Predação pós-dispersão de sementes do angico Anadenanthera falcata (Benth.) Speg. (Leguminosae-Mimosoideae) em mata de galeria em Barra do Garças, MT

Abstract

-(Post-dispersal seed predation of Anadenanthera falcata (Benth.) Speg. (Leguminosae-Mimosoideae) in a gallery forest in Barra do Garças, MT, Brazil). Seed predation is one of the bottlenecks for the regeneration of tropical trees. The influence of post-dispersal seed predation of A. falcata on seedling recruitment was studied in a gallery forest in "Parque Estadual da Serra Azul" (PESA) in Barra do Garças, MT. Field experiments were designed to assess the differences in post-dispersal seed predation by vertebrates and invertebrates with regards to temporal and spatial variation, leaf litter and distance from parent tree. Ants Solenopsis (Diplorhoptrum) sp. were the main seed predator of A. falcata. Seed mortality by insects varied through the fruiting season; it was more intense at the beginning and at the end of the fruiting season. The survivorship of seed did not vary among different microhabitats and was independent of litter cover and proximity to an adult fruiting tree. The results of this study indicated that predation by ants can limit the recruitment of A. falcata. However, rainfall reduces predation rate by promoting seed germination and favouring seedling recruitment of A. falcata.

Seed dispersal and predation of Buchenavia tomentosa Eichler (Combretaceae) in a Cerrado sensu stricto, midwest Brazil

“…The variation in fruit removal rates throughout the fruiting season might be associated to the higher attractiveness promoted by the abundance of fruits in the area. Several studies have demonstrated that predation rate tends to increase with the detection of the resource by the predator and with the increase in density of the resource (Bartimachi et al, 2008).…”

“…Seed predation may affect plant reproductive success and is one of the factors that control the population growth of plant species (Bartimachi et al, 2008).…”

“…However Hubbell (1980) suggested that when the quantity of seeds under the parent tree is extremely high, even with intense activity of predators in this site, a large number of seedlings could reach maturity, resulting in clustered populations. The massive seed production may satiate seed predators, resulting in a negative correlation between predation and density of seeds (Allmen et al, 2004;Bartimachi et al, 2008). For many species, this may be one of the most important strategies to avoid predation (Pedroni et al, 2002).…”

“…In addition, the stony endocarp of B. tomentosa fruit suggests that rodents act as seed predators, as they have the ability to break the endocarp; 2) Does the removal of diaspores on the ground vary with the distance from the parent tree and the fruiting period? Based on the Janzen-Connell model, we expect to find higher predation rates during the peak of fruiting (Bartimachi et al, 2008); 3) Does the passage of B. tomentosa seeds through the digestive tract of frugivores or the removal of pulp by animals affect their germination potential? Since the removal of the fleshy pulp that wraps diaspores increases the probability of seed survival and germination (Traveset et al, 2007), the passage of seeds through the digestive tract of frugivores and cleaning by ants can positively influence the fate of seeds (Christianini et al, 2007;Oliveira et al, 1995).…”

Estrutura populacional de quatro espécies de Pipridae na região de transição Cerrado – Amazônia

“…A precipitação média no período chuvoso (outubro a março) é 1400 mm e a temperatura 26,3 °C. No período seco (abril a setembro) a precipitação média é 180 mm e a temperatura 24,9 °C (Bartimachi et al 2008) e em Primavera do Leste, a precipitação pluviométrica é em torno de 1.560 mm/ano, variando de 5 mm a 300 mm como média mensal, sendo abundante no verão entre outubro a abril, com o inverno seco de maio a agosto. A umidade relativa do ar tem a média variando de 65% a 87% e temperatura média variando de 18ºC a 24ºC, com temperatura mínima oscilando entre 10ºC e 19ºC e a temperatura máxima variando entre 29ºC e 34ºC (Santana et al 2008).…”