📋Forestry Important Facts

Introduction

In the previous lesson, we studied silvicultural systems — the methods for managing forest regeneration and harvest. This final lesson in the agroforestry section compiles the essential reference facts that are frequently tested in competitive exams.

This lesson covers:

1. Important days related to forestry and environment
2. Forestry institutes and their locations
3. Tree measurement — diameter classes, colours, canopy density, and forest cover definitions
4. 39 tree species — a quick-reference table of key species, their common names, and uses
5. Forest legislation — timeline from 1865 to 1988
6. Miscellaneous facts — breast height, lay farming, and key research centres

These are pure recall facts — the kind that earn you quick marks in exams if you have memorised them.

---

Important Days Related to Forestry

Environmental and forestry days are frequently asked as direct recall questions. Knowing the month clusters (March has 3 important days, September has 2) helps you remember them systematically.

---

Institutes Related to Forestry

India’s forestry research is coordinated by the Indian Council of Forestry Research and Education (ICFRE), headquartered in Dehradun. The following institutes under ICFRE and other bodies are commonly tested in exams — pay special attention to location matching.

---

Tree Diameter/Girth Class & Colour ^{Asked in AFO-2022}

In forest inventories, trees are classified by their diameter at breast height (DBH) and each class is assigned a standard colour code for marking on maps and field records. This was directly asked in IBPS AFO 2022.

---

Forest Map Colours

In official forest working plan maps, different forest types are represented by standard colours. The two most exam-relevant are Sal (Blue) and Teak (Burnt Sienna) — exams test whether you can match the species to its map colour.

---

Crop Composition Classification

Forest stands are classified by how much of the canopy is dominated by a single species. A stand with more than 75% of one species is called a pure crop — this matters for silvicultural planning because pure and mixed stands require different management approaches.

---

Canopy Density Classes (ISFR)

The India State of Forest Report (ISFR), published biennially by the Forest Survey of India (FSI), classifies forest cover into density classes based on the percentage of canopy coverage visible in satellite imagery.

---

Forest Cover vs Tree Cover

This is a frequently confused distinction in exams. The area threshold of 1 hectare is the key differentiator — both require a minimum canopy density of 10%.

• Forest Cover: All patches of land with tree canopy density of more than 10% and area of 1 ha or more, irrespective of land use, ownership, and species. This is what ISFR measures using satellite data.
• Tree Cover: All patches of trees less than 1 ha in area — this includes trees on farms, roadsides, and small urban parks that do not qualify as “forest” but still contribute to the nation’s green cover.

---

Density and Canopy Class

Beyond the ISFR satellite-based classification, forest working plans use a numerical density scale (0 to 1.0) to describe canopy closure at the stand level. A density of 1.0 means the canopy is fully closed with no gaps.

---

Age Class and Symbols

In forest inventory maps, the age class of a stand is indicated by standard symbols. These symbols help foresters quickly identify the stage of a forest crop at a glance.

---

Silviculture of Important Trees — Quick Reference

This table is a comprehensive reference for 39 tree species commonly tested in forestry and agroforestry exams. Focus on matching the botanical name to the common name and its primary use — these three-way associations are the most frequently tested pattern.

39 Tree Species Table

---

Forest Legislation Timeline

India’s forest legislation evolved from colonial timber extraction policies to modern conservation frameworks. The timeline below covers the key acts and policies — exams most frequently test the years and the core objective of each.

---

Miscellaneous Important Facts

This section collects standalone facts that do not fit neatly into other categories but appear regularly in exams.

• Lay Farming: Rotation of arable crops with two or more years of sown pasture — the pasture phase restores soil fertility through organic matter and nitrogen fixation by leguminous grasses, reducing the need for chemical fertilizers in subsequent crop years
• IGFRI (Indian Grassland and Fodder Research Institute): Jhansi — the primary institute for grassland and fodder research in India
• NRCAF (National Research Centre for Agroforestry): Jhansi (Uttar Pradesh) — note that both IGFRI and NRCAF are located in Jhansi, making it a hub for agroforestry and fodder research
• Trees planted in silviculture should be oriented in East-West direction — this maximises sunlight interception by ensuring rows do not shade each other during the critical morning and afternoon hours
• Breast Height (BH) in India: 1.37 m (4 ft 6 in) above ground level — this is the standard height at which tree diameter (DBH) and girth (GBH) are measured
• In Europe, UK, and FAO: 1.3 m (4 ft 3 in) — the 7 cm difference between Indian and international standards is a common exam trap

---

Summary Cheat Sheet