My Exam III Study guide

Range condition - Excellent

76 - 100%

Consumption rate - light

< 15%

Timing is relative to __________ phase.

Growth

Slope - Sheep/Goat (> 45%)

Utilization sharply reduced

Forage production - stocking rate

- +/- 20 pounds/ acre - measuring/ testing plots - total available forage

Animal Unit (AU)

- 1000 pounds of animal - consumes ~ 20 pounds of forage a day - 600 pounds a month - 7300 pounds a year

Grazing intensity evaluation - moderate

- 50% of good/ fair plants - most accessible areas are somewhat used - little evidence of animal trailing

Allogenic retrogression

- Changes due to forces outside the plant community - Management, fire, wildlife density

Stocking Rate

- Primary factor related to vegetation quality, livestock/ wildlife condition, and economic returns - MOST IMPORTANT - amount of land allocated to each animal unit (AU) for the grazeable period of the year

Grazing intensity evaluation - light

- choice plants - no poor plants - appears undisturbed

Grazing intensity evaluation - heavy use

- clipped or mowed - > 50% of fair/ poor plants - significant animal trailing

Heavy Grazing

- decrease in photosynthesis - decrease in CHO storage - decrease in root growth - decrease in the ability to compete - decrease in mulch accumulation - decrease in water infiltration - INCREASE in soil erosion

What are utilization estimates and surveys used for?

- does actual match proper - estimates are made during the GRAZING PERIOD to adjust stocking rate

What should you consider when thinking about forage use?

- forage is a single year commodity - you shouldn't utilize 100% of your forage

Variable in Stocking rates

- forage production - range utilization by distance to water

Types of Trends

- improving - stable - degrading

Factors that influence or induce SECONDARY succession

- increase in undesirable plants - heavy overgrazing - seed spread by livestock - improved fire control methods - rodent and rabbit activity - climate shift - atmospheric change

Light/ Moderate Grazing

- increase photosynthesis - DECREASE shading - DECREASE transpiration - DECREASE excess mulch - stimulates growth

Factors to consider when calculating stocking rate

- land area - annual forage - forage demand - distance to water - slope - harvest coefficient

Decomposers

- microorganisms, ants, termites, and nematodes that prevent excess accumulation of organic matter (waste)

Secondary succession

- occurs after some type of disturbance - vegetational change - faster than primary succession and more predictable

Common causes of retrogression

- overgrazing, logging, fire, and cultivation

Retrogression

- plant change AWAY from climax

What have an effect on capacity?

- precipitation - wildlife population - invasive plants - grazing methods

Biotic components

- primary producers - consumers - decomposers - manipulators

Key plant monitoring

- proven highly useful in evaluating grazing effects on range vegetation - a forage species that serves as an indicator for ALL forages is used

What are intensity surveys used for?

- severity of defoliation - correctness of stocking rate - livestock distribution patterns - wildlife food and cover - soil cover

Key plants

- should be abundant - productive - palatable

Abiotic components

- soil and climate

What is sustainable and unsustainable range land based on?

- soil protection form erosion - unsustainable = accelerated erosion and degraded plant communities

Unintended consumption

- trampling - weathering - unmeasured wildlife

Strategies for balancing stocking rates

- use conservative stocking - high rate = good year capacity - constant AVERAGE stocking

Animal Unit Month

- used in periodic grazing - 600 pounds of forage in one month

Range condition - Poor

0 - 25%

Range utilization by distance to water - Cattle (0 - 1 mile)

0% decrease

Slope - Cattle (0 - 10%)

0% decrease

Slope - Sheep/Goat (0 - 45%)

0% decrease

Range utilization by distance to water - Cattle (> 2 miles)

100% decrease

Slope - Cattle (> 60%)

100% decrease (ungrazable)

Stubble height - Talkgrasses

12 - 14" 40 - 50% used

Water turnover rate - camel

185 cc/kg/day

Water turnover rate - goat

188 cc/kg/day - goats are well adapted to limited water and short term shortages

Water turnover rate - sheep

197 cc/kg/day

Stubble height - Shortgrasses

2 - 3". 30 - 40% used

Safe amount of forage to use - Arid climate

25 - 40% (less than 10" rain)

Range condition - Fair

26 - 50%

What percentage of the stem and leaf can be left for grazing animals?

