Managing Grasslands for
Diversity With Grazing
Dan Caudle
Texas and Cajun Prairie Symposium Lafayette, Louisiana September 24, 2016
Resident Research Associate Botanical Research Institute of Texas Fort Worth, Texas dcaudle@brit.org 1
Prairies and Savannas
Products of Historical Natural Disturbance Regimes 2
Plight of Southern Grasslands Prairies and Savannas in peril – disappearing at alarming rate Land use conversion
• Crop production (cotton, rice, sugarcane) • Monocultures (introduced forage species – bermudagrass e.g.) • Development (residential, commercial, industrial)
Encroachment/invasion of non-native species • Chinese tallow tree (Triadica sebifera) • Introduced grasses, forbs, shrubs, vines
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Reflections and Ruminations
“The disappearance of a major natural unit of vegetation from the face of the earth is an event worthy of causing pause and consideration by any nation.
Yet so gradually has the prairie been conquered by the breaking plow, the tractor, and the overcrowded herds of man, that scant attention has been given to the significance of this endless grassland or the course of its destruction.
Civilized society is destroying a masterpiece of nature without recording for posterity that which it has destroyed”
– John Ernest Weaver North American Prairie
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Tallgrass Prairie – Historical Occurrence
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Tallgrass Prairie – Historical Occurrence
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Grassland Ecosystems Products of Historical Natural Disturbance Regimes Evolved with and perpetuated by natural forces Fire Herbivory
Interconnected and codependent Need appropriate amounts of each
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LaSalle 1683 and Iberville 1698-99 9
Presettlement Explorers, trappers, traders, military expeditions, missionaries, and early settlers first entered new frontier Encountered wild landscapes Contrary to popular belief, it was not untouched wilderness Grazed and browsed by vast herds of large herbivores (bison, deer, elk, pronghorn, others) Manipulated by Native Americans for centuries 10
Ecological Drivers + Natural Disturbances Evolution and Maintenance of Grassland Ecosystems
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Ecological Drivers & Disturbances Drivers – Natural ecological processes continual and pervasive
Disturbances – Natural or Anthropogenic ecological events intermittent and episodic elimination or modification of ecological drivers 12
Ecological Drivers & Disturbances Drivers
Disturbances Weather
Climate
Hurricanes Flooding
Fire
Drought
Animal Impacts
Insects
Defoliation Trampling
Disease Modification
of Natural Processes Fire
Animal Impacts 13
Ecosystem Drivers & Disturbances The most negative disturbance in many ecosystems: Elimination or severe restriction of disturbance No disturbance is itself a disturbance of natural processes
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FIRE
Remove old growth Stimulate new growth Control woody sprouts Thin out shrubs and vines Maintain diverse herbaceous plant community
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FIRE
Remove old growth Stimulate new growth Control woody sprouts Thin out shrubs and vines Maintain diverse herbaceous plant community
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Fire and Grazing Historic fire-grazing interaction created shifting mosaics of disturbed and undisturbed areas
The end result: “messy� landscapes
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I MESSY LANDSCAPES “a little bit of chaos is a good thing”
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I MESSY LANDSCAPES even during the heat of summer or winter dormancy
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Species Richness & Biodiversity 
 Species Richness
number of different species in a given area
Biodiversity
measure of relative variability among species kinds, numbers (amounts), and proportions plants, mammals, birds, reptiles, amphibians, invertebrates, etc.
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Heterogeneity Variability in habitats & communities across landscape Architectural structure of the area Inherent
soils, physiographic features, hydrology, etc.
