Enhancement of Grassland Production Through Integration of Forage Legumes in Semi-Arid Rangelands of Kenya

Livestock production in semi-arid rangelands of Kenya is limited by the seasonal quantity and quality of fodder. Kirkman & Carvalho (2003) stated that these inter- and intra-seasonal quality and quantity fluctuations result in nutrient deficits that severely limit livestock production potential. The objective of this experiment was to study the effect of three forage legumes on the production of natural pastures in semi-arid rangelands of Kenya

Personal norms of sustainability and their impact on management – The case of rangeland management in semi-arid regions

We empirically study personal norms of sustainability, conceptualized according to the normactivation theory and operationalized under the notion of strong ecological-economic sustainability, for commercial cattle farmers in semi-arid rangelands of Namibia, a system that is subject to extensive degradation. We characterize farmers’ personal norms, study their determinants, and analyze their impact on actual management based on the dual-preferences model. We find personal norms of sustainability that are heterogeneous across farmers, but vary little with socio-demographic or environmental characteristics. We find no evidence for a significant impact of personal norms on actual management behavior, which may be due to farmers not feeling capable for averting adverse long-term consequences of their management. This may contribute to the observed degradation of rangelands in Namibia.commercial cattle farming, Namibia, norm-activation theory, personal norms, dual-preferences model, semi-arid rangelands, sustainability

Forecasting Annual Drought Conditions for Arid and Semi-Arid Rangelands

Long-term weather forecasts (\u3e14 days) have improved, but still lack accurate enough information to be valuable; thus, drought forecasts must be based on historical records and calculated probabilities of occurrence. The use of regression techniques to investigate linear dependence between current and preceding years\u27 precipitation or forage yield is illustrated. A 3-state Markov process is used to determine relationships between below-average, average and above­average consecutive annual herbage yields, and winter and spring precipitation amounts. Methods for using natl/ml resource simulation models to forecast ecosystem components such as herbage production, runoff, and erosion with their associated probabilities of occurrence are also discussed

Innovative Ways to Resolution of Native Title in Australia: Promoting Secure Futures on Pastoral Country

Negotiated agreements between traditional owners and pastoralists about use and management of lands held under pastoral lease tenures in the arid and semi-arid rangelands of Australia will promote secure futures for both parties. In this paper we will discuss this assertion and the processes of agreement making we are engaged in the South Australian rangelands. First we will explain the particular meaning of the Australian jargon we use throughout this paper - traditional owner, pastoralist and pastoral lease tenure. Following this we envision what the agreements that will result from current negotiating processes will deliver and how they will work 'on the ground'. We consider some of the challenges for the negotiating process and useful roles for business and property planning as tools to shape the content of agreements.Land Economics/Use,

Drought, change and resilience in South Africa's arid and semi-arid rangelands

Droughts can have serious ecological and economic consequences and will pose an increasing challenge to rangeiand users as the global climate is changing. Finding ways to reduce ecological and economic impacts of drought should thus be a major research thrust. Resilience, defined as the amount of perturbation a social or ecological system can absorb without shifting to a qualitatively different state, has emerged as a prominent concept in ecosystem ecology and more recently as a conceptual framework for understanding and managing complex social-ecological systems. This paper discusses the application and relevance of resilience to understanding and managing ecosystem change, and enhancing the capacity of land users to adapt to droughts. Drought can trigger vegetation change and factors such as grazing management can influence the likelihood of such transitions. Drought can cause differential mortality of perennial plants and this could provide an opportunity for rangeland restoration by opening up establishment sites for desirable species. The capacity of land users to cope with drought is influenced by the resilience of their agro-ecosystems, the diversity of livelihood options, access to resources and institutional support. By these criteria, current agricultural development approaches in South Africa, particularly in communal rangelands and areas of land reform, are unlikely to enhance land users' resilience to drought and other perturbations

Tree Legumes as Sustainable Ecosystem Services in Livestock Systems

Arboreal legumes provide multiple uses in pastures and rangelands. Trees directly and indirectly feed, house, doctor, and warm humans at minimal environmental cost through forage (fodder), timber, biofuel, medicines, as well as edible leaves, pods, and seeds. Leguminous trees, because they foster biological nitrogen fixation (BNF) and acquire deep-soil nutrients and moisture, compete less with herbaceous plants for shallow-horizon soil moisture and nutrients. Their ecosystem services (ES) are generally less obvious and quantifiable. These include converting CO2 to sequestered C and released O2 in N-poor soils where trees without BNF do not thrive. Other ES include shade for animals (including humans), plants, and soil microorganisms that would not otherwise survive in direct sunlight, in dry seasons, or under human mismanagement (overgrazing). Arboreal legumes in semi-arid and arid environments also provide habitat and nutrition to insects (pollinators), mammals, and birds during crucial drought seasons and years, facilitating repopulation to the ecosystem when rainfall returns. Additional ES include crucial ecosystem biological diversity, climatic stability, as well as aesthetic and cultural values. Humans have long recognized their value in natural semi-arid and arid ecosystems such as rangelands but have been slower to incorporate them into cultivated pastures where herbaceous monocultures dominate. Incorporating arboreal legumes with greater regularity into restored rangelands or cultivated pastures would not only increase overall productivity by adding non-herbaceous aerial and deep-soil root biomass but also provide ES that herbaceous species cannot match

Household-Level Livestock Marketing Behavior Among Northern Kenyan and Southern Ethiopian Pastoralists

Pastoralists in East Africa's arid and semi-arid lands (ASAL) regularly confront climatic shocks triggering massive herd die-offs and loss of scarce wealth. On the surface, it appears puzzling that pastoralists do not make extensive use of livestock markets to offload animals when climatic shocks temporarily reduce the carrying capacity of local rangelands, and then use markets to restock their herds when local conditions recover. In recent years, donors and policy makers have begun to hypothesize that investments in livestock marketing systems might quickly pay for themselves through reduced demand for relief aid,by increasing pastoralist marketing responsiveness to temporal variation in range conditions.Marketing,

