CONTENTS

ECOLOG1. Y & ECOSYSTEM .............. 1

ORIGIN OF LIFE FORMS1.1 ........................ 2Evolution of Earth ................................ 2

Origin of Life Forms ............................. 2

ECOLOGY & ECOSYSTEM1.2 ...................... 5Environment ....................................... 5

What is Biosphere? .............................. 5

What is Ecology? ................................. 6

What is Ecosystem? ............................. 8

Ecological Succession ........................10

Ecotone ...........................................12

FUNCTION2. S OF AN ...................... 15 ECOSYSTEM

FUNCTIONS OF AN ECOSYSTEM2.1 ..........16Energy Flow ......................................16

Bioaccumulation ................................22

Biomagnifi cation ................................22

POPULATION3. ECOLOGY .............. 24

POPULATION ECOLOGY3.1 ......................25Types of Species ................................25

Population Ecology .............................26

Population Growth Models ...................28

ADAPTATION & 4. .......................... 29 INTERACTIONS OF SPECIES

ADAPTATION4.1 & INTERACTION ............30 OF SPECIES

Homeostasis .....................................31

Interaction between Species ................32

TYPES O5. F ECOSYSTEMS ............ 35

TYPES OF ECOSYSTEM5.1 .......................36Terrestrial Ecosystem .........................37

Forest Ecosystem in India ....................38

Aquatic Ecosystem .............................42

AQUATIC ECOSYSTEM5.2 ........................42Tundra .............................................47

BIOMES OF THE WORLD5.3 ......................47Taiga ................................................48

Grassland .........................................49

Tropical Rainforest Biome ...................50

Desert Biome ....................................51

Deciduous Forest Biome ......................51

Plankton ...........................................53

MARINE ORGANISMS5.4 ..........................53Sea-grass .........................................55

Seaweeds .........................................56

NUTRIENT6. CYCLING .................... 57

CONCEPT O6.1 F BIOGEOCHEMICAL ..........58Concept of Bio-Geochemical Cycles ......58

Steps in Carbon Cycle .........................60

CARBON CYCLE6.2 ..................................60Different Steps of the Hydrological .......63 Cycle

HYDROLOGICAL CYCL6.3 E .......................66 NITROGEN CYCLE

ENVIRONMENT - I

OXYGEN CYCLE6.4 ..................................68

SULPHUR CYCLE6.5 ................................69

Parts of the Cycle ..............................70

PHOSPHORUS CYCLE6.6 .........................70

BIODIVERSITY7. ............................. 71

BASICS OF BIODIVERSITY7.1 ...................72

Biodiversity .......................................72

Bio-Geographical Classifi cation ...........74 of World

Bio-Geographical Classifi cation ...........74 of India

Biodiversity Hotspots .........................75

Causes of Biodiversity Losses .............78 (‘The Evil Quartet’)

THREATS TO BIODIVERSITY7.2 ................78

Invasive Species ................................79

Effects of Loss of Bio-Diversity ............81

Extinction of Species ..........................81

IUCN Red List ....................................81

Miscellaneous ...................................84

India Faces Grave Danger to ...........84 Soil Biodiversity: WWF

Floods trigger infl ux of alien ..........84 fi sh species in Kerala

Mangalajodi Ecotourism Trust .........85

BIODIVERSITY CONSERVATION8. .. 87

BIODIVERSIT8.1 Y CONSERVATION ...........88

Biodiversity Conservation ....................88

Miscellaneous ...................................95

Vetiver Grass .....................................95

Red Sanders ......................................96

Khangchendzonga Biosphere Reserve ...97 was included in the UNESCO’s ................ World Network of Biosphere ................... Reserve (WNBR)

Ex-situ Methods of Conservation ..........98 of Biodiversity

EX-SITU8.2 .............................................98

NATIONAL PARKS8.3 .............................100

Other National Parks ........................103

Miscellaneous .................................104

Bandipur National Park ................104

New Wildlife Sanctuary ...............104 at Ghodazari

Approval for the Trishna Gas ........105 project of ONGC which falls in the ...... Trishna Wildlife Sanctuary

