Startup Victoria - Leveraging the Local Growth Startup Ecosystem
NOTES - A Local Ecosystem
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Transcript of NOTES - A Local Ecosystem
8.2 A Local Ecosystem
1. The distribution, diversity and numbers of plants and animals found in ecosystems are determined by biotic and abiotic factors
DefinitionsEnvironment – all the factors that affect living thingsCommunity – a naturally occurring group of organisms that interact with each otherPopulation – a group of organisms of the same species living in a certain areaEcosystem – any environment containing living organisms interacting with non – living parts of environmentHabitat – the place where the organism lives
Compare the abiotic characteristics of aquatic and terrestrial environments
Abiotic features – the non – living factors or features of an environment (physical, chemical properties i.e. temperature, pH level, rainfall)Biotic features – the living components or biological features (members of the same species and members of other species
Abiotic Factors Aquatic Environments Terrestrial EnvironmentsViscosity High viscosity in water Air is less viscous than waterBuoyancy The buoyancy of water offers
support to both animals and plants, helps to maintain shape and to function is oceans depths
Buoyancy does not affect terrestrial flora and fauna. They need to be able to support themselves
Temperature Water heats up more slowly than air
Surface temperature varies far more on land than water
Pressure Water pressure increases with water depth
Air pressure decreases with height
Availability of Gases Gas availability in water depends on the temperature
Concentration of gases in higher
Availability of Water and Ions Organisms in water are surrounded by dissolved ions
Water availability varies
Light Penetration Decreases with depth Light intensity is high
Identify the factors determining the distribution and abundance of a species in each environment
Abundance – the abundance of a species means how many individuals there are at a specific time and areaDistribution – is where a species is found
Abiotic Factors Biotic Factors Light Abundance of food Wind and rainfall Number of competitors Temperature Number of mates Effect of topography Number of Predators Tide, currents and waves Diseases Salinity, pH and water availability
Measuring Abundance Direct counting Using sample area as a guide Estimate of percentage cover Quadrat
Measuring Distribution Profile sketch Transect Surface map Observations Radar, cameras or tagging
Quadrats
Number in the quadrat Number in total area Area of the quadrat Total area
Capture marking – recapture
Estimated Population = number of animals tagged x number of animals recaptured Average number of tagged animals recaptured
Describe the roles of photosynthesis and respiration in ecosystems
Photosynthesis is the process by which plants cells capture energy from sunlight and use it to combine carbon dioxide and water to make sugars and oxygen.Photosynthesis provides nutrients and energy to organisms herbivores, carnivores and so energy and materials are passed from organism to organism.
CO2 + H2O C6H12O6 + O2
Carbon dioxide + water Glucose + Oxygen
Respiration is the process where the cells obtain energy, and break down sugars to produce carbon dioxide and water and energy is then released Respiration occurs in the mitochondria of cells.Respiration is a process carried out in all living cells to release energy for living, respiration changes glucose into chemical energy.
C6H12O6 + O2 H2O + CO2 + energy/ATPGlucose + Oxygen Water + Carbon dioxide + energy/ATP
Identify the general equation for aerobic cellular respiration and outline this as a summary of a chain of biochemical reactions
Aerobic Respiration process whereby glucose is broken down into carbon dioxide and water using oxygen and releasing energy.ADP – Adenosine DiphosphateATP – Adenosine Triphosphate
When ATP is broken down it becomes ADP which releases a large amount of energy.
ADP + Glucose + Oxygen Carbon dioxide + Water + ATP (energy)
Respiration occurs in 2 stages: - First stage, in the cytoplasm of the cells, 2 molecules of ATP is produced, this occurs with
anaerobic respiration. Second stage, in the mitochondria of the cells 36 molecules of ATP is produced, occurring
with aerobic respiration.Respiration involves a series of chemical reactions. It occurs as a sequence of 50 different reactions, each catalysed by a different enzyme. The bonds in the organic molecules, such as sugar are broken releasing small amounts of chemical energy; this energy is transferred to the energy carrier molecule
A P P P A P P
ATP. The energy released is used to convert ADP to ATP so that the energy can be used all around the body. 40% of the energy in glucose is converted into ATP the rest is lost as heat.
Identify uses of energy by organisms
Respiration is a process carried out in all living cells, this energy is used For growth and repair For movement To keep organs working For chemical reactions For movement of substances in the organism To synthesise compounds
2. Each local aquatic or terrestrial ecosystem is unique
Examine trends in population estimates for some plant and animal species within an ecosystem
Population of organisms do not remain at a constant level in an ecosystem, but sometimes the population increases dramatically this is called a population explosion. Population may also decline due to, diseases, predation, competition from other species and human impact on the ecosystem and sometimes the organisms become extinct because of these factors.
