Managed Area Enclosure (Kallo) in the Afar Dry Rangelands Enhances Plant Diversity and Sustains a Healthy Rangeland

Abstract

Rangelands support livelihoods of half a billion people globally, but they are among the most degraded ecosystems particularly in arid and semi-arid regions such as in the Afar region of Ethiopia. Using resilience and state-and-transition Models (STM) frameworks, this study evaluates the ecological effectiveness of traditional rangeland management system (Kallo) in supporting healthy rangeland management. This study compared within and outside the area enclosure in terms of plant species diversity, community composition and functional indicators using field-based vegetation surveys and quantitative analysis including a generalized linear model, Shannon diversity, and Bray–Curtis dissimilarity. These  results showed a marked contrast between states where enclosed areas supported high diversity of plant species and families (62 species across 18 families) and only six species were recorded outside the Kallo. Species richness and diversity were significantly higher inside the enclosure (P < 0.001), and community composition differed strongly between treatments (Bray–Curtis dissimilarity = 0.91). The functional analysis revealed the dominance of perennial grasses (82% cover) and decreaser species such as Cenchrus ciliaris, indicating a relatively stable and productive state. In contrast, the presence of increaser and degradation-associated species, along with moderate representation of annual grasses, suggests a transitional but resilient system. Moreover, tree stem density (305.9 stems ha⁻¹) and a rangeland condition index (RCI = 1.07) further confirmed good ecological condition within the enclosure. Invasive alien species were often recorded, but their cover is extremely low (<1%) indicating the resilience of enclosure area and their limited ecological impact. The findings of this study showed that traditional enclosure-based management systems can facilitate ecosystems recovery toward a desirable rangeland state by enhancing biodiversity and strengthening ecosystem resilience. Finally, integration of functional indicators within the resilience and STM frameworks provides a valuable tool for assessing rangeland condition and informing sustainable management in dryland ecosystems.