Spondias mombin and Theobroma grandiflorum in agroforestry system: productivity implications

Abstract In agroforestry systems, little is known about the influence of the dominant species on that located in the lower layer of the canopy. The aim of this study was to evaluate if S. mombin plants, when in consortium with T. grandiflorum, caused some type of depression in the performance of T. grandiflorum and also to identify the most favorable S. mombin clones for this interaction. The experiment started on February 2005. During 11 years, four levels of influence of S. mombin on T. grandiflorum caused by the proximity between species were evaluated. As response variables, the vegetative development of S. mombin and T. grandiflorum was measured; the production of eight vintages T. grandiflorum trees was computed, and the mortality rate of plants was recorded. The results showed that the competition exerted by S. mombin moderately affected the initial development of plants, as well as the production of fruits in the last harvests, and the survival rate. The most favorable S. mombin clones to be used in agroforestry systems with T. grandiflorum trees were identified. According to results presented here, it was possible to conclude that S. mombin can be indicated as a species to compose AFS with T. grandiflorum.摘要 在农林复合系统（agroforestry systems）中，优势物种对冠层下层伴生植物的影响机制仍有待深入探究。本研究旨在评估：当S. mombin与T. grandiflorum混植时，S. mombin是否会对T. grandiflorum的生长表现产生抑制效应，并筛选出适配该组合的最优S. mombin无性系。本实验于2005年2月启动，历时11年，通过设置4个物种邻近梯度，探究S. mombin通过种间邻近效应施加的影响程度。本研究的响应变量包括：两种供试植物的营养生长指标、T. grandiflorum连续8个采收季的果实产量，以及植株死亡率。结果显示，S. mombin产生的种间竞争会适度抑制供试植株的初始生长、后期收获季的果实产量与植株存活率。本研究成功筛选出适配T. grandiflorum农林复合系统的优良S. mombin无性系。基于上述实验结果，可得出结论：S. mombin可作为与T. grandiflorum构建农林复合系统（AFS）的适宜物种。