Resource ecology

1. RESOURCESNATURALNATURAL
RESOURCESRESOURCES
AMRUTHA K HAMRUTHA K H
I MSc ZOOLOGYI MSc ZOOLOGY

2. SOILSOIL
• Mixture of minerals,organic matter, gases etc
• 2 general classes – topsoil & subsoil
• A natural body, part of pedosphere
• 4 important functions:-
1. Medium for plant growth
2. Means of water storage, supply & purification
3. Modifier of atmosphere of earth
4. Habitat for organisms

3. SOIL FORMATIONSOIL FORMATION
(PEDOGENESIS(PEDOGENESIS)
• It includes:
 Weathering of soil forming rocks
 Addition of organic matter,humification& mineralization
 Formation of organo-mineral complexes

4. 1.Weathering of soil forming rocks
• Weathering of parent rocks by physical, chemical
&biological agents
• Soil forming rocks are broken down into small paricles-
regoliths
• They develop into mature soil
(A)Physical weathering
• They are climatic in character-mechanical effect on
substratum forms regolith
• Commonly occur in desert, high and low altitude regions
• Does not cause any chemical transformation
• Temperature-causes breakdown of rocks which have
heterogeneous structure, due to expansion and
contraction of the components of rock

5. • Minerals have different degree of expansion
• During day-expand, during night-contract
• This causes cracks on rock and hence weather into finer
particles
• Water-rainwater,natural water drop on rock surface with
beating effect bring abrasion of massive rock into smaller
particles
• Torrent water-rapidly flowing water rolls the heavy rocks
and grinds them into fine particles
• Wave action-rapidly stricking waves dislocate solid
particles of varying diameter from sea shore rocks and
debris is settled at the sea bottom to form marine soil
• Frost action and glacial formation-when water is at
freezing state
• Freezes due to sudden fall in temperature

6. • Gravitational weathering-due to landslides and rock
slippages by earthquakes
• Wind-carry suspended sand particles causes abrasion of
exposed rock

7. (B)Chemical weathering
• Chemical transformation of parental mineral nutrients
into new mineral complexes or secondary products occur
• It needs the presence of moisture and air
• Not effective in deserts,includes the following:
1. Solution-water,most potent agent. It helps in the
removal of water-soluble minerals of weathered rocks
2. Hydrolysis-involves exchange of parts between water
and minerals. Chemical union of water with strong bases
produce hydroxides of Fe,Mg,Ca,Al.Acts in combination
with other reaction such as oxidation-reduction
3. Oxidation-results when O2 added to minerals to
produce oxides, when dissolved in H2O weakens the
rock and weathering results.

8. 4.Reduction- occurs in wet, poorly aerated sits. Means
removal of 02 from minerals
5.Carbonation- H20+CO2 forms carbonic acid-reacts with
hydroxide of Ca,Mg etc to form carbonates and
bicarbonates.
6.Hydration-H2O becomes chemically attached to
particular rock mineral-volume of parental rock
increases, hydrated minerals become soft and rapidly
weather.

9. Oxidized pyrite cubes Weathering Limestone

10. C)Biological weathering
• Micro-organisms,lichens and mosses of the surface –
helps in biological weathering
• Transform rock into dynamic system.storing energy and
synthesizing organic material
• Their activates affect the chemical composition and physical
structure of rock
Biological weathering of basalt by lichen

11. PRODUCTS OF WEATHERINGPRODUCTS OF WEATHERING
• Soil formed by weathering of soil-forming rocks-embryonic
or primary soil. It matures into different types:
i. Residual soil-mature soil lying immediately over the parent
rock
ii. Skeletal soil-partly weathered rock in which maturation does
not occur
iii. Secondary soil-weathered parent material is shifted to
different places by means of wind.rivers,land slides, wave
action etc

12. 2.Addition of organic matter,humification& mineralization
• Organic matter is continuously added to embryonic soil
formation soil formation by living organism
• Organic matter include excreta of animals, dead body of
plants etc
• All the organic plants debris fallen recently-litter
• These all add to the fertility of soil

13. 3.Formation of organo-mineral complexes
• Final stage-colloidal particles formed due to
weathering,humification and mineralization accumulate and
aggregate into crumbs
• Crumbs increase total pore space, allow food aeration and
drainage
• Thus, mature soil becomes complex system of living and
non-living material not inert but active

