Soil Spore Bank of Ferns in a Gallery Forest of the Ecological Station of Panga, Uberlândia, MG, Brazil

Abstract

The soil spore bank of ferns is a biotic component of plant communities, important for regeneration processes, population dynamics, and conservation programs. Each year it is enriched when new units are incorporated, and impoverished when they are lost by predation, loss of viability, or by germination. Soil was collected in three microhabitats of the gallery forest of the Panga Stream, at four depths, in the wet and the dry seasons. In general, independent of the season, 'dike' samples presented lower numbers of viable spores when compared to samples from the 'middle' and 'edge' of the forest. The number of viable spores and the number of fern species represented decreased with depth. At the end of the dry season, the number of viable spores decreased only in the first centimeters of the soil. Viable spores of thirteen terrestrial species were registered in the soil of this gallery forest. The presence of viable spores in the soil after six months drought and in deeper soil layers shows the existence of a persistent soil spore bank in the gallery forest of the Panga Stream.A diaspore bank is a biotic component of soil where dispersion units in quiescence or dormancy are found. This biological store can be enriched or impoverished each year, when new units are incorporated, or lost by predation, loss of viability, or germination. Therefore, the diaspore bank is a dynamic component that represents a continuous source of dispersion units important for regeneration processes and population dynamics of plant communities. It is this biological and genetic potential in the soil which permits the local survival of the species during unfavorable environmental conditions or disturbances.Most of the information about diaspore banks is related to the soil seed banks of plant communities (

Monilófitas da Estação Ecológica do Panga, Uberlândia, Estado de Minas Gerais, Brasil: Dennstaedtiaceae, Dryopteridaceae, Gleicheniaceae, Hymenophyllaceae e Lindsaeaceae

“…Pteridium arachnoideum ocorre em áreas abertas e alteradas, de 100-2.450 m altitude; desde o México e Mesoamérica às Antilhas, Colômbia, Venezuela, Trindade, Guiana, Suriname, Guiana Francesa, Equador, Peru, Brasil, Bolívia, Paraguai, Argentina e Uruguai (Mickel & Smith 2004). Na E. E. Panga foram coletados materiais em campo úmido e na mata de galeria, além do seu registro no banco de esporos de coletas de casca de árvores (Ranal 2003). A espécie é reconhecida pelas frondes grandes, lâminas coriáceas, com margens marcadamente revolutas que simulam um falso indúsio e lobos na raquíola de segunda ordem.…”

Distribution patterns of ferns and lycophytes in the Coastal Region of the state of Rio Grande do Sul, Brazil

“…Although this group of plants is capable of dispersing spores over long distances (Holttum 1938) and can form spore banks in the ground (Ranal 2003), the spores may not encounter the microclimatic (temperature, humidity and luminosity) and biotic conditions (mycorrhizal associations) needed for germination (Williams 1938;Sheffields 1996). Furthermore, gametophytes, even when possessing adaptations to desiccation and variable conditions of pH, soil nutrition, temperature and luminosity (Farrar et al 2008), can suffer from insufficient availability of free water in the environment, which in and of itself can be a limiting factor to their establishment.…”

Macrothelypteris e Thelypteris subg. Cyclosorus (Thelypteridaceae) da Estação Ecológica do Panga, Uberlândia, Minas Gerais, Brasil

“…A área apresenta fisionomias comuns do bioma Cerrado como campestres (campo úmido e veredas), savânicas (campo sujo, campo cerrado, cerrado s.s.) e florestais (cerradão, mata mesófila semidecídua de encosta e de galeria) (Schiavini & Araújo 1989, Cardoso & Schiavini 2002, Ranal 2003.…”

“…Em função do seu estado de preservação e dos diversos trabalhos que estão sendo realizados, incluindo florística, fitossociologia e dinâmica de populações, a área atualmente é considerada de alta importância biológica (Drummond et al 2005). Observações ecológicas mostram uma grande representatividade de Thelypteridaceae na área (Ranal 2003, 2004, Araújo et al 2002, se comparadas com as angiospermas. Por exemplo, a família Thelypteridaceae está entre as mais ricas do estrato herbáceo, alcançando a quarta posição em riqueza de espécies (11 espécies) em um estudo sobre o estrato herbáceo-arbustivo de um gradiente florestal do Panga (Arantes 2002).…”