教学大纲要求
1. 教学内容：
　　（1）人类影响作用的变化 (The Changing Role of Human Impact)
　　（2）污染的历史根源 (Historical Basis of Pollution)
　　（3）可恢复和不可恢复资源 (Renewable and Nonrenewable Resources)
　　（4）资源利用的代价 (Costs Associated with Resource Utilization)
　　（5）地球生态系统的利用与改变 (Utilization and Modification of Terrestrial Ecosystems)
　　（6）森林生态系统管理 (Managing Forest Ecosystems)
　　（7）草原生态系统管理 (Managing Rangeland Ecosystems)
　　（8）水生态系统管理 (Managing Aquatic Ecosystems)
　　（9）野生生态系统管理 (Managing Ecosystems for Wildlife)
　　（10）生物灭绝与生物多样性问题 (Extinction and Loss of Biodiversity)
2. 教学要求：
　　（1）了解随着社会和经济的发展，人类活动对自然界影响程度的变化情况；
　　（2）了解什么是可恢复资源，什么是不可恢复资源，以及消耗不可恢复资源的后果；
　　（3）了解资源利用的经济代价、能量代价和环境代价；
　　（4）系统掌握森林、草原、水系、野生环境等生态系统管理的要点和意义；
　　（5）深入领会生物灭绝、生物多样性丧失所带来的严重后果。
本单元授课计划
总授课时间：6学时（3次授课）
1. 第1次课（2学时）
　　（1）人类影响作用的变化；
　　（2）污染的历史根源；
　　（3）可恢复和不可恢复资源；
　　（4）资源利用的代价。
2. 第2次课（2学时）
　　（1）地球生态系统的利用与改变；
　　（2）森林生态系统管理；
　　（3）草原生态系统管理；
　　（4）水生态系统管理。
3. 第3次课（2学时）
　　（1）野生生态系统管理；
　　（2）生物灭绝与生物多样性问题；
　　（3）就本单元教学内容开展课堂讨论。
本单元重点与难点
1. Changing Role of Human Impact（人类影响作用的变化）

• As human population grew, and tools and methods of use became more advanced, the impact a single human could have on surroundings increased.（人口增加、技术进步带来环境影响加剧）
• Environmental modifications allowed larger, dense human populations to arise.（环境的人为改变使得人口增加）
• Nearly all earth's surface has been affected in some way by human activity.（地球的几乎每块地面都受到人类活动影响）

2. Historical Basis of Pollution（污染的历史根源）

• Two primary factors affect the amount of damage done by pollution: (1) Size of the population; (2) Level of technological development.（人口和技术开发水平是导致污染的主要因素）
• When the human population was small, waste products were generally bio-degradable.（人口稀少的条件下，污染物通常是可生物降解的）
• Human-caused pollution is produced when waste is generated faster than it can be degraded, especially as people began to congregate and establish cities.（城市化导致人为污染的集中产生）

3. Renewable and Nonrenewable Resources（可恢复和不可恢复资源）

• Natural Resources - structures and processes humans can use, but not create.（自然资源可供利用，但不可创造）
• Renewable - Can be formed or regenerated by natural processes.（可恢复资源的定义）
• Non-Renewable - Not replaced by natural processes, or, rate of replacement is ineffective.（不可回复资源的定义）

4. Costs Associated With Resource Utilization（资源利用的代价）

• Economic - Monetary costs necessary to exploit the resource.（资源开发的经济代价）
• Energy - Energy expended exploiting the resource.（资源开发的能源代价）
• Environmental - Environmental effect of resource exploitation (often deferred).（资源开发的环境代价）

5. Mineral Resources

• Mineral resources: Major form of nonrenewable resource with non-uniform distribution and many deposits have already been exploited.（矿物资源具有不可恢复性和非均匀分布性）
• Recycling of Mineral Materials: Many minerals are not actually consumed, but only temporarily held.（许多矿物资源并未完全消耗，因而具有可再生价值）
• In many industries, cost of purchasing recycled raw materials is higher than the cost of purchasing virgin materials.（再生资源的代价往往高于原材料的代价）
• Historically, monetary cost for energy has been low, thus no incentive to recycle.（能源价格过低与鼓励再生相矛盾）