Project Tiger ..............................106

SPECIES BASED8.4 ...............................106 CONSERVATION PROGRAMS

Project Elephant ..............................109

Project Snow Leopard .......................111

Vulture Conservation Project .............112

Crocodile Conservation Project ..........113

Ganges Dolphin Project .....................114

Other Projects .................................115

Miscellaneous .................................117

Nilgiri Tahr: Climate change .........117 threatening 60% of its habitat

Wild Horses Have Gone Extinct ......118

Assam to observe ‘Rhino Day’ ......119 on September 22

Rise in Rhino Population in ..........119 Kaziranga National Park

Swelling Salinity Threatens ..........119 Gangetic Dolphins

Indus Dolphins (BHULAN) .............120

Bahuda Rookery: Another Olive ....120 Ridley Nesting Site in Odisha

Global Tiger Recovery Program .....121

Tiger Census 2018 ......................121

Asiatic Lion Conservation Project’ .122 launched by Government

Vaccination of Gir lions against ....122 deadly canine distemper virus

Rajasthan’s fi rst lion safari ...........123 inaugurated at Nahargarh ................. Biological Park

NTCA, Cheetah Reintroduction .....123 Project: Nauradehi Wildlife ................ Sanctuary

Black Panther ............................124

Monkey Declared Vermin in .........124 Himachal Pradesh

Harrier Birds ..............................125

Odisha police launch drive to .......125 bust Pangolin smuggling racket

Uttrakhand HC declares entire ......126 animal kingdom as legal entities

Andaman & Nicobar Islands home ..126 to tenth of India’s fauna species: ZSI

World’s Smallest Land Fern ...........127

Conservation of migratory birds ....127 and their habitats

The National Wildlife Genetic ........127 Resource Bank

Conservation Assured | Tiger .......128 Standards (CA|TS) Partnership

Recovery Programme For Wildlife .128 Species

Prevention of cruelty to animals ...128 (Karnataka Amendment) Bill

International Whaling ..................129 Commission

AQUATIC9. ECOSYSTEMS ............ 130 & FOREST RESOURCES

ESTUARIES9.1 ......................................131

What are Estuaries? ..........................131

Characteristics of Estuaries ...............131

Types of Estuaries ............................131

Major Estuaries in Indian ..................132 Coastal States

Difference between Lagoon ...............134 and Estuary

What are Mangroves? .......................135

MANGROVES9.2 ....................................135

Legal and Regulatory Approaches .......136 for Protection

Mangroves in India ...........................137

What are Wetlands? ..........................139

Types of Wetlands ............................139

WETLANDS9.3 ......................................139

Wetlands in India .............................140

Conservation of Wetlands in India .......141

Ramsar Convention ..........................141

National Wetland Inventory and .........143 Assessment (NWIA) Project ..............143

National Plan for Conservation ..........143 of Aquatic Eco-systems

Wetland (Conservation and ...............144 Management) Rules, 2017

Miscellaneous .................................145

Floating Treatment Wetland ..........145

What are Coral Reefs? ..................147

CORAL REEFS9.4 ...................................147

Coral Reefs of Distribution? ...............148

What steps are being taken in ............148 India to conserve coral reefs?

Threats to Coral Reefs ......................149

Miscellaneous .................................149

STAPCOR – 2018 ........................149

Defi nition of Forests by FSI ...........151

Types of Forest Cover ..................151

FSI Report 2019 ..........................151

FOREST RESOURCE9.5 ..........................151

Deforestation ..................................152

Government Programmes for .............154 Conservation of Forests

Miscellaneous .................................158

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1

UNIT

1

ECOLOGY& ECOSYSTEM

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CHAPTER

1.1

Evolution of Earth

Geologists estimate that the earth is somewhat 4.5 billion year old.

The beginning of geological era, the Precambrian, which extended from 4.5 to 0.5 billion year’s ago, witnessed the production of an atmosphere and a hydrosphere. The evolution of preliving components and their autotrophic life takes place thereafter.

The internal reorganization of Earth and the development of ocean basins and continents took place simultaneously.