Disturbance driven
species composition functional and structural groups - vegetation dynamics stature of vegetation (height, width, density, foliar cover, canopy) distribution (spacing, gaps, bare ground, etc.) biomass
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Heterogeneity Indicator of ecological status and ecosystem health
Foundation of ecosystem management and conservation 25
What is Ultimate Objective 
 of Grassland Management? Ultimate Objective is to meet the: Physiological needs of the vegetation Nutritional and habitat requirements of the animals Goals and objectives of the landowner or manager
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Management & Restoration of Grasslands Know and Understand:
Soils Plants Animals Treatment Alternatives Management Practices 27
Know The Soils http://websoilsurvey.sc.egov.usda.gov/
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Know The Soils Soils LaA & DaA Clay TeA & FaC Fine Sandy Loam
EdA Sandy Clay Loam
Ecological Sites LaA & DaA Blackland TeA & FaC Loamy Prairie EdA Tight Sandy Loam 29
Know The Plants soha
pavi trd a
paca
paur
anvi
cocy
sonu
ange
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“There is not a sprig of grass that grows that is uninteresting to me” – Thomas Jefferson
Know The Plants
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Know The Plants 
 (Community Dynamics) Reference Plant Community Functional and Structural Groups Other Plant Communities -States/Transitions/Succesional Stages Species Composition (amounts, proportions) Median and Range of Annual Production (Aboveground Biomass) Growth Curves
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Know The Wildlife
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Wildlife Natural variability Excellent wildlife habitat Grassland birds Wading/Wetland birds Bobwhite quail Wild Turkey Deer Furbearers Reptiles/Amphibians Pollinators Invertebrates
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Species of Concern “Endangered species are an indicator of an ecosystem that is in balance. It’s important to manage these sites for endangered species because we feel that the land is far more productive, even from a business standpoint, when the ecological processes and all of the components are in place so ecosystems can function properly.� David Daigle
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Grazing – Good or Bad Decisions made at multiple levels by people and/or animals Landscapes Ecological sites/vegetation communities Patches Preferred grazing areas Individual plants Plant parts 36
Prescribed Grazing Stocking Rate – Most Crucial Decision
Initial stocking rate should be conservative
Nothing will compensate for overstocking
Based on available and consumable forage
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Fire and Grazing
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Patch burning coupled with rotational grazing is designed to rotate the fire and grazing across the landscape or through the management unit over time to create a shifting mosaic of vegetation and habitats
Historic fire-grazing interaction created shifting mosaics of disturbed and undisturbed areas
The end result: “messy” landscapes 39
I MESSY LANDSCAPES “a little bit of chaos is a good thing”
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Chapter 4: Physical Factors: Rock, Soil, Landform, Water, Wind Chapter 5: Fire, Big Animals, and Interactions Bottom-Up, Top Down, Sideways Fire Herbivores Interaction of Fire and Hydrology 41
National Wetlands Research Center
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Points To Ponder 44
Reflections and Ruminations RANGE MANAGEMENT “Nature is an open book for those who When You Work Hard Doing Something You Don’t Like care to read. Each grass covered Its Just A JOB hillside is a page on which is written When You Work Hard Doing Something You Love the history of the past, the conditions of the present,It’s a PASSION and the predictions for the future” – John Ernest Weaver
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Reflections and Ruminations
Those who do not understand nature are destined to deplete it
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Reflections and Ruminations • “The prairie is embedded permanently beneath my skin” - James R.
Page in Wild Prairie: A Photographer’s Personal Journey
• “I must confess I have a weakness for empty places” • – Tony Hillerman in A Museum Etched In Stone • “This land has invested me with its personality”
• – Linda Hasselstrom in Land Circle: Writings Collected From The Land
• “Maybe it’s my contrary nature that makes me love a landscape so despised by others” • – Mary Taylor in Land of Grass and Sky: A Naturalist’s Prairie Journey
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Fire and Grazing Fire with grazing important in establishment, improvement, and maintenance of diverse habitats to support a variety of plants and animals necessary for health of natural plant and animal communities and biodiversity We can’t duplicate historical fire and grazing regimes, but we can mimic them
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Because human activity has removed much of the naturally pyrogenic vegetation and introduced numerous firebreaks such as roads, there is little opportunity for lightning-ignited fires to burn with the frequency or to the extent they did historically. The landscape has been restructured into finer and finer partitions and into fire-protected compartments. implementing artificial disturbances is essential for maintaining the native flora and fauna of grassland 49
prescribed grazing should be used in conjunction with prescribed fire as a management tool wherever practicable and appropriate for the purpose of restoration and maintenance of grassland ecosystems 50
THANKS
Questions ??? Comments!!! 51
Dan Caudle Weatherford, Texas 817-597-0788 dcaudle@brit.org