📚 GCSE AQA Biology: Ecology Revision Notes | GCSE AQA 生物：生态学考点精讲
Ecology is the study of the interactions between living organisms and their environment. In GCSE AQA Biology, this topic covers how organisms depend on each other and how they are affected by physical factors. Understanding ecology helps us appreciate the delicate balance of nature and the impact humans have on ecosystems.
生态学是研究生物与其环境之间相互作用的学科。在GCSE AQA生物课程中，本专题涵盖生物如何相互依存以及如何受到物理因素的影响。理解生态学有助于我们认识自然的微妙平衡以及人类对生态系统的影响。
1. Introduction to Ecology | 生态学导论
Ecology examines the distribution and abundance of organisms, and how these are shaped by interactions with the environment. An ecosystem includes all the organisms in a particular area, along with non-living components. Populations of different species form a community.
生态学研究生物的分布和数量，以及这些特征如何受到与环境相互作用的影响。生态系统包括特定区域内的所有生物以及非生物组成部分。不同物种的种群构成群落。
Key terms: habitat (where an organism lives), population (all members of a single species in a habitat), community (all populations of different species), ecosystem (community plus abiotic environment).
关键术语：栖息地（生物居住的地方）、种群（一个栖息地中同一物种的所有个体）、群落（所有不同物种的种群）、生态系统（群落加上非生物环境）。
2. Abiotic and Biotic Factors | 非生物与生物因素
Abiotic factors are non-living physical and chemical elements in an ecosystem. Examples include light intensity, temperature, water availability, pH of soil, and oxygen concentration. These factors can limit the distribution of organisms.
非生物因素是生态系统中无生命的物理和化学元素。例如光照强度、温度、水分可用性、土壤pH值和氧气浓度。这些因素可能限制生物的分布。
Biotic factors are the living components, such as competition for resources, predation, disease, and availability of food. A change in one biotic factor can affect the entire community.
生物因素指的是有生命的组成部分，例如资源竞争、捕食、疾病和食物供应。一个生物因素的改变可能影响整个群落。
| Abiotic Factors (非生物因素) | Biotic Factors (生物因素) |
|---|---|
| Light intensity | Competition |
| Temperature | Predation |
| Moisture levels | Disease (pathogens) |
| Soil pH | Food availability |
The table above summarises common abiotic and biotic factors that influence ecosystems.
上表总结了影响生态系统的常见非生物和生物因素。
3. Food Chains and Food Webs | 食物链与食物网
A food chain shows the linear flow of energy from one organism to another. It begins with a producer (e.g. green plant) that converts sunlight into chemical energy via photosynthesis. Primary consumers (herbivores) eat producers; secondary consumers eat primary consumers, and so on.
食物链展示能量从一个生物流向另一个生物的线性过程。它起始于生产者（例如绿色植物），通过光合作用将光能转化为化学能。初级消费者（植食动物）吃生产者；次级消费者吃初级消费者，以此类推。
A food web is a more complex network of interconnected food chains, showing the many feeding relationships in an ecosystem. If one species is removed, it can have a knock-on effect throughout the web.
食物网是由相互连接的食物链组成的更复杂网络，显示生态系统中的多种捕食关系。如果一个物种消失，可能会对整个网产生连锁反应。
Energy is transferred along food chains, but much is lost as heat, movement and undigested material. Typically only about 10% of energy is passed on to the next trophic level.
能量沿食物链传递，但大部分以热量、运动及未消化的物质形式散失。通常只有大约10%的能量传给下一个营养级。
4. Interdependence and Competition | 相互依存与竞争
Organisms in an ecosystem are interdependent – a change in the population of one species affects others. For example, removing a top predator can cause an increase in herbivore numbers, leading to overgrazing of plants.
生态系统中的生物是相互依存的——一个物种种群的变化会影响其他物种。例如，移除顶级捕食者会导致植食动物数量增加，从而造成植物过度啃食。
Competition occurs when organisms need the same limited resources. Plants compete for light, water, minerals and space. Animals compete for food, mates and territory. Intraspecific competition is within the same species; interspecific competition is between different species.
