forest • LSHF : Lowland Sub-Humid Forest • WSNF : Windward Submountain Nuxia Forest • WSOF : Windward Submountain Ocotea Forest • WSTF : Windward Submountain Tambourissa Forest • WSWF : Windward submountain Weinmannia Forest • MVPC : Mosaic of vegetation at Psidium cattleianum • TkAN : Thicket at Nuxia pseudodentata • WSRF : Windward Submontain Rain Forest • LLRF : Lowland Rain Forest • WSEF : Windward Submontane Eucalyptus Forest Eucalyptus camaldulensis Conclusion and perspectives There are still relatively well-preserved forest remnants despite the different levels of invasions observed in Grande Comore Island. Results obtained in this study represent the first assessment of forest invasions in Comoros. In order to define management priorities, it is necessary to expand these surveys. The alternative approach to dealing with this fragmentation of habitats would be to orient a restoration plan in the natural and semi-natural habitat of Grande Comore. This results will contribute to improve decision-marking for Comoros national Park. Clidemia hirta Psidium cattleianum Major plant invaders Solanum mauritianum Gliricidia sepium Tristemma mauritianum Artocarpus altilis Solanum torvum Cinnamomum verum Senna hirsuta Artocarpus heterophyllus Syzygium aromaticum Cocos nucifera Pterocarpus indicus Syzygium jambos Jatropha curcas Coffea arabica Rubus rosifolius Clidemia hirta Furcraea foetida Mangifera indica Ocimum gratissimum Psidium cattleianum Eucalyptus robusta Of
Transcript of Rapid assessment of plant invasions in natural and semi-natural … · 2019-07-29 · Rapid...
Rapid assessment of plant invasions in natural and semi-naturalforest habitat in Grande Comore Island
Anziz AHMED ABDOU1, Mathieu ROUGET1, Olivier FLORES2, Vincent BOULLET3 and Dominique STRASBERG2
IntroductionComoros archipelago is a biodiversity hot spot characterized by a relatively dynamic land use change. Species introductions increased in the 1951s due to the massive development of agriculture by European settlers. These land use changes have direct consequences on the disturbance of natural habitats and indirectly on the proliferation of invasive alien species.
Aims and objectives
• Identify the most invasive plant species• Quantify the invasion levels of different habitat
types in natural and semi-natural forest of GrandeComore island
Classification of habitat
Most invasive species Canopy and understory invasion
Syzygium jambos
Studyarea
Vegetationsurvey
•Exotic woody species
•Vascular species whose height ≥ 1m
•44 transects = 250 sections (30 x 10m)
Habitat
•Elevation, slope and dominant species
•11 habitats vegetation and 5 land use types
Methodology
•Native vegetation
•Less anthropogenicsdisturbances
Natural
•Forest invaded
•Agriculture andtree logging
Semi-natural
•Exotic vegetationon canopy andunderstory
Plantation
1: UMR PVBMT - CIRAD, 7, Chemin de l’IRAT, 97410 St-Pierre, La Réunion
2: UMR PVBMT - University of La Réunion, 15 avenue René Cassin CS92003, 97744 Saint-Denis, La Réunion
3: Retired person, self-employed, France - France
•Grande Comore Island
•La Grille (1087m) and Karthala (2361m)Land uses• Fo : Forest• B : Banana plantation• C : Cropland• D : Deforestation• Of : Old fieldsHabitats• LSDF : Leeward Submountain Dry Forest• LSHF : Lowland Sub-Humid Forest• WSNF : Windward Submountain Nuxia Forest• WSOF : Windward Submountain Ocotea Forest• WSTF : Windward Submountain Tambourissa Forest• WSWF : Windward submountain Weinmannia Forest• MVPC : Mosaic of vegetation at Psidium cattleianum• TkAN : Thicket at Nuxia pseudodentata• WSRF : Windward Submontain Rain Forest• LLRF : Lowland Rain Forest• WSEF : Windward Submontane Eucalyptus Forest
Eucalyptus camaldulensis
Conclusion and perspectivesThere are still relatively well-preserved forest remnants despite the different levels of invasions observed in Grande Comore Island.Results obtained in this study represent the first assessment of forest invasions in Comoros. In order to define management priorities, it isnecessary to expand these surveys. The alternative approach to dealing with this fragmentation of habitats would be to orient a restoration planin the natural and semi-natural habitat of Grande Comore. This results will contribute to improve decision-marking for Comoros national Park.
Clidemia hirtaPsidium cattleianum
Major plant invaders
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