Resumen
- There is evidence that not all woody species have the same function in ecosystems and that this is related to their plant functional traits and the abundance of these traits in the community. In order to contribute with functional knowledge to the design of agroforestry systems for cacao, plant functional traits of woody species, specific leaf area (SLA), total height (TH), penetration resistance (PR), leaf nitrogen concentration (LNC) and leaf phosphorus concentration (LPC) were measured according to Pérez-Harguindeguy et al. (2013) y Cornelissen et al. (2013) for five common woody species found within a range of cacao production systems in Santander (Colombia). A variation range of the woody species along an axis of resource acquisition and competitiveness, represented by species with less trunk hardness (higher PR) and high diameter at breast height was identified. In the opposite side, species with less foliar phosphorus concentration and diameter at breast height and higher trunk hardness (lower PR). Albizia guachapelepresent higher SLA, followed by Cedrela odorata and Cordia gerascanthus. In this sense and according to global ecological findings about SLA and its correlations these species have morphological traits for high photosynthetic rates. Erythrina fusca was the most different species according to its traits variation in a PCA. In the cacao region of Santander, these species had the higher potential for a photosynthetic answer given its less investment in wood structure or penetration resistance. The woody species that in cacao agroecosystems of Santander are more usually found: C. odorata, C. gerascanthus, E. fusca, A. guachapele and Schizolobium parahyba were explained by 57% of the trait variation in a PCA. At the same time, it is important to mention that the presence of the five common woody species in the region are also evidence that farmers had been slightly driving the woody species selection by given more attention to plant traits related to fast growth that can offer shade and companion and conserve the cacao crop productivity (Figure 1). The diameter at breast height as a common woody species measurement should be accompanied by the determination of SLA and other plant functional traits that contribute bridging knowledge to improve the design for multifunctional agroforestry systems that integrate the functional tree biodiversity in cacao production systems.