Introduction
Rangelands are crucial part of the global ecosystem, covering an
estimated at 54% of the world’s terrestrial area (Teillard et
al. , 2016). They are home to a wide variety of plants, animals, and
microbes that are of ecological, economic, and cultural significance
(Seid, Kuhn and Fikre, 2016). Rangeland also provides about 70% of the
global forage for both domestic and wild ungulates through grazing and
browsing (Derner et al., 2006). In Africa, rangeland coverage is
estimated about at 43% of the total land area, and at 62% of
Ethiopia’s total landmass, making them a primary source of feed for
ruminants, and an important habitat for dry-land biodiversity. However,
the arid and semi-arid rangeland ecosystems face degradation from poor
management, population growth, deforestation, continuous overgrazing, as
well as land use and climate changes (Oba and Kotile, 2001; Maitimaet al. , 2004; Miehe et al. , 2010). The loss of traditional
indigenous knowledge and the decline in participation of the elders in
rangeland management are the leading causes of this degradation (Oba,
2012; CARE, 2015), resulting in the decline of rangeland resources and
biodiversity, negatively impacting forage production and conservation
efforts.
Pastoralism, with its inherent traditional rangeland management
practices, has shaped rangeland environments for thousands of years.
Traditional grazing management practices have a significant impacts on
the vegetation attributes of rangelands, such as composition, diversity,
and biomass yield (Abate et al., 2010; Angassa et al., 2010; Angassa &
Beyene, 2003; Briske et al., 2008; Gordon & Iii, 2017). For example,
the pastoralists in east Africa have been using enclosures to enhance
plant productivity and establish
mixed forage more effectively (Angassa and Oba, 2010a, 2010b; Haftayet al. , 2013; Wairore et al. , 2016). Several studies (
e.g. Teshome Abate et al., 2009; Abule et al., 2007; Beyene & Kenee,
2008; FAO, 2017; Terefe et al., 2010) show that a livestock mobility
grazing strategy favors biodiversity conservation and sustainable
rangeland management. Conversely, areas with limited mobility may
experience overgrazing, which endangers biodiversity conservation and
reduces biomass yield. Excessive grazing can also decrease the fuel
load, resulting in less intense fires and less damage to trees, leading
to an increase in woody vegetation (McGinty, Baldwin and Banner, 2009;
Bikila, Tessema and Abule, 2016; Mekuriaw, Mengistu and Tegegne, 2019).
Thus, balancing traditional indigenous knowledge and involving elders in
rangeland management is essential for ensuring the sustainability of
rangelands and positively impacting rangeland ecosystems, livestock
production, and the livelihoods of the pastoral communities.
The Somali Regional State in Ethiopia is predominantly a pastoral
ecosystem with 90% of its area being rangeland (Gezahegn, 2006). In
this region, there are around 800 endemic plant species out of the total
1600 found in the country, which makes up a quarter of Ethiopia’s flora
(Barkhadle, Ongaro and Pignatti, 1994). Pastoralists in this area use
various traditional rangeland resource management strategies such as
enclosures and splitting of herds. Enclosures are one of the various
management and rehabilitation strategies that are used to improve
species diversity, cope with drought and ecosystem productivity. They
also split their herds based on patchy resource distribution to ensure
optimum resource utilization, as different domestic animals have
different feed preferences. For example, the dominant animals in
browsing complex areas are goats and camels, while cattle and sheep are
raised in grazing complex areas. However, the potential benefits of
these alternative management practices have often been overlooked by
extension and research services, and little is known about changes in
vegetation attributes resulting from these grazing practices. Therefore,
this study investigates the effects of three grazing management
practices (enclosure, open grazing, and browsing lands) on herbaceous
and wood species composition, richness, diversity, biomass yield, and
wood density and canopy cover.