1 Successional pathways were evaluated in two Amazonian secondary forest co
mmunities with different land-use histories. Sites which had been clearcut
without subsequent use were dominated after 6-10 years by the pioneer genus
Cecropia (Moraceae), whereas those used for pasture before abandonment wer
e dominated by the pioneer genus Vismia (Clusiaceae).
2 There were 58 plant families and 300 species identified in Cecropia stand
s but only 43 families and 147 species were identified in Vismia stands. Th
ere were 77 species in common (Sorensen similarity = 0.34).
3 Differences in species number and composition of recruiting individuals b
etween stand types were significant and were a function of the dominant pio
neer genus, stem density, distance from primary forest, and land-use histor
y. Regeneration under Vismia canopy was dominated by small Vismia individua
ls (25% of plants < 2 cm basal diameter), whereas regeneration under Cecrop
ia canopy was more diverse and did not include a single young Cecropia.
4 The number of regenerating plants in both secondary stand types dropped o
ff sharply with distance (5, 25, 50, and 100 m) from primary forest, sugges
ting that seed dispersal was limiting plant recruitment. Species richness a
lso declined with distance and could be explained by the decline in plant d
ensity. Species richness in Cecropia stands increased linearly with plant d
ensity, but in Vismia stands the richness increase with density was a decel
5 For the central Amazon, secondary succession involves a more rapid return
of primary forest species if deforestation is not followed by use as pastu
re before abandonment.