30 - 50%

Slope - Cattle (11 - 30%)

30% decrease

Light Grazing - average percent of forage used

32%

Water turnover rate - cattle

347 cc/kg/day

Safe amount of forage to use - Semiarid climate

35 - 45% (~ 10 - 25" rain)

Harvest coefficient - Arid and semiarid climate

35%

What percentage of native grasses and Bermuda grasses are dry matter?

35%

Moderate Grazing - average percent of forage used

43%

Safe amount of forage to use - Humid climate

45 - 60% (25+" rain)

How much of the annual leaf and stem should be left for a metabolic resource for the plant?

50 - 70%

Harvest coefficient - Humid climate

50%

Range utilization by distance to water - Cattle (1 - 2 miles)

50% decrease

Range condition - Good

51 - 75%

Heavy Grazing - average percent of forage used

57%

Stubble height - Midgrasess

6 - 8" 40 - 50% used

Slope - Cattle (31 - 60%)

60% decrease

Grazing intensity - Light

Allows palatable species to maximize herbage producing capacity

Range Ecology

Applied ecology dealing with the manipulation of organisms and sometimes the environment

Rule of thumb for forage demand and use - Horses/ donkeys

Consume ~ 3% of their body weight in DM Per day (50% higher than ruminants)

Intensity

Cumulative effects of grazing animals over a defined period

Primary succession

Evolution from bare ground or open water

What is the most critical period in a plant's growth cycle?

Floral initiation for seed set

Plant health withstand ______ intensity during _________.

Greater, dormancy

During a drought, AU capacity will be ________ and result in ________ post drought recovery.

Higher, faster

Manipulators

Humans - positive and negative impacts

Decrease AU might decrease ________ for a given year.

Income

What is the goal of Range Ecology

Increasing the output that is useable to man

Consumers

Large/ small animals and insects - regulate standing crop

What is the main goal for calculating stocking rate and harvest coefficients?

Long term sustainability - long term average is better

Grazing/ carrying capacity

Max long term stocking rate without causing damage

What part of the United States has the highest net return with heavy grazing (assume normal rainfall)

North Central Texas (rolling plains)

"Ice cream" plants

Palatable but scarce

Range Condition

Percent of climax vegetation remaining - the state of health of the range

Utilization

Percentage of current year's herbage production consumed and destroyed by herbivores

As grazing intensity increases _____________ decreases.

Performance per animal unit

Primary producers

Plants converting solar energy to chemical energy

Key area monitoring

Portion of range that, because of its location, and grazing or browsing value, serves as an indicative sample of range conditions

Residue

Protects plants in dormant periods - crown and soil

Soil

Provides plants with anchorage and serves as a nutrient and water reservoir. Soil also provides a habitat for microorganisms and soil animals.

Rule of thumb for forage demand and use - Cattle

Ruminants consume 2% of their body weight in DM per day (1.5 - 3.0%)

What animals do NOT require water daily?

Sheep and goats - this means that they can use areas that are > than 2 miles away from a water source

General rule for grazing - short grass

Start when grass is 2"

General rule for grazing - mid grass

Start when grass is 4"

What is the preferred way to designate Range land?

Sustainable vs Unsustainable

Climatic factors

Temperature and precipitation - directly impact plant type and performance

Climax

The final or stable BIOTIC community in a succession series - equilibrium Best plant community

Harvest coefficient

The percentage of total forage production alloyed to animals for consumption and General rule: take half leave half

Drier climates are more sensitive to __________.

Times grazing

Grazing resistant plants are less palatable and productive than grazing plants (T/F)

True

As available stocking

Vary stocking to meet forage supply

When is the safest time to initiate grazing?

When plant growth cycle is at a point not to result in permanent damage and soil is dry enough to prevent deep tracks

Grazing intensity - Moderate

Will allow palatable forage species to maintain themselves BUT does NOT permit them to improve production ability - cannot spread

Grazing intensity - Heavy

Will not NOT permit desirable forage species to maintain themselves

Autogenic retrogression

changes due to forces from within the plant community - excess plant growth - function of dynamic cycle in climax state