abitat destruction pollution Agriculture food production conservation Humans and the environment cereal 谷物 Food production Humans and the environment Agricultural machinery (tractor/combine harvester) food production Agricultural chemicals (fertilizer / insecticide/ herbicide ) increasing food production machinery 机械 combine harvester 联合收割机 fertilizer 肥料 herbicide 灭草剂 insecticide 杀虫剂 variety 品种 Selective breeding (produce new and improved varieties of animals and plants ) Humans and the environment Negative impacts of monocultures ☼low biodiversity cereal 谷物 Food production Humans and the environment Negative impacts of monocultures ☼low biodiversity ☼lead to increase of pests populations spraying insecticides onto the crop →the insecticides will kill other harmless insects →very expensive →pests will have resistance to insecticides Ways for solving problems: mixing cropping biodiversity 生物多样性 Food production Humans and the environment Food production Negative impacts of intensive livestock production ☼welfare issues for the livestock which suffer in the crowded conditions ☼disease can spread easily Antibiotics → increase the risk that bacteria will develop resistance to the antibiotics ☼the waste from the intensive farming unit can pollute land and waterways nearby. cereal 谷物 Humans and the environment World food supplies ☼food distribute unequally on our planet ☼famine (weather: drought, flood; war ) cereal 谷物 Food production cereal livestock monoculture biodiversity machinery combine harvester fertilizer herbicide insecticide variety List four reasons why the quantity of food produced by agricultural has increased enormously in the last century Explain what is meant by a monoculture Describe two problems caused by monocultures Describe two problems caused by intensive livestock farming Humans and the environment water atmosphere soil temperature … Habitat destruction living organisms Humans and the environment Habitat destruction Examples of habitats destroyed ☼cut down native vegetation to make land available for growing crops, for farming livestock, for building house and factories, and for building roads. ☼we damage habitats when we mine for natural resources, such as metal ores or fossil fuels ☼add pollutants to land and water ☼remove key species in habitat habitat 生境 pollutant 污染物 mine 开采 Humans and the environment Deforestation Habitat destruction Humans and the environment Tropical rain forest ☼relatively high and constant temperature ☼high rainfall ☼high biodiversity ☼soil is very thin. Soil erosion easily tropical rain forest 热带雨林 erosion 侵蚀 Habitat destruction Humans and the environment Habitat destruction What happens if destruct tropical rain forest ☼soil erosion → it very difficult for the rainforest to grow back again → the soil can also be washed into rivers, silting then and causing flooding ☼many species will extinct silt 淤积 extinct 灭绝 Humans and the environment Habitat destruction What happens if destruct tropical rain forest ☼affect the water cycle —— transpiration extinct灭绝 Humans and the environment Habitat destruction How to reduce deforestation of tropical rainforest Need to provide alternative sources of income for people. ——sustainable way carbon credits carbon credit碳信用额 most tropical rainforests distribute in developing countries. Outline the main ways in which humans destroy habitats. Explain how extensive deforestation can affect the amount of carbon dioxide in the air. Explain how deforestation can cause soil erosion and flooding tropical rain forest erosion habitat pollutant mine extinct extinction carbon credit Humans and the environment greenhouse gases carbon dioxide * methane* nitrogen oxides CFCs greenhouse effect greenhouse gas 温室气体 greenhouse effect 温室效应 methane 甲烷 CFCs 氟氯烃 nitrogen oxide 氮氧化合物 short wavelength radiation 短波辐射 long wavelength radiation 长波辐射 infrared radiation 红外辐射 Pollution – greenhouse gases Humans and the environment enhanced greenhouse effect more greenhouse gases more infrared radiation will be trapped global warming enhanced greenhouse effect 增强的温室效应 global warming 全球变暖 Pollution – greenhouse gases Humans and the environment negative effects of global warming ♦ temperature rise ♦ ice cap melt ♦ floods (low-altitude areas) ♦ drought ♦ violent storms ♦ some species will extinct Positive or beneficial effects of global warming extra carbon dioxide and higher temperature might increase the rate of photosynthesis → high yield ice cap 冰盖 Pollution – greenhouse gases Humans and the environment Pollution – greenhouse gases Explain the difference between the greenhouse effect, the enhanced greenhouse effect and global warming. Humans and the environment Pollution – greenhouse gases How to prevent global warming ? Ways to prevent global warming cut down the emission of greenhouse gases ♦reduce the amount of the fossil fuels → carbon dioxide/ nitrogen oxides ♦reduce emission of methane (methane may be produced by bacteria living on organic matter, by animals which chew the cud, such as cattle, by some insects, such as termites, by decaying rubbish in landfill sites.) reduce the rate of deforestation cud 反刍的食物 termite白蚁 decay 腐败landfill 垃圾掩埋 Humans and the environment Pollution – greenhouse gases Explain of the following has been suggested as a way of reducing global warming. For each suggestion, explain why it would work. a reducing the top