potential threats to rangelands
TRANSCRIPT
Potential Threats to Rangelands
Threats include:
Overgrazing
Invasive plants
Human Population
Soil Erosion and Desertification
Wildland Fire & Climate Change
Complex Land Tenure
Other Factors
1. Overgrazing
Biggest Problem
Carrying Capacity- Cannot support grazing over a certain limit.
Overgrazing- in combination with:
Poor land use practices and
Absence of scientific grazing
system
Sharp decline of
many grasses
Inferior vegetatio
n invasion
2. Invasive Plants
Plants that interfere with the growth of desirable plants.
Abundance of native species- Reduced
Monoculture-where only one species dominates.
Water infiltration- Reduced
Altering soil characteristics
Altering fire intensity and frequency
Examples: Cheatgrass, leafy spurge, spotted knapweed, and salt cedar
3. Human Population
Demands for:
Food commoditi
es and
EnergyWoody
vegetation Overexploite
d For FuelTo meet
food requiremen
ts:
Rangelands converted
to agriculture
Results in:Soil Erosion and
Land Degradation
4. Soil Erosion and Desertification
Permanent loss of:
Productive rangelands
Loss of Biodiversity
Caused by:
Overgrazing
Excessive removal of vegetation
5. Climate Change
Rise in temperature = increase
rate of evapo-
transpiration
Leading to
Loss of moistur
e
Heat stress on Livestock
Incidence of pests and diseases- reduced livestock productivity
Socio-economic loss
6. Wildlife Fire
Role in maintaining rangeland
Depends largely on:
Growth form
Plant adaptations, and
Season of burning
Continued…
In Hot, dry, summer months is the most harmful- High Intensity Fires
Late summer and fall burns are the least harmful- Increased Moisture and Low Temperatures
7. Complex Land Tenure
Community owned and
Used as common property resource
Maximum benefits
Ethnic groups- Raising Livestock for generations
Ownership and Herders Conflict
8. Fragmentation of Rangelands
Increased Human activity and
Construction of roads and buildings
Rural subdivision and fragmentation lead to
Increased weeds
Loss of biodiversity, and
Degradation of pasture lands.
Continued…
Example: Houses built on wildlife winter habitat inhibits animals from moving down.
Rare and sensitive species-Limited to a Specific Habitat
Find themselves in danger
9. Lack of Institutional Setup
Forest Departments
Protection and development of forests rather than rangelands
Shortage of:
Technical expertise and
Financial resources
References
http://www.pfi.gov.pk/Ranglandpolicy.html
http://www.forestrynepal.org/notes/biodiversity/management/habitat/rangelandBrown, J.R., R.R. Blank. G.R. McPherson, and K.W. Tate. 2005. Rangelands a global change. Published by the Society for Range Management. Available online at: http://www.rangelands.org/pdf/Global_Issue_Paper.pdf.