当生物需要相同的有限资源时就会发生竞争。植物竞争光、水、矿物质和空间。动物竞争食物、配偶和领地。种内竞争发生在同种个体之间；种间竞争发生在不同物种之间。
5. Adaptations of Organisms | 生物的适应性
Adaptations are features that enable organisms to survive in their environment. They can be structural, behavioural or functional. For example, camels have structural adaptations (hump for fat storage, long eyelashes) to live in deserts.
适应性是使生物能在其环境中存活的特征。它们可以是结构上的、行为上的或生理上的。例如，骆驼具有结构适应（脂肪储存在驼峰、长睫毛）以在沙漠中生存。
Extremophiles are organisms adapted to extreme conditions, such as high temperature, pressure or salt concentration. Bacteria living in hot springs have enzymes that function at temperatures that would denature most proteins.
嗜极生物是适应极端条件（如高温、高压或高盐浓度）的生物。生活在温泉中的细菌具有能在使大多数蛋白质变性的温度下发挥作用的酶。
Plants in dry habitats (xerophytes) may have thick waxy cuticles, spines instead of leaves, and extensive roots. Animals in cold climates often have thick fur, blubber and small ears to reduce heat loss.
干燥环境中的植物（旱生植物）可能有厚厚的蜡质角质层、刺代替叶子以及发达的根系。寒冷气候中的动物通常有厚毛皮、鲸脂和小耳朵以减少热量散失。
6. The Carbon Cycle | 碳循环
The carbon cycle describes how carbon is recycled in nature. Carbon dioxide (CO₂) in the atmosphere is absorbed by plants during photosynthesis to make carbohydrates. Carbon is passed along food chains through feeding.
碳循环描述碳在自然界中如何循环利用。大气中的二氧化碳（CO₂）被植物通过光合作用吸收，生成碳水化合物。碳通过食物链的取食关系传递。
Respiration by all organisms returns CO₂ to the atmosphere. Decomposition by microorganisms also releases CO₂ and returns minerals to the soil. Combustion of fossil fuels and wood releases stored carbon as CO₂.
所有生物的呼吸作用将CO₂释放回大气。微生物的分解作用也释放CO₂并将矿物质归还土壤。化石燃料和木材的燃烧将储存的碳以CO₂形式释放。
Carbon is locked up in fossil fuels, limestone and sedimentary rocks over millions of years. The balance of the carbon cycle is being disrupted by human activities, leading to increased atmospheric CO₂.
碳以化石燃料、石灰岩和沉积岩的形式被固定了几百万年。人类活动正在破坏碳循环的平衡，导致大气CO₂增加。
Photosynthesis: 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂
Respiration: C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + energy
7. The Water Cycle | 水循环
The water cycle describes the continuous movement of water on, above and below the surface of the Earth. Water evaporates from oceans, lakes and rivers, and transpiration from plants releases water vapour into the air.
水循环描述水在地球表面、空中和地下的持续运动。水从海洋、湖泊和河流中蒸发，植物的蒸腾作用将水蒸气释放到空气中。
Warm, moist air rises, cools and condenses into clouds (condensation). Water returns to the surface as precipitation (rain, snow, etc.). Some water runs off into rivers and eventually back to the sea; some infiltrates the ground to form groundwater.
温暖潮湿的空气上升、冷却并凝结成云（凝结作用）。水以降水形式（雨、雪等）回到地表。部分水通过径流进入河流，最终回到海洋；部分渗入地下形成地下水。
Living organisms take up water and release it through respiration and excretion. The cycle is driven by solar energy and gravity.
生物体吸收水分并通过呼吸和排泄释放。该循环由太阳能和重力驱动。
8. Decomposition and the Decay Cycle | 分解与腐烂循环
Decomposition is the breakdown of dead organic matter by detritivores (e.g. earthworms, woodlice) and decomposers (bacteria and fungi). This process recycles nutrients back to the soil, which are then used by plants.
分解是指死去的有机物被食碎屑动物（如蚯蚓、鼠妇）和分解者（细菌和真菌）分解的过程。这一过程将营养物质循环回土壤，然后被植物利用。
Factors affecting the rate of decay include temperature, water availability and oxygen. Warmer and moist conditions speed up decay because decomposers are more active. In waterlogged or acidic soils (e.g. peat bogs), decay is slow, leading to peat formation.
