ausblenden:
Schlagwörter:
flood plain forest; flooding gradient; seed germination; seedling establishment; submergence; survival strategies
Zusammenfassung:
In Central Amazonian flood plains, seedlings after few months are submerged
for up to 210 days every year. Among 31 analysed tree species, those from
high levels in the flooding gradient germinated earlier and had longer
leaves and taller seedlings than those from low levels. Species with
hypogeal germination dominated with 59.1 %, compared to 40.9 % with epigeal
germination. 80 % of the chosen species from nutrient-poor igapó had
hypogeal germination with big, fleshy cotyledons, in contrast to 30 % in
nutrient-rich várzea. Species with high seed mass growing at high elevations
in the flooding gradient in igapó had higher percent germination, and
significantly bigger leaf length and seedling height. The four species with
seed mass >25 g had hypogeal germination, and the 13 species with seed mass
below 1 g all had epigeal germination with foliaceous cotyledons. All
species depended on emersion of the soil for germination.
