Ecology of the Seed Bank in the Amazon Rainforest

Abstract

The seed bank is directly related to forest resilience because it contributes to the greatest number of regenerants after the occurrence of disturbances. Changes in seed density, floristic composition, and life forms completely alter the successional trajectory of forest environments. These changes are directly related to land use. For example, suppression of the seed bank can occur in pastures, that experience frequent fires with increase of density of seeds and predominance of herbs are typical of highly degraded areas, such as Poaceae, Rubiaceae, Asteraceae, and Cyperaceae. Melastomataceae seedlings are an important component of the seed bank in the Amazon rainforest. On the other hand, Urticaceae has greater representation in forests that exhibit low-impact land use. Any change in seed bank functionality is bound to compromise the diversity, regeneration potential and overall maintenance of tropical forests. Therefore, it is necessary to expand studies that investigate seed banks in the Amazon rainforest. It is as important to prioritize sampling methods and pursue standardization of data presentation, as well as improve the identification of species that occur in the seed bank.

Caracterização do Banco de Sementes do Solo em Floresta Ombrófila Aberta na Amazônia Ocidental

“…A maior parte dos pontos amostrais apresentaram similaridade entre 0,25 e 0,5, indicando que na área do parque a composição do banco de sementes é semelhante, pois, segundo Mueller-Dombois e Ellenberg (1974), podem ser consideradas como ambientes similares em termos de composição florística os que apresentam pelo menos 25% de espécies comuns. A densidade de plântulas emergidas observada na área de estudo foi semelhante aos verificados em alguns trabalhos na Amazônia (Bordon;Leal Filho e Bentos, 2021;Leal Filho et al, 2013;Sousa et al, 2017) e está dentro da amplitude encontrada para florestas neotropicais, que variam de 25 a 3350 sem.m² (Garwood, 1989) e florestas menos perturbadas (Sousa et al, 2017;Bordon;Leal Filho e Bentos, 2021).…”

Ecosystem and Biodiversity of Amazonia

“…Forest fragments are stretches of forest inserted in a matrix of different types of land uses, typically of anthropic origin [38,[100][101][102]. The areas used in this study encompass a variety of forest fragments, requiring a more detailed analysis of the characteristics of each.…”

“…Increase in seed density and changes in the floristic composition of the seed bank intensify in small fragments inserted in a matrix composed of pastures, as well as recurrence of disturbances in these forest fragments [5,24,34,74,100]. While large forest fragments over 100 ha have a density and floristic composition more similar to the seed bank of old-growth forests, the seed bank also contains species typical of anthropized areas [7,19,102,103].…”

“…The second most common genus in the Amazon is Ixodes, with six reported species: Ixodes amarali, Ixodes bocatorensis, Ixodes lasallei, Ixodes luciae, Ixodes schulzei and Ixodes spinosus (Table 3). Although there are two exclusive species on birds in Brazil [65], all species recorded in the Brazilian Amazon parasitize mainly wild mammals [13,16,31,32,88,99,102]. Ixodes spp.…”