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To cite this version:
Taugourdeau, Simon and Huguenin, Johann and Balent, Gerard and Blanfort, Vincent Can functional traits explain the
dynamic of undesirable species in tropical grasslands? (2016)
In: 53. Annual Meeting of the Association for Tropical Biology and Conservation, 19 June 2016 - 23 June 2016 (Montpellier, France).
Can functional traits explain the dynamics of
undesirable species in tropical grasslands?
Simon Taugourdeau1
Johann Huguenin1, Gérard Balent2 and Vincent Blanfort1 1 CIRAD, UMR SELMET, Montpellier, France
2 INRA, UMR DYNAFOR, Castanet-Tolosan, France
S71: Functional traits in tropical
agroecology
Implanted Grasslands
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In many tropical regions, grasslands are implanted
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Implanted with one C4 perennial grass species
(generally)
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Ranching systems
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Implanted grassland and spontaneous species
Implantation “Spontaneous” forage species Less palatable species Toxic species Undesirable speciesIn
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Implanted grassland and spontaneous species
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Economical and environmental costs ATBC 06/23/2016 Implantation
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Agro-ecological management
Intensity and frequency of grazing Implantation
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Dynamics of undesirable species
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Understand the dynamic of the undesirables with
management.
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Different species in the different tropical regions.
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Use of functional traits to compare flora from different
regions
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Can functional traits explain the dynamic of
undesirable species in tropical grasslands?
with existing data from three tropical regions
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8 French Guyana Equatorial climate Reunion Island: Tropical to temperate climate New Caledonia:
Wet and dry tropical climate
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1229 historical surveys (G286,NC313,R630) 425/726 species in TRY TRY request for 82 traits
Data for 368 species
(26 traits with more 10% of value) List of undesirable and forage species
111 species with traits and undesirable/forage status
111 species with 14 traits
Cleaning and addition of data with Internet research “A lot of key undesirable species are missing”
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111 species with 14 traits
Categories:
PGF(Plant growth form): 100% of the species
PP(Photosynthetic pathway): 100% of the species PW (Plant woodiness): 99% of the species
PL (Plant lifespan): 92 % of the species
DS (Dispersal Syndrome): 38% of the species PN (Plant Nitrogen fixation):92 % of the species LT (Leaf Type):89 %of the species
PRP (Plant Reproductive Period): 25% of the species
Continuous:
LNC (Leaf Nitrogen Content):21% of the species SLA (Specific Leaf Area):19 % of the species SDM (Seed Dry Mass): 57 % of the species
SGR (Seed Germination Rate):37 % of the species PH (Plant Height): 91 % of the species
LL (Leaf Length): 29 % of the species
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111 species with 14 traits dissimilaritiesGower PCOA
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High functional diversity of forage species and undesirable species
Difference between forage and
undesirable
species
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111 species with 14 traits 74 undesirable species Gower dissimilarities Hierarchical Clustering 74 undesirable species in three functional groups
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U1: High PH, high SDM C3, W, Tree
U3: Low PH, low SDM C4,NW
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1229 surveys (G286,NC313,R630) 3 groups of undesirables P/A of groups of undesirables 44 variables of management and environment (climate and soil)
Only 8 common variables between the 3 regions
437 plots with 8 variables and associated surveys with
undesirable presence
No undesirable on Guyana survey
318 surveys on Reunion and New Caledonia
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8 variables Categories: RAIN: Rainfall in mm AREA: plot area in ha
ACC: Accessibility (Easy, Med, Hard)
DIST: Distance plot farm (Short, Med, Far) FERT: Fertilization (Yes, No)
ROT: Rotary flail (Yes, No)
CHEM: Chemical Weeding (Yes, No) GRAZ: Grazing intensity (Int, Med, Ext) Decision tree on the presence/absence of the different
undesirable groups
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U1: Undesirable tree species
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Different decision trees between the type of undesirables species
U1: Undesirable tree species U3: C4 herb species
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ATBC 06/23/2016Not yet…….
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Can functional traits explain the dynamic of
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with existing data from three tropical regions
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