Envi.-Sci.-Midterms-Reviewer PDF

Sustaining Biodiversity: The Ecosystem Approach [What are the Major Threats to Forest Ecosystems?] 2 TYPES OF FORESTS: (based on their AGE and STRUCTURE) 1. Old Growth Forest/Naturally Grown: UNCUT or REGENERATED primary forest that has not been seriously disturbed by huma...

Sustaining Biodiversity: The Ecosystem Approach [What are the Major Threats to Forest Ecosystems?] 2 TYPES OF FORESTS: (based on their AGE and STRUCTURE) 1. Old Growth Forest/Naturally Grown: UNCUT or REGENERATED primary forest that has not been seriously disturbed by human activities or natural disasters for several hundred years or more. [The short rotation cycle of cutting and regrowth of a monoculture tree plantation] 2. Second-growth Forest: A stand of trees RESULTING from SECONDARY ECOLOGICAL SUCCESSION that develops after the trees in an Short rotation cycle for a monoculture tree plantation area have been removed by human activities such - a type of forestry practice where a single tree as CLEAR CUTTING for Timber or CROPLAND or species is planted and harvested in regular by natural forces such as FIRE, HURRICANES, or intervals. This cycle is designed to maximize VOLCANIC ERUPTION. timber production while minimizing environmental impact. [PROCESS:] 8. Weak Trees Removed 1. Clear Cut - Throughout the cycle, weak or diseased trees may - The entire stand of trees is harvested at once, be removed to improve the overall health and leaving a bare area. productivity of the plantation. 2. Seedlings Planted Benefits of Short Rotation Cycles: - Immediately after the clear-cut, seedlings of the Increased productivity: By harvesting trees at a same tree species are planted in the cleared area. younger age, they can be replanted more frequently, leading to higher overall timber yields. 3. 5 Years Reduced environmental impact: Shorter rotations - The seedlings grow and develop for 5 years. can help to minimize soil erosion and nutrient loss compared to longer rotation cycles. 4. 10 Years Improved biodiversity: While monoculture - The trees continue to grow and reach a suitable plantations have lower biodiversity than natural size for thinning. forests, short rotation cycles can create opportunities for wildlife habitat and promote 5. Thinning biodiversity in some cases. - Some trees are removed to reduce competition and promote the growth of the remaining trees. Potential Consequences: Monoculture risks: Planting a single tree species 6. 15 Years can increase the risk of pests, diseases, and other - The trees continue to grow until they reach disturbances. maturity. Soil degradation: Intensive harvesting and replanting can lead to soil compaction and nutrient 7. Harvest depletion. - The mature trees are harvested, and the cycle Loss of biodiversity: While short rotation cycles begins again. can support some wildlife, they may not provide  the same level of habitat and biodiversity as landslides, reduce sedimentation in rivers, and natural forests. preserve the fertility of the land. [Forests provide many important ECONOMIC & Absorb and release water ECOLOGICAL SERVICES] - Forests act as natural water regulators. Through a process called transpiration, trees release water {ECOLOGICAL SERVICES} vapor into the atmosphere, contributing to the Support energy flow and chemical cycling formation of clouds and regulating the local water - Forests play a crucial role in the energy flow cycle. Forests also absorb rainfall, which reduces through ecosystems and the cycling of essential the risk of flooding during heavy rains. The elements like carbon, nitrogen, and phosphorus. absorbed water seeps into the ground, Trees and plants capture solar energy through replenishing groundwater reserves and photosynthesis, converting it into chemical energy, maintaining stream flows during dry seasons. which supports food chains and energy transfer among organisms. Additionally, when plants and Purify water and air animals die, their decomposition recycles - Forests act as natural filters. The roots of trees nutrients, making them available for new growth. and plants help to filter pollutants from water as it This process helps maintain the balance of moves through the soil, improving the quality of nutrients in the ecosystem. rivers, lakes, and groundwater. Forests also purify air by absorbing pollutants like sulfur dioxide, Reduce soil erosion nitrogen oxides, and particulate matter. Through - Soil erosion occurs when wind or water removes photosynthesis, trees absorb carbon dioxide and the top layer of soil. Forests help prevent this by release oxygen, improving air quality and reducing stabilizing the soil with their root systems. Tree greenhouse gas levels in the atmosphere. roots bind the soil, while fallen leaves create a protective layer that reduces the impact of rainfall, preventing the soil from being washed away. By maintaining soil structure, forests protect against  Influence local and regional climate RECREATION - By absorbing heat and releasing moisture through JOBS transpiration, forests help cool the surrounding environment. The presence of trees influences [UNSUSTAINABLE LOGGING is a major threat to forest weather patterns, such as rainfall and ecosystems] temperature. Large forests like the Amazon are sometimes referred to as the "lungs of the planet" {Problems associated with harvesting trees:} because of their role in climate regulation. 1. Increased erosion and sediment runoff into waterways. Store atmospheric carbon - When trees are removed, their root systems, - Forests act as carbon sinks, meaning they absorb which naturally stabilize the soil, are also lost. more carbon dioxide (CO₂) from the atmosphere This destabilizes the land, leading to erosion (soil than they release. Through the process of washing away). photosynthesis, trees and plants capture CO₂ and - Sediment from eroded soils can flow into nearby store it as carbon in their biomass (trunks, rivers and lakes, harming aquatic ecosystems by branches, leaves, roots). This carbon storage helps blocking sunlight, clogging fish gills, and mitigate climate change by reducing the amount disrupting habitats for aquatic plants and animals. of CO₂, a major greenhouse gas, in the atmosphere. 2. Habitat fragmentation - Habitat fragmentation occurs when large, Provide numerous wildlife habitats continuous forests are broken into smaller, isolated patches due to logging, road construction, {ECONOMIC SERVICES} or development. FUELWOOD - Fragmentation creates barriers for animals, LUMBER limiting their ability to move freely, find mates, and PULP TO MAKE PAPER access food. Small, isolated populations are more MINING vulnerable to extinction. LIVESTOCK GRAZING  3. Loss of Biodiversity 2. Clear-Cutting: Involves removing all trees in an - Direct Loss: Cutting down trees directly removes area, leading to severe ecological damage like species' habitats, causing some species to decline habitat loss and soil erosion. or even become extinct. - Indirect Loss: Even species that don’t depend 3. Strip Cutting: A more sustainable method where directly on trees may suffer as their food sources trees are cut in narrow strips, reducing the or breeding areas are disrupted. For example, ecological impact while allowing natural pollinators lose the plants they rely on when regeneration of the forest between the strips. forests are logged. 4. Forest exposure to invasion by nonnative pests, diseases, and wildlife species. - Logging opens up forest areas to invasion by nonnative species, which may outcompete native plants and animals. - Invasive species can dominate and change the ecosystem’s balance, pushing native species towards extinction. They often bring diseases that local species have no resistance to or alter the soil composition, affecting tree regrowth. {Methods of TREE HARVESTING:} 1. Selective Cutting: Only mature or specific types of trees are cut, which minimizes damage to the forest ecosystem and allows younger trees to thrive. Which is the best type of logging? 