RT Journal Article
SR 00
ID 10.1073/pnas.1610206114
A1 Falster, D.
A1 Brännström, Å.
A1 Westoby, M.
A1 Dieckmann, U.
T1 Multitrait successional forest dynamics enable diverse competitive coexistence
JF Proceedings of the National Academy of Sciences
YR 2017
FD 2017-03
VO 114
IS 13
SP 2719
OP 2728
K1 niche; coexistence; trait; plant; adaptive dynamics
AB To explain diversity in forests, niche theory must show how multiple plant species coexist while competing for the same resources. Although successional processes are widespread in forests, theoretical work has suggested that differentiation in successional strategy allows only a few species stably to coexist, including only a single shade tolerant. However, this conclusion is based on current niche models, which encode a very simplified view of plant communities, suggesting that the potential for niche differentiation has remained unexplored. Here, we show how extending successional niche models to include features common to all vegetation—height-structured competition for light under a prevailing disturbance regime and two trait-mediated tradeoffs in plant function—enhances the diversity of species that can be maintained, including a diversity of shade tolerants. We identify two distinct axes of potential niche differentiation, corresponding to the traits leaf mass per unit leaf area and height at maturation. The first axis allows for coexistence of different shade tolerances and the second axis for coexistence among species with the same shade tolerance. Addition of this second axis leads to communities with a high diversity of shade tolerants. Niche differentiation along the second axis also generates regions of trait space wherein fitness is almost equalized, an outcome we term “evolutionarily emergent near-neutrality.” For different environmental conditions, our model predicts diverse vegetation types and trait mixtures, akin to observations. These results indicate that the outcomes of successional niche differentiation are richer than previously thought and potentially account for mixtures of traits and species observed in forests worldwide.
PB National Academy of Sciences
SN 1091-6490
LK https://pure.iiasa.ac.at/id/eprint/14354/