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Abstract Detail



Ecological Section

Alves Meira Neto , Joao Augusto [1], Gastauer, Markus [1], Maganago, Luiz [1], Clemente, Adelaide [2], Correia, Otilia [2].

When fire is welcome in Mediterranean plant communities: a phylogenetic perspective on assembly rules.

Mediterranean communities are disturbed by fires of different intensities. The effects of fire disturbances on the function of Mediterranean communities have been investigated mostly by means of two functional groups: obligate seeders (seeders) and obligate resprouters (resprouters). It has been detected that the more frequent the fires, the stronger the phylogenetic clustering due to environmental filtering. If we assume that closely related species are more similar and share more traits, it is implied that fire filtering and decreased interactions cause phylogenetic clustering. In contrast, the increasing level of interactions and competitive exclusion possibly cause phylogenetic overdispersion. Our working hypothesis was that phylogenetic clustering caused by fire filtering in Mediterranean communities decreases during post-fire succession until the time at which phylogenetic signaling changes to overdispersion caused by the predominance of competition and other density-dependent interactions. The present study was carried out in Serra da Arrábida, Portugal, where fire is leading to patchy habitats with different ages. To analyze the phylogenetic structure of each patch’s age, generalized linear models (GLM) and generalized additive models (GAM) related age, altitude and the Net Relatedness Index as well as the Nearest Taxon Index calculated for each plot. All GLMs show that the turning point from clustering to overdispersion occurs at 60-80 years after a fire, confirming the working hypothesis. The GAM shows that phylogenetic distance decreases during nine years after a fire and rises during the next seven decades, resulting in a U-shaped curve. The phylogenetic signaling shows that sprouting after fire is predominantly a trait shared among close relatives rather than among more distant relatives. Germination after a fire is also a trait predominantly shared among close relatives, but this finding was only marginally significant. These findings indicate a weaker effect of interactions than of environmental filtering during this fire-ruling time, and it means that a second fire that occurs less than 60 years after the preceding fire would superimpose more than one fire filtering. However, with decreased fire filtering and increased interactions, a second fire would attenuate competitive exclusion and density dependent effects. Because this second fire would be at a small scale and there would be enough patches of different ages that would preserve interactions, it would be a welcome fire, resulting in increased phylogenetic diversity, attenuation of interactions to lower levels, avoidance of competitive exclusion and avoidance of the accumulation of too much fuel that increases the intensity of a fire.


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1 - Universidade Federal de Vicosa, Departamento de Biologia Vegetal, Campus UFV, Laboratory of Ecology and Evolution of Plants - LEEP, Vicosa, Minas Gerais, 36570-000, Brazil
2 - Universidade de Lisboa, Departamento de Biologia Vegetal, FCUL, Campo Grande, Edificio C2, Lisbon, Lisbon, Portugal

Keywords:
Assembly rules
Evolutionary ecology
functional ecology.

Presentation Type: Oral Paper:Papers for Sections
Session: 47
Location: Clearwater/Grove
Date: Tuesday, July 29th, 2014
Time: 3:45 PM
Number: 47007
Abstract ID:210
Candidate for Awards:None


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