1. Selective Cutting (Most Sustainable) 2. Strip Cutting (Good Compromise) Method: Only certain trees, usually mature or Method: Trees are harvested in long, narrow strips, commercially valuable ones, are harvested, leaving leaving uncut areas in between. These uncut strips the rest of the forest intact. help the forest regenerate naturally. Environmental Impact: Environmental Impact: ○ Minimal Disturbance: By removing only ○ Moderate Disturbance: Although trees are selected trees, selective cutting helps removed from some sections, the adjacent preserve forest structure, biodiversity, and strips help prevent excessive soil erosion habitats for wildlife. and allow for quicker forest recovery. ○ Regrowth: Younger trees are left to grow, ○ Regrowth: Uncut strips promote natural and the forest can regenerate naturally regeneration by providing seeds and shelter without needing replanting. for wildlife. This method also supports ○ Soil and Water Protection: It maintains root some species that rely on forest continuity. systems and ground cover, which reduces Biodiversity: soil erosion and preserves the forest’s role ○ Moderate: Strip cutting is more disruptive in the water cycle. than selective cutting but less harmful than Biodiversity: clear-cutting. It preserves more habitat than ○ Positive: Selective cutting preserves more clear-cutting but may still cause of the original forest ecosystem and its fragmentation for species with large diversity. Wildlife can continue to live in the territories. forest with minimal disruption. Best For: Areas where timber production is Best For: Areas where maintaining biodiversity, important but conservation of ecosystem services preventing habitat fragmentation, and reducing like water filtration and soil stabilization is still a soil erosion are priorities. concern. [FOREST FIRES:] Stimulates Seed Germination: Some species, like 1. Surface Fires the giant sequoia, rely on surface fires to release - Characteristics: Surface fires burn the seeds from their cones. undergrowth, leaf litter on the forest floor, and smaller plants but generally leave larger, mature 2. Crown fires trees intact. - Characteristics: Extremely hot fires that leap from treetops, burning whole trees. These are much Kills seedlings and small trees but spares most more destructive, as they leap from tree to tree, mature trees and allows most wild animals to burning entire forests, including mature trees. escape. - Can destroy most vegetation, kill wildlife, increase Burns away flammable ground material and may soil erosion, and burn or damage human help to prevent more destructive fires. structures in their paths. Frees valuable mineral nutrients tied up in slowly decomposing litter and undergrowth. Consequences: Releases seeds from the cones of lodgepole Habitat Destruction: Crown fires can wipe out pines. large forested areas, destroying habitats for Stimulates the germination of certain tree seeds countless species. (e.g. giant sequoia and jack pine). Soil Erosion: After crown fires, the loss of Helps to control tree diseases and insects. vegetation can lead to severe soil erosion. Wildlife Mortality: Unlike surface fires, crown fires Reduces Fire Hazards: By burning away the are too intense for most animals to escape. flammable ground material, surface fires prevent the accumulation of fuel that can lead to larger, more destructive fires. Nutrient Recycling: They release nutrients locked in dead plant matter, promoting new plant growth. [DEFORESTATION] erosion. The topsoil, which is the most fertile layer, What is Deforestation?: gets washed or blown away. - Deforestation is the temporary or permanent removal of large expanses of forests, often to - Impact: As soil fertility decreases, the land make way for agriculture, settlements, urban becomes less productive for agriculture and development, or logging for timber. natural regrowth. This leads to desertification in severe cases, making it harder for ecosystems to Global Impact: recover and reducing land utility for future farming. Climate Change: Forests act as carbon sinks, so deforestation contributes to higher levels of Runoff of eroded soil into aquatic systems atmospheric carbon dioxide, exacerbating climate - What Happens: With forests gone, soil eroded by change. rain can easily wash into nearby rivers, lakes, and Loss of Ecosystem Services: Forests purify air and streams. water, regulate climate, and provide habitats for - Impact: This leads to siltation, which clouds water wildlife. Deforestation removes these vital and harms aquatic ecosystems by clogging fish services. gills, reducing sunlight for aquatic plants, and Soil Degradation: Without tree cover, soils are degrading habitats. It also leads to sedimentation quickly eroded, and nutrients are lost, making the in reservoirs, which reduces water quality and land less productive. increases the risk of flooding. [HARMFUL EFFECTS OF DEFORESTATION] Premature extinction of species with specialized {NATURAL CAPITAL DEGRADATION} niches - What Happens: Many species depend on forests Decreased soil fertility from erosion for their specific habitats, especially those with - What Happens: Trees and plants help hold soil in narrow or specialized niches. place with their roots. When forests are cleared, - Impact: When forests are destroyed, species that the lack of vegetation leads to increased soil can only thrive in those particular environments  may face extinction because they cannot adapt to [Causes of Tropical Deforestation:] new conditions or migrate to new areas. *Tropical forests are disappearing rapidly: Biodiversity loss accelerates, weakening - At least half of the world’s known species of ecosystems and reducing genetic diversity critical terrestrial plants and animals live in tropical for adaptation to environmental changes. forests. Regional climate change from extensive clearing - TROPICAL FORESTS: At the current rate of - What Happens: Forests play a key role in global deforestation, 50% of the world’s remaining regulating regional climates by absorbing sunlight, old-growth tropical forests will be gone or severely transpiring water, and contributing to the water degraded by the end of this century. cycle. When large areas of forest are cleared, this balance is disrupted. [NUMBER OF INTERCONNECTED UNDERLYING - Impact: This can result in drier climates (as less & DIRECT CAUSES] water is released into the atmosphere), altered Population Growth: As populations grow, people rainfall patterns, and increased temperatures in need more land for agriculture, housing, and cleared areas. These changes can have a domino resources. Subsistence farming, especially in effect, influencing agricultural productivity, water developing countries, leads to forest clearance. availability, and the overall livability of the region. Government Subsidies: Governments may offer - subsidies for activities like logging or ranching, Release of CO2 into atmosphere making it financially attractive to cut down forests. Acceleration of flooding For example, soy plantations in Brazil and palm oil Loss of habitat for native species and migratory plantations in Southeast Asia have led to massive species such as birds and butterflies deforestation. Agriculture and Ranching: ○ In the Amazon, forests are cleared for cattle grazing and large-scale crops like soybeans.  ○ In Southeast Asia, forests are replaced with oil palm plantations, leading to habitat destruction for species like orangutans. Fuelwood Harvesting: In Africa and other developing regions, people rely on wood for cooking and heating. This demand leads to deforestation and habitat degradation. 1. Input = Drivers and causes of deforestation (agriculture, logging, development). 2. Processor = Methods and processes of clearing forests (clear-cutting, burning, selective logging). 3. Output = Environmental and societal consequences (loss of biodiversity, climate change, soil erosion). 