Rangeland Management

Start Studying!

Terms

undefined, object

copy deck

Photosynthesis equation: Water + CO2 + energy = oxygen + C6H1206
How is chemical energy stored in plants?: - soluble CHOs for immediate energy - digestible (sucrose and starch)
- structural CHOs - cannot be used for energy - cellulose
what is the most abundance carbohydrate in the world?: -cellulose
principle form in which soluble CHOs are transported and stored: -sucrose and starch
respiration equation: C6H1206 + O2 = CO2 + H20 + energy
what is energy used for in plants?: -assimilation
-maintenance
-growth
assimilation: -synthesis of compounds (e.g. cellulose, etc.)
-active transport
-mineral uptake
energy used for maintenance in plants: -respiration of living material
-respiration during dormancy
vegetative growth: -regrowth after dormancy
-bud formation
-regrowth after disturbance
reproductive growth: -elevation of apical meristem
-apical dominance
-flower and seed formation
factors affecting photosynthesis and respiration: -water
-leaf area
-sunlight
-temperature
-carbon dioxide
-soil nutrients
how does grazing alter plant physiological activities?: -change leaf area
-change soil nutrient availability
-removal of meristematic tissue
-compensatory photosynthesis
compensatory photosynthesis: -after grazing, photosynthetic rate increases (15-50%) in some plants
factors of plant growth considered in planning range activities: -dormant period is least damaging
-period of growth initiation is intermediate relative to negative effects of defoliation
-most critical period for foliage removal is from floral initiation through seed development
how are range activities harmful to plants during the dormant period?: -soil compaction
-damage to meristems
effects of range activities in spring intermediate due to...: -low energy demands
-moitsure and nutrients largely available
-lots of time to recover
-meristems not accessible
floral initiation through seed development: -high energy demands for reproductive parts and daily maintenance
-limited available nutrients and water
three kinda os meristems: -apical (top of plant, flower, or seed)
-axillary (nodes from which new leaves grow0
-intercallary (base of petioles and leaves, internodes)
apical dominance: -apical meristem releases hormones to keep axillary meristems in dormant state
-when apical meristem removed: -axillary buds begin to make a new tiller or leader
-axillary buds change into apical buds, produce flowers and fruit
after defoliation: -growth from axillary buds
-expansion of intercallary meristems
growth in dicots (forbs and woodies): first - new leaves
second - new stems
----expansion from base to tip
growth in grasses: -expansion from tip to base
--first - intercallary meristems
--second - new leaves
--third - new stem/tillers
apical meristem stays at base until flowering, then expansion of internodes causes: -bolting
positive effects of grazing: -compensatory growth
-tillering
-nutrient cycling
-change sunlight access
-remove respiratory materail (save water)
-seed dispersal
-increase in diversity
-reduction of fuel for fire
-reduce mulch
negative effects of grazing: -removal of photosynthetic material
-removal of meristems and root crown
-removal of seeds
-transport disease
-ground compaction
-soil compaction and erosion
-spread of weeds
-reduce mulch
grazing vs. fire: -selective, leaves remnants
-easy to control
-occurs year-round
-slow rate
-changes communities
grazing avoidance mechanisms: -thorns, prickles, spines
-growth form (sodgrass vs. bunchgrass, or prostrate)
-plant size
-location of meristems
-live:dead ratio of culms or shoots
leaf replacement potential: -rate at which a plant reestablishes leaves
CHOs needed in plant for...: -reestablishing photosynthetic material
-seed production
-root growth
most energy for regrowth comes from...: -current photosynthesis
-NOT stored reserves
three major factors determining nutritive value of plants: -cell structure (cell wall: cell contents)
-degree of lignification
-anti-quality agents
NDF: -neutral detergent fiber
-in cell walls
why are fruits, seeds, and flowers generally more nutritious?: -higher levels of cell contents (solubles)
-seeds also contain significant levels of fat
why are leaves more nutritious than stems?: -lower cell wall: cell content ratio
-more soluble energy and nutrients
in shrubs, current season growth more nutritious than old growth. why?: -CHOs stored in stems
-old stems not as efficient or metabolically active, and have more lignin that gradually turns to wood
why does nutritive value decrease as a plant matures?: -reduced cell contents
