Geomatics - Andhra Pradesh Forest Inventory

Andhra Pradesh Forest Inventory

To begin with JFM and WP (Working Plan) inventory data available with the department was analysed with the objective of using the same for pre-inventory. Detailed consultations were held with the experts in the field. it was decided to go in for area proportionate Stratified Random Sampling Technique using Satellite Imageries (LISS III of IRS 1C/1D) of 2004 season with about 7000 number of sample plots of 0.1 ha each. The intensity of the inventory came to 0.01% approximately.  
The no. of inventory points per strata was calculated using the following formula:

N= t2.CV2/ (AE %) 2  
            N          = No. of sample plots in the canopy stratum.
            CV        = Coefficient of Variation of sample plot volumes.
            AE        = Allowable error percentage (20% in the present design)
            t           = Constant available in t2 table  

  1. Salient features of the activity:-

a) Objective: The main objective of the inventory was to collect quantitative and qualitative information, about the forest resources to serve the data needs of development planning at State and Division level.
Information related to growing stock of timber and its species-wise distribution and volume was proposed to be got generated through this Inventory.
Besides assessing growing stock, the information regarding the following has also been collected

  • Timber and Bamboo resources,
  • herbs, shrubs & weeds,
  • soil
  • factors causing damage to the forests like incidences of
    • insects,
    • pests,
    • grazing,
    • fire,
    • illicit felling

b )Methodology

The field inventory was carried out by the 70 Teams, specially constituted for the purpose. Each Team consisted of a Team Leader, an Assistant Team Leader, local Forest Officer (FBO or ABO) and 4 Inventory Assistants. Extensive trainings were given to them in data collection.

A customized software for entry of data collected by the field Inventory Teams, was specially developed for Andhra Pradesh. The Circle/Division level data entry operators were given training in handling the software at APFA (AP Forest Academy) Dulapalli, on data entry. Subsequently, they entered the data at Circle / Division levels using the above mentioned software. The data was regularly transferred to head office through division offices. The data checking was done thoroughly at head office and data processed systematically.

Outputs of the Inventory

  • Estimates of Growing Stock in Cubic Metres (M3) by species and diameter class.
  • Estimate of number of stems by species and diameter Class.
  • Regeneration status, over all and species wise.
  • Estimate of stock of Bamboo & Bamboo bearing areas.
  • Regeneration Status of Bamboo.

Besides above the tables, charts and graphs have also been generated for the State and each of the Division depicting

    • Forest area,
    • Growing Stock (Total, per ha & diameter and species wise),
    • Number of Stems (Total & per ha),
    • Top 15 Species based on Volume & No. of Stems each (diameter class wise),
    • basal area,  status of Bamboo regeneration,
    • distribution and availability of Bamboo (Diameter Class & age wise),
    • status of regeneration through seedlings & coppices,
    • various soil characteristics such as distribution of soil depth-, Humus-& stoniness, extents of acidic, alkaline & neutral soils (pH) and extent  of Organic Carbon;
    • incidences of weeds, grasses, fire, grazing, illicit felling and pests etc. 

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