CHAPTER 2: ECOLOGICALCONCEPTS ANDECOSYSTEM PRINCIPLES

DEFINITIONAND SCOPEOF ECOLOGY

It isderived from the Greek words for " "and" " for" "
or " "
Initsmost basicdefinition, ecologyisthe studyof the interconnected homes on
Earth, whichinclude humans, plants, animals, and microorganisms.
Ecologycanbe considered asthe "study of the structure and function of
nature," withthe understandingthathumans are apartof nature since it is
concerned notjust with creatures but also withenergyflows and material cycles on
the land, the sea, the air, and infreshwater.
Biocentrism is the idea that humans are a part of nature.
Anthropocentrism isthe idea that humans are separate fromnature.
A furtherdescriptionof ecology is the "totality orpatternof relationships
betweenorganisms andenvironment."
This pattern of relations is quite complex and non-linearunder field settings.
Therefore, ecology is the study of howacreatureinteracts with its
surroundings.
Althoughthis definitionappears simple, it is quite complex. Because there are so
manyvariables that might affect an organism's (oranorganism's environment),
even interactions betweenmoderately complex creaturesinjust moderately
complex environment are intractablycomplicated.
Thus, the fields of research collectively referredto as ecologyhave a reputation for
being extremelychallenging. Fortunately, ecological understanding tendsto be
established on onlya few broadlyapplicable principles, at least at a basic level.
Considerthe concept of levels of organizationtodefine ecologyinterms of
shifting emphasis (figure 1).
The ecosystem is the basic functional unit onearththat sustainlife.
System and Model
The natural world is extremely complex. Scientists typically attempt to
conceptualize the phenomena of nature as a system to comprehend itscomplexity.
A system is made up of several interrelated components that are contained inside
a physical boundary and that behave as a whole in a way that is fundamentally different
from how they behave individually. Particularly, the system's behavior is more stable than
the behavior of its separate parts.
Systems are frequently represented or depicted as component blocks
connected in some way. For instance, the picture in Figure 2 below explains how the
Earth intercepts solar energy. The preceding definition of the term " " has a
comparable scientific meaning to that ofthe word " ."
The Earth and Sun are represented by two colored circles of varying sizes in this
systemas the parts orcomponent blocks. The sketched line serves as an illustration of the
connection between the solar emission process and the Earth's capacity to absorb solar
radiation.
WhatKeepsUsandOtherOrganismsAlive?
Life is supported by gravity, the movement of nutrients within the biosphere, and
the flowof solarenergythroughit.
CommonCharacteristics of Most Systems:
1. The components andprocesses that make up asystem define its structure.
2. Systems are abstractions from the real world.
3. Systems frequentlyoperate inthe same way. This involves material, energy, and
informationinputsand outputs that are processed to transform it insome way.
Thesystem contains three different types of characteristics inside its defined
boundary:
1. Elements - The kind of objects orsubstances that make up the systemare called
elements. They could be smaller units ofthings like atoms or molecules orlargerones like
sand grains, raindrops, plants, orcows.
2. Attributes- The qualities of anelement that maybe perceivedare called attributes.
Some examples are quantity, size, color, volume, temperature, and mass.
3. Relationships- The linkagesbetweenelements andattributes that are based oncause
and effect are referred to as relationships.

Stateof theSystem
When each of the system's properties—such as its elements, attributes, and
relationships—has a specificvalue, the state of the systemis known.
System Hierarchy
A hierarchy is a type of organizational system where things are ranked by
importance. The majority of organizations, governments, and organized religions follow
hierarchies.
System of itemsorpeople arranged ina hierarchy.
Describes hierarchically structured systems, where eachrow of things is
connected to the objects nearest to it.
In daily life, hierarchical structures are everywhere. For instance, the army is a
hierarchical organization, with generals at the top and privates at the bottom of the
pyramid. Similar to this, a hierarchy is used to categorize plants and animals according to
species, family, genus, and otherfactors.

[OnlineImage] https://www.simply.science/index.php/organization-of-life
ECOSYSTEM
ECOLOGICALSYSTEM (RoyClapham coined thisterm in 1930)
Ecosystem: According to the Convention on Biological Diversity (1992), it is "a
dynamic complex of plant, animal, and microorganism communities and their
non-living environment interacting as a functional unit."
Any ecological unit that consists of all the living things, communities, and their
interactions with one another and their physical surroundings, resulting in a flow of
energy that produces a system with a well-defined trophic structure, biotic
diversity, and material cycle.
A groupof livingthings that interactas a system, includingbothnon-living andliving
elements of their surroundings.

Ashajyoti (2020) [OnlineImage] https://sciencequery.com/biotic-

factors-and-abiotic-factors-in-the-ecosystem/
What distinguishes anecosystem from alandscape?

Ecosystems are made up of groups of living things and the surroundings in which
theylive.
In terms of the spatial context of scales (physical aspects of landforms, living
elements of land cover, human elements, and transitory properties), the landscape
has a largerdefinition.
What distinguishes thebiospherefrom the ecosystem?
All ecosystems are included inthe biosphere (lithosphere, atmosphere, and
hydrosphere).
As opposed to an ecosystem, which is a single community of living things. The area on or
near the surface of the Earth that is home to and sustains living things is known as the
biosphere.Thelithosphere,atmosphere,and hydrosphereareitsthreedivisions.
What distinguishes anecosystem from the environment?

Environment refers tothe area aroundyou.

