Tree and Liana Growth in Three Neotropical Dry Forests: Coherent Patterns and Individualistic Responses to Climate Variability

Tropical dry forests (TDFs) are among the ecosystems most threatened by agricultural use and climate warming. However, the long-term growth responses to climate variability of woody plants in TDFs are understudied because not all TDF species form conspicuous annual rings. To address this issue, we sampled trees (26 species) and lianas (2 species) in TDFs subjected to contrasting climate conditions and located in Colombia, Ecuador, and Bolivia. First, we examined the potential to form conspicuous tree-ring boundaries in 22 tree species (Amyris pinnata, Aspidosperma tomentosum, Beilschmiedia sp., Bursera graveolens, Caesalpinia pluviosa, Ceiba pentandra, Centrolobium microchaete, Citharexylum kunthianum, Cordia alliodora, Croton gossypiifolius, Cupania cinerea, Eugenia sp., Genipa americana, Guarea guidonia, Hymenaea courbaril, Machaerium capote, Pithecellobium dulce, Rapanea guianensis, Sapindus saponaria, Senna spectabilis, Zanthoxylum monophyllum, Zanthoxylum rhoifolium, and Zanthoxylum verrucosum) and two liana species (Bignoniaceae and Combretaceae families). Second, we built mean series of ring-width indices in selected tree (A. tomentosum, B. graveolens, C. alliodora, C. cinerea, C. microchaete, P. dulce, S. spectabilis, and Z. verrucosum) and liana species and related them to climate variables. Wet conditions during the current and prior growing seasons enhanced growth in tree and liana species in different TDFs. Coexisting species showed individualistic responses to climate variability.