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Are vegetation classes good proxies for changes in floristic composition in Amazon forests?

Are vegetation classes good proxies for changes in floristic composition in Amazon forests?. Thaise Emilio, Bruce Nelson, Juliana Schietti , Sylvain Desmolière , Juliana Ortega & Flávia Costa Manaus, 2008. VEGETATION CLASSES AS PROXIES FOR BETA DIVERSITY.

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Are vegetation classes good proxies for changes in floristic composition in Amazon forests?

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  1. Are vegetation classes good proxies for changes in floristic composition in Amazon forests? Thaise Emilio, Bruce Nelson, Juliana Schietti, Sylvain Desmolière, Juliana Ortega & Flávia Costa Manaus, 2008

  2. VEGETATION CLASSES AS PROXIES FOR BETA DIVERSITY Vegetation maps was used sistematically in conservation planning since 1999 for represent beta diversity of brazilian Amazon 1 This use assumes that there is a correlation between species distribution and vegetation types 2 1 Ferreira et al .2001, Nelson & Oliveira 2001; 2 Ferrier & Watson 1997

  3. FOREST HOMOGENEITY? Distance-decay relationship Environmental determinism Tuomisto et al. 2003, Condit et al. 2002

  4. AIM • Evaluatevegetationtypes as surrogates for canopytrees beta diversitywithtreedifferentaproaches: • Analisingthedistance-decayrelationshipbetweenplots; • Examiningthecongruencebetweenvegetationtypesand beta diversityspatialpatterns; • Testingthefloristicseparationstrengthbetweenvegetationtypes.

  5. DATABASE ANALYZED DATA : genus level dets; more evenly-spaced grouped inventories ORIGINAL DATABASE , RADAMBRASIL 2,719 standard inventories of 1 ha; (20 x 500 m)trees >31.2 cm DBH Centroids of 1,196 inventories grouped into sets of 4, generating 296 groups 12 vegetation types (Aap, Abb, Abp, Asc, Asp, Dae, Dau, Dbe, Dse, Dsu, LO, Fs) 45 vegetation types

  6. EVALUATED VEGETATION TYPES Dse = Upland dense forest with emergente trees (N = 47) Dae = Inundated dense forest with emergent trees (N = 23) LO = Sand forest(N = 8) Dsu = Upland dense forest without emergent trees (N = 4) Dbe = Lowland dense forest with emergent trees (N = 80) Aap = Inundated open forest with palms (N = 18) Abp = Lowland open forest with palms (N = 30) Dau = Inundated dense forest without emergent trees (N = 6) Asc = Upland open forest with lianas (N = 35) Abb = Lowland open forest with bamboos (N = 8) Fs = Semideciduous dry forest(N = 8) Asp = Upland open forest with palms (N = 29)

  7. RESULTS FLORISTIC DISTANCE x GEOGRAPHIC DISTANCE The floristic similarity presents a linear decay with distance increases. At genus level, non-directional geographic distance determines the minimum and maximum floristic difference between any two inventories (dotted lines). Others factors determine floristic differences above this threshold. Inventories from distinct vegetation classes (graph C) appear no more different than pairs chosen from within the same vegetation class (graph B).

  8. RESULTS SPATIAL FLORISTIC GRADIENT CONGRUENT WITH FOREST CLASSES Floristic composition of canopy trees changes gradually in space (A). Spatial floristic variation at genus level is congruent with the distribution of four general forest classes (B). Differences occurs mainly in SE, Acre region. This spatial pattern is similar to edaphic-climate variation patterns.

  9. RESULTS FLORISTIC HETEROGENEITY WITHIN VEGETATION CLASSES Internal floristic heterogeneity (see beta diversity values) is present in all vegetation classes, including the finer classes of the hierarchy. Turnover is greater in the N/S direction than in the E/W direction

  10. RESULTS FLORISTIC SEPARATION BETWEEN VEGETATION CLASSES Significant floristic differences (asterisks) occur between some, but not all vegetation types. Strength of separation for selected type pairs is shown in 2-dimension NMDS and is independent of the range of variation or number of inventories. Correlated geographic effects have not been removed.

  11. COMPARISON BETWEEN FLORISTIC AND VEGETATION SIMILARITY At genus level some forest types are not floristically different. UPGMA dendrogram is different from the hierarchy inherent in the logic of the RADAM classification system. Three geographically restricted vegetation types are most distinct from all other types -- possibly because geographic distance effects cannot be removed.

  12. MAIN CONCLUSIONS AND FINAL CONSIDERATIONS • At genus level, floristic composition of canopy trees changes gradually at Brazilian Amazonia scales; • Twonearareasofdifferentvegetationtypesmaybe more similar thantwodistantareasofsamevegetationtypes; • Floristic turnover is greater in the N/S than in the E/W direction; • Physiognomic vegetation classes exhibit different amounts of internal floristic variation, particularly if they cover different latitudinal distances. • Atspecieslevel, thisdiffercesmaybegreatherand more irregular distributed. • The use ofvegetationtypes as directsurrogateof beta diversity are notrecomended for canopytrees.

  13. Thank you! thaise.emilio@gmail.com

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