Chapter 5 (Part 2): Forest Types

Major Groups II–V, bioclimatic formulae, coding architecture and silvicultural applications

Montane ForestsAlpine ForestsBioclimatic Indices

1. Major Groups II–V: Montane & Alpine Forests

Major Group II — Montane Subtropical Forests (Groups 8–10)

Group	Forest type	Altitude / distribution	Important species and types
8	Subtropical Broad-leaved Hill Forests	1000–1700 m	South: Eugenia wightiana, Rhododendron nilagiricum (8A/C1). East: Castanopsis, Schima wallichii (8B/C1).
9	Subtropical Pine Forests	1000–1800 m	Chir pine, Pinus roxburghii (Himalayas, 9/C1); Pinus insularis (Kasiya, Khasi/Naga hills, 9/C2).
10	Subtropical Dry Evergreen Forests	Siwalik foothills below 1000 m	Olea cuspidata scrub (10/C1a); Acacia modesta (10/C1b).

Major Group III — Montane Temperate Forests (Groups 11–13)

Group 11: Montane Wet Temperate Forests

11A Southern: Above 1500 m in Nilgiri, Annamalai and Palni hills. Known as Sholas. Key species include Ternstroemia, Rhododendron nilagiricum and Michelia nilagirica.

11B Northern: 1800–3000 m in the Eastern Himalayas; includes Quercus lamellosa.

Group 12: Himalayan Moist Temperate Forests

Altitude: 1500–3300 m; snowfall occurs.

Oak altitudinal zonation:

Ban Oak — Quercus incana (1800–2300 m; 12/C1a)
↓
Moru Oak — Quercus dilatata (2000–2500 m; 12/C1b)
↓
Kharsu Oak — Quercus semecarpifolia (2500–3300 m; 12/C2a)

Conifers: Cedrus deodara (12/C1c); Western mixed coniferous forest with Picea smithiana and Abies pindrow (12/C1d).

Group 13: Himalayan Dry Temperate Forests

Distribution: Inner dry Himalayan valleys including Sutlej, Kinnaur, Kishtwar and Ladakh.

Climate: Rainfall below 1000 mm, mainly as snow.

Key species: Pinus gerardiana (Chilgoza/Neoza pine, 13/C2a), Dry Deodar (13/C2b) and Juniperus macropoda (13/C5).

Major Group IV — Sub-Alpine Forests (Group 14)

2900–3500 m

Group 14: The topmost tree forest in the Himalayas, occurring below alpine scrub.

Key species: Betula utilis (Bhojpatra), Abies spectabilis, Pinus wallichiana and Rhododendron.

Major Group V — Alpine Scrub (Groups 15 & 16)

Group 15: Moist Alpine Scrub

Altitude above 3500 m. Includes stunted Rhododendron scrub (15/C1) and alpine pastures with Primula and Anemone (15/C3).

Group 16: Dry Alpine Scrub

High, arid alpine zone with dwarf xerophytic shrubs such as Eurotia, Juniperus wallichiana, Artemisia and Caragana.

2. Altitudinal Forest Sequence — Quick Understanding

Montane Subtropical Forests
Groups 8–10

↓ Increasing altitude

Montane Temperate Forests
Groups 11–13

↓ Higher elevation

Sub-Alpine Forests
Group 14; approximately 2900–3500 m

↓ Above tree-forest zone

Alpine Scrub
Groups 15–16; moist and dry alpine scrub

This is a broad learning sequence. Actual vegetation distribution also depends on local environmental conditions.

3. Bioclimatic Formulae & Coding Architecture

A. Emberger's Bioclimatic Value — Seth & Khan (1959)

Used to distinguish dry-zone bioclimates in India.

Q = (P × 100) / [((M + m)(M − m)) / 2]

• P: Annual rainfall in mm.
• M: Mean maximum temperature of the hottest month (°C).
• m: Mean minimum temperature of the coldest month (°C).

B. Paterson's CVP Index (1956)

Climate–Vegetation–Productivity index.

I = (T_v / T_a) × P × (E / 100) × (G / 12)

• T_v: Hottest month temperature.
• T_a: Temperature range.
• P: Precipitation.
• E: Evapotranspiration.
• G: Number of growing months.

C. Hierarchical Coding System

Code	Meaning
C	Climatic Climax
E	Edaphic Climax
1S	Primary Sere
2S	Secondary Sere
TS	Tropical Swamp
FS	Freshwater Swamp

Example: Type 3C/C_2a

Type 3 → Tropical Moist Deciduous
↓
3C → North Indian sub-group
↓
C → Climatic Climax
↓
2a → Moist Siwalik Sal

4. Silvicultural Applications of Forest Classification

1. Selecting plantation species

Prevents planting exacting climax species on raw, immature seral soils.

2. Standardizing tending and regeneration

Helps tailor shelterwood, clear-felling and selection systems to forest type requirements.

3. Maintaining commercial sub-climaxes

Guides controlled burning or grazing to maintain commercially valuable Sal, Teak and Deodar stands as stable sub-climaxes.

5. High-Value Exam Comparison Table

Group	Forest type	Key identification / species
8	Subtropical Broad-leaved Hill	Castanopsis, Schima wallichii; 1000–1700 m.
9	Subtropical Pine	Pinus roxburghii; 1000–1800 m.
10	Subtropical Dry Evergreen	Siwalik foothills below 1000 m.
11	Montane Wet Temperate	Southern Sholas; Nilgiri, Annamalai and Palni hills.
12	Himalayan Moist Temperate	Oaks, Deodar, Spruce and Fir; 1500–3300 m.
13	Himalayan Dry Temperate	Chilgoza; inner dry valleys; rainfall below 1000 mm.
14	Sub-Alpine	Betula utilis; 2900–3500 m.
15	Moist Alpine Scrub	Rhododendron, Primula, Anemone.
16	Dry Alpine Scrub	Eurotia, Artemisia, Caragana.

6. Quick Revision Box — Chapter 5 Complete

• Champion & Seth (1968): Revised classification into 5 Major Groups and 16 Type Groups.
• Group 1: Tropical Wet Evergreen — Dipterocarpus, Mesua.
• Group 3: Tropical Moist Deciduous — Teak and Sal.
• Group 7: Tropical Dry Evergreen — Carnatic Coast; retreating North-East monsoon.
• Group 9: Subtropical Pine — Pinus roxburghii.
• Group 11A: Southern Montane Wet Temperate — Sholas.
• Group 12: Himalayan Moist Temperate — Ban, Moru and Kharsu Oaks.
• Group 13: Himalayan Dry Temperate — Chilgoza pine.
• Group 14: Sub-Alpine — Betula utilis (Bhojpatra).
• Groups 15–16: Moist and Dry Alpine Scrub.
• Emberger's Q: Used by Seth & Khan for dry bioclimate classification.
• Paterson: Developed the CVP index.

7. Interactive MCQ Quiz

18 questions. Tap an option to see the correct answer and explanation straight away, then go to the next question.

Silviculture notesAll quick revision notes →

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