Outline factors that affect numbers in predator and prey populations in the area studied
Predator – An organism that obtains food by killing other organismsPrey – An organism that is killed for food
Size of ecosystem Diseases Availability of food Migration Reproduction Human activity Competition
Identify examples of allelopathy, parasitism, mutualism and commensalism in an ecosystem and the role of organisms in each type of relationship
Interactions Definition ExampleSymbiosis Species that live together in
communities, and interact with each other
Parasitism One species benefits and the other is harmed because of its presence
Leech and Human, leech sucks human blood while the human body is harmed
Mutualism Where two species interact with each other and benefit from both species
Tick bird and Zebra, tick bird removes parasites from the zebra and is also in access to food
Allelopathy The chemical inhibition of one species by another
Casuarina, it produces metabolites that prevent growth of plants in the same area
Commensalism One species gains and the other has no effect
The remora and shark, the remora is in access to food while the shark makes no attempt to feed on it
Describe the role of decomposers in ecosystems
Decomposers are organisms that absorb nutrients from dead tissue or waste products and returns organic material to the soil. They also make materials produced by decomposition available to plants, which is then recycled into the food chains. Bacteria and fungi are usually the main decomposers in an ecosystem.
Explain trophic interactions between organisms in an ecosystem using food chains, food webs and pyramids of biomass and energy
Trophic Interaction – Feeding relationship between organismsTrophic Level – Feeding level of an organismIn a natural environment, energy from sunlight enters through the process of photosynthesis then flows onto other organisms via food chains and webs. Photosynthesis can change the sun’s energy into chemical energy for other organisms.
Food ChainsA food chain illustrates what organisms eat what; the arrows indicate “is eaten by” and usually the food chain starts off with a producer.
Food WebsA food web is many food chains joined together; it shows the trophic interactions, energy flow of all living things in an ecosystem.
Producer – an organism that makes its own food, autotrophsConsumer – an organism that feeds on another living thing, heterotrophsHerbivore – a consumer that only feeds on plant materialCarnivore – a consumer that only feeds on animals
Biomass PyramidBiomass – The measure of the mass of all organisms at a particular trophic levelIn each transfer of energy about 90% is lost as heat and 10% is transferred to the consumer.
Energy Pyramid- Represents each trophic level- The amount of energy lost with each level
Define the term adaptation and discuss the problems associated with inferring characteristics of organisms as adaptations for living in a particular habitat
AdaptationThe area where an organism lives is because they survive in that habitat. Organisms have features that help them adapt to the environment which helps them survive. There are 3 types of adaptations:
1. Structural Adaptations – This refers to the physical structure of the organism2. Physiological Adaptations – This refers to the way the organism functions3. Behavioural Adaptations – This refers to the behaviour, how organisms respond to
its environment
CarnivoresHerbivoresProducers
Producers1st Order consumer2nd Order consumer3rd Order consumer
The word adaptation should be used carefully, human observations of characteristics of organisms come from human perspectives it not to say that a characteristic is an adaptation and an animal or plant in a specific location does not mean it has special adaptations to the habitat.
Identify some adaptations of plants and an animal from the local ecosystem
Mangroves KangaroosSupport and Movement Anchored by complex root
systems in the groundWell muscled hind legs are made for travelling at high speeds
Gaseous Exchange Gaseous exchange occurs through the aerial root’s tips
Use lungs for respiration
Water balance Mangroves control their salt level through:
Cells maintain higher concentrations of cell solutes
Secrete salt from leaves
Sufficient leaves will help them survive
Internal temperature Its leaves have thick cuticle and are hard and leathery, prevents water loss and wilting in hot weather
They seek shade of trees and bushes to maintain their body temperature
Obtaining light It is abundant to light for photosynthesis
They are nocturnal animals but are active in the early morning and early evening
Reproduction The seeds germinate before they are dropped from their parent plant to insure a root system for rapid growth
Marsupial process of reproduction
Describe and explain the short – term and long – term consequences on the ecosystem of species competing for resources
Short term- Availability of resources decreases- The growth of the population may decrease- If the population decreases the availability of food may increase
Long term- Degradation of the environment- Diversity of organism will be reduced- Extinction of species- Evolution
Identify the impact of humans in the ecosystem studied
- Land clearance and habitat destruction- Erosion and loss of soil- Salination and desertification- Pollution of air, water and soil- Fertilisers and pesticides- Loss of biological diversity- Exploitation and depletion of natural non – renewable resources- Production of poisonous materials- Introduction of new species of fauna and flora