Ecology: Nutrient and Nitrogen Cycles

• Ecology is the study of the relationships between living organisms and their environment.

Nutrient Cycles

• Nutrient cycles are processes that move essential elements through the biotic and abiotic components of an ecosystem.

Nitrogen Cycle

• Nitrogen is converted into multiple chemical forms as it circulates among the atmosphere, terrestrial, and marine ecosystems.
• Nitrogen-fixing bacteria convert atmospheric nitrogen (N2) into ammonia (NH3) in the root nodules of leguminous plants.
• This process allows nitrogen to combine with hydrogen gas, forming ammonia/ammonium ions.
• Nitrates, which are nitrogen-containing compounds, are formed in the soil which plants absorb by active transport or diffusion.
• The nitrates absorbed by plants are then used to make amino acids that are required to make proteins for growth, enzymes, hormones, and nucleic acids (DNA).
• Saprophytic bacteria/decomposers break down dead plants, animals, and organic waste products to release proteins into amino acids.
• Amino acids are converted into ammonium ions and sugars.
• The ammonium ions are then deaminated into ammonium ions/ammonia.
• Nitrifying bacteria transforms ammonium ions into nitrite and then into nitrate under aerobic conditions, these nitrates are then absorbed by plants

Denitrification

• Denitrification is when nitrates are converted back into nitrogen gas by denitrifying bacteria under anaerobic conditions, such as waterlogged soils.
• Nitrogen is necessary for plants to produce proteins for growth, which are then passed on to humans and animals.
• Summary of Nitrogen Cycle:
  • Nitrogen Fixation: Lightening/nitrogen-fixing bacteria in root nodules of leguminous plants.
  • Decomposition: Performed by saprophytic bacteria/decomposers.
  • Nitrification: Under aerobic conditions, nitrifying bacteria convert ammonium ions into nitrites, and then nitrates.
  • Denitrification: Denitrifying bacteria convert nitrates back into nitrogen gas under anaerobic conditions.

Carbon Cycle

• Carbon cycles through the environment via multiple pathways
• Factors affecting the carbon cycle:
  • Deforestation: Increases CO2 concentration in the atmosphere as there are fewer photosynthesizing plants, and decomposition of dead roots releases CO2.
  • Burning of fossil fuels: Increases CO2 levels due to the rising energy demands and number of vehicles.
  • Increased population: Leads to increased respiration, thereby increasing CO2.
• Greenhouse Effect: As short-wave radiation is reflected as long-wave radiation; CO2 traps this long-wave radiation in Earth's atmosphere.

Water Cycle

• The water cycle consists of evaporation/transpiration, condensation and cloud formation, and precipitation/rainfall.
• Factors affecting water cycle:
  • Deforestation: Reduced transpiration due to fewer leaves results in less water vapor added to the atmosphere.
  • Less rain fall

Energy Flow

• Energy flows through an ecosystem from one trophic level to the next.
• Food Chain Example:
  • Plant (Producer at the first trophic level) → Rabbit (Primary Consumer/Herbivore at the second trophic level) → Tiger (Secondary Consumer/Carnivore at the third trophic level)
• Definitions:
  • Producer: Organisms that make their own food through photosynthesis.
  • Decomposers: Microorganisms like bacteria and fungi that gain energy from dead materials and return minerals back to the soil.
  • Herbivores: Organisms that feed on plants.
  • Carnivores: Organisms that feed on animals only.
  • Trophic Level: The position of an organism in a food web or food chain.
  • Food Web: Several food chains that are linked together.
    • Advantages: Each living organism has more than one food source.
• Efficient energy transfer occurs in shorter food chains; highest trophic levels have smaller populations.

Energy Transfer in Trophic Levels

• Only 10% of energy is transferred to the next level with 90% being lost to the environment through excretion, respiration, movement, and egestion (undigested food).
• Less energy available for organisms at higher trophic levels limits the size of their populations.
• Population sizes may also be impacted by disease, hunting, introduction of new species, and habitat destruction.

Biomass Production in Aquatic Food Webs

• Primary consumers use energy to produce biomass for secondary consumers through:
  • Animal feed on other organisms
  • Digesting food particles
  • Utilizing small soluble substances like glucose and amino acids.
  • Glucose is used in respiration for energy, growth, and cell division (mitosis).
  • Building large biological molecules, such as protein molecules, and storing excess as glycogen/fats.

Pyramids

• Pyramids are used to graphically represent ecological relationships.

Pyramids of Numbers

• Represents number of organisms at each trophic level.
• Limitations: One large individual (e.g. tree) is counted the same as a tiny one and don't account for organism size, so is not always pyramid shaped.

