Rangelands
Conceptual model Source: Knight, 1994
What are rangelands?
Task (3 minute each) Why are rangelands important?
Why are rangelands important? Livestock Production Forage Wildlife Habitat Recreation Water Native Plants Open Space Energy Minerals Source: Karen Launchbaugh
Rangeland management Multiple Use Source: Karen Launghbaugh
Terminology Difference between a tree and shrub?
Terminology (cont.) Source: Krasny et al., 2003
Invasives Source: http://www.weeds.slco.org/html/weedinfo/id/leafyspurge1.html
Task (5 minute each) How do you think earthworms (introduced from Europe) could have changed ecosystems? Source: http://www.backyardnature.net/earthwrm.htm
Weed/Invasive Control Approaches
Grazing Source: http://www.blm.gov/id/st/en/prog/grazing.html
Task (3 minute each) What factors affect nutritive value of plants?
The 3 major factors determining nutritive value in plants
Plant adaptations - Grazing
Task (3 minute each) Examples of how plants avoid and tolerate grazing?
Plant adaptations - Grazing
Secondary compounds Chemical defenses against pathogens and herbivores are most strongly developed in species adapted to low-resource environments such as infertile soils and drought Why?
Morphological adaptations Source: Karen Launchbaugh and www.usu.edu/weeds http://www.wildmanstevebrill.com/plants.folder/longleafplantain.html http://www.cals.uidaho.edu/weeds/fra/yellowstarthistle.html
Plant adaptations - Grazing
Morphological adaptations Growing points the more, the better
Comparative Nutritive Value of Grasses, Forbs, and Shrubs Source: Karen Launghbaugh. Graph adapted from Parker, 1969.
Effect of grazing on plant communities Source: Rangelands An Introduction to Wild Open Spaces. Roselle et al., 2011
Effect of grazing on plant communities (cont.) Preferred forage
Effect of grazing on plant communities (cont.) Cattle Sheep
Natural landscape Source: http://www.ars.usda.gov/is/pr/2004/040811.2.htm?pf=1
Wildlife and livestock interaction Source: Star-News Increased patchiness Source: http://prairieecologist.com/page/2/
Vegetarian Solution? Shorter food chain/web = less loss of energy Vegetarianism results in a decrease of human position on food chain. Is vegetarianism is the best way to feed a large population? Will this solve the world food problem?
Two Good Reasons 1) Cellulose most abundant, naturally occurring organic molecule on earth Humans can t digest cellulose, Ruminants & Hind-gut fermentors can. We need cows, sheep, goats, horses, llamas, alpacas, etc. to digest cellulose for us. 2) Only about 10% of the earth land surface can be farmed. The rest is too rocky, too cold, or too dry. We need animals to harvest these land for us.
Allelopathy Source: http://www.sustland.umn.edu/implement/trees_turf.html
Fire Adaptation Suppression Benefit Source: http://www.uidaho.edu/projectfinder/projectprofiles/sagebrushsteppeandfireinlavalakeranch and http://www.blm.gov/id/st/en/res/environmental_education/wildland_fire_education0.html and Mike Pellant
Impact on Invasives (e.g., Cheatgrass) on wildfire cycle Source: Mike Pellant
Fragmentation Source: http://boiseguardian.com/2007/06/06/boise-promotes-urban-sprawl-movement and www.boisedailyphoto.com
Rangelands weather and climate Robert Whittaker s classification of biomes, based on annual precipitation, temperature
General adaptation to drought conditions Drought avoidance Drought deciduous Thick roots Shallow and deep rooting system Increasing root to shoot ratio Stomata are sunken below the leaf surface Thick cuticle layer Vessel instead of tracheids in the xylem Changes in leaf angle
Photorespiration Reaction catalyzed by Ribulose-1,5-bisphospate carboxylase/oxygenase (RubisCO)
C 4 Plants Leaf Surface (Epidermis) C3 and C4 Mesophyll cells Leaf Cross-section Epidermis Catalyzed by Phosphoenylpyruvate carboxylase Mesophyll cells Bundle sheath cells Oxygen concentration decreases only C4 Mesophyll cells Epidermis Bundle sheath cells Catalyzed by RubisCO C3 and C4 Source: Raven et al., 1999
C 4 Plants No rubisco Spatially separated O 2 Concentration decreases Source: http://users.rcn.com/jkimball.ma.ultranet/biologypages/c/c4plants.html
Task (15 minutes/3 groups) Explain C4 photosynthesis Jennifer Peterson
Measuring plant water status Water potential
Should I close or should I open? Source: Raven et al. 2000 and Gurevitch et al., 2002
Task (1 minute each) Most important invention in the last hundred years? Source: wickedreport.com
Fertilizer Hydrogen feeder stock 5000 C Pressure (200 bars)
Source:Phillips et al., 2008 Source: http://www.biology.lsu.edu Importance of N
Source: http://www.biology.lsu.edu
Bacteria Fixation NΞN Rhizobia Source: http://en.wikipedia.org/wiki/file:medicago_italica_root_nodules_2.jpg
Microphytic Crust Source: http://www.nps.gov/cany/naturescience/soils.htm
Lichen http://climate.uvic.ca/climate-lab/front_page_pics/lichen.html
Bluebunch Wheatgrass Jennifer Peterson Jennifer Peterson
Tailcup Lupine Poisonous plant contains alkaloids Jennifer Peterson Jennifer Peterson
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