Chapter 15 (Human Influence On The Environment) Flashcards
What are the demand we needed with the increasing population?
- Food supply
- Materials to build structures
- Fuel to heat homes and power vehicles
- Space to build homes, schools and others
- Space to dump our wastes
How do farmers make profit from their farms?
They try to control the environment to maximize their crop yields.
What are some factors controlled by the farmer to maximize crop yield?
- Soil ions
- Soil structure
- Soil Ph
- CO2, light, heat
How can farmers control soil ions and why?
- Adding fertilizers
- Growing in hydroponic culture
Extra ions for plants
- To make protein
- For growth
How can farmers control soil structure and why?
- Ploughing (Break up compacted soil)
- Adding manure (improve drainage, aeration)
It can provide better uptake of mineral ions and water.
How can farmers control soil ph?
By adding lime (calcium salts) to acidic soil
How can farmers control the rate of CO2, light intensity and temperature?
Growing in glasshouses or polytunnel
Why greenhouses can provide controlled conditions for plants to grow?
- Transparent wall allow enough natural light in summer and additional lighting in winter for longer day allowing photosynthesis
- It has greenhouse effect increasing the temperature
- Glasshouses can be heated manually
- Usage of fossil fuels provide CO2, water vapors.
- Growing in hydroponic culture provide right balance of mineral ions for crops
Why glasshouses have greenhouse effect?
Short wavelength infrared waves enter the glasshouse and got absorbed by greenhouse gases and re-radiated as longer wavelength which cannot escape through the the glass heating up the house.
What does water vapor do in the glass house?
- It maintains a moist atmosphere
- It reduce the water loss by transpiration
What are the green houses gases?
- CO2
- Methane
- Water vapor
- Chlorofluorocarbons
What does green houses gases increase the earth’s temperature?
They absorb the infrared radiation (heat) come from the sunlight warming up the atmosphere.
Why drainage around soil is not good?
Denitrifying bacteria are found in swampy soil which convert nitrate into nitrogen gases stealing ions from plants.
What do farmers do to replace lost nitrogen in soil?
Adding fertilizer.
Why do farmers have to monitor carefully about the amount of fertilizer added?
To ensure the maximum growth and yield of the crop
Using excessive fertilizers save money.
False
What are 2 main types of fertilizers?
Organic and inorganic
What are difference between organic and inorganic fertilizer?
- Organic - faeces of farm animals mixed with straw
- Inorganic - potassium nitrate or ammonium nitrate manufactured by factories
What is another name of organic fertilizer?
Farmyard manure
What are the advantages and disadvantages of using organic and inorganic fertilizer?
Organic - improve soil structure, can only replace portion of lost nitrogen
Inorganic - can’t improve soil structure but can replace nitrate and ions lost
Why farmyard manure can improve soil structure?
They contain decaying matters
What is another way apart from adding to replace lost nitrogen and how it work?
Growing legume crop which has nitrogen fixing bacteria in nodules on their roots.
What are pests?
Organisms that reduce the yield of crop plants or stock animals.
How can a pest harm yield of a crop?
- Lowering the amount by reducing growth
- Affecting the appearance or quality of a crop
What are the ways to control pest number?
- Using chemical pesticides
- Using biological control
What are name of pesticides for different organisms?
plant - herbicides
insect - insecticides
fungi - fungicides
mollus - molluscicides
What is an example of plant pests?
Weed
What are examples of insect pests?
Caterpillars and whiteflies
When are pest considered as problem?
When they are present in big enough numbers to cause economic damage.
What is monoculture?
Cultivating large areas of land with a single crop.
What is the advantage and disadvantage of monoculture?
- make harvesting the crop easier
- Encourage pests
What is crop rotation and what is its advantage?
Crop rotation is where a different crop is grown each year.
Advantage - breaks the pest cycle
What are disadvantages of using pesticides?
- Pest may develop a resistance to the chemical
- They are not specific
- They can cause environmental damage
What are some properties of ideal pesticide?
- Be biodegradable
- Be safe to transport
- Be easy to apply
What does biological control use?
It uses another organism to reduce the number of a pest.
What is the advantage and disadvantage of using biological control?
- It is specific
- But it never fully gets rid of a pest
What are some examples of methods of biological factors?
- Introducing natural predator
- Introducing herbivore
- Introducing a parasite
- Introducing a pathogenic
- Introducing sterile males
- Using pheromones
What are sterile males?
These mate with females but no offspring is produced.
What is pheromones?
Natural chemicals (produced by insects) used to attract pests to traps.
What is pollution?
Pollution is the contamination of the environment by harmful substances that are produced by the activities of humans.
What are the reasons for increased CO2 in atmosphere?
- Increase burning of fossil fuels
- Increasing usage of vehicles
- Heavy deforestation
What is another name for global warming?
Enhanced greenhouse effect
What is one example of green house gas which is not created by humans?
Chlorofluorocarbons
Greenhouse gases trap the longer wavelength infrared radiation.
True
What are the consequences of global warming?
- Polar ice cap melts
- Sea level rise
- Flood with occur
- Habitat destruction
- Species migrate/ extinct
- Change in climate and rainfall patterns
How are methane produced?
- Decomposition of wastes materials
- Cattle farming
- Fermentation by bacteria in rice fields
What is difference between CO2 and methane?
Each molecule of methane has a much bigger greenhouse effects.
How are chlorofluorocarbon produced?
- Spray
- Refrigerator
Where is Carbon monoxide be found?
Exhaust gases
What will happen if person inhale large amount of carbon monoxide?
It may lose consciousness and eventually die, as no oxygen is reaching the cells, for the organs to work.
What does acid rain contain?
- Sulfur dioxide
- Nitrogen oxides
How does sulfur dioxide and nitrogen oxides form acid?
By combining with water droplets in the air.
What is the ph of normal rain?
5.5
What are used to monitor the different levels of sulfur dioxide pollution?
Patterns of lichen growth
The darker the lichen?
The higher level of sulfur dioxide
What produce sulfur dioxide and nitrogen oxides?
- Volcanic eruption
- Lightening
- Burning of fossil fuels
What are consequences of acid rain?
- Damage limestone building
- Acidification of lakes and soils
- Death of conifers
Why does deforestation occur?
It occurs due to the enormous growth of the human population.
What are consequences of deforestation?
- Global warming
- Soil erosion
- Leaching of minerals ions
(- Habitat destruction
- Reduced soil quality
- Exposed soil
- Climate change)
How to solve deforestation?
- Reforestation
- Law for deforestation
What is eutrophication?
Well-fed.
It refers to a situation where large amounts of nutrients enter a body of water.
What are 2 main sources of eutrophication?
- From untreated or treated sewage
- From inorganic fertilizer
What is leaching?
Streams and rivers that run through agricultural lands which use artificial fertilizer become concentrated with nitrate and phosphate.
What are consequences of eutrophication?
- Algae bloom
- Blocking sunlight
- Prevent photosynthesis and plant died
- Death of algae
- Decomposition by bacteria
- Bacteria used up oxygen
- Fish and aquatic animals died
What to prevent eutrophication?
Using organic fertilizer
