Data from: Multiple stages of tree seedling recruitment are altered in tropical forests degraded by selective logging

Tropical forest degradation is a global environmental issue. In degraded
forests, seedling recruitment of canopy trees is vital for forest
regeneration and recovery. We investigated how selective logging, a
pervasive driver of tropical forest degradation, impacts canopy tree
seedling recruitment, focusing on an endemic dipterocarp Dryobalanops
lanceolata in Sabah, Borneo. During a mast-fruiting event in intensively
logged and nearby unlogged forest, we examined four stages of the seedling
recruitment process: seed production, seed predation, and negative
density-dependent germination and seedling survival. Our results suggest
that each stage of the seedling recruitment process is altered in logged
forest. The seed crop of D. lanceolata trees in logged forest was
one-third smaller than that produced by trees in unlogged forest. The
functional role of vertebrates in seed predation increased in logged
forest while that of non-vertebrates declined. Seeds in logged forest were
less likely to germinate than those in unlogged forest. Germination
increased with local-scale conspecific seed density in unlogged forest,
but seedling survival tended to decline. However, both germination and
seedling survival increased with local-scale conspecific seed density in
logged forest. Notably, seed crop size, germination and seedling survival
tended to increase for larger trees in both unlogged and logged forests,
suggesting that sustainable timber extraction and silvicultural practices
designed to minimize damage to the residual stand are important to prevent
seedling recruitment failure. Overall, these impacts sustained by several
aspects of seedling recruitment in a mast-fruiting year suggest that
intensive selective logging may affect long-term population dynamics of D.
lanceolata. It is necessary to establish if other dipterocarp species,
many of which are threatened by the timber trade, are similarly affected
in tropical forests degraded by intensive selective logging.