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Can functional traits explain the dynamic of undesirable species in tropical grasslands?
Simon Taugourdeau, Johann Huguenin, Gerard Balent, Vincent Blanfort
To cite this version:
Simon Taugourdeau, Johann Huguenin, Gerard Balent, Vincent Blanfort. Can functional traits explain the dynamic of undesirable species in tropical grasslands?. 53. Annual Meeting of the Association for Tropical Biology and Conservation, Jun 2016, Montpellier, France. 463 p., 2016, Annual Meeting of the Association for Tropical Biology and Conservation. �hal-01602994�
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
U2: low PH, low SDM C3, NW ATBC 06/23/2016
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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
undesirable species in tropical grasslands?
with existing data from three tropical regions
20 ATBC 06/23/2016