1. Precipitation Precipitation is the process where water, in various forms such as rain, snow, sleet, or hail, falls from [HYDROLOGICAL CYCLE] clouds to the Earth's surface. It occurs when - The hydrological cycle (also known as the water atmospheric water vapor condenses and becomes cycle) is the continuous movement of water on, heavy enough to fall due to gravity. above, and below the surface of the Earth. It Mechanism: Cloud droplets combine to form describes the processes that move water between larger droplets until they are too heavy to stay various reservoirs, including the atmosphere, suspended in the atmosphere, resulting in oceans, rivers, lakes, and land. The hydrological precipitation. cycle is powered by solar energy and gravity. Forms: Rain (liquid), snow (solid), sleet (partially Here's a detailed explanation of the main frozen), and hail (solid ice). processes involved: 2. Interception 4. Surface Runoff Interception happens when precipitation is Surface runoff is the flow of excess water over the captured by vegetation (such as leaves and Earth's surface, which occurs when the soil is branches) before it reaches the ground. This water saturated, or precipitation exceeds the land's may eventually evaporate back into the infiltration capacity. This water flows into streams, atmosphere (called interception loss) or drip down rivers, lakes, and eventually oceans. to the ground as throughfall. Importance: Runoff plays a crucial role in Importance: Interception reduces the amount of transporting water from land to rivers and oceans, water reaching the soil directly and can reduce but it can also lead to erosion, pollution transport, surface runoff, which helps prevent erosion. and flooding if excessive. Throughfall and Stemflow: Water that drips off leaves and flows down branches or trunks to the 5. Evaporation ground. Evaporation is the process where liquid water is converted into water vapor due to heat energy 3. Infiltration from the sun. Water from oceans, lakes, rivers, and Infiltration is the process by which water from soil rises into the atmosphere as vapor. precipitation seeps into the soil. Once in the soil, it Importance: Evaporation is a major component of replenishes moisture levels and contributes to the hydrological cycle, as it transfers water from underground water supplies. Earth's surface into the atmosphere, where it can Factors Affecting Infiltration: Soil type (sand eventually condense and precipitate again. allows faster infiltration than clay), vegetation Key Influencing Factors: Temperature, wind, and cover, land use, and precipitation intensity all humidity levels control the rate of evaporation. influence how much water infiltrates. Soil Saturation: When the soil is fully saturated, 6. Transpiration infiltration stops, leading to increased surface Transpiration is the process by which water is runoff. absorbed by plants' roots and later released as water vapor through small pores (stomata) in leaves.  Combined Process (Evapotranspiration): The Water Table: The upper surface of the combination of evaporation from land and water groundwater reservoir is called the water table. surfaces and transpiration from plants is called 9. Depression Storage evapotranspiration. It represents the total loss of Depression storage refers to water that water to the atmosphere from the surface. temporarily collects in small depressions on the land surface, such as puddles or shallow ponds. 7. Condensation This water either evaporates or infiltrates into the Condensation occurs when water vapor in the soil over time. atmosphere cools and changes back into liquid Role: Depression storage delays surface runoff droplets. This process forms clouds. and allows time for infiltration, which can reduce Mechanism: As warm, moist air rises, it cools, the potential for flash flooding. causing the water vapor to lose energy and condense into droplets that gather around dust 10. Percolation particles in the air. Percolation is the movement of water deeper into Importance: Without condensation, clouds would the soil layers, passing through porous materials not form, and precipitation wouldn’t occur. until it reaches an impermeable layer or the groundwater table. It replenishes aquifers and 8. Groundwater Flow underground water supplies. Groundwater flow refers to the movement of water Aquifer Recharge: This is the process where water that has infiltrated into the soil and percolated percolates to replenish groundwater sources, a down to fill aquifers (underground layers of rock or crucial part of maintaining sustainable water sediment that hold water). This water moves supplies. slowly and can eventually emerge in springs or contribute to rivers and lakes. 11. Interflow Importance: Groundwater is a critical source of Interflow (also called subsurface runoff) is the freshwater for drinking and irrigation. It also lateral movement of water within the soil layer supports base flows of rivers during dry periods. above the water table. It occurs after infiltration  when water moves sideways through the soil to Summary of the Hydrological Cycle eventually enter rivers or lakes. Difference from Surface Runoff: Unlike surface Precipitation delivers water to Earth's surface. runoff, interflow takes place below the surface but Water is intercepted by vegetation or seeps into above the groundwater table. the ground through infiltration. Surface runoff occurs when excess water flows 12. Impermeable Lens over land into rivers and streams. An impermeable lens refers to a layer of rock or Water vapor returns to the atmosphere through dense soil that prevents water from percolating evaporation and transpiration. deeper. Instead of moving downward, water is Condensation forms clouds, leading to more forced to move laterally (horizontally) along the precipitation. surface of the impermeable layer. Water that infiltrates can percolate into Importance: These lenses control the flow of groundwater, which flows through aquifers or groundwater and influence the location of springs eventually emerges to contribute to streams and or streams. rivers. 13. Stream Channel A stream channel is the physical conduit through which water flows in rivers and streams, ultimately returning to larger water bodies such as oceans, lakes, or seas. Streamflow: The water flow in rivers and streams is a crucial part of the water cycle as it returns water that has traveled over land or through groundwater back to the oceans. 1. Population Growth as a Cause of Tropical education on sustainable practices often push Deforestation people to clear more land than necessary, causing - Population growth puts immense pressure on long-term ecological damage. tropical forests as increasing numbers of people require more land for agriculture, housing, and infrastructure. As populations expand, forests are IN GENERAL, often cleared to make space for farming, urban - Subsistence farming involves clearing small plots development, and the extraction of resources like of forest to cultivate crops for personal timber. Subsistence agriculture, where local consumption. However, due to poor soil quality communities depend on forest land to grow food, and the lack of sustainable farming techniques, also escalates with population growth. This these lands quickly become degraded, forcing widespread land conversion leads to habitat farmers to move deeper into the forest and clear destruction and the depletion of forest more land. ecosystems. - Landless people, particularly in impoverished 2. Poverty as a Cause of Tropical Deforestation regions, may have no other option but to settle in - Poverty exacerbates deforestation as forested areas, where they engage in activities economically disadvantaged populations often such as illegal logging, charcoal production, and rely on forest resources for survival. In hunting to generate income. Without secure land impoverished areas, people depend on tenure or access to alternative livelihoods, these slash-and-burn agriculture, illegal logging, and