Rita Mesquita, Tony Vizcarra Bentos, Bruce Williamson, e Catarina Jakovac.

Apresentação em tema: "Rita Mesquita, Tony Vizcarra Bentos, Bruce Williamson, e Catarina Jakovac."— Transcrição da apresentação:

1 Rita Mesquita, Tony Vizcarra Bentos, Bruce Williamson, e Catarina Jakovac

2 Rural setlements Eixos de “desenvolvimento”

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4 borda interior

5 Species replacement rate increasing and some species are being lost from fragments R s = -0.630 P=0.00001 R s = -0.612 P=0.00003 Faster dynamics

6 Change in species richness 1162 species or morpho- species analised

7 Tree composition is changing

8 Floristic composition of fragments after 25 years

9  Cronosequences of secondary vegetation from 1 to 22 years old  3 main use types:  Cut, no burn and abandoned  Cut, burnt and pasture established  Cut, burnt, planted with perenials and then abandoned

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15 Regeneração no sub-bosque das capoeiras

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18 Fire effect on biomass recovery

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20  Very high  Large variability at the local scale  Detectable by remote sensing  Shows a relationship between use intensity and biomass and species richness recovery

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23 NMDS illustrating broad- scale compositional variation among transects. Floristic similarity among transects was calculated using the Chao-Jaccard estimator based index. Filled circles refer to transects that have been burned more that one time, and open dots refer to transects that have been burnt zero to one time. (Norden et al, accepted) Large-scale variation in floristic composition between transects

24 Successional trajectories and the density dependent effects (1) Positive frequency dependence: the most frequent species show a higher per capita growth rate relative to the others, leading to monodominance, (2) No frequency dependence, (3) Negative frequency dependence: the more frequent species are reduced in frequency over time, (4) Null model: species frequency at time 1 is unrelated to species frequency at time 0, (5) Strong negative dependence: species frequency shifts so that frequent species become rare species and vice versa.

25 Differences in “climax”versus old growth successional sites 1.abundant regeneration of dominant shade-tolerant canopy tree species, 2.slow-growing species, 3.trees with dense wood and large gravity- or animal-dispersed seeds, 4.Lower abundance of shrubs, 5.highly diverse and abundant epiphytes, and 6.abundant large woody lianas.

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27  11 properties at the Suframa District  Previous floristic inventory (DBH ≥ 2 cm)  Define the dominant species  Original basal area calculated  Paired experimental and control plots (20x20m) ▪ 40% removal of basal area (Mesquita 2001)

28 Material e Métodos Planting (feb - april 2008) –Agricultors counterpart – “coveamento” –45 seedlings per plot –3 x 3 m spacing Implementation

29 Experimental design 22 plots 20 x 20 m 11 control plots 11 treatment plots 45 seedlings per plot 9 native tree species Idade estimada da capoeira CecropiaVismiaMista 1x 5x 6 a 8xx 8 a 10x 9 a 10x 11 a 14x 15 a 17xx 18x 20x Delineamento

30 Andiroba p=0,033 BacabaCacau Castanha Copaíba Cumaru p=0,010 Jatobá Mogno Pau Rosa Relative Growth Rate(RGR) CONTROL X TREATMENTO Teste pareado não paramétrico de Wilcoxon Controle Tratamento

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32 Menos de uma muda morta por parcela Mortalidade total = 63 mudas = 6,4%

33 interação positiva entre os dois efeitos (idade e dominante). Em capoeiras dominadas por Cecropia sp. o crescimento das mudas diminui com o aumento da idade da capoeira (r2= 0,248; p<0,001).

34 Capoeiras dominadas por Cecropia: 1.existem vários estratos de vegetação (sub-bosque, sub-dossel, dossel e emergentes), 2.interceptam a luz solar, fazendo com que o ambiente ao nível das plântulas, nas capoeiras mais velhas seja escuro, 3.existe competição por nutrientes nas raízes. Capoeiras dominadas por Vismia sp.: 1. apresentam desde o inicio um único estrato, com as Vismias no dossel e pouca coisa crescendo em seu sub- bosque. 2.o efeito de idade sobre crescimento em altura pode nem existir.

35  Custo estimado de implantação: R$ 2.400,00/ha  Mão de obra  Compra de mudas  40% = custo com compra de mudas – R$ 960,00  Produção das mudas no local diminui o custo  Custo final = R$ 1. 440,00