Rangeland Management. Rangeland GEOG/ENVS 657 SPRING 2007 B.A.HOLZMAN NATURAL RESOURE MANAGEMENT GEOG/ENVS 657. Dr. B.A. Holzman

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1 Rangeland Management Summary GEOG/ENVS 657 Dr. B.A. Holzman Rangeland Land supporting native vegetation that is either grazed or has the potential to be grazed and managed as a natural ecosystem: includes grassland, grazeable forest, shrubland, pastureland Nearly 80% of the lands of the West are classified as rangelands whereas only 7% of some areas near the East Coast are classified as rangelands. 1

2 Rangeland Management Management or manipulation of rangeland components to obtain optimum combination of goods and services for society on a sustained basis Rangeland Management Two components 1) protecting and enhancing soil and vegetation complex. 2) maintaining/improving output of consumable range products (meat, fiber, wood, water, and wildlife) Herbivory: The consumption of plants by animals. Grazing: The consumption of standing forage (edible grasses and forbs) by livestock or wildlife. Browsing: Consumption of edible leavers and twigs from woody plants (trees and shrubs) by large hoofed animals. 2

3 Concepts of RM Rangeland is renewable Energy from the sun fuels the system Rangelands supply humans with food and fiber (cost less than pasture) Productivity (amount of available forage) is determined by characteristics of soil topography, and climate Variety of products can be produced (food, fiber, wildlife, minerals, and timber) and harvested from rangelands What goods and services are derived from rangelands? a habitat for animal species; a habitat for native plant species; a source of high quality water, clean air and open spaces; a setting for recreation the foundation for low-input, fully renewable food and fiber production History of Rangelands and US Native grazing : Livestock introduced s Gold rush, Cattle drives: Animals in California Homestead Acts 1862, 1909,1916 Tragedy of the Commons 3

4 Grazing laws/range Management Severe drought/scs ( 35) 1934 Taylor Grazing Act 1960 MUSY/ 1976 FLPMA 1970s The Sagebrush Rebellion 1990 The Wise Use Movement Range Management techniques Can vary Animal numbers Animal distribution Season of Use Kinds/ Class of Animals Intensity of use (long duration, short duration, cycling, etc.) Rangeland Measurements AUM Weight/biomass Area/Cover Density/Frequency 4

5 Weight/biomass How much food is there? Grazing capacity Clipped plot Grazing capacity per unit area (dry weight per unit area X species use factor) for each plant species animal unit requirement Animal Units/AUM AU= 1 cow or cow with suckling calf (1000lb) AUM : 26 lbs dry matter (DM) per day, plus trampling and waste 25%, results in an estimate of about 1000 pounds of dry matter (DM) equals one AU each month Animal Units (AUs) Mule deer 0.2 Ewe and lamb White-tail deer Full grown horse

6 Problem Set I want to manage my land primarily for deer. I have 1200 acres of mixed grassland that produces 2000 lbs/ac of usable forage, and 3800 acres of brush that produces 100 lbs/ac of usable forage 1) How many total AUMs are available? 2) How many deer (.2 AU) could I support yearlong? 1200 ac X 2000 lbs/ac = 2,400,000lbs 2,400,000 X AUMs/1000lbs = 2400AUMs 3800 ac X 100lbs/ac =380,000lbs * AUMs/1000lbs = 380AUMs 2400 AUMs AUMs = 2780AUMs 2780 AUMs/12 months = 233 AUs 233 AU X deer/.2au = 1165 deer A disease caused all my deer to die off, so I can t restock with deer for a years. How many cows could I graze during a 5 month grazing season? 6

7 Answer Total AUMs available (from last problem) 2780 AUMs 2780 AUMs/ 5 months= 556 AUs 1 AU=1 cow Number of cows for 5 months = 556 Other considerations Water availability and distribution Type of species being grazed Availability and quality of forage Will supplemental food be necessary? Potential predators Noxious weeds Disease potential Grazing Intensity Heavy Use: clipped or mowed appearance, trail evidence, all areas show use Moderate Use: about ½ of good/fair forage, value plants used, little trailing evident, most of the range shows some use Light Use: choice plants and areas used, no use of poor forage, range lightly disturbed 7

8 Used to evaluate: soil protection, watershed health, rangeland condition and range trend Aerial or canopy cover (% cover by species or types) Basal cover Area/cover Methods: ocular estimation, step point method, line intercept method, point frame Used to determine plant survival, monitor regrowth, look at grazing affects Density: number of individual plants per area Density/Frequency Frequency: quantitative expression of presence/absence of individuals of a species in a population (present in? % of plots or transects) Methods: counts, step point method, line intercept method, point frame 8

9 Growth form Parts of a grass plant Parts of a grass flower Grass Taxonomy 9

10 Grass Taxonomy Avena sp. Bromus spp. Briza sp. Elymus glaucus Leymus triticoides Bromus carinatus Nassella pulchra Grazing on Public Lands??? Issues Advantages/Disadvantages 10

11 Other issues? 11