Herbivory and fire promote changes in vegetation patches of arid environments, and recruitment plays a key role in their maintenance. We studied seedling dynamics in seven sites with different land use histories related to grazing and fire in north-eastern Patagonian Monte, Argentina. We selected shrub patches in grazed/burned areas. On each shrub patch, we established seven microsites along an under-canopy windward/leeward transect. Seedling recruitment of perennial grasses (PGR) and annual species (ASR) were registered on each microsite. PGR was higher in sites with low-intensity disturbances, and lower in those severely disturbed or not disturbed. PGR was similar on the leeward side, suggesting that shrubs generate similar microsites for their establishment on that side whatever the surrounding disturbance. Severe disturbances promoted non-native ASR. PGR overall was low and apparently, conditions that enhanced ASR also decreased PGR. This situation leads to the replacement of a native-dominated community to one dominated by non-native AS. Our findings suggest that vegetation cover in heavily grazed sites in this semiarid region are sustained mainly by grass re-sprouting capacity, as recruitment is scarce. In contrast, sites that have a fire background and/or are ungrazed show higher PGR, especially in under-canopy microsites.

食草和火能促进干旱环境中植被的变化，而募集在其维护中起着关键作用。我们在阿根廷东北巴塔哥尼亚蒙特地区的七个具有不同土地利用历史的地点研究了幼苗的动态，这些土地利用历史与放牧和火灾有关。我们在放牧/燃烧的地方选择了灌木丛。在每个灌木丛上，我们沿着冠层下的迎风/背风断面建立了七个微型站点。在每个微型站点上注册了多年生草（PGR）和一年生物种（ASR）的幼苗招募。在低强度干扰地区，PGR较高，而在严重干扰或未干扰地区，PGR较低。在下风侧，PGR相似，这表明灌木在该侧的建立都会产生类似的微地点，而不受周围干扰的影响。严重的干扰会导致非本地ASR。PGR总体较低，显然，增强ASR的条件也降低了PGR。这种情况导致将以本地为主的社区替换为以非本地AS为主的社区。我们的发现表明，由于稀缺，该半干旱地区高放牧地带的植被覆盖主要由草的发芽能力维持。相比之下，具有火背景和/或无毛病的地点的PGR较高，尤其是在冠层下的小型地点。我们的发现表明，由于稀缺，该半干旱地区高放牧地带的植被覆盖主要由草的发芽能力维持。相比之下，具有火背景和/或无毛病的地点的PGR较高，尤其是在冠层下的小型地点。我们的发现表明，由于稀缺，该半干旱地区高放牧地带的植被覆盖主要由草的发芽能力维持。相比之下，具有火背景和/或无毛病的地点的PGR较高，尤其是在冠层下的小型地点。