range 3

Range condition classes:

% of present plant community that is climax for that range site Excellent 76 - 100 Good 51- 75 Fair 26 - 50 Poor 0 - 25

Ecological Sites (site potential approach)

(currently used by NRCS, USFS, BLM). They are based on State and Transition Models of Succession and use a Reference Plant Community (rather than the climax or potential natural vegetation) to assess multiple land use benefits (rather than a grazing- centric interpretation). Ecological sites comprise a land classification system that describes ecological potential and ecosystem dynamics of land areas. They are used to stratify the landscape and organize ecological information for purposes of monitoring, assessment, and management.

Range Site Characteristics:

-- It is the plant community best adapted to that environmental complex. -- It is relatively stable. -- Normal disturbances are inherent development factors (e.g., drought, fire, native animal grazing). -- Plant composition and forage yield vary annually, however, the site is recognizable as a unit.

Classification of Plants Based on Their Response to Grazing Stress CAVEATS

-- Many factors influence the response of individual plant species to grazing stress. -- Few truly universal decreaser, increaser and invader species exist. -- A plant species may be a decreaser on some sites and an increaser or invader on others. -- Plant responses differ with different kinds of livestock. -- Plant responses differ with different seasons of use. -- Invader species may not necessarily have low relative grazing value or grazing preference.

How do we know what climax rangelands look like for an area?

-- Relict sites -- Historical accounts and botanical records -- Ecological and grazing research Initial site descriptions are always subject to revision.

if native range/pastures don't meet needs, supplemental feed must be employed such as

-41% protein cottonseed cake (gossypol limited) 20% range cubes -liquid feeds (urea nitrogen) -silage can meet dry cow protein requirements (corn 7.5-8%, sorghum 5.5-6%)

to set stocking rates:

-estimate forage production -calculate ignition stocking rate -estimate utilization and range condition trend -adjust stocking rates

quality, quantity, and stability are key factors in range vegetation management

-grasses are the quantity component -forbs are the quality component -shrubs are the stability component

energy requirements change drastically through the year and are needed for:

-maintenance -activity -reproduction -milk production -production

maximum gains per unit area under heavy stocking are made at the expense of having

-no forage reserve -lower quality forage -high resource degradation

four key principles to proper range resource management:

-proper stocking rate -proper distribution of grazing use -proper season of grazing -proper kind and class of livestock

good management cures many nutritional problems

-proper stocking rate -proper utilization -proper brush management/burning good condition pastures with good management can generally get by without supplementation

matching nutritional requirements to available forage

-seasonal ranges (mountains/deserts) -timing of production cycles -burn (in spring) for high quality pastures -complementary forages (haygrazer: summer forage / wheat: spring/winter)

nutritional status of range livestock influenced by:

-stocking rate -grazing system -forage species types -animal type -season of use -management practices (burning, fertilization, seeded, pasture, brush control, supplemental feed)

factors affecting stocking rates:

-type and class of livestock -season of use -physiological status of the animal -length of grazing season -yearly variation in forage base

priority of nutrient requirements on rangelands:

-water: quantity and quality -mineral: Mg, Cu, Co, Na, P, Zn, Se; mature plants low in K and P -Vitamines- A, carotene -Protein -Energy- CHO (structural & nonstructural)

Basic 5 steps in natural resource inventory:

1) Map vegetation & other features (streams, fences, water developments) -- assess the resources available -- done with maps and aerial photos. 2) Assess vegetation attributes 3) Assess forage utilization: percentage of current years' herbage production consumed or destroyed by grazing. - end of season to check stocking rates - during season to make adjustments in stocking rates 4) Estimate range condition: excellent, good, fair, poor. 5) Assess trend - direction of change in range condition - upward - downward - stable

Weaknesses in Range Condition Analysis

1) Terms Excellent/Good/Fair/Poor might not be relevant to management objectives. Use of terms such as: climax, high-seral, mid-seral and low-seral may be more appropriate. 2) It is difficult to determine true climax and most rangelands have deteriorated. 3) It does not allow evaluation of rangelands invaded by exotic species. 4) The method is not well suited to forest & wooded rangeland.

