Abstract
In many plant communities, there is a negative interspecific correlation between
relative growth rates and survival of juveniles. This negative correlation is most likely caused
by a trade-off between carbon allocation to growth vs. allocation to defense and storage.
Nonstructural carbohydrates (NSC) stored in stems allow plants to overcome periods of stress
and should enhance survival. In order to assess how species differ in carbohydrate storage in
relation to juvenile light requirements, growth, and survival, we quantified NSC concentrations
and pool sizes in sapling stems of 85 woody species in moist semi-evergreen and dry
deciduous tropical forests in the rainy season in Bolivia.
Moist forest species averaged higher NSC concentrations than dry forest species.
Carbohydrate concentrations and pool sizes decreased with the light requirements of juveniles
of the species in the moist forest but not in the dry forest. Combined, these results suggest that
storage is especially important for species that regenerate in persistently shady habitats, as in
the understory of moist evergreen forests.
For moist forest species, sapling survival rates increased with NSC concentrations and pool
sizes while growth rates declined with the NSC concentrations and pool sizes. No relationships
were found for dry forest species. Carbon allocation to storage contributes to the growth¿
survival trade-off through its positive effect on survival. And, a continuum in carbon storage
strategies contributes to a continuum in light requirements among species. The link between
storage and light requirements is especially strong in moist evergreen forest where species sort
out along a light gradient, but disappears in dry deciduous forest where light is a less limiting
resource and species sort out along drought and fire gradients.
Key words: Bolivia; growth¿survival trade-off; shade tolerance; starch; sugar; total nonstructural
carbohydrates (NSC); tropical forest.
Original language | English |
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Pages (from-to) | 1000-1011 |
Journal | Ecology |
Volume | 88 |
Issue number | 4 |
DOIs | |
Publication status | Published - 2007 |
Keywords
- seedling survival
- leaf traits
- growth-rate
- shade
- allocation
- patterns
- ecology
- size
- acclimatization
- regeneration