影响腐烂速度的因素包括温度、水分可用性和氧气。温暖潮湿的条件会加速腐烂，因为分解者更活跃。在水涝或酸性土壤（如泥炭沼泽）中，腐烂缓慢，导致泥炭形成。
Humans use decomposition in composting and sewage treatment to recycle organic waste safely.
人类利用分解作用进行堆肥和污水处理，以安全地回收有机废物。
9. Biodiversity and Its Importance | 生物多样性及其重要性
Biodiversity is the variety of all species on Earth, the genetic variation within species, and the range of ecosystems. High biodiversity ensures ecosystem stability, because many species can fill roles if one is lost.
生物多样性是地球上所有物种的多样性、物种内的遗传变异以及生态系统的范围。高生物多样性确保生态系统的稳定性，因为即使一个物种消失，许多物种可以填补其角色。
Biodiversity provides us with food, medicines, clean water and pollination services. It also has cultural and aesthetic value. Declining biodiversity threatens these essential services.
生物多样性为我们提供食物、药物、清洁水和传粉服务。它还具有文化和美学价值。生物多样性的下降威胁着这些基本服务。
10. Human Impact on Ecosystems | 人类对生态系统的影响
Human activities greatly affect ecosystems. Pollution of air (sulphur dioxide, nitrogen oxides) leads to acid rain, which damages plants and aquatic life. Water pollution by fertilisers causes eutrophication: excess nutrients trigger algal blooms, blocking light and depleting oxygen.
人类活动极大地影响着生态系统。空气污染（二氧化硫、氮氧化物）导致酸雨，损害植物和水生生物。化肥造成的水污染引起富营养化：过多的营养物质引发藻类大量繁殖，遮蔽光线并耗尽氧气。
Global warming, caused by increased greenhouse gases (CO₂, methane), is raising average global temperatures. This leads to climate change, sea-level rise, and shifts in species distribution.
温室气体（CO₂、甲烷）增加导致的全球变暖正在提高全球平均气温。这导致气候变化、海平面上升和物种分布变化。
Deforestation removes forests for timber or land. It reduces biodiversity, disrupts the carbon cycle (less CO₂ absorbed), and can cause soil erosion. Peat bog destruction releases huge stores of carbon.
砍伐森林为了木材或土地，减少生物多样性，破坏碳循环（吸收的CO₂减少），并可能导致土壤侵蚀。泥炭沼泽的破坏会释放大量储存的碳。
Overfishing reduces fish populations and disrupts marine food webs. Waste production and habitat destruction push many species toward extinction.
过度捕捞减少鱼类种群并破坏海洋食物网。废物产生和栖息地破坏导致许多物种濒临灭绝。
11. Maintaining Biodiversity and Sustainability | 维护生物多样性和可持续性
Conservation programs aim to protect species and their habitats. Breeding programs in zoos, seed banks, and national parks are examples. Reforestation and habitat restoration help reverse damage.
保护计划旨在保护物种及其栖息地。动物园的繁育计划、种子库和国家公园都是例子。重新造林和栖息地恢复有助于扭转破坏。
Sustainability means meeting our needs without compromising the ability of future generations to meet theirs. Sustainable fisheries use quotas and mesh size limits to let young fish escape. Reducing carbon emissions, recycling, and using renewable energy are key efforts.
可持续性意味着满足我们的需求而不损害后代满足其需求的能力。可持续渔业使用配额和网眼尺寸限制，让小鱼逃脱。减少碳排放、回收和使用可再生能源是关键举措。
Government regulations and international agreements (e.g. CITES) control trade in endangered species. Individuals can help by reducing waste, planting native species, and supporting conservation charities.
政府法规和国际协议（例如CITES）控制濒危物种的贸易。个人可以通过减少浪费、种植本地物种和支持保护慈善机构来提供帮助。
12. Trophic Levels and Biomass Pyramids | 营养级与生物量金字塔
Trophic levels represent the stages in a food
Published by TutorHao | GCSE Biology Revision Series | aleveler.com
更多咨询请联系16621398022（同微信）
屏轩国际教育cambridge primary/secondary checkpoint, cat4, ukiset,ukcat,igcse,alevel,PAT,STEP,MAT, ibdp,ap,ssat,sat,sat2课程辅导，国外大学本科硕士研究生博士课程论文辅导