Indian Vegetation and Soils

2020-04-29 00:43:47

Natural Vegetation

Types of Forest

Tropical Evergreen and Semi Evergreen Forests

Evergreen
- warm and humid areas; Well stratified
- annual precipitation of over 200cm and mean annual temp of 22°C
- ex Rosewood, Mahogany, Aini, Ebony

Semi Evergreen
- Mixture of moist deciduous and Evergreen
- undergrowing climbers provide evergreen character
- Ex cedar, hollock and kail

Tropical Deciduous Forests : Rainfall b/w 70-200cm

Further divided into moist and dry
- Moist Deciduous : rainfall b/w 100-200cm, ex Teak, Sal, Shisham, Hurra, Mahua, Amla
- Dry Deciduous : rainfal b/w 70-100cm, teak tress interpersed w/ grass, ex Tendu, Palas, Amaltas etc

Tropical Thorn Forests

rainfally less than 50cm ie semi arid areas
plants are leafless throughout the year
Ex Date palm, Neem, Khejri, Palas

Montane Forests

Northern Montane

Him areas show succesion of vegetation from tropical to tundra
Lower Foothills have Deciduous forests
Succeeded by Wet Temperate type at 1000-2000 mts
In NE and hilly areas of WB from 1500-1750 Evergreen broad leaf trees ex Oak and Chestnut are common; Pine forests are also found here
Blue Pine and Spruce at 2,225-2048 mts; temperate grasslands also found
Higher reaches Alpine forest and pastures found at 3000-4000 mts ex Silver Firs, Junipers, Pines, Birch, Rhododenrons found

Southern Montane

found in Western Ghats, Vindhyas and Nilgiris
Vegetation is temperate in higher reaches and Subtropical on lower ones
Temperate forests are called Sholas in Nilgiri, Anaimalai and Palani hills
Trees like Magnolia, Laurel, Cinchona, Wattle found

Littoral and Swamp Forests.

70% area under paddy cultivation
variety of wetland habitats
Creeks, stagnant water and tidal flows present, vegetation is salt tolerant
Ex Mangrove

Forest Conservation

Social Forestry : mgt and protection of forests and afforestation on barren land to bring environmental, social and rural dev
- Urban Forestry : raising trees on public and privately owned land
- Rural Forestry : promotion of agro and community forestry
  - Agro forestry is raising of trees, agri crops on same land
  - Community forestry aims at providing benefits ex providing jobs to landless classes in forestry
- Farm Foresty : farmers grow trees for commercial and non commercial purposes

Doabs and Rivers -

Name	Rivers
Sindh Sagar Doab	Indus and Jhelum
Jech Doab	Jhelum and Chenab
Rechna Doab	Ravi and Chenab
Bari Doab	Ravi and Beas
Bist Doab	Beas and Sutlej
Raichur Doab	Krishna and Tungabhadra

Soils

2020-04-28 23:46:39

Soil Formation

Result of Decay and Medium of Growth is mixture of rock debris and organic materials
Soil Science aka Pedology, soil formation/ Pedogenesis
3 layers are
- Horizon A : topmost zone, where organic material is incorporated w/ mineral matter, nutrients and water
- Horizon B : transition b/w A and C, very less organic matter
- Horizon C : composed of loose parent material

The Soil Forming Factors Are :

Parent material : ex size fo debris, structure, mineral and chemical composition.
Topography
- diff topographic features would have diff exposures to sunlight, drainage etc.
- Soils will be thin on steep slopes, thick over flat uplands.
Climate
- Moisture - Low moisture/humidity leads to salt accumulation in soils -> aridity.
- Temp - affects chemical and biological activity
Biological activity ex action of nitrogen fixing bacteria, humus accumulation.
Time

Classification of Soils

Alluvial Soils :

40% of total area of country, depositional; nature varies from sandy loam to clay.
Are rich in potash but poor in phosphorous.
Colour varies from light grey to ash grey.
Khadar is new alluvium and Bhangar is older both contain calerous conc of Kankars.

Black Soil :

aka as Regur Soil or Black Cotton soil.
Are clayey, deep and impermeable.
Develop deep cracks and swell when water is added called self-ploughing.
Absorption and loss of moisture is slow but retains moisture for very long.
rich in lime, iron, magnesia and alumina.
also contain potash but lack Phosphorous, N2 and organic matter.

Red and Yellow Soil :

Develops on crystalline igneous rocks in areas of low rainfall.
becomes yellow when hydrated.
Are poor in Nitrogen, Phosphorous and Humus.
fine grained yellow soil is fertile but coarser ones are not.

Laterite Soil :

Develops in areas with high temp and rainfall.
Due to intense leaching Lime and silica are leached.
poor in organic matter, Nitrogen, Phosphate and calcium.
Iron oxide and Potash are in excess.
crops like Cashewnut etc is grown, not suitable for cultivation.
used to make bricks, found in higher areas of Peninsular plateau.

Arid Soils

Vary from Red to Brown in colour, are sandy and saline.
Lack Moisture and humus, Nitrogen.
Kanker layer is common here.

Saline Soils :

also known as Usara soils.
large proportion of Na, K and Mg.
waterlogged and swampy areas and arid/semi-arid regions.
Due to capillary action salt gets deposited on the top layer of fertile soils making them saline. To avoid this Gypsum is added.

Peaty Soil :

Found in areas of heavy rainfall and high humidity.
has high humus and organic content upto 40-50%.
Normally heavy and black in colour.
Sometimes be alkaline.

Forest Soils :

loamy and silty on valley sides and coarse grained in upper slopes.
In snow bound areas they are acidic with low humus content.
Lower levels they are fertile.

Soil Degradation : decline in soil fertility due to erosion and misuse, degree varies from topography, wind velocity and amount of rainfall.

Soil Erosion : destruction of soil cover when far exceeds soil formation, water and air are the most powerful agents.

Soil Conservation

Check open cultivation on slopes.
Slopes of gradient 15-25% not be used for cultivation.
Check overgrazing and shifting cultivation.
Contour bunding, Countour terracing, regulated forestry, controlled grazing, cover cropping, mixed farming, crop rotation.
Prevent gully erosion through check dams.
Uncultivable lands be converted into pastures for grazing.
Stabilize sand dunes in arid areas.
Central Soil Conservation zone set up for this.

kegy106.pdf - Soils

kegy105.pdf - Natural Vegetation

2.2 Indian Vegetation