Key Factors in Assessing Apparent Trend:

1) Vegetation. - plant vigor - reproductive success (seedling establishment) - degree of present utilization - evidence of past utilization 2) Soil. - litter accumulation - soil trampling - presence and condition of gullies - evidence of rill and sheet erosion (plant pedestals) - rodent and insect activity - soil crusting

stocking rate strategies fall into 4 categories:

1) stock conservatively: range is never overstocked, even in severe droughts, but can under-use forage 2) stock at a high rate, commensurate with forage available in good years: results in destructive grazing in most years, poor livestock performance, high feed needs, and unstable livestock numbers 3) stock at the average forage supply: allows stable livestock numbers if low utilization in good years allow recovery in bad years 4) vary stocking rate to meet forage supplies for the year: difficult to achieve as it requires heavy culling during drought, stocking-up in good years

Range sites differ based on differences in:

1. kind of species. 2. proportion of species. 3. total annual yield. When these differences are great enough to require unique site management (e.g., stocking rate) they may be considered distinct range sites.

harvest efficiency is roughly equal to ___ utilization

1/2

the daily requirement for a dry cow (maintenance and grazing activity) is about ___ megacalories

16.7

twenty days after a calf is born, it increases 50% to about ___ megacalories

24

historically an AU has been considered

26lb/day dry matter consumption this value is still used in many cases

required for a cow and a 7 month calf is ___ megacalories, ___% more than a dry cow

33 100%

well cured range grass in much of Texas will average ___ digestible energy

50-60%

dry, pregnant mature cows have a total crude protein requirement of about ___

6% (concentration in ration dry)

a cow nursing a calf (3-4 months post-parturition) requires about ___ protein

9.2% good managers try to match the physiological stage of the cow with the nutritional output of forage by regulating breeding time

Permanence (stability) of Range Sites:

Alteration of existing vegetation does not alter range sites (which are based on site potential). Alterations occur from: -- Grazing -- Drought -- Fire -- Short-term tillage These effects do not normally alter site potential, but, any of these factors (or combination of factors) that are severe enough to cause soil loss can alter site potential.

which are more digestible, C3 or C4?

C3= more digestible -more mesophyll cells -less densely packed cells (easier microbial decomposition) C4= less digestible -less mesophyll -more densely packed cells -bundle sheaths (vascular bundles)

what is ESD used for?

ESDs and associated information are used primarily to stratify the landscape for monitoring and assessment, interpretation of resource hazards and opportunities, and to prioritize and select management actions. ESDs are developed and housed by the NRCS and its partners, and used by the U. S. Bureau of Land Management (BLM), U.S. Forest Service, The Nature Conservancy, and many other entities. A recent memorandum of understanding between the NRCS, BLM, and U.S. Forest Service establishes ESD development as an interagency priority and will establish national standards and protocols for ESD development.

Range nutrition is viewed from the standpoint of:

Forage -amount -availability -acceptability/palatability -nutrient content/concentration -nutrient availability/digestibility animals -grazing behavior/animal distribution -forage preferences -nutrient requirements -level of intake/consumption -digestive morphology (large ruminants vs large cecal fermenters vs small ruminants)

potassium and nutrition

K is readily lost from plants by leaching -dormant and mature plants may lack -hay can capture K in place -molasses based liquid feeds with K -K is stored about 10 days in body, so it must be available constantly

Range Site Names:

Names are based on permanent physical site features -- Soils -- Climate -- Topography -- Combination of these Example range sites: blackland; loamy bottomland; igneous hill and mountain, gravely.

phosphorus and nutrition

Phosphorus (P) is the most likely nutrient to be deficient on western ranges it is easily supplemented as phosphoric acid in liquid feed, as bone meal and as di-calcium phosphate P is not stored in body

range site description and vegetation

Range sites are closely correlated with soil types (series) and plant associations. Vegetation is the ultimate expression of integrated environmental site factors.

Range Condition:

The historic approach - it was defined as the present state of the plant community on a range site in relation to the potential natural plant community (climax) for that site. An ecological rating of the plant community.

What are alternative approaches to Range Condition Analysis?

The site potential approach -- a method designed to relate current site production to its potential for a specific use (most desired plant community). Thus, a site might be rated excellent for livestock use, but only fair for deer habitat.

