Soil seed banks

Abstract

The goal of this literature review is to discuss some of the major aspects of the soil seed bank, from its characteristics down to methodological aspects of its determination. Soil seed bank is the reservoir of viable seeds or of vegetative propagules that are present in the soil and that are able to recompose a natural vegetation. In the agroecossystems the soil seed bank is related to weeds, and the knowledge of its size and composition in terms of species can be used in the prediction of future infestations, to built simulation models of population establishment through time and also the definition of soil and cultural management programs, in order to have a rational use of herbicides. Key Words: weed, soil seed bank, population dynamics BANCO DE SEMENTES DO SOLO RESUMO: O objetivo desta revisão é discorrer sobre alguns pontos importantes no estudo do banco de sementes no solo, desde as sua características até aspectos metodológicos para sua determinação. Denomina-se de banco de sementes a reserva destas ou de propágulos vegetativos viáveis presentes no solo e que são capazes de recompor uma vegetação. Nos sistemas agrícolas o banco está relacionado com o estudo das plantas daninhas; o conhecimento do seu tamanho e das espécies que o compõem poderá ser utilizado na previsão de infestações futuras, na construção de modelos de estabelecimentos populacionais no tempo e consequentemente na definição de programas de manejo de solo e culturais, visando racionalizar a utilização de herbicidas. Descritores: planta daninha, banco de sementes, dinâmica de populações

Problemática da ocorrência de diferentes espécies de capim-colchão (Digitaria spp.) na cultura da cana-de-açúcar

“…A aplicação rotineira de herbicidas gera pressão de seleção sobre a flora infestante, e as duas principais formas de resposta das plantas daninhas são a mudança específica na flora, por meio da seleção de espécies de plantas daninhas mais tolerantes, ou seleção intraespecífica de biótipos resistentes aos herbicidas (Christoffoleti & Caetano, 1998).…”

Soil Seed Bank and Natural Regeneration of Trees

“…Roberts (1981) cited in Christoffoleti and Caetano (1998), mentioned as the best and preferred method of examining soil seed bank and regeneration is to observe the emergence of the seedlings right at the site. He went on saying as the most frequent used method however, involves the physical excavation of soil samples, put them in a conducive environment and examine the number of emerging seedlings or else it can also involve the physical separation of seeds from the soil particles.…”

“…According to Garwood, cited in Christoffoleti and Caetano (1998) seed banks can be categorized as temporary or persistent, whereby temporary banks are those which are composed of seeds of short life, which do not present dormancy and are dispersed in time for short periods during the year. Persistent seed banks are those which are composed of seeds that have more than one year of age and reserves of seeds remain in the soil year after year, generally buried into the soil.…”

“…The longevity of seed is also another factor that determines the success of regeneration. Different seeds have different potentials of longevity as it all depends on the nature of the seed, soil depth, factors like rainfall and temperature and the presence of seed dispersal agents (Christoffoleti and Caetano, 1998).…”

<b>Diaspore bank of aquatic macrophytes maintaining species diversity in a Neotropical pond

“…It is also a fundamental component in succession and development of plant communities in wetlands (Valk, 1981). The diaspore bank reflects the historical process of the life cycle of plants, since their establishment in the habitat until their distribution in space and time (Christoffoleti & Caetano, 1998). In the secondary succession, which involves replacement of vegetation after a disturbance, the composition and density of species of the diaspore bank helps determine the structure of the plant community (Orlóci, 1993).…”