-increased lignification and structural CHOs
-decrease in ratio of leaves to stems
-leaching of nutrients by rain in dormancy
browse: -portion of shrubs used for forage
-generally includes leaves and current season's twigs
nutrition during growing and dormant season: -forbs>grasses>shrubs = growing season
-browse important for nutrients
warm season (c4) plants less nutritious than cool season (c3) plants because...: -more schlerenchyma, epidermis, vascular tissue
-cell walls more lignified
effects of high temperature on plants: -decrease water-soluble CHOs and protein levels
-lignification and maturation occur more quickly
moisture stress: -moderate moisture stress increases nutritive value by delaying maturation
-severe moisture stress hastens translocation of nutrients to roots and senescence (dormancy)
fertile soils may: -delay maturity and increase leaf:stem ratios
high levels of soil nitrogen: -increase protein content of plants
factors influencing grazing tolerance: -intensity
-frequency
-time (season)
-competition from neighboring plants
cecal fermenters or ruminants can eat lower quality food?: -cecal fermenters
-greater rate of passage
-can eat more
fermentation: -microbes break down cellulose
-release volatile fatty acids as byproduct
-VFAs absorbed, trnaported to liver
-converted to useable energy - glucose, acetyl coA, oxyacetyl acid, fat
ruminants - examples: -cows, sheep, deer, bison, elk, pronghorn
cecal fementers - examples: -horses, rabbits, some rodents
protein for ruminants vs. cecal fermenters: -rumen is BEFORE small intestine (cecum after SI) s microbes can be digested for protein
on yearly basis, what requires greatest amount of energy by the animal?: -maintenance = basal metabolism + minimum movement + foraging
four greatest energy requirements in animals: -maintenance
-reproduction
-lactation
-growth
energy percentage comparisons: standing vs. sitting, range vs. stable-fed: -15% more energy required for standing than sitting
-40-46% more energy for range animals than stall=fed
grazers and roughage feeders: -eat mostly grass, isn't as nutritious as forbs but more abundant
-cattle, musk oxen, bison
intermediate feeders: -flexible in diet habits
-may choose all grass when it is young, then switch to forbs and shrubs later in season
-moose, sheep, goats, elk
concentrate selectors: -all monogastrics - cannot digest cellulose, must choose high quality diet
-deer, giraffe, rabbit
-special harvesting skills like small nose/mouth
small or large - which must subsist on higher quality diets?: -smaller animals
stocking conservatively: -ensures supply and allows selection
-reduces energy requirements for grazing
manipulating vegetation to meet animal needs: -plant introduced pastures to provide abundance high quality forage during particular season
-manage for palatable shrubs
-manage for plant diversity
how do grazing animals cope with periods of low quality forage?: -build up fat when forage quqliaty is high
-lower BMR
-nitrogen recycling
-soil ingestion
-supplementation
why is energy rarely econmical to supplement?: -use of range vegetation generally decreases
major operations expense confronting range livestock industry: -supplementation
high quality energy: -grains
-impactical except under drought or heavy snow
-young animals can be permanently stunted if undernutrition
low quality energy: -hay or straw
-supplemented when animals cannot meet daily dry matter requirements (winters, droght)
-energy source - cellulose
high protein feeds: -alfalfa, cottonseed meal, soybean meal
-use of range may actually increase with N supplementation
non-protein nitrogen: -urea and biuret
-lower cost than true protein
-made into protein by rumen microbes
-can be used to meet 1/3 total protein requirements
types of toxins: -cyanide compounds
-alkaloids
-fungal endophytes
-nitrate
-tannins and phenolics
-terpenes
what is range management?: -the use and stewardship of rangeland resources to meet goals and desires of humans
7 concepts of rangeland management: -rangelands are renewable resources
-rangelands are managed by extensive and ecological principles
-produce variety of products for multiple use
-must be managed to maintain soil and water quality and health
-chance through succession and disturbance
-only constant is change
-many important public concerns across multiple ownerships
what is the basis of rangeland management?`: -monitoring
most important elements of monitoring: -committment to monitor
-interpretation of data
-making management changes if needed

Start Studying!

Deck Info

Number of cards 71