Last Updated on February 25, 2020 by Naeem Javid Muhammad Hassani
“The maximum stocking rate possible without inducing damage to the vegetation or related resources”._ SRM – 1974
OR; “The maximum animal number which can graze each year on a given area of range for the specific number of days without influencing the downward trend in forage production, forage quality or soil”. _ (Stoddart, Smith, Box)
Methods of Evaluating the Carrying Capacity:
- Sampling methods to be used:
- Size, shape, and number of quadrats to be required.
- The arrangement of types of equipment to be used.
- Quadrat or frame [1m2]
- Paper or plastic bag
- Spring balance or another weighing machine
- Field data form, pencil, eraser, papers, etc
- Metallic tape
- Selection of homogenous or representative sites
- The layout of the transect line – stretching metallic tape over it
- Placing the quadrat on sample point along the line
- Clipping the vegetation within each quadrat by species or by life form (Forbs, Herbs, Shrubs, etc)
- Grasses are cut about 2 cm above ground level
- keep the cut material in separate bags for separate quadrats
- Record the green weight of each sample by the spring balance and write on the form
- Label the plastic bag or paper bag of each quadrat by date, spp sample, site, etc.
- Plastic or paper bags should be punched to allow the air circulation
- All the material is brought to the headquarter
- Air dry the sample unit until when there is no change in dry weight.
- Average dry weight is calculated.
Average air dry weight = Total air dry w.t in gm / Total number of quadrats studied
- Air dry weight in kg/ha is calculated by multiplying with 10 to the average dry w.t. gm/ m2
i.e. if air dry weight 20 gm / m2
Then, in kg/ha, we have
i.e., 20 * 10,000 / 1 * 1000
0r, 20 * 10 kg/ha (just multiply with 10)
- Calculate the allowable air-dry biomass on the range by using the proper use of the factor of 0.5 or 50%
- Calculate the requirement of air-dried biomass for one animal unit for one month grass. Eg taking 9 kg air-dry biomass for one animal unit for one day. (Then, 9 * 30 days = 270 kg)
- Two methods of calculating Carrying Capacity:
Second Method (Forage Factor Method):
- In this method, common sense is used.
- No complicated data is used
- Reconnaissance is done at first
- Mention different range types which are mapped on a survey with important activities
- Recognize subtypes
- Estimate the spp composition and cover percentage by visualizing
- Proper Use Factor for all species should be known
- To calculate carrying capacity, the area should be known.
For correction and improvements please use the comments section below.
NJMH is working as Deputy Conservator of Forests in Balochistan Forest & Wildlife Department (BFWD). He is the CEO of Tech Urdu (techurdu.net) Forestrypedia (forestrypedia.com), Majestic Pakistan (majesticpakistan.pk), All Pak Notifications (allpaknotifications.com), Essayspedia, etc & their YouTube Channels). He is an Environmentalist, Blogger, YouTuber, Developer & Vlogger.