rnrtest3

rnrtest3 - Grasslands Rangelands 11:06:00 ← Grasslands...

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Unformatted text preview: Grasslands - Rangelands 19/10/2009 11:06:00 ← Grasslands • Grasslands cover about 26% of the world’s land surface • 10% classified as rangelands that are used to graze livestock • 25% of rangeland is in developing countries – cleared forests, abandoned cropland • 80% of annual production of beef and mutton • extremely important in grain-poor nations ← ← Rangelands • From 1950-2001: o World population: 2.51 to 7.1 billion o Cattle: 720 million to 1.53 billion o Sheep and goats: 1.04 to 1/75 billion o Degraded rangeland: 680 million ha worldwide, increasing • How can rangeland be managed sustainably, when dealing with these issues? o Population pressure o Climate change o Invasive species • 10 billion domesticated animals worldwide o 30% are ruminants meaning it has multi-chamber stomachs o ¾’s of the world’s domesticated ruminants feed on rangelands, the rest is on feedlots areas where you can grow crops for cows to eat in order to later eat the cows o 200 million people graze livestock on rangeland 85% in Africa and Asia ← ← U.S. Rangeland • <5% of the world’s population, 9% of the world’s cattle • livestock graze >33% of north America • More than ½ of U.S. croplands planted with livestock feed • Focus mainly on cattle • Livestock production uses 50% of the annual water consumption in the U.S. • 1 poud of feedlot-fattened beef = 5 pounds of grain and 280 gallons of water • 1000 lb cow = 280,000 gallons of water ← ← Rangeland • Minimal use land without irrigation • Renewable resource for many materials • Vegetation collectively known as forage • Forbs broad-leaved flowing plants such as sunflower and goldenrod • Sedges perennial herb with triangular stems • Rushes grass-like herbs with round stems ← ← Rangeland Plant Characteristics • Most grasses, sedges, rushes perennial , forbs often annual, biennial • Deep, fibrous root systems need huge root system to capture as much water as possible, also stabilizes soil • Highly tolerant of low moisture conditions don’t grow for years • Highly tolerant of fire • Grasses grow from the base of the plant • The lower part of the grass (-50%) is called to metabolic reserve (if you clip that off repeatedly it will die) • Needed for nourishment of extensive root system • Chronic loss of the metabolic reserve from overgrazing can destroy rangeland sustainability ← ← Rangeland Forage • Decreasers highly palatable, decline in abundance with grazing • Increasers divided into 2 groups o Increasers 1: moderately palatable, secondary forage, slightly increase...
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This note was uploaded on 09/13/2011 for the course RNR 1001 taught by Professor W.kelso during the Spring '08 term at LSU.

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rnrtest3 - Grasslands Rangelands 11:06:00 ← Grasslands...

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