the communities often prioritize short-term survival extraction of forest products like firewood, over long-term forest conservation. This charcoal, and wild game for subsistence. Lacking continuous cycle of land clearing contributes alternative livelihoods or access to sustainable significantly to tropical deforestation, as forests farming methods, poor communities are forced to are lost at an unsustainable rate to provide land and exploit the forest intensively, leading to resources for marginalized populations struggling deforestation. The absence of economic to make a living. incentives to conserve forests and the lack of Major underlying and direct causes of Population growth: Increasing population pressure can lead to greater demand for land and the destruction and degradation of resources, contributing to deforestation and tropical forests. It highlights how various factors, degradation. both human-induced and natural, contribute to the Direct Causes: decline of these vital ecosystems. Roads: The construction of roads in forested areas can facilitate access to previously Underlying Causes: inaccessible areas, leading to deforestation for Not valuing ecological services: Tropical forests agriculture, logging, and settlement. provide numerous ecosystem services, such as Fires: Both natural and human-caused fires can clean air, water filtration, biodiversity conservation, destroy large areas of forest, particularly during and climate regulation. When these services are dry seasons. not valued or properly accounted for, it can lead to Cattle ranching: Clearing forests for cattle grazing unsustainable exploitation of forest resources. can lead to deforestation and soil erosion. Crop and timber exports: The demand for Logging: Selective or illegal logging can deplete agricultural products and timber from tropical forest resources and disrupt ecosystems. forests can drive deforestation and degradation. Settler farming: The expansion of agricultural land Government policies: Poorly designed or into forested areas can destroy habitats and implemented government policies, such as degrade ecosystems. inadequate land use planning or subsidies for Tree plantations: Monoculture tree plantations unsustainable activities, can contribute to can replace diverse native forests, reducing deforestation. biodiversity and ecosystem services. Poverty: Poverty can force people to rely on forest Cash crops: The cultivation of high-value cash resources for their livelihoods, leading to crops, such as palm oil and soy, can drive unsustainable practices like illegal logging and deforestation and land conversion. slash-and-burn agriculture.  Ways to Grow and Harvest Trees more CONSERVATION CONCESSIONS occur when Sustainably governments or private conservation Identify and protect forest areas high in organizations pay nations for agreeing to preserve biodiversity their natural resources. Rely more on selective cutting and strip cutting Stop clear-cutting on steep slopes Ways to Reduce Tropical Deforestation Stop logging in old-growth forests Consumers can reduce the demand for products Sharply reduce road building in uncut forest areas that are supplied through illegal and unsustainable Leave most standing dead trees and fallen timber logging in tropical forests. for wildlife habitat and nutrient cycling 1. For building projects, use recycled waste, Put tree plantations only on deforested and lumber or wood alternatives, such as degraded land recycled plastic building materials and Certify timber grown by sustainable methods bamboo. Include ecological services of forests in estimates 2. Reduce the use of throwaway paper of their economic value products and replace them with reusable plates, cups, and cloth napkins and We can Improve Management and Reduce the handkerchiefs. Individuals can plant trees Demand for Harvested Trees DEBT-FOR-NATURE SWAP can make it financially Reduce inefficient use of construction materials, attractive for countries to protect their tropical excess packaging, overuse of junk mail, forests. inadequate paper recycling, and failure to reuse or CONSERVATION CONCESSIONS occur when find substitutes for wooden shipping containers governments or private conservation Paper can be made from fiber that does not come organizations pay nations for agreeing to preserve from trees. their natural resources. DEBT-FOR-NATURE SWAP can make it financially attractive for countries to protect their tropical forests.  Ways to Protect Tropical Forests and use We can Rehabilitate and Restore Ecosystems them more sustainably that we have Damaged - We can reserve much of this harm through [PREVENTION]: ECOLOGICAL RESTORATION: the process of Protect the most diverse and endangered areas repairing damage caused by humans to the Educate settles about sustainable agriculture and biodiversity and dynamics of natural ecosystems. forestry Subsidize only sustainable forest use Examples of Restoration: Protect forests through DEBT-FOR-NATURE - Replanting forests swaps and conservation concessions - Restoring grasslands Certify sustainably grown timber - Restoring coral reefs Reduce poverty - Restoring wetlands and stream banks Slow population growth - Reintroducing native species - Remove invasive species [RESTORATION]: - Freeing river flows by removing dams Encourage regrowth through secondary succession Four Steps to Speed Up Ecological Restoration Rehabilitate degraded areas 1. Restoration: Bringing an ecosystem back to its Concentrate farming and ranching on original condition. already-cleared areas 2. Rehabilitation: Turning a degraded ecosystem into a functional one, though it may not be identical to WORD TO REMEMBER: its original state. Biodiversity Hotspots: Areas especially rich in 3. Replacement: Substituting a degraded ecosystem plant species that are found nowhere else and are with another productive ecosystem, like replacing in great danger of extinction. a damaged forest with grassland.  4. Creating Artificial Ecosystems: Constructing 2. Great Dissolving Power: Water is often called the man-made ecosystems, such as artificial "universal solvent" because it can dissolve more wetlands, to replace lost ecological services. substances than any other liquid. This is due to its polar molecular structure, which allows it to interact with various ions and molecules. For example, when salt is added to water, the positive end of water molecules (hydrogen) attracts the WATER SYSTEM negative chloride ions, and the negative end (oxygen) attracts the positive sodium ions, effectively separating them. This property is Water’s Unique Properties: crucial for biological processes, as it allows water Changes temperature slowly to carry nutrients, minerals, and waste products in Great dissolving power living organisms. It also plays a vital role in Expands when it freezes chemical reactions that occur in cells, making water essential for life. 1. Changes Temperature Slowly: Water has a high specific heat capacity, meaning it can absorb and 3. Expands When It Freezes: Most substances store a lot of heat without changing temperature contract when they freeze, but water behaves quickly. This property helps regulate the climate by differently. When water freezes, its molecules form moderating temperature extremes in both natural a crystalline structure that is more open and less and human environments. For instance, large dense than liquid water. As a result, ice floats on bodies of water like oceans and lakes heat up and water, which is vital for aquatic ecosystems. The cool down more slowly than land, leading to milder insulating layer of ice that forms on the surface of temperatures in coastal areas. This stability allows lakes and ponds protects the water below, organisms to adapt better to their environment allowing aquatic life to survive in the colder and creates more favorable conditions for months. This unique property also helps to ecosystems. stabilize temperatures in bodies of water,  preventing rapid temperature