Silvopasture, an agroforestry practice combining forages, livestock, and trees, has been shown to optimize productivity and mitigate the effects of environmental stress on livestock, yet few ranchers in Panama deliberately incorporate trees into pastures. Panama’s Azuero Peninsula experiences a five-month dry season that results in substantial losses in grass productivity. We studied three cultivars of Guinea grass (Megathyrsus maximus cv. Massai, cv. Mombaza, and cv. Tanzania) under open (O), moderate (M), and dense (D) tree canopies. We hypothesized that changes in soil properties, herbage mass, and nutritive value would be optimized in M in agreement with the stress gradient hypothesis, which predicts an increase in facilitation with increasing environmental stress. Results after two years showed few changes in soil chemical properties, but bulk density decreased with increasing tree cover. Annually, O produced more herbage mass than M and D and Massai produced more herbage mass than Mombaza, but not compared to Tanzania. Nutritive value improved under tree cover, with D and M showing higher relative feed values than O. Massai demonstrated the greatest tolerance to drought in M, producing more herbage mass in February when compared to D and O. Results partially support the hypothesis, suggesting that herbage mass is greatest in M for Massai during the dry season, but greatest in O over the year. The observed productivity under moderate tree densities could result in improved animal welfare between the months of December and May, the critical dry period for this region.

Silvopasture是一种将牧草，牲畜和树木结合在一起的农林业实践，已被证明可以提高生产力并减轻环境压力对牲畜的影响，但是巴拿马很少有牧场主有意将树木纳入牧场。巴拿马的阿苏罗半岛（Azuero Peninsula）经历了五个月的干旱季节，导致草场生产力大幅下降。我们研究了几内亚几内亚草种（Megathyrsus maximus简历。Massai，简历 蒙巴扎和简历。坦桑尼亚）在开放（O），中等（M）和密集（D）的树冠下。我们假设，与应力梯度假说相符，在土壤中的土壤特性，牧草质量和营养价值的变化将在M中得到优化，该假说可预测随着环境压力的增加，促进作用的增加。两年后的结果表明，土壤化学性质几乎没有变化，但是堆密度随着树木覆盖率的增加而降低。每年，O生产的牧草比M和D多，而Massai生产的牧草比蒙巴萨多，但与坦桑尼亚相比没有。树木覆盖下的营养价值得到改善，D和M的相对饲料价值高于O。马赛对M的干旱表现出最大的耐受性，与D和O相比，2月份的牧草产量更高。结果部分支持了这一假说，这表明在干燥季节马萨诸塞州M的牧草质量最大，而一年中O的牧草质量最大。在适度的树木密度下观察到的生产力可能会改善12月至5月（该地区的关键干旱时期）之间的动物福利。