Range Site (older terminology)

a distinctive kind of rangeland, which in the absence of abnormal disturbance & physical site deterioration, has the potential to support a native plant community typified by an association of species different from that of other sites. range condition concept is based on methods described by E.J. Dyksterhuis (1949, 1958) and are considered an ecological approach.

stocking rates, thus forage consumption, should be adjusted so that

a minimum level of residue is left to maintain soil condition, plant vigor, animal diet quality, and wildlife habitat this can be achieved by limiting utilization of key species

protein and nutrition

almost all protein requirements are met on rangelands when animals eat enough forage to supply they energy requirements insufficient protein occurs on mature and weathered pastures, low grade hays w/ insufficient forage protein levels are highest in actively growing plants leaves of grasses, forbs, and shrubs are higher in protein than stems leaves of forbs and shrubs are generally higher in protein than grass leaves at comparable stages of growth forbs and shrubs can be significant in meeting protein requirements through the grazing cycle

Monitoring

an evaluation process, usually conducted to determine the response of a site to some management program. Occurs at intervals over a long time period -- like an inventory repeated through time.

decreased forage availability reduces:

animal selectivity, resulting in a lower quality diet and greater energy expenditure on foraging activity

AUs can be expressed as an

animal unit day (AUD)- the forage required by an animal unit for one day (20lbs) animal unit month (AUM)- the forage required for one month (600 lbs) animal unit year (AUY) -the forage required for one year (7300 lbs)

Inventory

assessment and recording of resources or physical features at one point in time. data baseline to aid in management planning

utilization is usually determined when?

at the end of the grazing period to make stocking rate adjustments

palatability

attractiveness of a plant to animals as forage (plant quality)

supplementation is used to ____, not to ____

augment shortages in forage not to replace forage

____ plant types tend to store "food" in stems (rather than crowns and roots); therefore, the grazable plant parts do not decrease greatly in protein, carotene, and CHO during drought or winter

browse plants

for the arid southwest, an economical and ecologically sound stocking rate strategy is

constant stocking at 90% of the average proper stocking rate, with some reductions during prolonged severe drought this gives: -high economic stability to the ranching operation -relatively the same income as flexible stocking -moderate to low risk of range damage -moderate to low risk of financial crisis during droughts

flexible stocking rate practices would be ideal, but there are many disadvantages to this strategy:

difficult to estimate forage yield cost of buying extra animals in good years could introduce parasites & disease with new animals people are reluctant to cull heavily, even in drought

Invaders

encroach onto a site from adjacent sites in later stages of range deterioration. (Not part of the climax community or introduced exotics).

whereas grasses are low in protein during parts of the year they are usually excellent sources of ___ throughout the year

energy thisis due to their high cellulose content in cell walls

NRCS range site technical guides give

estimates of initial stocking rates based on range condition these are conservative estimates used when other information is not available

___ plant types generally don't cure well and are poor forage during drought and winter; during their growing seasons, however, they are often the most nutritious forage component available

forbs

range ungulates are divided into 3 major groups based on foraging habits:

grazers: consume grass dominated diets (cattle, elk, bighorn sheep, mountain goats, musk oxen, bison) browsers: consume primarily forbs and shrubs (moose, pronghorn antelope, mule deer, domestic goats, white-tailed deer); they avoid dry, mature grass intermediate feeders: consume nearly equal amounts of grasses, forbs and shrubs (domestic sheep, burros, caribou)

how is utilization determined?

hard to estimate but there are three basic procedures: -estimated based on plant height -based on weight of plants (weight before graze - weight after graze = weight utilized) -grazed plant methods

death losses and supplemental feed costs are higher for ___ grazing compared with ___ grazing

heavy moderate

Decreasers

highly palatable plants that decline in abundance with grazing pressure -- those plants most preferred by grazers. (Members of the climax community).

minerals and nutrition

if a mineral is deficient, animals can't make efficient use of protein and energy in the diets mineral blocks can be used for "insurance" with trace minerals (Cu, Zn, Mg) which are often marginally adequate, and supplemented for a low cost

key area

indicator area portion of the range which, because of its location, grazing or browsing value, and/or use serves as an indicator of range conditions, trend or degree of seasonal use guides general management of the entire area for which it is a part

key species

indicator species a plant whose use indicates the degree of use for associated species- often decreasers

animal unit (AU)

is defined as one mature cow (1000lb live wt), or its equivalent, based on an average daily forage consumption of 2% body wight (20lbs) dry matter

Range Animal Nutrition differs from classical animal nutrition because

it involves land management -nutritional requirements are hard to define -higher energy levels required for: -traveling-> foraging -environmental stresses

___ plant types normally have the highest protein content

legumes

Increasers

less palatable plants within the community that increase in relative dominance with continued grazing. (Also members of the climax community).

low rate of passage=

less selective diet, lower quality forage (large ruminants: cattle, bison / large fore-gut fermenters: elephant

general rules to grazing capacity

maximum productivity occurs at about 50% of the maximum number of animals that may be carried gross economic returns are generally maximized with heavy grazing but the zone of maximum net profit occurs at a stocking rate lower than that for maximum production per acre, ie. at moderate stocking rates productivity per AU declines as stocking rate increases but productivity per unit area increases- up to a point: this is why heavy grazing is tempting in the short term prolonged heavy grazing is detrimental to range resources

Type I Invaders

may eventually decrease with forced utilization.