14. PHYSICAL & CHEMICAL
PROPERTIES OF SOIL

15. PHYSICAL PROPERTIES
• Includes:-
a) Texture
b) Structure
c) Density
d) Porosity
e) Consistency
f) Temperature
g) Color
h) Resistivity

16. (a)Texture
• Refers to size of soil particles
• Proportion of each size group in a given soil cannot be
altered and it is considered as a basic property of soil
• Sand-most stable mineral components of soil, contain
rock fragments, quartz particles (diameter:2 to.05 nm)
• Slit-ranges from 0.05 to .002nm
• Clay- .002nm or less in diameter
• Soil texture larger than 2nm is considered as rock and
gravels
• Soil texture influences:-
 Nutrient supplying ability
 Water relationships
 Aeration
 Root growth and health

17. (b)Structure
• Clumping of soil textural components of sand, slit and clay
causes aggregates to form and then association of those
into larger units creates soil structure called pedoliths or
peds
• Based on the shape and arrangement of peds they are,
1. Platy
2. Prismatic & columnar
3. Angular and sub angular
4. Granular and crumb
• It influences soil aeration, water infiltration and drainage
• Gives clues about texture, organic matter, biological
activity, part of soil evolution, human use etc

18. Types of soil structures

19. (c)Density
• It is weight per unit volume
• Soil particle density= mass of solid particle
volume of solid particle
• It includes only mineral particles that make up the
soil(excludes pore space & organic matter)
• Soil particle density is typically 2.60 to 2.75g/cm3
• Soil bulk density = dry mass of soil
volume of soil
• Included air space and organic materials
• Soil bulk density is inherently always less than soil particle
density

20. (d)Porosity
• Part of the bulk volume of soil that is not occupied by
either mineral or organic matter but is open space
occupied by either gases or water.
• Ideal pore space-50% of soil volume
• Gas space-to supply O2 to organisms decomposing
organic matter, humus and plant roots
• Allows movement and storage of water
• 4 categories of pores :-
1. Very fine pores:< 2µm
2. Fine pores: 2-20µm
3. Medium pores: 20-200µm
4. Coarse pores: 200µm-0.2 mm

22. (e)Consistency
• Ability of soil to stick to itself or to other objects
• Ability to resist deformation and rupture
• Measured at 3 moisture conditions:air-dry,moist and wet
• Used in predicting cultivation problems
• Estimating the ability of soil to support buildings and
roads.

23. (f)Temperature
• Depends on ration of energy absorbed to that lost
• Temperature range of soil is -20°C to 60°C
• Factors influencing soil temperature are:
1. Climate
2. Topography
3. Soil color etc
• Lower temperature = lower biological activity
• Higher temperature = higher organic matter accumulation
• Change in temperature –breaks down mineral grains
• Warmer temperature- increase chemical weathering
• Many nutrients are poorly available at low temperature,
especially phosphorus

24. (g)Color
• Determined by organic matter content, drainage conditions
and degree of oxidation
• Soil color is used in :-
 Distinguishing boundaries
 Determining origin of soils parent material
 Indication of wetness & waterlogged conditions
 Qualitative means of measuring organic salt & carbonate
contents of soil
• Soil color is due to various minerals
• Iron---red color
• Organic matter decomposing----- black & brown
• Mn/Sulfur/Nitrogen----- black
• Aerobic conditions---- uniform /gradual color changes
• Anaerobic conditions----rapid color change

26. (h)Resistivity
• Measure of soils ability to retard the conduction of an
electric current
• Higher moisture content can lower resistivity and increse
conductivity. Hence increases rate of corrosion
• Soil resistivity values ranges from 2 to 100 Ωm
• More extreme values are not unusual

27. CHEMICAL PROPERTIES
a) Cation exchange capacity
b) Soil pH

28. (a)Cation exchange capacity
• Ability of soil clay &organic matter to absorb and
exchange cations with those in soil solution
• Silicate clays and organic matter have negative charge
because of cation substitution
• Opposite charges attract
• Quantity of cation exchange is measured per unit of soil
weight-cation exchange capacity
• Organic colloids exhibit greater cation exchange capacity
than silicate clays
• Cation exchange capacity of soil depends on both
organic matter content and type of silicate clays.

