Potential threats to rangelands

Post on 14-Jan-2017

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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.