Fragmented tropical forests lose mutualistic plant-animal interactions

Author(s):Show less -

Marjakangas, Emma-Liina ^[1] ; Abrego, Nerea ^{[1, 2]} ; Grotan, Vidar ^[1] ; de Lima, Renato A. F. ^[3] ; Bello, Carolina ^[4] ; Bovendorp, Ricardo S. ^[4] ; Culot, Laurence ^[5] ; Hasui, Erica ^[6] ; Lima, Fernando ^{[4, 7]} ; Muylaert, Renata Lara ^[4] ; Niebuhr, Bernardo Brandao ^[4] ; Oliveira, Alexandre A. ^[3] ; Pereira, Lucas Augusto ^[5] ; Prado, Paulo I. ^[3] ; Stevens, Richard D. ^{[8, 9]} ; Vancine, Mauricio Humberto ^[4] ; Ribeiro, Milton Cezar ^[4] ; Galetti, Mauro ^{[4, 10]} ; Ovaskainen, Otso ^{[1, 11]}

Affiliation:Show less -

^[1] Norwegian Univ Sci & Technol, Ctr Biodivers Dynam, Realfagbygget E1-137, Hogskoleringen 5, Trondheim - Norway

^[2] Univ Helsinki, Dept Agr Sci, Helsinki - Finland

^[3] Univ Sao Paulo, Inst Biociencias, Dept Ecol, Sao Paulo - Brazil

^[4] Univ Estadual Paulista UNESP, Dept Ecol, Inst Biociencias, Rio Claro - Brazil

^[5] Univ Estadual Paulista UNESP, Inst Biociencias, Dept Zool, Ctr Aquicultura, Rio Claro - Brazil

^[6] Univ Fed Alfenas, Inst Ciencias Natureza, Alfenas - Brazil

^[7] IPE, Nazare Paulista - Brazil

^[8] Texas Tech Univ, Dept Nat Resources Management, Lubbock, TX - USA

^[9] Museum Texas Tech Univ, Lubbock, TX - USA

^[10] Univ Miami, Dept Biol, Miami, FL - USA

^[11] Univ Helsinki, Fac Biol & Environm Sci, Helsinki - Finland

• Document type: Journal article
• Source: DIVERSITY AND DISTRIBUTIONS; v. 26, n. 2 NOV 2019.
• Web of Science Citations: 2

Abstract

Aim Forest fragmentation is among the principal causes of global biodiversity loss, yet how it affects mutualistic interactions between plants and animals at large spatial scale is poorly understood. In particular, tropical forest regeneration depends on animal-mediated seed dispersal, but the seed-dispersing animals face rapid decline due to forest fragmentation and defaunation. Here, we assess how fragmentation influences the pairwise interactions between 407 seed disperser and 1,424 tree species in a highly fragmented biodiversity hotspot. Location Atlantic Forest, South America. Methods We predicted interaction networks in 912 sites covering the entire biome by combining verified interaction data with co-occurrence probabilities obtained from a spatially explicit joint species distribution model. We identified keystone seed dispersers by computing a species-specific keystone index and by selecting those species belonging to the top 5% quantile. Results We show that forest fragmentation affects seed dispersal interactions negatively, and the decreased area of functionally connected forest, rather than increased edge effects, is the main driver behind the loss of interactions. Both the seed disperser availability for the local tree communities and in particular the proportion of interactions provided by keystone seed dispersers decline with increasing degree of fragmentation. Importantly, just 21 keystone species provided >40% of all interactions. The numbers of interactions provided by keystone and non-keystone species, however, were equally negatively affected by fragmentation, suggesting that seed dispersal interactions may not be rewired under strong fragmentation effects. Conclusions We highlight the importance of understanding the fragmentation-induced compositional shifts in seed disperser communities as they may lead to lagged and multiplicative effects on tree communities. Our results illustrate the utility of model-based prediction of interaction networks as well as model-based identification of keystone species as a tool for prioritizing conservation efforts. Similar modelling approaches could be applied to other threatened ecosystems and interaction types globally. (AU)

• FAPESP's process: 15/17739-4 - Landscape effects and the interaction between mammals and hantavirus in the Atlantic Forest
• Grantee: Renata de Lara Muylaert
• Support type: Scholarships in Brazil - Doctorate
• FAPESP's process: 13/50421-2 - New sampling methods and statistical tools for biodiversity research: integrating animal movement ecology with population and community ecology
• Grantee: Milton Cezar Ribeiro
• Support type: Regular Research Grants
• FAPESP's process: 13/25441-0 - Changes in functional and phylogenetic diversity of small mammals in defaunated Atlantic Forest landscapes
• Grantee: Ricardo Siqueira Bovendorp
• Support type: Scholarships in Brazil - Post-Doctorate
• FAPESP's process: 17/09676-8 - Effect of landscape modifications and climate changes on the persistence of amphibians in the Atlantic Forest
• Grantee: Maurício Humberto Vancine
• Support type: Scholarships in Brazil - Master
• FAPESP's process: 14/14739-0 - The effect of fragmentation on primate ecological functions
• Grantee: Laurence Marianne Vincianne Culot
• Support type: Research Grants - Young Investigators Grants
• FAPESP's process: 14/18800-6 - Patch landscape size effects on functional and phylogenetic diversity thresholds for Atlantic Forest small mammals
• Grantee: Ricardo Siqueira Bovendorp
• Support type: Scholarships abroad - Research Internship - Post-doctor
• FAPESP's process: 17/08440-0 - Antropic disturbances and the seed dispersal service by primates: the case of the state of São Paulo
• Grantee: Lucas Augusto Pereira
• Support type: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 17/21816-0 - Spatiotemporal dynamics of hantavirus disease in a fast-changing country
• Grantee: Renata de Lara Muylaert
• Support type: Scholarships abroad - Research Internship - Doctorate
• FAPESP's process: 13/08722-5 - The role of functional diversity in structuring tropical tree communities: a model-based approach
• Grantee: Renato Augusto Ferreira de Lima
• Support type: Scholarships in Brazil - Post-Doctorate
• FAPESP's process: 14/01986-0 - Ecological consequences of defaunation in the Atlantic Rainforest
• Grantee: Mauro Galetti Rodrigues
• Support type: Research Projects - Thematic Grants