fluctuations that Readily accessible freshwater is scarce: Only a could be harmful to aquatic organisms. tiny fraction of Earth's total water is readily Together, these properties of water contribute to its available for human use. ability to support life on Earth. They help maintain stable Groundwater is a significant source: Groundwater climates, allow for the transport of essential nutrients, makes up a substantial portion of the readily and protect ecosystems from extreme temperature accessible freshwater. changes, all of which are fundamental for the survival of Lakes and rivers are relatively small: Lakes and countless organisms. rivers, while important, hold a small percentage of the total freshwater. Supply of water resources on Earth: Surface Water Total Freshwater: 0.592% of the Earth's total water - Surface water refers to all water that is found on the surface of the Earth, including rivers, lakes, Ice caps and glaciers: 0.582% (98.4% of ponds, reservoirs, and streams. It is a crucial part freshwater) of the Earth's hydrological cycle, where water Groundwater: 0.592% (1.5% of freshwater) evaporates, condenses, and falls back to the Readily accessible freshwater: 0.014% (Only 2.4% surface as precipitation. Surface water is vital for of freshwater) various uses, such as drinking, irrigation, ○ Lakes: 0.0007% (5%) recreation, and supporting ecosystems. ○ Rivers: 0.0001% (1%) ○ Soil moisture: 0.0005% (4%) Surface runoff ○ Atmospheric water vapor: 0.0001% (1%) Reliable runoff ○ Biota: 0.0001% (1%) Watershed Key takeaways: Drainage basin Most freshwater is frozen: The majority of Earth's freshwater is locked up in ice caps and glaciers. 1. Surface runoff happens when water from rain, resources, predicting floods, and protecting melted snow, or other sources flows over the aquatic ecosystems. ground instead of soaking into it. This occurs when the ground is too saturated or when it’s Summary made of hard surfaces like concrete. Surface In summary, these terms describe how surface water runoff helps carry water into rivers and lakes but moves and is managed. They are essential for can also lead to flooding and pollution. understanding our water resources, ensuring we have enough clean water, and protecting the health of our 2. Reliable runoff is the amount of surface water rivers, lakes, and ecosystems. flow that can be expected consistently over time from a particular area, like a watershed. It helps in Soil Properties planning for water supply needs for things like Infiltration agriculture and drinking water, as it shows how Porosity/Permeability much water will be available during different Texture weather conditions. Infiltration: This refers to the rate at which water can 3. A watershed is the area of land that drains water enter the soil. It depends on factors like soil texture, into a specific body of water, like a river or lake. It structure, and organic matter content. is defined by high points in the landscape, like hills, Porosity/permeability: These terms relate to the amount that guide the flow of water. Activities in a of pore space in the soil and how easily water can flow watershed, such as farming or urban development, through it. can affect the quality of the water that ends up in the rivers or lakes. High permeability: Soils with large pores, such as sand and gravel, allow water to infiltrate quickly. 4. A drainage basin is a larger area that includes Low permeability: Soils with small pores, such as multiple watersheds. It is all the land where water clay, have a slower infiltration rate. drains into a main river or lake. Understanding drainage basins is important for managing water Texture: This refers to the relative proportions of sand, or saturated. This can lead to pooling of water on silt, and clay in the soil. It affects the soil's physical and the surface and increased erosion. chemical properties. Groundwater: Water may not infiltrate as easily into low-permeability soils, limiting groundwater Water and High Permeability (Sand, Gravel) recharge. Sand and Gravel: These soils have large, Drainage: These soils can be prone to well-connected pores. This means that water can waterlogging, especially in areas with high rainfall easily move through them, making them highly or poor drainage systems. permeable. Infiltration: Water infiltrates quickly into sandy or In summary, high-permeability soils (like sand and gravel) gravelly soils, often leading to rapid runoff if the allow water to infiltrate and move quickly, while soil is saturated. low-permeability soils (like clay and gravel) can restrict Groundwater: These soils can easily allow water water movement. to percolate into the groundwater table, which is important for replenishing aquifers. Groundwater - Groundwater refers to the water stored beneath the Drainage: High-permeability soils are well-draining, Earth's surface in the tiny spaces or pores between making them suitable for drainage systems and rocks, soils, and sediment. It accumulates in preventing waterlogging. underground layers called aquifers, which vary in depth and capacity. Water and Low Permeability (Clay, Gravel) Clay and Gravel: Clay soils have very small, tightly Hydrological cycle and the role of groundwater. Here's a packed pores, while gravel soils have a wide range breakdown of the key components: of pore sizes. Both types can have low Hydrological Cycle: permeability depending on their specific Precipitation: Water falls from the sky as rain, composition and structure. snow, or sleet. Infiltration: Water infiltrates slowly into clay and Infiltration: A portion of the precipitation infiltrates gravel soils, especially when they are compacted into the soil.  Runoff: Some of the precipitation flows over the Over-extraction of groundwater can lead to surface as runoff, eventually reaching streams, depletion of aquifers and water shortages. rivers, and lakes. Protecting groundwater quality is essential for Evaporation and transpiration: Water from the ensuring a sustainable supply of clean water. surface and from plants evaporates into the atmosphere. Use of Water Resources Groundwater: Humans use about 50% of reliable runoff: This means Unconfined aquifer: This is a layer of permeable that humans use approximately half of the water that rock or sediment that contains water that is not flows through rivers and streams. confined by impermeable layers above or below. United States: The pie chart shows the breakdown of The water table is the upper surface of the water use in the United States: unconfined aquifer. Confined aquifer: This is a layer of permeable rock Agriculture: 38% of water is used for agriculture, or sediment that is confined between impermeable including irrigation and livestock. layers. Water in a confined aquifer is under Industry: 38% of water is used for industrial pressure and may rise above the water table when purposes, such as manufacturing and power a well is drilled into it. generation. Artesian well: A well that flows naturally due to the ○ Power cooling: 38% of industrial water use pressure of water in a confined aquifer. is for cooling power plants. Recharge area: The area where water infiltrates Domestic: 11% of water is used for domestic into the ground and replenishes the aquifer. purposes, such as drinking, cooking, and bathing. Public: 10% of water is used for public purposes, Key points: such as firefighting, public parks, and fountains. Groundwater is an important source of freshwater. The movement of groundwater is influenced by the permeability of the underlying rock or sediment.  