Effects of rapid climate change on community structure and cranial morphology of small mammals

• Ano de defesa: 2017
• Autor(a) principal: Rodolfo German Antonelli Vidal Stumpp
• Orientador(a): Adriano Pereira Paglia
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Universidade Federal de Minas Gerais
• Programa de Pós-Graduação: Programa de Pós-Graduação em Ecologia, Conservacao e Manejo da Vida Silvestre
• Departamento: ICB - INSTITUTO DE CIÊNCIAS BIOLOGICAS
• País: Brasil
• Palavras-chave em Português: Community dynamics; Environmental variables; Neotropical mammals; Rapid Morphological Change; Temporal Variability
• Link de acesso: http://hdl.handle.net/1843/36212

Human activities have altered drastically environments on Earth on the last centuries. One of these human-induced rapid environmental changes is climate change, which has been linked to many effects on different levels of biodiversity. In small mammals, group of animals that exerts great influence on the forest dynamics, there is a relative lack of knowledge on how climate changes affect morphological and ecological traits, especially on Neotropical region. To this end, we have tested the impacts of climate change that operate at individual and community scales. First, we analyzed temporal changes in the community structure of small mammal in two fragments of Atlantic forest, a small in regeneration (EPTEA Mata do Paraíso) and a large mature forest fragment (PERD). In both fragments we could see significant temporal changes in community structure. However, temporal dissimilarity was higher in PERD. Directional changes in the structure seem to be more associated with small fragments, while in larger fragment the community seems to reflect a loose equilibrium. Then, we tested the influence of these temporal biotic variations, combined with climatic changes, in Rapid Morphological Changes (RMCs) of four rodent species – Akodon cursor, Cerradomys subflavus, Oligoryzomys nigripes and Oxymycterus dasytrichus - of the small mammal community in EPTEA Mata do Paraíso. We tested differences in size and shape of the skull between specimens collected in two temporal series. We also explored the best relationships between cranial changes and environmental drivers. Our analysis showed RMCs in all species and theses changes were strongly influenced by maximum temperature, showing a negative association with size. Besides, precipitation, humidity, richness of rodents and minimum temperature had a positive association with size. Additionally, abundance also was negatively associated with size in Ol. nigripes and Ox. dasytrichus. After testing the temporal variation in size in this community, we analyzed how fluctuating asymmetry (FA), in different populations, is influenced by climatic drivers. We created 11 space-temporal groups for A. cursor and 13 for Ol. nigripes. Each group consisted of specimens from the same locality divided in two time series. Five groups of A. cursor showed significant variation on asymmetry over time and, for Ol. nigripes, we found variation in FA in six groups. The best model to explain FA in A. cursor included only Maximum Temperature, while for Ol. nigripes the best model included only Humidity. Increased FA generally negatively affects fitness of the species. That way, understanding which factors most affect developmental stability and which species have the potential to adapt to changes is central for the future of biodiversity conservation.