Data from: Legume Abundance Along Successional And Rainfall Gradients In Neotropical ForestsThis database is the product of the 2ndFOR collaborative research network on secondary forests. The database contains total basal area data (in m2 ha-1) of legume trees (Leguminosae) for 1207 secondary forest plots differing in time since abandonment. The plots belong to different chonosequence studies. For a description of the database, see Gei et al. 2018. Legume Abundance Along Successional And Rainfall Gradients In Neotropical Forests. Nature Ecology and Evolution. The file "Legume basal area 2ndFOR data.csv" contains the following variables: Chronosequence: name of the chronosequence site Age: age of the plot (in years), "OG" indicates old-growth forest of unknown age LBA: total basal area of legume trees (Leguminosae) of the plot in m2 ha-1 Reference: a citation for the chronosequence study, if available PI/contact person: name(s) of the principal investigator(s) or contact person(s) for the chronosequence study.Legume basal area 2ndFOR data.csv

The nutrient demands of regrowing tropical forests are partly satisfied by nitrogen (N)-fixing legume trees, but our understanding of the abundance of those species is biased towards wet tropical regions. Here we show how the abundance of Leguminosae is affected by both recovery from disturbance and large-scale rainfall gradients through a synthesis of forest-inventory plots from a network of 42 Neotropical forest chronosequences. During the first three decades of natural forest regeneration, legume basal area is twice as high in dry compared to wet secondary forests. The tremendous ecological success of legumes in recently disturbed, water-limited forests is likely related to both their reduced leaflet size and ability to fix N2, which together enhance legume drought tolerance and water-use efficiency. Earth system models should incorporate these large-scale successional and climatic patterns of legume dominance to provide more accurate estimates of the maximum potential for natural N fixation across tropical forests.