Phenological patterns of Oreopanax fulvus (Araliaceae) in remnants of Araucaria Rainforest in Paraná, Brazil

Abstract

Oreopanax fulvus is a species endemic to the Brazilian Atlantic Forest, assessed as rare and vulnerable in the states of Paraná and Rio Grande do Sul, respectively. This adverse situation requires conservation actions that must be supported by the understanding of its autecology. We aimed to identify the phenological patterns of O. fulvus populations from two Araucaria Rainforest remnants in Paraná. Monthly phenology monitoring of 19 trees in each site was performed over 24 months. We quantified the vegetative (i.e., leaf flushing, mature leaves, and leaf-senescence) and reproductive phenophases (i.e., buds production, blooming, immature, and mature fruits). Circular statistics based on activity index were applied to identify the phenophases seasonality. Spearman correlations were performed among phenophases and meteorological parameters. Leaf flushing and mature leaves were recorded in all months, with a decrease of mature leaves during November and December. Leaf-senescence was seasonal, occurring from May to December. The reproductive phenophases were seasonal: blooming from January to May; and fruiting from March to November, with fruits starting to mature in September. Vegetative and reproductive phenophases were highly influenced by average temperature and photoperiod. Although there were dissimilarities in reproductive phenological patterns, the different populations studied had similar phenological performances.

Seasonality in niche occupation revealed through bird community functional structure in the southern Atlantic rainforest

“…The lower species richness found in the mixed forest is in accordance with the idea that food limitation plays a role in causing some birds to migrate, which leads to species that depend on more seasonal resources to move more (Boyle et al 2011, Ryder & Sillett 2016, Macario et al 2017, Miller et al 2021. Seasonal variation in fruit abundance has been found in different areas of the Atlantic Rainforest (Malizia 2001, Castro et al 2007, Pinto et al 2021, and is likely to be linked to the decrease in niche occupancy associated with the consumption of fruits in winter in the mixed forest. Temperature is not very low in semi-deciduous and dense forests in winter, which could maintain this niche space throughout the year in these forest types.…”

“…2007, Pinto et al . 2021), and is likely to be linked to the decrease in niche occupancy associated with the consumption of fruits in winter in the mixed forest. Temperature is not very low in semi‐deciduous and dense forests in winter, which could maintain this niche space throughout the year in these forest types.…”

Contribuições da estatística circular para a obtenção de dados fenológicos reprodutivos em populações e comunidades vegetais florestais

“…A umidade relativa, em especial, demonstrou pouca influência sobre as fenofases.Em regiões de clima temperado, podemos destacar o estudo realizado por Bauer et al (2014), que detectou um padrão sazonal nas fenofases de Ocotea pulchella, Myrcia brasiliensis e Psidium cattleyanum, em formação secundária de Floresta Semidecídua no município de Novo Hamburgo-RS, estando a época de floração destas influenciadas pelo comprimento do dia (fator predominante para a regulação das fenofases em áreas distantes da região equatorial), temperatura e pela ação de agentes polinizadores. Neste estudo, a precipitação não foi um fator preponderante Pinto et al (2021),. ao observar os eventos reprodutivos de Oreopanax fulvus, em dois remanescentes de Floresta com Araucária no Paraná, observou que, apesar destas possuírem características ambientais semelhantes, os padrões de floração Laguncularia racemosa, no litoral Norte do estado da Paraíba, verificaram uma sincronia intraespecífica na ocorrência das fenofases de ambas as espécies, que é um fator relevante para a atração de polinizadores e a intensificação da polinização cruzada.…”

“…Através de métodos estatística circular, foi possível detectar a sazonalidade dos eventos.Conforme Pinto et al (2021), a temperatura e o fotoperíodo foram os gatilhos para desencadear as fenofases reprodutivas, o que é corroborado por Bauer et al (2014). Os dados fornecidos por esta pesquisa também poderão auxiliar na elaboração de calendários de coleta de sementes, auxiliando na conservação desta espécie, especialmente porque foram detectados períodos de escassez dos frutos, devido a interações com a fauna(Pinto et al, 2021).Resultados semelhantes foram encontrados por Müller e Schmitt (2018) para a espécie Guarea macrophylla em área de Mata Ciliar no município de Campo Bom-RS. As flores dos indivíduos avaliados floresceram mais cedo, após um período de inverno ameno.…”