Type I Increasers

moderately palatable plants which serve as secondary forage species.

high rate of passage=

more selective, better quality diet (small ruminants: deer, sheep / hind-gut fermenter:, rabbits, horses)

selection of forage based on:

nutrient content (digestible protein) taste moisture content mineral content essential oils (select against) fiber and lignin content (select against) texture

vitamins and nutrition

only vitamins A and D appear to be of importance to range animals Vitamin D is obtained from sunlight, rarely deficient Vitamin A is important for growth in the young, maintenance of healthy membranes, and to prevent night blindness -it is formed from carotene -carotene is abundant in fresh, green feed -may be deficient in animals on dry feed -stored in liver fat -carotene is high in new growth, but is rapidly lost in dormant grasses and forbs; relatively stable in shrubs

factors affecting utilization:

palatability preference

utilization must be estimated to determine what?

proper range use

water and nutrition

quantity and quality of water of immediate importance to livestock needs: cattle > sheep = goats if water levels inadequate, animals cannot make efficient use of other nutrients

Ecological site descriptions (ESDs)

reports that describe the a) biophysical properties of ecological sites b) vegetation and surface soil properties of reference conditions that represent either i) pre-European vegetation and historical range of variation (in the United States) or ii) proper functioning condition or potential natural vegetation c) state-and-transition model graphics and text d) a description of ecosystem services provided by the ecological site and other interpretations. Ecological sites are connected to spatial data via soil map units of the National Cooperative Soil Survey. Classification of land areas to ecological sites can be easily visualized via Web Soil Survey of the USDA Natural Resources Conservation Service.

most ranges will meet energy requirements throughout the maintenance and production cycle if

sufficient quantity available (often not available on poor & fair condition range)

utilization is based on what premise?

that no range of any significant size will be utilized uniformly

animal unit equivalent (exchange ratio)

the approximate amount of forage required by a given kind and class of animal

Apparent Trend

the direction of change in range condition, observed or measured, over time. -- Improper management practices may not be readily detected based on species composition and range condition analysis. -- Present range condition does not infer that current management practices are right or wrong. -- Poor condition range might be in upward trend. -- Excellent condition range may be in a downward trend.

digestible energy is

the energy forage supplies measured as total digestible nutrients (TDN)

carrying or grazing capacity refers to

the maximum stocking rate possible year after year without inducing damage to vegetation or related resources -varies annually, seasonally, with kind of stock, past grazing use, range condition, familiarity of stock with plants -based on biomass estimates -basis for setting stocking rates

stocking density

the number of livestock grazing a unit of land

stocking rate

the number of livestock grazing or utilizing a unit of land for a specified period of time expressed as AU/section (in the Southwest) or acres/AUM (in the Intermountain region)

harvest efficiency

the percent of forage that may be consumed by grazing (the amount of forage that makes it into the gut of the animal)

range utilization

the proportion of current year's forage production that is consumed or destroyed by grazing animals throughout a grazing period percent of plant move ground grazed (herbs) or percent current year's growth browsed (shrubs)

many ranges that are primarily warm season grass ranges (or monocultures like farm pastures of either warm or cools season species) fail to meet what?

the protein needs for production for significant periods of the year

preference

the selection of plants by animals (an animal characteristic)

rate of passage through animal is related to

type of forage (digestibility) animal gut size

Type II Increasers

unpalatable or unreachable plants that increase in abundance with excessive use.

Type II Invaders

unpalatable or unreachable, they continue to increase through the final stages of range deterioration.

stocking rate varies annually with

varying forage production

plant indicators that grazing is too heavy include:

vegetation dominated by a few species palatable shrubs hedged and w/ dead branch stubs presence of a high percentage of annual plants, particularly forbs

inventories may include

vegetation types, soil types, streams, water developments, fences, topographic features, etc.

selection of correct stocking rate is the most important of all grazing management decisions from the standpoint of

vegetation, livestock, wildlife, and economic return