Using Dams and Reservoirs to Supply More Downstream cropland and estuaries are deprived Water of nutrient-rich silt: Dams trap sediment and Benefits: nutrients that would naturally flow downstream, Provides water for year-round irrigation of affecting the health of downstream ecosystems. cropland: Dams and reservoirs can store water Downstream flooding is reduced: While dams can during wet seasons and release it during dry reduce flooding downstream, they can also periods, ensuring a reliable water supply for increase the risk of flooding upstream if the agriculture. reservoir becomes full. Reduces downstream flooding: Dams can help Migration and spawning of some fish are regulate water flow, reducing the risk of flooding disrupted: Dams can block the migration of fish, downstream. disrupting their reproductive cycles and affecting Produces cheap electricity: Hydropower plants fish populations. can generate electricity by harnessing the energy Tapping Groundwater of flowing water, providing a renewable and - Tapping groundwater refers to the process of cost-effective source of power. accessing and extracting water from underground Reservoir is useful for recreation and fishing: aquifers or wells. This is done by drilling into the Reservoirs can create recreational opportunities ground to reach water-bearing layers, which can for boating, fishing, and swimming. then be pumped to the surface for various uses, Drawbacks: such as drinking, irrigation, and industrial Flooded land destroys forests or cropland and processes. displaces people: The construction of dams often - It is commonly tapped using wells, boreholes, or involves flooding large areas of land, destroying springs, allowing people to utilize the stored water forests, cropland, and displacing communities. beneath the Earth’s surface. Large losses of water through evaporation: Reservoirs can lose significant amounts of water A. Year-Round Use: Groundwater can be accessed through evaporation, reducing the overall water throughout the year, making it a reliable source of supply. water, especially in areas with limited rainfall.  B. No Evaporation Losses: Unlike surface water, agriculture, industry, or improper waste disposal, groundwater doesn’t evaporate, so all of it can be making it unsafe to drink. used for drinking, irrigation, and other purposes. C. Often Less Expensive: In many cases, tapping into Converting Salt Water to Fresh Water and Making it Rain groundwater can be cheaper than other water - Converting salt water to fresh water refers to sources because it requires less treatment and processes that remove salt and impurities from infrastructure. seawater, making it suitable for human D. Potential Problems: While groundwater has many consumption, irrigation, or other uses. This is benefits, there can be issues such as crucial in regions with limited freshwater over-extraction and contamination that can affect resources. its availability and quality. Two common methods for desalination (the process of Problems with Using Groundwater converting salt water to fresh water) are: A. Water Table Lowering: Excessive pumping of groundwater can lower the water table, making it A. Distillation Desalination: This method involves harder to access water in the future. boiling salt water to create steam. The steam B. Depletion: Overuse of groundwater can lead to rises, leaving the salt behind, and is then depletion, meaning the water supply is reduced to condensed back into liquid water, which is now unsustainable levels. free of salt. C. Subsidence: When too much groundwater is B. Reverse Osmosis Desalination: In this process, removed, the ground can sink or collapse, leading salt water is forced through a special membrane to damage to buildings and infrastructure. that allows only water molecules to pass through, D. Saltwater Intrusion: In coastal areas, excessive effectively filtering out the salt and producing groundwater pumping can cause saltwater to fresh water. move into freshwater aquifers, making the water - Desalination is Very Expensive: Both desalination unusable for drinking or irrigation. methods require significant energy and E. Chemical Contamination: Groundwater can infrastructure investments, making them costly become contaminated by chemicals from options for producing freshwater.  water consumption and minimize waste in production. C. Making it rain involves techniques like cloud E. Water Efficient Landscaping: Designing gardens seeding, which is a method of enhancing and landscapes with native plants that require less precipitation. This process introduces substances water can conserve water and create sustainable (like silver iodide or sodium chloride) into clouds outdoor spaces. to encourage them to produce rain. By altering the conditions within the clouds, it can increase the Too Much Water: Floods likelihood of rainfall, helping to provide water in Natural phenomena areas that may be experiencing drought or water Renew and Replenish scarcity. Floods: Using Water More Efficiently Natural phenomena: Floods are a natural A. Reduce Losses Due to Leakage: Fixing leaks in occurrence that can be caused by various factors, pipes and water systems can save a significant such as heavy rainfall, snowmelt, and overflowing amount of water, ensuring that more reaches its rivers. intended destination. Renew and replenish: While floods can cause B. Reform Water Laws: Updating laws and significant damage, they also play a vital role in the regulations around water use can promote more natural water cycle by renewing and replenishing sustainable practices and better management of water resources. water resources. C. Improve Irrigation Efficiency: Using advanced Flood Control Measures: irrigation techniques, like drip irrigation, can help Reservoirs: Dams and reservoirs can help regulate farmers use less water while still growing crops water flow and reduce the risk of flooding by effectively. storing excess water during wet periods. D. Improving Manufacturing Processes: Factories Levees and floodwalls: These structures are built can adopt water-efficient practices to reduce their to protect communities from flooding by preventing water from overflowing riverbanks.  Floodplain: The area adjacent to a river or stream Water Conservation that is prone to flooding. Floodplains can help Water Consumption: absorb excess water and reduce flood damage. Average American water use: The average American uses 90 gallons of water per day. SUMMARY: Global water use: Europeans use 53 gallons per - Floods are natural events that occur when there is day, while Sub-Saharan Africans use only 5 gallons too much water in an area, often caused by heavy per day. rainfall, melting snow, or rivers overflowing. While floods can lead to significant damage to homes, Water Conservation Tips: infrastructure, and the environment, they also play Fix leaks: Repairing leaky faucets and pipes can an important role in the water cycle by renewing save a significant amount of water. and replenishing water resources. To manage and Replace old toilets: Older toilets use much more control floods, various measures can be water than newer, more efficient models. implemented. Reservoirs and dams can store Replacing old toilets with newer models can save excess water during heavy rains, reducing the risk water and money. of flooding downstream. Levees and floodwalls Use efficient washers: Washing machines that use are built to keep water from spilling over less water can significantly reduce water riverbanks and flooding nearby areas. Floodplains consumption. are the flat areas next to rivers that can absorb excess water, helping to lessen flood damage. Benefits of Water Conservation: Overall, while floods are a natural part of the water A switch to water-efficient appliances by a family cycle and can have beneficial effects, of 4 can save 23,000 gallons a year: By adopting human-made interventions can help reduce their water-saving practices, a family of four can reduce impacts and protect communities. It’s essential to their water consumption by a significant amount. have effective flood management plans in place to safeguard people and infrastructure from flooding.  