Functional trait strategies of trees in dry and wet tropical forests are similar but differ in their consequences for succession.
Global plant trait studies have revealed fundamental trade-offs in plant resource economics. We evaluated such trait trade-offs during secondary succession in two species-rich tropical ecosystems that contrast in precipitation: dry deciduous and wet evergreen forests of Mexico. Species turnover with succession in dry forest largely relates to increasing water availability and in wet forest to decreasing light availability. We hypothesized that while functional trait trade-offs are similar in the two forest systems, the successful plant strategies in these communities will be different, as contrasting filters affect species turnover. Research was carried out in 15 dry secondary forest sites (5-63 years after abandonment) and in 17 wet secondary forest sites (<1-25 years after abandonment). We used 11 functional traits measured on 132 species to make species-trait PCA biplots for dry and wet forest and compare trait trade-offs. We evaluated whether multivariate plant strategies changed during succession, by calculating a 'Community-Weighted Mean' plant strategy, based on species scores on the first two PCA-axes. Trait spectra reflected two main trade-off axes that were similar for dry and wet forest species: acquisitive versus conservative species, and drought avoiding species versus evergreen species with large animal-dispersed seeds. These trait associations were consistent when accounting for evolutionary history. Successional changes in the most successful plant strategies reflected different functional trait spectra depending on the forest type. In dry forest the community changed from having drought avoiding strategies early in succession to increased abundance of evergreen strategies with larger seeds late in succession. In wet forest the community changed from species having mainly acquisitive strategies to those with more conservative strategies during succession. These strategy changes were explained by increasing water availability during dry forest succession and increasing light scarcity during wet forest succession. Although similar trait spectra were observed among dry and wet secondary forest species, the consequences for succession were different resulting from contrasting environmental filters.
Forest Ecology and Forest Management Group, Wageningen University, PO Box 47, 6700 AA, Wageningen, The Netherlands; Centro de Investigaciones en Ecosistemas, Universidad Nacional Autónoma de México, Campus Morelia, Antigua Carretera a Pátzcuaro 8701, Ex-hacienda de San José de la Huerta, 58190, Morelia, Michoacán, Mexico.
Madelon
M
Lohbeck
Forest Ecology and Forest Management Group, Wageningen University, PO Box 47, 6700 AA, Wageningen, The Netherlands; Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, Ancon, Panama; Departamento de Ecología y Recursos Naturales, Facultad de Ciencias, Universidad Nacional Autónoma de México, 04510, México, Distrito Federal, Mexico.
Edwin
E
Lebrija-Trejos
Centro de Investigaciones en Ecosistemas, Universidad Nacional Autónoma de México, Campus Morelia, Antigua Carretera a Pátzcuaro 8701, Ex-hacienda de San José de la Huerta, 58190, Morelia, Michoacán, Mexico.
Miguel
M
Martínez-Ramos
Departamento de Ecología y Recursos Naturales, Facultad de Ciencias, Universidad Nacional Autónoma de México, 04510, México, Distrito Federal, Mexico.
Jorge A
JA
Meave
Forest Ecology and Forest Management Group, Wageningen University, PO Box 47, 6700 AA, Wageningen, The Netherlands.
Lourens
L
Poorter
Forest Ecology and Forest Management Group, Wageningen University, PO Box 47, 6700 AA, Wageningen, The Netherlands.
Frans
F
Bongers
D000220:Adaptation, Biological; D055864:Droughts; D004784:Environmental Monitoring / Q000379:methods*; D065928:Forests; D008027:Light; D008800:Mexico; D011891:Rain; D014197:Trees / Q000145:classification* / Q000502:physiology*; D014329:Tropical Climate; D014867:Water
D014867:Water