DISTRIBUTION AND ABUNDANCE OF GRASSES IN FADAMA AND UPLAND AREAS OF KWAKWALAWA AND DUNDAYE IN SOKOTO METROPOLIS, NORTHERN NIGERIA.

Abstract

Grass species play a fundamental role in the structure and functioning of savanna ecosystems, particularly in semi-arid regions such as Sokoto Metropolis, where they contribute significantly to soil protection, livestock forage, and ecological stability. This study assessed and compared the diversity, abundance, and distribution of grass species in the Fadama area of Kwakwalawa and the upland area of Dundaye in order to understand how environmental gradients influence vegetation patterns. A systematic sampling technique was used, and a total of sixteen (16) quadrats measuring 1 m × 1 m were randomly placed across the two study sites. Species present in each quadrat were identified, counted, and subjected to quantitative ecological analyses, including density, frequency, abundance, and Importance Value Index (IVI). The results revealed marked differences in species distribution between the two ecological zones. Kwakwalawa (Fadama) recorded higher moisture-loving and nutrient-demanding species such as Panicum maximum and Brachiaria mutica, reflecting the influence of seasonal flooding and fertile alluvial soils. In contrast, the upland area of Dundaye was dominated by drought-tolerant species such as Cenchrus biflorus, Sporobolus pyramidalis, and Imperata cylindrica, indicating adaptation to sandy, fast-draining soils and higher disturbance pressure. However, Andropogon gayanus and Pennisetum pedicellatum emerged as the dominant species across both sites due to their broad ecological amplitude and strong competitive ability.