DEFAUNATION IMPLICATIONS FOR ECOSYSTEM CARBON STORAGE IN TROPICAL FORESTS

Transcription

1 DEFAUNATION IMPLICATIONS FOR ECOSYSTEM CARBON STORAGE IN TROPICAL FORESTS Mauro Galetti Carolina Bello and Laurence Culot Departamento de Ecologia, Universidade Estadual Paulista (UNESP) Rio Claro, SP

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3 @Pedro Jordano

4 Frugivores are at risk of extinction

5 Frugivores are at risk of extinction Tapirus Pipile Ateles Mazama spp. Alouatta Penelope Ramphastos Pecari tajacu Tayassu pecari Dasyprocta Cuniculus Cebus 60 milhões animais abatidos/ano Peres (2000). Cons. Biol. Number of animals killed/year

6 Galetti et al. (2017) Animal Conservation

7 Amazon forests have ~ 6x more mammals than the Atlantic forests

8 Aburria jacutinga (Cracidae) lost 95% of its original distribution BRAZIL Paraguay Argentina

9 Pristine bird community in the Atlantic forest

10 Defaunated bird community in the Atlantic forest Small bodied frugivores Small gape size (<12 mm)

11 Tropical rainforests store 55% of forest Carbon 49% 25% 26% Saatchi et al (2011) PNAS

12 How do animal help in carbon storage? Large seeds Large Trees Higher Wood Density Brodie and Gibbs (2009) Non-Defaunated Forest Higher C storage

13 Extinction of large frugivores Dispersal limitation of large seeded plants Defaunated Forest

14 Disappearance of Large seeds - Large Trees, Harwood Increase in small seeded softwood plants Erosion of Carbon storage Defaunated Forest

15 Consequences of defaunation on ecosystem services Dirzo et al. (2014). Science Carbon stock? L H

16 Linking defaunation to C storage How defaunation affects carbon storage in tropical rainforests? What are the effects of defaunation of on future carbon storage?

17 Atlantic forest trees depend on frugivores From 45 to 91% of tree species are dispersed by animals (~59% by birds) Almeida-Neto et al. (2008). Global Ecol. Biog.

18 8679 fruit-frugivore interactions 789 plants, 357 frugivore Jordano

19 Most recorded frugivores genera

20 Most recorded plant genera

21 Fruit trait (e.g seed and fruit size) Correlated evolution Seed disperser trait (e.g., increased participation of mammals)

22 Seed diameter explains seed dispersal strategy Dispersal Treshold = 12 mm seed diameter Bello et al. (2017) Ecology

23 Relationship between seed size and wood density - Atlantic forest rs=0.28, P<0.001, N=486

24 Strong relationship between seed size and wood density Dispersal Treshold (12 mm) Not dispersal limited hardwood tree species dispersal limited hardwood tree species Not dispersal limited softwood tree species dispersal limited softwood tree species Bello et al. (2015). Sc. Adv.

25 Co-extinction event in real world scenarios Atlantic-Tree Atlantic - Tree is the dataset of >2000 communities that contains the composition and density of tree species in the Atlantic forest We chose 31 communities (largest forest blocks >1000 ha) Simulate hardwood removal due to large seed dispersers extinction (co-extinction) Lima et al. (in prep) 2,000 communities 2355 tree species

26 Co-extinction simulations - Assumptions Extinction of large seeded Replace with remaining sp. 1 Saturated communities with zero-sum game dynamic (Hubell 2001) 2 Basal area and number of individuals remained constant 3 Immigration rate equals to zero 4 More abundant species would have a higher probability to replace endangered trees 5 Large-seeded species could replace by dispersal of bats or rodents

27 Results of simulations 31 non-fragmented plant communities 813 tree species (21% have large seeds) 101,211 individuals Bello et al. (2015). Sc. Adv.

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29 Conclusions A series of evidences have shown that defaunation of large seed dispersers and consequent seed limitation of large seeded trees can erode carbon storage in tropical rainforests Bello et al. (2015) Science Advances Peres et al (2016) PNAS Osuri et al. (2016) Nat. Com.

30 Linking defaunation to C storage If defaunation affect carbon storage in tropical rainforests? What are the effects of defaunation on future carbon storage?

31 Nature is complex P. Jordano

32 Density compensation

33 Defaunated forests and rodentization 2.5x more rodents Dominance of rodents in seed predation leading to 3x more seed predation 9% 98% Galetti et al. (2015) Biol. Cons. Galetti et al. (2015) Global Ecol. and Conserv.

34 Choosing a species to test defaunation and C loss Large seeded hardwood tree species Relatively common Widespread in the Atlantic forest High fruit production and annual Strong interaction with dispersers and predators

35 Choosing a species to test defaunation and C loss

36 Studied Species - Cryptocarya mandioccana Seed Dispersers Seed Predators Muriqui Peccaries Howler monkey Pacas and agoutis Jacutinga Small rodents

37 Study sites A Brazil C Atlantic Forest Continuous forest B

38 Disperser effects on plant recruitment Recruitment success = % of seeds that recruited Disperser contribution Removal probability Germination probability Dispersal distance probability 1 year seedling survival Focal Camera traps Germination experiment in situ Primate following Searching for faeces Seed Predation experiment

39 Dispersal distances generated by frugivores

40 Plant recruitment is affected by both seed dispersers and predators Defaunated

41 Plant recruitment is affected by both seed dispersers and predators Defaunated

42 Plant recruitment is affected by both seed dispersers and predators Defaunated

43 Density compensation RODENTIZATION

44 Disperser contribution Pm=54% Ph=15% Hardwood trees with large seeds Pj=1.5% 12 ha plot 88 ton of C/ha

45 Putting a Price Tag in Each Seed Dispersal Service on Carbon Storage

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47 THANK YOU

48 Mauro