speed limit for cars and trucks b insulating houses in countries with cold climates c increasing the number of nuclear power station d encouraging people to recycle more of their rubbish Acid rain Humans and the environment sulfur dioxide Pollution – acid rain a.irritate the linings of the breathing system. b.poisonous to many kinds of plants. One of the biggest problems of acid rain: Acid rain usually fall faraway from where it was produced. Sulfur (natural gas, coal, and oil) irritate 刺激 aluminium 铝 gill 腮 Aluminium ions are very poisonous to fish (affect their gills) The acid rainwater seeps into the soil and wash out ions such as calcium, magnesium and aluminium. Humans and the environment Pollution – acid rain How to prevent acid rain ? Ways to prevent acid rain —— cut down emission of sulfur dioxide and nitrogen oxides ♦reduce to bure coal reduce coal-burning power stations ♦remove sulfur dioxide from waste gases when burn fossil fuel ♦ using renewable energy resources, such as wind power, wave power, or solar power ♦ remove nitrogen oxides by catalytic converters which are fitted to the exhaust system in car engines catalytic converter 催化转化器 exhaust system排气系统 What causes acid rain ? How does acid rain damage trees ? How does acid rain damage fish ? Summarise what is being done to try to reduce the production of acid rain? Humans and the environment Pollution – nuclear fall-out accidents at nuclear power stations ↓ release radioactive substances ↓ cause radiation sickness and burns (exposure to large amounts of radiation. ionizing radiation (alpha, beta and gamma) ↓ increase mutation rates in DNA in our cells (lead to cancer) radiation 辐射 ionizing radiation 电离辐射 mutation 突变 nuclear 核 eutrophication 富营养化 Humans and the environment Eutrophication Aerobic respiration 有氧呼吸 Pollution – eutrophication Humans and the environment Eutrophication Nitrates and phosphates used on farm get washed out in to streams, rivers and lakes. Aerobic respiration 有氧呼吸 Pollution – eutrophication Humans and the environment Eutrophication Nitrates and phosphates used on farm get washed out in to streams, rivers and lakes. Algae and green plants grow faster. They may completely cover the water and block out the light for plants growing beneath them. Aerobic respiration 有氧呼吸 Pollution – eutrophication Humans and the environment Eutrophication Nitrates and phosphates used on farm get washed out in to streams, rivers and lakes. Algae and green plants grow faster. They may completely cover the water and block out the light for plants growing beneath them. Bacteria decompose the remain of dead plants and alga Aerobic respiration 有氧呼吸 Pollution – eutrophication Humans and the environment Eutrophication Nitrates and phosphates used on farm get washed out in to streams, rivers and lakes. Algae and green plants grow faster. They may completely cover the water and block out the light for plants growing beneath them. Bacteria decompose the remain of dead plants and alga The bacteria breed rapidly. They will use up oxygen in water. Aerobic respiration 有氧呼吸 Pollution – eutrophication Humans and the environment Eutrophication Nitrates and phosphates used on farm get washed out in to streams, rivers and lakes. Algae and green plants grow faster. They may completely cover the water and block out the light for plants growing beneath them. Bacteria decompose the remain of dead plants and alga The bacteria breed rapidly. They will use up oxygen in water. No oxygen or little oxygen will cause many organisms die, such as fish. Aerobic respiration 有氧呼吸 Pollution – eutrophication Humans and the environment Eutrophication Pollution – eutrophication Humans and the environment Eutrophication silage 青储饲料 sewage 污水 Pollution – eutrophication Causes of eutrophication: fertilisers, animal waste and silage (containing nitrates and other nutrients), untreated sewage Humans and the environment Pollution – eutrophication Could we stop using nitrate fertilisers? manure Organic fertilisers are better than inorganic ones: & They do not contain much nitrates which can easily be leached out of the soil. & they release nutrients gradually over a long period Nevertheless, the manure also cause pollution if they are be washed. Ways of precaution of eutrophication: $ use organic fertilisers properly $ not use too much once $ not apply fertilisers to empey fields $ not spray near to streams and rivers. manure 粪便 Humans and the environment Pesticides (insecticides, fungicides, herbicides) → higher yield manure 粪便 Pollution – pesticides Humans and the environment Pollution – pesticides accumulation of pesticides DDT ♦ persistent (does not break down) ♦ nonspecific (harm many organisms) e.g. affecting the breeding success of peregrine falcons, by making their egg shells very weak, so that they very rarely hatched. accumulation 积累，富集 Humans and the environment Pollution – chemical waste Chemical waste May contain heavy metals, such as lead, cadmium or mercury chemical waste 化学废料 Heavy metal 重金属 lead 铅 cadmium 镉 mercury 水银 Humans and the environment Pollution – nonbiodegradable plastics Non-biodegradable plastics Non-biodegradable means that decomposers can not break down @Plastics in animals stomachs @Plastics containers may trap animals 。。。 