Pyramids of Biomass

• Shows the total mass of organisms at each trophic level.

Pyramids of Energy

• Represents amount of energy present at each trophic level.
• Only about 10% of energy is transferred from lower to higher trophic levels.
• Energy loss occurs at each trophic level, resulting in a pyramid shape.

Food Production

• Modern Machinery:
  • Positive: Faster cultivation and harvesting, enabling more land use.
  • Negative: Increased fossil fuel consumption, leading to pollution, and soil compaction, which hinders rainwater penetration.

Use of Artificial Fertilizers:

- Positive: Increasing soil fertility by providing minerals like nitrates and magnesium.
- Negative Effect Eutrophication
    - Increasing population of bacteria/decomposers
    - Acting as decomposers
    - Decomposers Respire aerobically
    - Decrease the O2 concentration in water
    - Damage to the aquatic life
    - Less food for consumers / loss of biodiversity
- Solutions:
    - Control use of fertilsier
    - Only apply on growing plants
    - Don't spray near rivers and streams
    - Never apply on empty field
    - Don't place when rain forecast
    - Use animal manure

Use of Pesticides and Herbicides

• Herbicides kills herbs
• Insecticides kill insects
• Fungicides kill fungi that might infect plants
  • Positive Effect:
    • Insecticides kill insects to avoid crop damage, enhancing crop yield.
    • Herbicides eliminate herbs, thus preventing competition for nutrients, light, and water, which results in increased crop yield
  • Negative:
    • Non-biodegradable chemicals lead to bioaccumulation and biomagnification.
    • Disrupts food chains and decreases biodiversity, increasing the risk of extinction.
    • Insects/herbs might become resistant to insecticides/herbicides.
    • Kill useful plants or insects, leading to pollution.
  • Solutions:
    • Check the weather forecast to avoid transfer to nearby area
    • Avoid kill useful insects/plants
    • Only apply the required number of times
    • The pesticide/herbicide should be biodegradable

Monoculture

- Positive:
    - Efficient food production and less land area required
    - Mechanical harvesting is easier.
- Negative:
    - Increases the risk of disease spread due to crowded conditions with one type of plant.
    - Depletes specific minerals from the soil, decreasing soil fertility and necessitating artificial fertilizers, which can lead to eutrophication and damage aquatic life.
    - Increases pest populations and reliance on insecticides.
    - Kills useful insects such as pollinators, and causes bioaccumulation.
    - Decreases other pest populations.
    - Disrupts food chains and decreases biodiversity and increases risk of extinction
    - Deforestation.

Deforestation..

• Destroys habitats and limits food/shelter options for species
• Disrupts food chain
• Soil erosion
• Desertification
• Increase of CO2 concentration increase, enhanced green house effect and global warming
• Solutions: - Applying mixed crop rotation - By planting different crops in the same field can reduce pest population - By breaking their life cycles and allow mineral balance, so less use of fertiliser

Modern Irrigation System

- Positive:
    - Provides water to growing plants, which removes a limiting factor
- Negative:
    - Can lead to leaching of minerals from soil

Selective Breeding (Intensive Farming)

- Positive:
    - Improved variety of animals and plants
    - High quantities of food to feed animals so increases production of milk, meat and wool
    - Given regular medications to animals so they stop developing diseases
    - Maximizing their growth rate by keeping them under a controlled temperature
- Negative:
    - Over crowded places leads to spread of disease
    - They increase dosing of antibiotic so increasing the chance that bacteria becomes resistant to antibiotics
    - Decrease in genetic diversity and biodiversity...increase risk of extinction
    - Waste and left overs from animals cause pollution.
    - Bad smell
    - Water borne disease
    - Visual pollution
    - Increases of organic content of rivers
    - Increase of growth of decomposers
    - Increase of plant growth
    - Eutrophication
    - Feed them with high energy food will increase cost
    - Methane gas from cattle chewing enhance greenhouse effect...global warming

Selective Breeding

• Selective breeding is used in artificial selection
• Involves breeding animals using artificial insemination (AI).
• Used in conservation, captive breeding programs, AI and IVF
• Genetic Diversity
• Is total alleles in a gene pool within same species
• Biodiversity involves genetic diversity, species diversity, habitat diversity

Genetic Engineering

- Positive:
    - Crop plants resistant to herbicide
    - Example: soya beans... Less competition... So more growth... So increase in crop yield
    - Resistance leads to less use of insecticides
    - Golden rice is rich in vitamin A

• Can be engineered into a more convenient, such a potatoes which absorb less fat becoming more crisper. - Plants can be modified to be Pathogen resistant... Increase crop yield - Resistant to drought