5. Utilization and Modification of Terrestrial Ecosystems（地球生态系统的利用与改变）

• Natural ecosystems have greater biodiversity than human-managed ecosystems.（自然生态比人为管理的生态系统更具有生物多样性）
• Impact of agriculture on natural ecosystems: 40% of world's land surface converted to cropland and permanent pasture; Most productive natural ecosystems are the first to be modified by humans.（农业活动对自然生态系统造成严重影响）
• Pressures to modify the environment are greatest in areas with high population density.（人口密集是环境条件人为改变的动因）

6. Managing Forest Ecosystems（森林生态系统管理）

• Forested areas are under increasing pressure to provide wood products and agricultural land.（木材采伐和农业活动对森林的影响不断增大）
• Environmental implication of harvesting: (1) Clear cutting - removal of all trees in an area; (2) Patch-work clear cutting - clear cutting in small, unconnected patches; (3) Selective harvesting - single tree-harvesting.（森林采伐的不同方式对环境的影响各异）
• Plantation forestry: Many lumber companies maintain forest plantations as crops and manage them in the same way farmers manage crops.（人工造林是提供木材的方式之一）
• Special concerns about tropical deforestation: Tropical forests have greater species diversity than any other ecosystem.（热带森林的破坏备受关注）
• Deforestation concerns: (1) Significantly reduces species diversity; (2) Impacts climate via lowered transpiration; (3) CO2 trap – increased global warming.（森林破坏造成多种影响：生态多样性破坏、气候影响、全球变暖）

7. Managing Rangeland Ecosystems（草原生态系统管理）

• Rangelands - Lands too dry to support crops, but received enough precipitation to support grasses and drought-resistant shrubs.（草原的生态特点）
• Environmental costs of utilizing rangelands: Management techniques and selective grazing of animals may lead to the elimination of non-preferred species; it is important to regulate number of livestock on rangelands - especially in dry areas.（草原利用的环境代价）
• Wilderness and remote areas: Many areas in the world have had minimal human impact; some are remote and may have harsh environmental conditions.（人类影响微弱的原生态区域）

8. Managing Aquatic Ecosystems（水生态系统管理）

• Aquatic ecosystems divided into marine and freshwater.（海洋生态和淡水生态）
• Environmental costs related to utilizing marine ecosystems fall into two categories: (1) Over-fishing; (2) Environmental effects of harvesting.（海洋生态系统利用的环境代价）
• Environmental costs associated with utilizing freshwater ecosystems: Water quality; Exotic species.（淡水生态系统利用的环境代价）

9. Managing Ecosystems For Wildlife（野生生态系统管理）

• Animals have highly specific habitat requirements that change throughout the year. Once habitat requirements are understood, steps can be taken to alter habitat and improve species success.（动物栖息需求与野生生态直接相关）
• Wildlife managers use population censuses to check if populations are within appropriate levels. With suitable habitat and protection, most wild animals can maintain a sizeable population, but high reproductive capacities and/or heavy protection can cause very large populations.（动物数量与野生生态系统的条件相关联）
• Predator and competitor control: Human modification of habitat has a greater impact than natural predation; Many species do require refuges where they are protected from competing species or human influence.（捕食者与竞争者的控制）

10. Extinction and Loss of Biodiversity（生物灭绝与生物多样性问题）

• Of the estimated 500 million species believed to have existed on earth, 98-99% are now extinct.（生物灭绝的危机）
• Human-accelerated extinction: Wherever humans have become the dominant organisms, extinctions have occurred.（人类加速生物的灭绝）
• Ethical - Animals have a fundamental right to exist.（伦理学上，动物也有生存权）
• Threatened - Still exist in large numbers in current range, but are declining in most areas.（生物受威胁的定义）
• Endangered - Very low populations, could become extinct in very near future.（生物濒临灭绝的定义）

作业与习题要求
　　本单元布置一定量的思考题，让学生结合本单元教材内容进行思考，准备答案，下一次课进行课堂讨论。同时布置一定量的习题，作为课后作业。

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