biodegradable 生物降解的 non-biodegradable 生物不能降解的 degrade 降解 Humans and the environment Female contraceptive hormones Prevent the male hormone, testosterone Reduce sperm count Pollution – female contraceptive hormones eutrophication silage sewage chemical waste Heavy metal lead cadmium mercury manure faeces accumulation bioaccumulation biodegradable non-biodegradable degrade conservation conservation保护 Humans and the environment Conservation Conservation is the process of looking after the natural environment. biodiversity Tropical rain forest have high biodiversity habitat 生境 biodiversity 生物多样性 Humans and the environment Conservation—sustainable resources Sustainable resources biomass (fish), wood, wind, water non-sustainable resources fossil fuels recycle sustainable resource 可持续 non-sustainable resource 不可持续的 Humans and the environment recycle resources → recycling glass Glass is made from sand (silicon oixde) and a few other chemicals, such as lime and soda. These are non-sustainable resources. Making new glass involves heating these chemicals to very high temperatures. It release a lot of carbon dioxide. Conservation—sustainable resources Humans and the environment recycle resources → recycling plastics Plastics are made from fossil fuels. Conservation—sustainable resources Humans and the environment recycle resources → recycling paper Paper is made of cellulose fibres from plants. Recycling paper can reduce deforestation. The main advantage is that it causes less water and land pollution. But during recycling paper would use much fossil fuels in collecting and transporting the used paper. Conservation—sustainable resources Humans and the environment recycle resources → recycling metals Metals from ores. Non-sustainable resources ore 矿石 Conservation—sustainable resources Humans and the environment Sewage treatment Conservation—sewage treatment recycle water and resolve shortage of water raw sewage ♥ many bacteria and other microorganisms ——may be pathogenic ♥ nutrients for plants and microorganisms —— may cause eutrophication raw sewage 未经处理的污水 sewage 污水 sewage treatment 污水处理 Humans and the environment Sewage treatment Conservation—sewage treatment first, the raw sewage is passed through screens → trap large objects such as grit trickling filters In settlement tank, where any other insoluble particles drift to the bottom, and form sediment screen 滤网 settlement tank 沉淀箱 sediment 沉积物 trickle 滴，慢慢流 filter 过滤 trickling filter 滴流生物滤器 Liquid is trickled onto the surface of the stones through holes in a rotating pipe. >trickle— mix air with liquid >slow—give microorganisms plenty of time to work Small stones and clinker, many aerobic microorganisms live on the surface of the stones Humans and the environment Conservation—sewage treatment Sewage treatment activated sludge activated 有活性的 sludge 淤泥 effluent 污水 fertiliser for farming Humans and the environment Conservation—sewage treatment Sewage treatment Something in sewage may harm the microorganisms e.g. heavy metals——toxic detergent —— cause foaming, stop oxygen getting into liquid To solve these problems, the sewage should be diluted before being allow to enter the trickling filter bed or the activated sludge tank. foam 泡沫，形成泡沫 conservation conservation保护 Humans and the environment Conservation Sustainable development ——providing for the needs of an increasing human population without harming the environment sustainable development 可持续发展 Humans and the environment Conservation Conserving forests ♦ governments can refuse to grant licences to companies who want to cut down valuable forests ♦ just a small proportion of the trees are cut down, instead clear-felling ♦ many deciduous trees will regrow after they are cut down ♦ where large numbers of trees are cut down, new ones should be planted to replace them. ♦ education can help to make sure that people understand how important it is to conserve forest. Grant licence颁发证书 Humans and the environment Conserving fish stocks ♦ impose quotas of fish resources. Specify different amounts for different species. ♦ breed large numbers of them in fish hatcheries, and then release them. fish stock 鱼群，鱼类资源 quota 定额，配额 fish hatchery 鱼孵化 Conservation Humans and the environment Endangered species A species whose numbers have fallen so slow that it is at risk of becoming extinct is said to be endangered endangered濒危的 Conservation Humans and the environment Conservation Endangered species Genetic variation If genetic variation is lost, it will become low of chance of surviving for population when the habitat change. Humans and the environment Endangered species Reasons of endangered species ♦ habitat destruction ♦ hunting ♦ pollution ♦ introduced species endangered濒危的 Conservation Humans and the environment Endangered species The ways of conserving endangered species ♦ monitoring and protecting the species in its natural habitat ♦ using captive breeding programmes ♦ educating local people about the importance of conservation, and what they can do to help. monitor监控 breeding program繁育项目 Conservation Humans and the environment Conservation Reasons for conservation programs ♦ we have no right to make any species extinct. ♦ if we damage ecosystem, we can be doing harm to ourselves. ♦ losing species from an ecosystem can have wide-reaching effects. -- food chain ♦ many plant species contain chemicals that can be used as drugs. ♦ wild relatives of our crop plants contain different alleles of genes that could be useful in future breeding programs.
