Forest Survey of India

The Forest Survey of India (FSI) is a premier national organisation under the Ministry of Environment, Forest and Climate Change (MoEFCC), Government of India, responsible for the assessment and monitoring of the country’s forest resources. Established to provide accurate, consistent, and comprehensive data on forest cover and related environmental parameters, the FSI plays a critical role in sustainable forest management, environmental planning, and policy formulation in India.

Background and Establishment

The origins of the Forest Survey of India can be traced back to the Pre-Investment Survey of Forest Resources (PISFR), which was initiated in 1965 with the assistance of the Food and Agriculture Organization (FAO) and the United Nations Development Programme (UNDP). The purpose of this initiative was to collect reliable data on forest resources to support industrial and economic development.
Recognising the need for a permanent institutional framework, the Government of India established the Forest Survey of India in June 1981, headquartered in Dehradun, Uttarakhand. The FSI was created by reorganising the PISFR and expanding its mandate to include periodic forest resource assessment, mapping, and monitoring across the country.

Objectives and Functions

The primary objectives of the FSI are to generate and disseminate reliable data on India’s forests to support environmental management and national development policies. Its functions include:

• Assessment of forest cover through satellite-based remote sensing and ground-truth verification.
• Inventory of forests and trees outside forests (TOF) for estimation of growing stock and biomass.
• Monitoring of changes in forest cover and forest density over time.
• Preparation of thematic maps related to forests, vegetation, and land use.
• Evaluation of forest fire incidents, their causes, and patterns.
• Research and training in modern techniques such as Geographic Information Systems (GIS), Global Positioning Systems (GPS), and remote sensing for forestry professionals.
• Support to national and international reporting, including India’s commitments under the United Nations Framework Convention on Climate Change (UNFCCC) and other environmental protocols.

Forest Cover Assessment and Methodology

The FSI carries out a biennial forest cover assessment, published in the form of the India State of Forest Report (ISFR) every two years. The assessment utilises satellite imagery, primarily from the Indian Remote Sensing (IRS) satellites, combined with digital interpretation and ground verification to provide precise estimates of forest area.
Forest cover is categorised into three main classes:

• Very Dense Forest (VDF): Tree canopy density greater than 70%.
• Moderately Dense Forest (MDF): Tree canopy density between 40% and 70%.
• Open Forest (OF): Tree canopy density between 10% and 40%.

In addition, the FSI reports on Scrub areas, Mangrove cover, and Trees Outside Forests (TOF). The assessment includes both forested land under legal classification and areas outside traditional forests that exhibit significant tree cover.
The use of remote sensing and GIS technologies enables the FSI to conduct nationwide assessments efficiently, providing data at scales of up to 1:50,000. Ground verification and field surveys are carried out to ensure the accuracy and reliability of satellite-based interpretations.

Publications and Reports

The most important publication of the organisation is the India State of Forest Report (ISFR), which provides comprehensive statistics on:

• Forest cover by state and union territory.
• Forest type and density classification.
• Growing stock and biomass estimation.
• Carbon stock assessment.
• Tree cover outside forests.
• Forest fire vulnerability and incidents.
• Forest health and biodiversity indicators.

In addition to the ISFR, the FSI releases Special Thematic Reports, National Forest Inventory (NFI) reports, and technical manuals on various aspects of forestry assessment and data analysis. These publications are extensively used by policymakers, researchers, and environmental agencies for planning and conservation initiatives.

National Forest Inventory

The National Forest Inventory (NFI) is one of the major components of FSI’s activities. It involves systematic field sampling across the country to estimate the growing stock, density, species composition, and regeneration status of forests. The NFI provides critical information for calculating forest biomass and carbon sequestration, thereby contributing to India’s climate change mitigation commitments.
Sampling under NFI is conducted using scientifically designed plots based on statistical methods to ensure national and regional representation. Data collected include tree species, diameter, height, and volume measurements, which are later used for calculating timber potential and ecological value.

Technological Innovations

The Forest Survey of India is a leader in adopting advanced technologies for forest resource management. Major innovations include:

• Use of high-resolution satellite data for more accurate delineation of forest boundaries.
• Development of Forest Fire Alert System and Forest Fire Early Warning System (FFEWS) for real-time monitoring and dissemination of fire alerts through satellite detection.
• Implementation of Digital Change Detection Techniques for identifying deforestation and degradation patterns.
• Use of LiDAR (Light Detection and Ranging) and drone-based mapping for detailed forest structure analysis.
• Creation of Forest Resource Information System (FRIS) for centralised digital management of forest data.

These technologies have significantly enhanced the precision, frequency, and accessibility of forest data in India.

Significance and Applications

The data and analyses produced by the FSI serve multiple national and international purposes:

• Policy Formulation: Helps in framing the National Forest Policy and state forest management strategies.
• Environmental Planning: Supports watershed management, biodiversity conservation, and ecological restoration programmes.
• Climate Change Mitigation: Provides data for estimating carbon stocks and reporting under international conventions.
• Forest Fire Management: Facilitates timely response to fire outbreaks through satellite monitoring.
• Academic and Research Use: Supplies scientific data for studies in forestry, ecology, and climate science.

Achievements and Recent Developments

Over the decades, the FSI has achieved several milestones, including:

• Establishment of a consistent national database of forest resources.
• Introduction of geo-spatial technologies for forest assessment.
• Expansion of coverage to include Trees Outside Forests, contributing to a holistic view of national tree resources.
• Collaboration with other national agencies such as the Indian Space Research Organisation (ISRO) for advanced remote sensing applications.
• Integration of real-time forest fire alerts using MODIS and SNPP-VIIRS satellite data.

Recent India State of Forest Reports indicate steady improvements in tree and forest cover, although challenges such as deforestation, urban expansion, and forest degradation persist in certain regions.

Challenges

Despite its success, the Forest Survey of India faces challenges in data integration, inter-agency coordination, and addressing discrepancies between forest cover and land use classifications. Rapid land use changes, encroachment, and natural calamities also pose obstacles to maintaining accurate and updated records. Additionally, expanding the inventory to private and community lands requires substantial logistical and technical support.