Ben-Gurion University of the Negev" Vegetation Ecology Course 2015/16 Bertrand Boeken Rangeland ecology I Grazing systems Human intervention Rangeland management Rangeland problems 1
Variability of grazing systems Climate (Semi)-arid Tropical Temperate Arctic Vegetation Forests Open landscapes History Recent Age-old Culture Tradition Social structure Nomadism (trans-humance) Levels of intervention Farming Herding Free-ranging Domestic animals Cattle, Sheep, Goats Horses, Donkeys Camels, Llamas Geese, Ostriches Pigs Grazing intensity Density Timing Distribution Frequency 2
Grazing systems Grassland, New Mexico Savanna, Tanzania Grass steppe, Mongolia New Forest, England Shrubland, Negev Alpine grassland, Nepal Shrubland, Kazakhstan Tundra, Lapland 3
Human intervention Environment Ø Vegetation Planting/Seeding Tending/Irrigation Ø Landscape Clearing/Fire Pitting/Trenching Ø Other organisms Pests/Disease Competitors Predators Sheep on heathland, NL Cattle on cultivated meadow, NL Livestock Ø Rearing Stables High-tech Ø Herding Pastoralism Nomadism Ø Rounding up Domestic Wild animals 4
Management aims Maximizing livestock production Ø Sustenance Ø Profit Long-term sustainability Ø Prevention of land degradation Ø Resource conservation Ø Mitigation of drought Conservation of biodiversity Ø Species diversity Ø Endangered species Ø Prevention of biological invasion Ø Landscape heterogeneity Ø Successional stages Preservation of cultural/social traditions Ø Traditional know-how Ø Cultural diversity Ø Indigenous rights 5
Management approaches Various combinations of Ø Technical orientation Maximizing primary production Control of grazing density, timing and spatial distribution Prevention of invaders, pests, competitors and predators Subsidy of water, energy, nutrients Palatability / nutritional value of plants Selection of desirable livestock species/races Based on reductionist, holistic or hierarchical paradigms (agricultural engineering or ecosystem management) Ø Analytical orientation Ecological principles of grazing - side issues or fundamental perspectives Dynamic systems approach to range utilization, quality and change Based on scientific research and insights (depends on paradigm) 6
Rangeland problems Variability of rangelands and their utilization Ø Are there general or only local/ad-hoc principles? No plug-in models predicting system behavior Conceptual models with local components and relationships Ø Are classical research methods appropriate? Replicated systems with controls impossible Interviewing managers and observing success of operation (from businesses management) Small and intermediate-scale experiments important Up-scaling by remote imaging and modeling Combining different rangeland uses and needs Ø Livestock production Ø Long-term sustainability Ø Biodiversity conservation Ø Ecotourism 7
Rangeland problems Maximizing livestock production vs. sustainability Ø Grazing distribution Maximum or heterogeneous biomass harvesting Excluding grazing from sensitive areas of importance for resources and colonization Ø High-yield or stress-tolerant livestock species High-yield: Stress and mortality during drought Stress tolerant: Damage to the landscape Cattle vs. sheep/goats in riparian systems: Spatial distribution of grazing Sheep vs. goats in shrubland: Utilization of vegetation Camels vs. cattle in savanna Utilization of vegetation 8
Rangeland problems Livestock production vs. biodiversity Ø What level of grazing intensity opens sites for more species of plants and animals? Ø What grazing intensity constitutes overgrazing? Ø Special treatments and grazing exclosures Species richness IDH Biodiversity Grazing intensity High sheep and goat density in semi-arid zones: degradation and desertification Livestock production Declining rangeland profitability in western and southern Europe: from heathland, scrub or savanna to closed-canopy forest 9
Rangeland problems Ecotourism vs. production and biodiversity Ø Ecotourism can compensate for - production loss (if biodiversity requires lower intensity) and - low profitability (if higher intensity is needed) Gazers and grazers Ø Effects of ecotourism Damage to landscape, vegetation or livestock Facilitation of invasion of nonnative/undesired animal and plant species and diseases Interactions between visitors and livestock / wildlife And trailblazers 10