Phylogenetic constraints do not explain the rarity of nitrogen-fixing trees in late-successional temperate forests.

ABSTRACT:

Background

Symbiotic nitrogen (N)-fixing trees are rare in late-successional temperate forests, even though these forests are often N limited. Two hypotheses could explain this paradox. The 'phylogenetic constraints hypothesis' states that no late-successional tree taxa in temperate forests belong to clades that are predisposed to N fixation. Conversely, the 'selective constraints hypothesis' states that such taxa are present, but N-fixing symbioses would lower their fitness. Here we test the phylogenetic constraints hypothesis.

Methodology/principal findings

Using U.S. forest inventory data, we derived successional indices related to shade tolerance and stand age for N-fixing trees, non-fixing trees in the 'potentially N-fixing clade' (smallest angiosperm clade that include

SUBMITTER: Menge DN 

PROVIDER: S-EPMC2917374 | biostudies-literature | 2010 Aug

REPOSITORIES: biostudies-literature