MARINE ENVIRONMENT Division of the Marine Environment: The marine environment can be divided based on physical characteristics, including depth, light, and Marine Environment temperature. - refers to all the ecosystems found in the world's oceans and seas, covering about 71% of the Vertical Zones: Earth's surface. This environment is home to a Photic Zone: diverse range of plants and animals, from tiny Also known as the sunlight zone. Extends from plankton to massive whales. Marine ecosystems the ocean surface to a depth of about 200 meters include coral reefs, mangroves, estuaries, and (656 feet). deep-sea habitats, each supporting unique species Receives sufficient sunlight to support and playing important roles in the Earth's photosynthesis by marine plants and algae. This ecological balance. zone is home to the majority of marine life, including fish, corals, and whales. Ocean Coverage: Oceans cover 71% of the Earth's surface. Aphotic Zone: The Northern Hemisphere is 61% ocean and 39% Also known as the midnight zone. Extends from land. below the photic zone to the ocean floor. The Southern Hemisphere is 80% ocean and 20% Receives no or very little sunlight. Due to the lack land. of sunlight, photosynthesis is not possible in this Marine Ecosystem: zone. The marine ecosystem is the largest aquatic Organisms in the aphotic zone must adapt to system on Earth. survive in darkness and often rely on It includes oceans, coral reefs, and estuaries. chemosynthesis (using chemical reactions to produce food) or feeding on organic matter that sinks from the photic zone. 2 Major Divisions: Bathypelagic Zone (Midnight Zone): This zone 1. Benthic Realm: This is the bottom of the ocean, extends from 1,000 to 4,000 meters (3,281 to where organisms live on or in the sediment. This is 13,123 feet) deep. It is completely dark, and most the entire seafloor, from the deepest parts to the organisms in this zone are adapted to survive in tide-influenced areas. It includes the ocean floor extreme conditions. and the sediment beneath it. Abyssopelagic Zone (Abyssal Zone): This zone 2. Pelagic Realm: This is the water column above the extends from 4,000 to 10,000 meters (13,123 to seafloor. It is further divided into five subdivisions 32,808 feet) deep. It is the deepest part of the based on depth and light penetration. ocean, with high pressure and low temperatures. Hadal Zone: This is the deepest part of the ocean, 5 Subdivisions of the Pelagic Zone: found in trenches. 1. Epipelagic Zone: ○ Depth: From the ocean surface to 200 1. Division of the Benthic Realm: meters. 1.1 Intertidal Zone: This is the area between the ○ Also known as the photic or euphotic zone. lowest low tide and the highest high tide marks. It ○ Receives sunlight, allowing for is periodically exposed to air and water. photosynthesis by marine plants and algae. 1.2 Sublittoral Zone: This extends from the lowest ○ Contains 90% of all ocean life. low tide mark to the shelf break, which is around 200 meters (656 feet) deep. It is part of the 2. Mesopelagic Zone: continental shelf. ○ Depth: From 200 to 1000 meters. 1.3 Bathyal Zone: This extends from the shelf ○ Also known as the disphotic or twilight break to 4000 meters (13,123 feet) deep. It zone. coincides with the continental slope and rise. ○ Receives only blue light. 1.4 Abyssal Zone: This extends from 4000 to 6000 ○ Temperature decreases to 10°C (50°F) at meters (13,123 to 19,685 feet) deep. It includes this depth. the average depth of the deep ocean floor. 1.5 Hadal Zone: This is the deepest part of the ocean, extending beyond 6000 meters. It includes  the trenches, which are the deepest parts of the They are free-floating organisms with limited seafloor. locomotory powers, meaning they cannot swim against currents or waves. Pelagic Organisms: Planktons are transported horizontally by water There are approximately 31 phyla of pelagic movements, tides, currents, and wave actions. organisms. They can be found in both the photic (sunlit) and Phytoplankton: aphotic (dark) zones of the ocean. Phytoplankton are photosynthesizing autotrophic primary producers. This means they can produce Two Main Groups: their own food using sunlight and carbon dioxide. 1. Planktons: These are free-floating organisms that They contain chlorophyll a, a pigment essential for are carried by ocean currents. They can be divided photosynthesis. into two subgroups: Examples of phytoplankton include microalgae, ○ Phytoplankton: These are plant-like diatoms, and silicoflagellates. organisms that use photosynthesis to produce their own food. Zooplankton: ○ Zooplankton: These are animal-like Zooplankton are consumer organisms that organisms that feed on other plankton or migrate towards surface water vertically. organic matter. They are an important intermediate link in the 2. Nektons: These are actively swimming organisms marine food web. that can move independently of ocean currents. Examples of zooplankton include jellyfish, krill, and They include fish, squid, and marine mammals. copepods. Zooplankton can be further divided into Planktons: holoplankton (organisms that spend their entire The term "plankton" comes from the Greek word lives as plankton) and meroplankton (organisms "planktos," meaning "wanderer" or "drifter." that spend only part of their lives as plankton). Nektons: photosynthesis. This process converts sunlight Nektons are active swimmers that include and carbon dioxide into energy, forming the base chordates (vertebrates) and invertebrates. of the marine food web. High marine productivity Examples of nekton include mollusks, arthropods, occurs in areas with abundant nutrients, such as cephalopods (like squid), fish, and sea turtles. near coastlines or upwelling zones where Some deep-sea fish have bioluminescent organs nutrient-rich waters rise to the surface. (photophores) that produce light. Nektons generally play various roles in the marine Factors Affecting Marine Productivity: ecosystem, including carnivores, predators, 1. Temperature: scavengers, and filter feeders. ○ Can be a barrier for nutrient distribution, as warmer water tends to be less dense and Benthic Organisms: may not mix well with colder water. Represent 98% of all marine creatures. ○ Contributes to the geographical location of Can be found in various habitats, including: organisms, as different species have ○ Intertidal rocky shores adapted to specific temperature ranges. ○ Mudflats ○ Affects respiration rates within cells, with ○ Sandy beaches warmer water generally leading to higher ○ Coral reefs metabolic rates. ○ Kelp forests ○ Warmer water can also support higher Include both mobile and sessile creatures. primary productivity due to increased Some benthic organisms, such as chemosynthetic photosynthesis. bacteria, obtain energy from chemical reactions rather than sunlight. Poikilotherms and Homeotherms: Poikilotherms: These are cold-blooded animals, Marine Productivity including marine plants, invertebrates, fish, and - Marine productivity refers to the rate at which reptiles. Their body temperature varies with the marine organisms, particularly plants and surrounding environment. phytoplankton, produce organic matter through  Homeotherms: These are warm-blooded animals, Other salt constituents: including seabirds and marine mammals. They In addition to sodium and chloride, seawater can regulate their body temperature independently contains other salts, including: of the environment. ○ Calcium (Ca) ○ Potassium (K) Stenothermal and Eurythermal Organisms: ○ Magnesium (Mg) Stenothermal organisms: These are organisms ○ Sulfate (SO4) that have a narrow tolerance for temperature ○ Silicic acid (H4SiO4) fluctuations. Examples include corals. ○ Strontium sulfate (SrSO4) Eurythermal organisms: These are organisms that can tolerate a wide range of temperatures. 3. Light: Photosynthesis and breeding cycles: Light is Ocean's Role in Regulating World Temperature: essential for photosynthesis, the process by which The ocean stores heat from the sun, helping to plants and other organisms convert sunlight into regulate global temperatures. energy. It also affects the breeding cycles of many marine organisms. 