Congruence between floristic patterns of trees and lianas in a southwest Amazonian rain forest
The congruence in floristic patterns between different life-forms of woody plants remains poorly understood in tropical rain forests. We explored whether the floristic patterns of woody plants, divided into small trees 2.5â€šÃ„Ã¬10 cm dbh, large trees â€šÃ¢â€¢10 cm dbh, and lianas â€šÃ¢â€¢2.5 cm dbh were associated with each other or with patterns in soil properties, elevation, and geographical distances between sample plots. We also tested whether ecological amplitudes in relation to environmental variables differed among the plant groups. Trees and lianas were inventoried in 44 0.1-ha plots, distributed among three lowland and two submontane sites in the Madidi National Park, Bolivia. Soil samples were analysed for physico-chemical properties. Floristic differences between sites (as measured with each plant group separately) yielded significant Mantel correlations with each other, and with pH, Ca, Mg, elevation and geographical distance. Mantel correlations with edaphic distances were higher for large trees than small trees, but for Mantel correlations with geographical distance the situation was reversed. Environmental and geographical distances explained 31% of the variation in floristic differences for large trees, 22% for small trees, and 10% for lianas. The ecological amplitudes of lianas were wider than those of all trees for pH, Mg and elevation. The amplitudes of the two size classes of trees did not differ. In principal coordinates ordination, the three plant groups produced similar overall floristic patterns that were explainable by environmental factors.