Working Within Constraints: Managing African Savannas for Animal Production and Biodiversity

The mean density of livestock biomass on African rangelands now greatly exceeds that of indigenous large herbivores, although livestock cannot fully substitute for wildlife with respect to co-evolved ecosystem processes involving herbivory. The dominance of livestock in semi-arid rangelands is largely due to water provision, which uncouples livestock population dynamics from the rainfall-driven trajectories followed by indigenous ungulate species in wildlife areas. Ecological sustainability cannot be achieved with a few exotic species maintained at unprecedented biomass densities in savanna ecosystems, which are evolutionarily adapted for species-rich communities of ungulates of a wise range of sizes. Integrating wildlife and livestock in multi-species animal production systems offers a partial solution. Community-based ecotourism can effectively augment pastoralism in semi-arid rangelands but, as rainfall increases, the opportunity costs become too high. Direct payment approaches show promise for offsetting opportunity costs, although major obstacles remain in the form of political corruption and obstructive practices by national governments

Bush encroachment control and risk management in semi-arid rangelands

We study the role of bush encroachment control for a farmer’s income and income risk in a stochastic ecological-economic model of grazing management in semiarid rangelands. In particular, we study debushing as an instrument of risk management that complements the choice of an adaptive grazing management strategy for that sake. We show that debushing, while being a good practice for increasing the mean pasture productivity and thus expected income, also increases the farmer’s income risk. The optimal extent of debushing for a risk-averse farmer is thus determined from balancing the positive and negative consequences of debushing on intertemporal and stochastic farm income.bush encroachment, expected utility, farm income, intertemporal optimization, risk aversion, risk management, semi-arid rangeland

Recovery of rangelands : the functioning of soil seed banks in a semi-arid African savanna

Rangelands in Africa provide important forage resources for herbivores; particularly perennial grasses provide grazing for domestic and wild herbivores. However, semi-arid African rangelands experience severe vegetation and soil degradation due to heavy grazing, causing negative impacts on the ecosystems, livestock production and livelihoods of the people. Semi-arid African rangelands can be described by a state-and-transition models, often with three stable states, the first one being a state with ample herbaceous cover, perennial grasses and scattered trees, the second one as a state with a poor cover of annual grasses, absence of perennial grasses, and the third state with a high proportion of bare soil and/or often bush encroached. This thesis aims to fill important information gaps concerning soil seed banks that play in the recovery and possible restoration of degraded semi-arid African rangelands with particular emphasis on Ethiopia. This was done through investigating the mechanisms of how heavy grazing affects the soil seeds bank dynamics so as to understand stable states and transition processes of aboveground vegetation. In this thesis, aboveground vegetation and soil seed bank dynamics were studied under heavy and light grazing pressures in a field and experimental conditions. Results show that heavy grazing resulted in the disappearance of perennial grasses, a reduction in herbaceous species diversity and their plant abundance, standing biomass and basal cover, as well as a decrease in the soil nutrient conditions. The soil seed banks was correlated to differences in grazing pressure, with a greater seedling density under light grazing compared with heavy grazing. Immediately after seed dispersal, the seedling density increased over the first first three months until the eight months of soil sampling, and decreased thereafter. Under light grazing, perennial grass species dominated, whereas annual species were abundant at the heavily grazed sites, indicating that perennial grasses, with good fodder value, are replaced by annual species in the soil seed banks due to heavy grazing. With increasing soil depth, the seedling density and its species richness declined. Moreover, the seeds of perennial grasses were less abundant in the soil seed banks under heavy grazing. The similarity in species composition between the soil seed banks and aboveground vegetation was low under heavy grazing. Results also show that annual grasses had a lower germination and mortality, and higher viability, leading to a longevity of 62% over the 120 days burial in the soil, which was high compared to the 28% for perennials. Moreover, most perennial grasses germinate rapidly after initial seed dispersal at the first rains early in the year, whereas annual grasses show a linear germination pattern over time, indicating that perennial grasses have different survival strategy in semi-arid Africa. As a result, annual species are expected to dominate the soil seed banks, whereas most perennial grass species do not form persistent soil seed banks.The mean mortality from the seedling stage to adult plants in grass species was 65%, and the seed–to–seedling stage was found the most critical transitional stage for grass survival on these rangelands, suggesting that exclusion from grazing and trampling in the early germination stage is important to facilitate the transition from seedling to established plants. Depletion of perennial grass seeds in the soil due to heavy grazing coupled with high seedling mortality leads to a strong decrease in perennial grasses both in the soil seed banks, as well as in the aboveground vegetation. I found that the positive relationship between plant cover and differences in soil seed bank dynamics, i.e., seed density, seed germination rate and longevity, trigger the transition from perennial grasses to annuals and from annual plant cover to bare soil under heavy grazing. I hypothesize that the restoration of perennial grasses from the soil seed banks in heavily grazed areas in semi-arid African rangelands cannot be successful without an extraneous source of perennial grass seeds and without protecting the young plant’s regrowth from trampling and grazing. Therefore, the persistence of species and maintenance of biodiversity in semi-arid rangelands depends mainly on the recruitment of seedlings from annual species, and on vegetative reproduction of perennial grasses and woody species. These findings have important implications for the management, conservation and restoration of semi-arid African rangelands. Keywords:Africa; Aboveground vegetation; Ethiopia; Pastoral system; Rangeland; Restoration; Soil seed bank; Savanna; Semi-arid ecosystem; Vegetation and soil degradation </p