• Positive: - Plants can be genetically modified to have a high rate of growth to increase crop yield and food production

    - Negative:
    - Reduces natural biodiversity, and may lead to creating a super weed if the herbicide resistant plant cross pollinate with a wild relative. or cause bacteria to escape from laboratories and result in unpredicted consequences
  

Deforestation

• Increase land area available for food production, agriculture
• Gets wood for buildings
• Gets wood for furniture
• Urbanization
• Wood as a source of energy Negative effects:
  • Atmosphere;
    • Releases carbon dioxide and increases atmosphere temperatures -Global Increase / rise in sea levels
    • Flood
    • Destruction of habitat
    • Disruption of the food chain
    • Puts animals at risk of extinction
• Soil
• Causes water logging
• Puts animals at risk of extinction
• The loss of top soil can cause animals to go homeless
• Rivers
• Results washed soil into the rivers which causes flood

Air Pollution

• Human influence:
• Describes the role of different chemicals needed to increase food production
• Carbon dioxide Source Deforestation:
• Results:
• Decrease in Co2 amount
• Can be attributed to less growth
• The atmosphere's carbon dioxide increase is increase respiration
• Burning of fossil fuels: Increase Co2 concnetraction'
• Results:
• Increase of air polution

Methane Gases

• Originates from the decaying of rubbish, cattle chewing, and anaerobic activity

Nuclear Fall Out

• Mutation, so change, damage DNA and deformities in babies that results in death

Causes of Water Pollution

• Caused by fertilizers and untreated sewage
• Causes pollution

4. Non biodegradable plastics:
   • .plastic contains toxins/harmful chemicals

• BLOCK digestive system of animals if mistakenly swallowed...cause their death.
• BLOCK flow of water in streams...stationary water...spread of disease
• Causes oxygen concretion to decrease and migration / damage will occur to aquatic animals

Ecosytems

• Results in a decrease of biodiversity.
• Non biodegradable....bioaccumulation.
• Can cause death
• Blocks photosynthesis

Loss in Soil Fertility

• Results after the removal of the top layer of soil Causes
• Desertification
• Water loggin
• Disruptiuon of the food chain
• Plant decrease in biodiverstiyy extinction

Conservation

• The cycle of is the process of looking after natural environment to maintains the biodiversity and abiotic (non living)

Biotic

• (living- maintain the biodiversity of plants and animals)

Abiotic (non living such as water, fossil fuels in the coming generations

Conserve plants and animals

• Maintain biodiversity
• Prevent extinction
• Preserve resources
• Support food availability
• Provides medicine that is uses for research
• Encourage gentle diversity

Definition Of Endagered specie

• Species that are found in low population so hard to breed and maintain genetic diversity,

Problems of Lack of Population

• increase inbreeding -Little variation, increase in homozygosity Increase change of genetic diseases less increase competition for survival and change

Reason Behind Lack Of Population

• deforestation
• Pollution
• Hunting and over fishing
• Climate change
• intereeding

Ways Of Conserving Species

i. capative breedin ii. Conserving fish and restocking iii. Education g the people iv. Conserving forrest

Other Steps:

• Providing animal the right place from not allowing not to cause disease by either by use of (IvF or AI

Conserving Fish Stocks

• Apply a no catch zones
• Limit the fishing seasons
• Monitoring fish's population
• Enforce the use of fish stocking
• Educating people To avoid catching and decrease the fish number

To help protect Fish in natural habit implement

• provide a habitat
• provide food and space
• Reduce the anmount you allow the people to catch

To help Control and ban hunting, Educate endangered species

Governmental Rules to conservation

• Restricts the use and not grant license for cutting forest
• Selecticly felling instead of cutting all trees
• Reduce to the a meter
• planting new ones

SEED Bank

Store At vey dry temperature'

• Collect and store( at very low and dry condition
• Plant may not beable to seeds that do not need Much
• Genetic location help
• More adapted

Ways of conserving Abiotic Factor

• Using a sustainble resource
• Recycling
• Why Non sustainable resource need million of yaers

A) Recycling Paper Less forrest clear d

Follow These Process

• Shreeding
• Pulp
• Soaking
• Lessen the air polution

Reduce:

• Decrease the amount of water
• Recyclung Water
• Less carbon emission

Sustainability

• Is about Providing the needs of a population by having a great local government.
• Local people should be farmers

How can adaptive features have been inherited by help as organism to service?

• Fitness" the organism to servive?

Defention:

• Population; member of same specie Community
• Living together Ecosystem A unit that is self sustained Evolution the change of factors