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Key concepts

In this session we will focus on summarising what you need to know about:

  • Concept of an ecosystem
  • Structure and ecosystem function related to abiotic factors and biotic factors
  • Factors that influence terrestrial and aquatic primary production

Terminology&Definitions

Ecosystem - a community plus the physical environment that it occupies at a given time

Abiotic factors – non-living factors . Eg soil, air.

Biotic factors – living factors. Eg trees, insects.

Producer – organism that manufactures food by photosynthesis.

Herbivore – an organism that feeds on plants only.

Carnivore – an organism that feeds on animals only.

Omnivore – an organism that feeds on both plants and animals.

Saprotroph – an organism that feeds on dead and decaying matter. (fungi)

Decomposers – an organism that causes the decay of dead and dying organisms. (bacteria)

Scavenger – an organism that feeds on remains of animals.

Predator – an animal that hunts for its food.

Prey – an animal that is hunted and is food for the predator.

Food chain – a chain showing feeding relationships between organisms.

Content

An ecosystem is a community of living organisms interacting with each other and their environment. Ecosystems occur in all sizes. A tidal pool, a pond, ariver, and a yellowwood forest are all examples of ecosystems. The living organisms (plants and animals) are referred to as biotic factors.The non-livingcomponents make up the abiotic factors. Organisms living in a particular ecosystem are adapted to the prevailing abiotic and biotic conditions.

Abiotic components

Abiotic factors may be grouped together as:

  • Physical / Climatic factors: sunlight, water, temperature and gases.
  • Edaphic factors: soil type, soil pH.
  • Physiographic factors: slope, aspect and altitude and latitude.

Climatic factors:

Sunlight

  • Light is a fundamental necessity.
  • The amount of sunlight an ecosystem receives is called insolation. This is critical for plant survival, especially in aquatic ecosystems. Light decreasesand water depth increases.
  • Amount of light changes from season to season.
  • In summer – days are longer, ecosystems gets more hours of sunlight than during short winter days.
  • The amount of sunlight affects other features of the ecosystem such as temperature, and the types of plants and animals that are found there.

Temperature

  • Temperature increases with an increase in both latitude and altitude.
  • Temperature affects the rate at which photosynthesis, respiration and decomposition take place. The higher the temperature, the faster the processes.

Water

  • Water is one of the most important factors in the ecosystem.
  • It is the main component of living cells and is essential for all living organisms.
  • About 80% of the human body and 90% of the plant body consists of water.
  • Water is evenly distributed over the earth.
  • It is abundant in aquatic ecosystems and least in deserts
  • Plants are adapted to the available amount of water in the following ways:
    • Xerophytes are plants that are able to live in dry habitats, or in regions with low annual rainfall. These plants are resistant to drought, have to cope withshortage of water, high temperatures and light intensities and dry warm winds. ie Cactus, Aloe
    • Hydrophytes are plants that are able to live entirely or partially in submerged water ot in very wet soil. These plants have to cope with a water surplus. ieWater lily, Water hyacinth
    • Mesophytes are plants that need an average, regular supply of water. ie Fruit trees, wheat

Questions & Answers

the diagram of the digestive system
Assiatu Reply
allimentary cannel
Ogenrwot
How does twins formed
William Reply
They formed in two ways first when one sperm and one egg are splited by mitosis or two sperm and two eggs join together
Oluwatobi
what is genetics
Josephine Reply
Genetics is the study of heredity
Misack
how does twins formed?
Misack
What is manual
Hassan Reply
discuss biological phenomenon and provide pieces of evidence to show that it was responsible for the formation of eukaryotic organelles
Joseph Reply
what is biology
Yousuf Reply
the study of living organisms and their interactions with one another and their environments
AI-Robot
the study of living organisms and their interactions with one another and their environment.
Wine
discuss the biological phenomenon and provide pieces of evidence to show that it was responsible for the formation of eukaryotic organelles in an essay form
Joseph Reply
what is the blood cells
Shaker Reply
list any five characteristics of the blood cells
Shaker
lack electricity and its more savely than electronic microscope because its naturally by using of light
Abdullahi Reply
advantage of electronic microscope is easily and clearly while disadvantage is dangerous because its electronic. advantage of light microscope is savely and naturally by sun while disadvantage is not easily,means its not sharp and not clear
Abdullahi
cell theory state that every organisms composed of one or more cell,cell is the basic unit of life
Abdullahi
is like gone fail us
DENG
cells is the basic structure and functions of all living things
Ramadan
What is classification
ISCONT Reply
is organisms that are similar into groups called tara
Yamosa
in what situation (s) would be the use of a scanning electron microscope be ideal and why?
Kenna Reply
A scanning electron microscope (SEM) is ideal for situations requiring high-resolution imaging of surfaces. It is commonly used in materials science, biology, and geology to examine the topography and composition of samples at a nanoscale level. SEM is particularly useful for studying fine details,
Hilary
cell is the building block of life.
Condoleezza Reply
what is cell divisoin?
Aron Reply
Diversity of living thing
ISCONT
what is cell division
Aron Reply
Cell division is the process by which a single cell divides into two or more daughter cells. It is a fundamental process in all living organisms and is essential for growth, development, and reproduction. Cell division can occur through either mitosis or meiosis.
AI-Robot
What is life?
Allison Reply
life is defined as any system capable of performing functions such as eating, metabolizing,excreting,breathing,moving,Growing,reproducing,and responding to external stimuli.
Mohamed
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Source:  OpenStax, Siyavula: life sciences grade 10. OpenStax CNX. Apr 11, 2012 Download for free at http://cnx.org/content/col11410/1.3
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