29. • Cation exchange capacity is important phenomenon for 2
reasons :
1. Exchangeable cations(Ca,Mg,K )easily available for plant
uptake
2. Cations absorbed to exchange sites are more resistant to
leaching
• Ca-predominant exchangeable cation in soil, even in acid
weathered soil
• Al-may be dominant in highly weathered soils
• Order of retention :
Aluminum >Calcium>Mangnesium>Potassium>Soidum>Hydrogen
• Cations with increasing positive charge and decreasing
hydrated size are tightly held

30. • Basic cation- cations of Ca,Mg,K produce alkaline reaction
• Acid cation-Al & Hydrogen ions produce acidity in water
• Percentage base solution- % of cation exchange capacity
occupied by basic cation
• Greater the percentage base solution ,higher the soil pH.

31. (b)Soil pH
• Soil pH 7- neutral
• Soil pH <7 –alkaline
• Soil pH>7-acidic
• Soil pH typically ranges between 4 to 8.5
• It affects :-
 Plant growth
 Quantity, activity & type of micro-organisms
 Decomposition of crop residues
 Nutrient transformations
• Bacteria becomes active in slightly acid to alkaline condition

32. SIGNIFICANCE OF SOIL
FERTILITY
• Soil fertility-ability of soil related to plants,fittness of seed bed
and impedance to seedling emergence and root penetration
by providing nutrients and suitable soil structures to support
the plants/trees growth
• Significance include :
 Provide nutrients for plant growth(including NPK)
 Provide micronutrients like Fe,Cl,Mg,Mn,Zn etc
 Provide soil organic matter that improves soil structure &soil
moisture retention
 Provide home for range of micro-organisms

33. MINERAL RESOURCES WITH
REFERENCE TO INDIA
• Minerals are non renewable,exhaustable resources. They
cannot be regenerated

34. • 3 categories :
A.Metallic minerals
i. Copper
ii. Zinc
iii. Iron ore
iv.Chromite
B. Non metallic minerals
i. Garnet group
ii. Wollastonite
iii. llimenite
iv.Pyrophyllite
C.Minor Minerals
i. Marble

35. A.Metallic minerals
• Contain one or more metallic elements
• Occur in rare naturally formed concentrations know as mineral
deposits
• Metallic minerals available in India are Zn,Iron
ore,Gold,Silver,Lead etc
i. Copper
 Mainly used in industrial applications, electronic equipments
etc
 Major resource of copper is Rajasthan ,Madhya Pradesh &
Jharkhand
 India is one of the 20 major
producer of copper

36. ii. Zinc
 Bluish-white lustrous mineral
 Fair conductor of electricity
 Type of zinc ores are-sulphide,carbonate,silicaused in
automotive, electrical and machinery industries
 India is worlds 4th
largest zinc reserve
 Most of the resources are available in Rajastan
 Minor resource are available in Andhra
Pradesh,Bihar,Maharatra

37. iii. Iron ore
 India is the world’s 3rd
biggest exporter
 Major iron ores-Hematite & Magnetite
 Hematite is found in Orissa,Jharkhand,Karnataka,Goa(major)
 Minor Hematite is found in Assam, Bihar etc
 Major amount of Magnetite is found in Karnataka, Andhra Pradesh
 Minor amount of Magnetite is found in Assam,Goa,Kerala,Meghalaya
& Nagaland
 It is mainly used for manufacturing of pig iron, sponge iron, steel etc
 Also used in cement, glass industries
Hematite Magnetite

38. iv. Chromite
• Oxide of chromium & iron
• Only commercial source of chromium
• Major amount seen in Orissa
• Minor amount in Manipur,Nagaland,Karnataka etc
• India ranks 2nd
• Chromium provides additional strength &resist corrosion
• Mainly used in metallurgical applications
• It can withstand sudden temperature change, hence used
in refractories & also has chemical applications

39. B. Non metallic minerals
• Do not yield new products on melting
• Associated with sedimentary rocks
• Available from India are
Phosphorite,Dolomite,Gypsum,Cadmium,Limestone,Zinc
i. Garnet group
 Group of complex silicate minerals and has similar chemical
compositions
 Group of garnet-Al garnet group, chromium garnet group, Fe
garnet group
 Mineral in Al garnet are pyrope, grossular etc
 Mineral in chromium garnet group is uvarovite
 It is hard, resistant to chemical exposure
 Used as semi-precious stone, sand blasting etc
 Available in Kerala,Orissa,Tamil Nadu etc

40. ii.Wollastonite
Meta-silicate of calcium
White in color, occur as bladed or needle like crystals
Mostly available in Rajasthan
Minor amount in T.N
Used in ceramic, metallurgical applications

