1

RangelandecologyI

•  Grazingsystems•  Humanintervention•  Rangelandmanagement•  Rangelandproblems

Ben-GurionUniversityoftheNegev

VegetationEcologyCourse2018/19BertrandBoeken

2

VariabilityofgrazingsystemsClimate

•  (Semi)-arid•  Tropical•  Temperate•  Arctic

Vegetation•  Forests•  Openlandscapes

History•  Recent•  Age-old

Culture•  Tradition•  Socialstructure•  Nomadism(trans-

humance)

Levelsofintervention• Farming• Herding• Free-ranging

Domesticanimals• Cattle,Sheep,Goats• Horses,Donkeys• Camels,Llamas• Geese,Ostriches• Pigs

Grazingintensity• Density• Timing• Distribution• Frequency

3

Grazingsystems

Grassland,NewMexicoSavanna,Tanzania

Grasssteppe,Mongolia

Shrubland,Negev

NewForest,England Alpinegrassland,Nepal

Tundra,Lapland

Shrubland,Kazakhstan

4

Humanintervention

Sheeponheathland,NL

Cattleoncultivatedmeadow,NLEnvironment!  Vegetation

•  Planting/Seeding•  Tending/Irrigation

!  Landscape•  Clearing/Fire•  Pitting/Trenching

! Otherorganisms•  Pests/Disease•  Competitors•  Predators Livestock

!  Rearing•  Stables•  High-tech

!  Herding•  Pastoralism•  Nomadism

!  Roundingup•  Domestic•  Wildanimals

5

Managementaims•  Maximizinglivestockproduction

! Sustenance! Profit

•  Long-termsustainability! Preventionoflanddegradation! Resourceconservation! Mitigationofdrought

•  Conservationofbiodiversity! Speciesdiversity! Endangeredspecies! Preventionofbiologicalinvasion! Landscapeheterogeneity! Successionalstages

•  Preservationofcultural/socialtraditions! Traditionalknow-how! Culturaldiversity! Indigenousrights

6

ManagementapproachesVariouscombinationsof

! Technicalorientation•  Maximizingprimaryproduction•  Controlofgrazingdensity,timingandspatialdistribution•  Preventionofinvaders,pests,competitorsandpredators•  Subsidyofwater,energy,nutrients•  Palatability/nutritionalvalueofplants•  Selectionofdesirablelivestockspecies/races

Basedonreductionist,holisticorhierarchicalparadigms(agriculturalengineeringoragro-ecosystemmanagement)

! Analyticalorientation•  Ecologicalprinciplesofgrazing-sideissuesorfundamentalperspectives

•  Dynamicsystemsapproachtorangeutilization,qualityandchange

Basedonscientificresearchandinsights(dependsonparadigm)

7

RangelandproblemsVariabilityofrangelandsandtheirutilization

!  Aretheregeneraloronlylocal/ad-hocprinciples?•  Noplug-inmodelspredictingsystembehavior•  Conceptualmodelswithlocalcomponentsandrelationships

!  Areclassicalresearchmethodsappropriate?•  Replicatedsystemswithcontrolsimpossible•  Interviewingmanagersandobservingsuccessofoperation(frombusinessesmanagement)•  Smallandintermediate-scaleexperimentsimportant•  Up-scalingbyremoteimagingandmodeling

Combiningdifferentrangelandusesandneeds!  Livestockproduction!  Long-termsustainability!  Biodiversityconservation!  Ecotourism

8

Rangelandproblems

Camelsvs.cattleinsavannaUtilizationofvegetation

Cattlevs.sheep/goatsinripariansystems:Spatialdistributionofgrazing Sheepvs.goatsinshrubland:

Utilizationofvegetation

Maximizinglivestockproductionvs.sustainability! Grazingdistribution

•  Maximumorheterogeneousbiomassharvesting•  Excludinggrazingfromsensitiveareasofimportanceforresourcesandcolonization

! High-yieldorstress-tolerantlivestockspecies•  High-yield:Stressandmortalityduringdrought•  Stresstolerant:Damagetothelandscape

9

RangelandproblemsLivestockproductionvs.biodiversity

! Whatlevelofgrazingintensity“openssites”formorespeciesofplantsandanimals?

! Whatgrazingintensityconstitutes“overgrazing”?! Specialtreatmentsandgrazingexclosures

Species

richne

ss

Grazingintensity

IDH

Livestockproduction

Biodiversity

DecliningrangelandprofitabilityinwesternandsouthernEurope:fromheathland,scruborsavannatoclosed-canopyforest

Highsheepandgoatdensityinsemi-aridzones:degradationanddesertification

10

RangelandproblemsEcotourismvs.productionandbiodiversity

! Ecotourismcancompensatefor-  productionloss(ifbiodiversityrequireslowerintensity)and-  lowprofitability(ifhigherintensityisneeded)

Gazersandgrazers

!  Effectsofecotourism–  Damagetolandscape,vegetationor

livestock

–  Facilitationofinvasionofnon-native/undesiredanimalandplantspeciesanddiseases

–  Interactionsbetweenvisitorsandlivestock/wildlife

Andtrail-blazers