A community that exists within anenvironment is called an ecosystem.
What distinguishes anecosystem from acommunity?

By"community," we meanthe biotic elementsof an ecosystem.

An ecosystem ismade upof biotic and abioticelements.

TYPES OF ECOSYSTEMS
1. Natural ecosystems
Functionindependently of significant human influence. basedonthe specifictype of
habitat.
Terrestrialenvironments including asingle log, grassland, desert, and forest.
 TerrestrialEcosystems -referstotheterrestrial ecology.
Byarea,it makes up28%oftheearth.
Extremely abundantfloraandfauna.
Differentandmorecomplex thanaquatic environments.
Classifiedaccordingtoclimatedifferences.

Aquatic ecosystemscan be furtherbrokendownintothe following categories:

(a)Freshwater ecosystems
(b)Marine ecosystems
Main Difference:
Waterrestrictions
Temperature changes
Thepresenceofsunlight
Gas availability
2. Artificial ecosystems
Man-made or manufactured ecosystems are called artificial ecosystems. These are
maintained artificially by man in places where the natural balance is routinely disturbed by
the addition of energy and intentional manipulations, such as croplands like sugarcane,
maize, wheat, and rice fields, orchards, gardens, towns, cities, dams, aquariums, and
mannedspaceships.

What distinguishes abiomefrom amicrohabitat?

A microhabitat is atinyhabitat that exists witha largerone.
While the biomeprovides afarmore comprehensive description of the sort of land.
What is aBiome?
A huge regionthat is categorized according to its climate and the kind of species
that cansurvive there.
BIOMES
 A biome is an extensive group made up of different species of plants and animals.
Every biome has the same type of climax vegetation—grasses, conifers, and deciduous
trees—but various regions of the biome mayhave different plant species.

The followingare the MajorBiomes:

Tundra
Taiga
Moist temperate coniferous forest biome 
TemperateDeciduous forest biome
Temperategrasslandbiome
Savanna
Desert biome
Tropicalrainforest biome
Chaparral biomes

ECOSYSTEM THEORY
The structural and functional core of ecology is the ecosystem, which is where
interactions between living things and their surroundingstake place.
FUNCTIONS OF ECOSYSTEM
It maintains stability, supports life systems, and controls important ecological
processes.
Additionally, it is in charge of the transfer of nutrients between biotic and abiotic
elements.
It keepsthe ecosystem's various trophic levels ina state of balance.
The minerals are cycled throughthe biosphere.
The synthesis of organic components, which requires the exchange of energy, is
assisted bythe abiotic components.
What HappenstoEnergy in anEcosystem?
 Energy moves throughfood chains andwebs inecosystems.
The amount of chemical energy accessible to animals at each consecutive feeding
level decreases asenergymoves throughecosystemsinfood chains andwebs.

ENERGY FLOW
FOODCHAIN
Life is moved by energy. The movement of energy via various trophic levels in an
ecosystem is the basis of the energy cycle. The energy and nutrients that cycle through
our ecosystem come from several external sources.
The sun is the primary energy source for the planet. All plant life depends on it for
the energy needed to function. Plants use this energy to create their food through the
process of photosynthesis.
Light energy is transformed into chemical energy and transferred through
successive stages during this biological process. The term "food chain" refers to the
transfer of energy from a producer to a consumer and ultimately to an apex predator or a
detritivore. Scavengers break down organic waste and dead and decaying stuff into their
parts. These components are then absorbed by the reducers. After gaining energy, the
reducers release moleculesinto the environment that the producers canuse again.
[OnlineImage] https://www.vedantu.com/question-answer/give-a-diagrammatic-representation-of-energy-class-12-
biology-cbse-5faa148e6ce1fc00b07bbbb8

FOODWEB
A network of connected food chains is referred to as a food web. It includes every
food chain found in a particular ecosystem. Understanding that plants form the basis of all
foodsystems is essential.
OnlineImage} https://www.legendsoflearning.com/learning-objectives/food-webs-in-an-ecosystem/

NUTRIENT CYCLE
The transfer and interchange of organic and inorganic material to create new living
things. The previously described food web routes, which convert organic materials into
inorganic nutrients, control the process. Within ecosystems, there are nutrient cycles.
Water, carbon, oxygen, andnitrogencycles are examples of nutrient cycles.
ColumbiaEnvironmental ResearchCenter(2021). [OnlineImage}
https://www.usgs.gov/media/images/basic-overview-nitrogen-cycle
OPENSYSTEM
Interacts withits surroundings by bringing inenergy and materials from outside
sourcesandsending outputs there.

A tree gathers energy from the sun, as well as nutrients and water from the soil,
CO2 from the air, and other materials. A tree's "system" produces oxygen, water, and litter
inthe form of fallenleaves. Similar to opensystems, humans and othercreatures are.

CLOSEDSYSTEM
Systems that are isolatedand onlyexchange energyrather thanmatter.
 The distribution of water as a liquid, solid, or gas is constant throughout the water
cycle. Neithermore waterfrom space nor water evaporating from the Earthis happening.

BiogeochemicalCycles
Anyofthenaturalpathwaysbywhichessential elements ofliving matter are
circulated.
Elementswithinbiogeochemicalcyclesflowin variousformsfromthenonliving
(abiotic)componentsofthe biosphere totheliving(biotic)componentsandback.
TypesBiogeochemicalCycles
WaterCycle
CarbonCycle
NitrogenCycle
OxygenCycle
Phosphorouscycle
SulphurCycle