Resumen
- Sheep and goats are one of the most important livelihood capitals of wayuu indigenous communities in La Guajira, Colombia. These populations are being affected by the effect of climatic variability on the availability of forage for animal feed. The present study assessed the biomass production and resprouting capacity of four native forage species during two contrasting periods (rain and drought). A total homogenization pruning at two meters of height was performed for individuals of the species Prosopis juliflora, Tabebuia chrysanta, Phitecellobium dulce and Capparis odoratissima; in trees with a diameter at breast height (DBH) between 5 and 20 cm. Monthly counting, marking and recording of sprouts was carried out during each contrasting period (three months for rain season and three months for drought season). At the end of each period the regrowths were harvested and divided into fractions: fine < 5 mm (thin leaves and stems) and thick > 5 mm (thick leaves and stems). In the rainy period P. juliflora and T. chrysanta had the highest sprouting capacity with 114.5 and 113 sprouting / tree respectively, followed by P. dulce and C. odoratissima with 86 and 3.5 sprouting / tree. However, the dry season influenced significantly the production of sprouts in these species, being the exception of P. juliflora with 214 sprouts / tree. There were differences in the production of edible biomass between the species. For the first period, the T. chrysanta and P. juliflora species showed higher value with 356.5 and 222.57 g/DM/tree respectively. while in the second period P. juliflora presented a better response to drought with a production of 503.7 g/DM/tree; followed by T. chrysanta with 7.63 g/MS/tree. With respect to the leaf - stem relationship, the species with the best relation correspond to T. chrysanta with 1.48, followed by P. dulce with 1.21 and P. juliflora 1.06. It was not possible to estimate this relationship for C. odoratissima due to the low production of sprouts during the development of the investigation. The fractionation analysis of the biomass in the thin and thick components showed that the P. dulce species assigns a percentage of total biomass for the edible biomass fraction with 98.27%, followed by P. juliflora and T. chrysanta with 95.21 % and 85.26% respectively, while for C. odoratissima the fine fraction of the leaf is the most important. As a conclusion it can be said that the species P. juliflora behaves in an effective way in its ability to regrow and produce biomass in relation to the other species of the study for the two assessed periods. In this sense, it is necessary further research about the effect of frequent pruning on the survival of P. juliflora and also to propose the inclusion of silviculture management practices, such as tree pruning, into the animal feeding strategies of wayuu communities. The species C. odoratissima showed the lowest capacity for regrowth and biomass production for the assessed periods.