On the whole over the years of the geological past, the Earth’s geomorphology, climate and biotic community changed gradually. In early Paleozoic era ( just after Precambrian) some million years ago, there were separate land masses existed in earth viz Asia, North America and Europe and Gondwanaland (which includes present day Africa, South America, Australia, New Zealand and Antartica).

During late Palaeozoic era around 420 million years ago, North America and Africa lay close together around the south pole and the rest of Gondwanaland lay on the far side of the south pole, pointing towards the equator. Subsequently such land mass slowly moved northward by carboniferious period (340 millions years ago).

During the Permian periods, however, all three blocks of land masses joined together forming a single landmass called “Pangaea”, which further moved north ward, and began to break apart slowly by mid Mesozoic period.

Subsequently, by the mid-cretaceous (about 100 million years ago), Africa and South America had split apart and also by the end of cretaceous period, Gondwanaland had broken up. But North America land remained intact till lower Eocene period.

Then it split into North America and Europe connected by Greenland and Scandinavia. Thus the formation, breakup and northward drift of continents resulted in broad climate changes and the formation of geological barriers that affected evolving plant and animal’s life.

Origin of Life Forms

Aerobic life cannot exist without oxygen, which was not a part of the original atmosphere. However, life in the form of primeval bacteria and algae evolved without oxygen; these life-forms consumed carbon dioxide and nitrogen, which were in the original atmosphere, and emitted oxygen as a waste.

In addition to adding oxygen to the atmosphere, this process also formed the ozone layer, which fi lters out harmful ultraviolet radiation from the sun. The fi rst life-forms evolved in the seas.

As indicated in Table, there is evidence of life-forms as early as 3,500 mya, of an ozone layer 2,500 mya, and of a breathable oxygenated atmosphere 1,700 mya. Such early life-forms were not affected by the absence of an ozone layer because they lived below the surface of the water.

ORIGIN OF LIFE FORMS

3

Oxygen-breathing life, initially single and later multi-celled, appeared following the creation of a suitable atmosphere. Soft-bodied animals, comparable to jellyfi sh, evolved 650 mya, and shelled animals about 70 million years later.

Human ancestors diverged from the ape line approximately 6 mya. The most compelling evidence of a common origin is that humans and chimpanzees differ in only about 1 per cent of their genes; this means that these species could not have been evolving separately for more than about 6 million years.

Eons Era Period EpochAge/Years

Before PresentLife/Major

Events

Cainozoic (From 65 million years to the present times)

QuaternaryHolocene 0 - 10,000 Modern Man

Pleistocene 10,000 - 2 Million Homo Sapiens

Tertiary

Pliocene 2 - 5 MillionEarly Human Ancestor

Miocene 5 - 24 MillionApe: Flowering Plants and Trees

Oligocene 24 - 37 Million Anthropoid Ape

Eocene 37 - 58 Million Rabbits and Hare

Palaeocene 57 - 65 MillionSmall Mammals: Rats - Mice

Mesozoic 65-245 Million

Cretaceous 65 - 144 MillionExtinction of Dinosaurs

Jurassic 144 - 208 Million Age of Dinosaurs

Triassic 208 - 245 Million Frogs and turtles

Palaeozoic 245 - 570 Million

Permian 245 - 286 MillionReptile dominate-replace amphibians

Carboniferous 286 - 360 MillionFirst Reptiles: Vertebrates: Coal beds

Devonian 360 - 408 Million Amphibians

Silurian 408 - 438 MillionFirst trace of life on land: Plants

Ordovician 438 - 505 Million First Fish

Cambria 505 - 570 MillionNo terrestrial Life: Marine Invertebrate

Proterozoic

Pre Cambrian 570 Million - 4.800 Million

570 - 2,500 Million

Soft-bodied arthropods

Archean2,500 - 3,800 Million

Blue green Algae: Unicellular bacteria

Hadean3,800 - 4,800 Million

Oceans and Continents form - Ocean and Atmosphere are rich in Carbon dioxide

4

Origin of Stars

5,000 - 13,700 Million

5,000 Million Origin of the sun

Supernova 12,000 MillionOrigin of the universe

Big Bang 13,700 Million

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