41. iii.Llimenite
 Compound of iron & titanium
 Color-iron black/steel grey
 Non-toxic material
 Used in biomedical substances
 Available in Kerala

42. iv.Pyrophyllite
 Hydrous alumino-silicate
 Chemically inert, high melting point &low electrical
conductivity
 Used in refraciories,dressing,pesticides,ceramics,rubber
etc
 Found mainly in Madhya Pradesh, Orissa U.P,Rajasthan
& Maharashtra

43. C.Minor Minerals
• Available are building stone, brick earth,marble,granite etc
• Used for construction purpose
i.Marble
 Metamorphosed limestone formed by re-crystalization
 Available in different color & texture
 Used in Indian mainly for construction of temples, tombs &
palaces
 Used for flooring homes & offices-because of durability
and water resistance
 Available in Rajastan,Gujarat,Haryana,Andhra Pradesh etc

45. IMAPCTS OF MINING ON
ENVIRONMENT
• Removal of all vegetation(flora) & fauna from the area
required for mining
• Water pollution due to pollutants and leaching from
overburden dumps
• Dust formed during mining deposit on the leaves of plants
and retard their growth
• Noise and vibrations due to blasting and operation of
machines drive away wild animals and birds from nearby
forest

46. • Water scarcity due to mining on water remige affect
vegetation of the surrounding area
• Top soil lose its vegetation supporting capacity
• Drilling and blasting of overburden and mineral contribute to
SPM and explosive fumes into atmosphere
• Minerals &rock mass having sulfur and its compounds
contribute to sulfurdioxzide
• Some sedimentary rocks may have methane and when
mined may contribute this gas to the surrounding air
• Bioaccumulation also affects mining

47. Acid mine drain in Portugal

48. FOREST RESOURCES
• Forest cover 30% of the earth’s surface
• Forest resources have economic value when they yield income. Eg:
timber,water,minerals,fish,wildlife
• Greatest economic contribution is trees
• They are made intotimber,pulpwood,poles etc
• They even have social value that are related to aesthetic
considerations such as scenic qualities of forest area
• Social values are also concerned with biological aspects such as
uniqueness of plants & animals found in forest

49. DEFORESTATION
• It is the large scale removal of a forest or area of trees
inorder to clear land for human development
• It is direct or indirect induced conversion of forest land to
non-forest land
• Causes :-
1. Population increase
2. Cultivation
3. Overgrazing
4. Fuel wood
5. Forest fire
6. Timber
7. Forest diseases
8. Landslides
9. Mining

50. 1.Cultivation
 Countries clear large are of land to develop them
 Nutrients depleted
 Fertility of soil id exhausted due to repeated cropping
2.Overgrazing
 It destroys newly regenerated growth
 Makes soil more compact
 Causes soil erosion

51. 3.Fuel wood
 People near forest uses fuel wood, charcoal for cooking
and heating
 Also for keeping the fire for warmth at night
4.Forest fire
 Frequent fire are the major cause of destruction of forest

52. 5.Timber
 Timber & plywood industries causes destruction of trees
 Increase demand of timber leads to a rapid depletion of
forest
6.Forest diseases
Disease caused by parasitic fungi,rust,viruses causes
death and decay of forest plants
Disease such as heart rot, blister rust,oak,wilt ,phloem
necrosis etc damage the forest in large number.

53. PHLOEM
NECROSIS WILT
HEART ROT

54. 7.Landslides
 Developmental activities like construction of
roads,railways on mountains leads to landslides
 This leads to deforestation

55. 8.Mining
 For metals such as gold,copper,aluminium etc clears
large area of natural forest

56. FOREST SCENARIO OF INDIA
• India’s geographical area is 328mha,human population 1
billion and cattle population about 0.5 billion
• India is the 2nd
most populous & 7th
largest country in the
world
• India’s forest cover is 2% of world’s forest sustain the need
for 17% of human and 18% of livestock population of the
world
• One of the 12 mega diversity regions in the world.flora-
47500 & fauna-89000 sps
• Of 570,000 villages in the country,30% of villagers depend
on forest resources for daily needs
• About 60% of country’s cattle gazing in the forest area
• About 5% of geographical area covered under 572 protected
areas

57. Madhya Pradesh has the
largest forest cover in India
Arunachal Pradesh has the
2nd largest forest cover in
India

58. Western Ghats are another
bio-active forest cover of
India
Forests in
Himachal Pradesh

59. A NASA photo of India's North Sentinel Island
covered with forest

60. THANK
YOU