Demographic rates and stature of tree species in 13 sub-tropical forests: annual growth, annual survival, annual recruitment >( 1 cm dbh), stature (max dbh)

Organisms of all species must balance their allocation to growth, survival and recruitment. Among tree species, evolution has resulted in different life-history strategies for partitioning resources to these key demographic processes. Life-history strategies in tropical forests have often been shown to align along a trade-off between fast growth and high survival, i.e. the well-known fast-slow continuum. In addition, an orthogonal trade-off has been proposed between tall stature – resulting from fast growth and high survival – and recruitment success, i.e. a stature−recruitment trade-off. However, it is not clear if these two independent dimensions of life-history variation structure tropical forests worldwide.

We used data from 13 large-scale and long-term tropical forest monitoring plots in three continents to explore the principal trade-offs in annual growth, survival and recruitment as well as tree stature. These forests included relatively undisturbed forests as well as typhoon-disturbed forests. Life-history variation in twelve forests was structured by two orthogonal trade-offs, the growth−survival trade-off and the stature−recruitment trade-off. Pairwise Procrustes analysis revealed a high similarity of demographic relationships among forests. The small deviations were related to differences between African and Asian plots.

Synthesis. The fast-slow continuum and tree stature are two independent dimensions structuring many, but not all tropical tree communities. Our discovery of the consistency of demographic trade-offs and life-history strategies across different forest types from three continents substantially improves our ability to predict tropical forest dynamics worldwide.