Carrying Capacity
CARRYING CAPACITY:
“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:
Procedure:
- Sampling methods to be used:
- Systematic
- Random
- 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
- Clipboard
- Scissors
- 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:
First Method:
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.
Naeem Javid Muhammad Hassani is working as Conservator of Forests in Balochistan Forest & Wildlife Department (BFWD). He is the CEO of Tech Urdu (techurdu.net) Forestrypedia (forestrypedia.com), All Pak Notifications (allpaknotifications.com), Essayspedia, etc & their YouTube Channels). He is an Environmentalist, Blogger, YouTuber, Developer & Vlogger.