Banca de DEFESA: MERY INGRID GUIMARAES DE ALENCAR

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : MERY INGRID GUIMARAES DE ALENCAR
DATE: 20/02/2020
TIME: 14:00
LOCAL: Sala de aula Didático 1
TITLE:

Generalities of priming effect: evaluating the effects of interactions between flowers and leaves

KEY WORDS:

non-additive effects ;functional diversity ;intraspecific variation;functional trait

PAGES: 50
BIG AREA: Ciências Biológicas
AREA: Ecologia
SUMMARY:

The interaction between litter with different qualities generate non-additive effects on the decomposition, a phenomenon called priming effect (PE). Despite the global relevance of PE in decomposition, generalizations are still poorly understood, especially in tropical environments. The PE studies are concentrated on leaf litter and rhizosphere, but litter with higher chemical quality, such as flowers, can affect the dynamics of nutrient cycling at local and regional scales, producing mineralization hotspots. The PE relevance could be greater in tropical environments, as leaf litter is nutritionally poor and the interaction with higher quality litter can increases the magnitude of the phenomenon. Thus, this dissertation addresses, in two chapters, the relative importance of effects of floral and leaf detritus on the occurrence, magnitude and direction of the priming effect. In the first chapter we seek to understand the effects of the priming effect at the intraspecific level. For this, we conducted experimental tests with mixtures between floral and leaf litter, for 30 species with wide phylogenetic distribution. The interaction between litter resulted in non-additive effects for most treatments, with synergistic and reciprocal interactions for 53% of the species. The second chapter we aim the relative effect of intra and interspecific variation and their interactions on the magnitude of the priming effect. For this we use an experimental approach with floral and leaf litter of three species decomposing individual and mixture in all pairs of possible combinations, both intra and interspecific. Floral litter showed higher concentrations of important attributes for decomposition, which resulted in higher decomposition rates compared to leaf litter (F=197.4, p<0.0001). Functional differences between types of litter bring synergistic effects on decomposition, for most treatments with interaction between flowers and leaves. The greater magnitude occurring in interspecific interactions than intraspecific interactions. Despite the widespread occurrence of non-additive effects, we found no relationship between the magnitude of PE and functional dissimilarity in either chapter. Possibly the absence of a relationship between magnitude and functional dissimilarity is a result of the non-quantification of structural attributes (i.e. lignin) important for the decomposition. Thus, the results show that the intra and interspecific interaction between floral and leaf litter is an important pathway for the priming effect, further increasing the ecological relevance and universality of the phenomenon.

BANKING MEMBERS:
Externo à Instituição - ANDRÉ TAVARES CORRÊA DIAS - UFRJ
Presidente - 1714892 - ADRIANO CALIMAN FERREIRA DA SILVA
Interno - 3060333 - ANDROS TAROUCO GIANUCA