2. Salinity: Turbidity: Turbidity, which is the cloudiness or Open ocean salinity: The average salinity of the murkiness of water, affects light penetration. open ocean is about 35 parts per thousand (ppt). Higher turbidity reduces the amount of light that The Red Sea has a higher salinity of 46 ppt. can reach deeper depths. Sodium and chloride: Sodium (Na) and chloride Zonation of marine life: The distribution of marine (Cl) make up about 80% of the salts in seawater. organisms is influenced by the availability of light. Importance of salinity: Salinity is important for the Organisms that require sunlight for photosynthesis osmoregulation of marine organisms, which is the are found in the photic zone (the upper part of the process of maintaining the proper balance of salts ocean), while those that can survive in darkness and water in their bodies. are found in the aphotic zone (the deeper part of the ocean). Light Penetration: 5. Waves: 50% of sunlight reaches the ocean surface: Only Caused by winds: Waves are generated by the about 50% of the sunlight that reaches the Earth's wind blowing over the ocean surface. atmosphere penetrates the ocean surface. Affects intertidal areas: Waves can have a 1% penetrates down the sea: Less than 1% of significant impact on intertidal areas, eroding the sunlight penetrates to depths below 100 meters shoreline and shaping the coastline. (328 feet). This limits the depth at which Mix oxygen: Waves help to mix oxygen into the photosynthesis can occur. water column, which is important for marine life. Prevent desiccation: In intertidal areas, waves can 4. Pressure: help to prevent organisms from drying out by Affects deposition of calcium carbonate: Calcium periodically submerging them in water. carbonate, which is a major component of coral reefs and shells, is more soluble at high pressures. 6. Tides: This means that in the deep ocean, where Tides are caused by the gravitational pull of the pressure is high, calcium carbonate can dissolve moon and sun on the Earth's oceans. more easily, limiting the growth of coral reefs and Tides affect the duration of exposure of marine other organisms that rely on it. organisms to air and water in intertidal zones. Eurybathic and stenobathic organisms: Eurybathic The timing of tides can influence the feeding and organisms can tolerate a wide range of depths and reproductive behaviors of marine organisms. pressures, while stenobathic organisms have a narrow tolerance for pressure. 7. Currents: Vertical migration: Many marine organisms, such Ocean currents are driven by a variety of factors, as zooplankton, exhibit vertical migration, moving including the sinking of large chunks of ice up and down in the water column to feed or avoid (thermohaline circulation), wind, and the Earth's predators. Pressure can influence these migration rotation. patterns. Currents play a crucial role in ocean circulation, moving water and nutrients around the globe.  Cool, denser water moves along the ocean floor, Aquatic Environments: Types, Components, and while warmer water moves near the surface. Limiting Factors Currents transport nutrient-rich water, supporting - Aquatic environments can be classified into marine productivity in certain areas. marine systems (saltwater) and freshwater systems (low salinity). 8. Dissolved Gases: - Key components include organisms like plankton Dissolved oxygen: Oxygen is essential for the (tiny floating organisms), nekton (free-swimming respiration of marine organisms. animals), and benthos (bottom-dwelling Dissolved carbon dioxide: Carbon dioxide is a key creatures). nutrient for photosynthesis, the process by which - Limiting factors may include water temperature, plants and other organisms produce their own light availability, and nutrient levels. food. A. Freshwater systems 9. Dissolved Nutrients: - Freshwater systems include lakes, rivers, streams, Source: Dissolved nutrients come from the and wetlands. They provide habitats for numerous dissolved feces of marine animals and upwelling, organisms and are essential for human uses like which brings nutrient-rich water to the surface. drinking water, agriculture, and recreation. NPK: NPK refers to nitrogen (N), phosphorus (P), and potassium (K), which are essential nutrients for plant growth. B. Saltwater Life Zones Silica: Silica is a nutrient that is required by - Saltwater life zones include diverse habitats such diatoms, a type of phytoplankton. as the coastal zone, estuaries, coastal wetlands, Iron: Iron is another essential nutrient for mangroves, and intertidal zones, which all support photosynthesis. rich biodiversity and serve essential ecological functions.  Coastal zone Intertidal zones - The coastal zone is where land meets the ocean, - Intertidal zones are coastal areas that are exposed featuring diverse habitats like beaches, salt to air at low tide and submerged at high tide. marshes, and mangroves. This area is highly These zones host unique ecosystems that include productive and supports a wide range of marine various plants and animals adapted to changing life. conditions. Estuaries Coral Reefs - Estuaries are transitional areas where freshwater - Coral reefs play a vital role as the breeding from rivers meets and mixes with saltwater from grounds of the marine ecosystem. They provide a the ocean. They are rich in nutrients, making them safe and structured environment for fish and vital habitats for many fish and bird species. other marine species to reproduce and lay their eggs. Coastal wetlands - Coral reefs support a wide variety of marine life, - Coastal wetlands are areas where water covers providing shelter, food, and breeding grounds for the soil or is present at or near the surface for part fish, crustaceans, and other sea creatures. They of the year. They provide critical habitat for wildlife, also help protect coastlines from erosion and help filter pollutants, and protect shorelines from storms. erosion. - Coral reefs thrive in warm, shallow waters and are sensitive to changes in water temperature, Mangroves pollution, and human activities like overfishing. - Mangroves are coastal trees that grow in salty or brackish water. They provide important habitats C. Freshwater Life Zones for marine life, help stabilize shorelines, and - Freshwater life zones include standing water protect coastal areas from storms and erosion. bodies, like lakes and ponds, and flowing water bodies, like rivers and streams. Each zone  supports different types of organisms and organisms, including fish, insects, and ecological processes. crustaceans. 1. Standing water - Standing water refers to lakes and ponds where Types of Lakes: water does not flow. These habitats can support A. Oligotrophic diverse life forms and are essential for recreation, - Oligotrophic lakes are characterized by their low drinking water, and irrigation. nutrient content and limited productivity. Lakes and ponds: These are bodies of water that KEY FEATURES: are surrounded by land and do not have a strong Oligotrophic lakes have low concentrations of current. They are home to a variety of aquatic nutrients, such as nitrogen and phosphorus. This organisms, including fish, frogs, turtles, and limited nutrient availability restricts the growth of insects. algae and other aquatic plants. Wetlands: These are areas where the land is Oligotrophic lakes typically have little or no saturated with water for part of the year. Wetlands shoreline vegetation, as the lack of nutrients limits can be marshes, swamps, or bogs. They provide plant growth. important habitat for many species of plants and Limnetic Zone: The limnetic zone is the open animals. water area of the lake. In oligotrophic lakes, this zone has low concentrations of nutrients and 2. Flowing water plankton. - Flowing water includes rivers and streams where Oligotrophic lakes often have a sparse fish water continuously moves. These systems are population due to the limited food resources dynamic environments that support various available. organisms and contribute to nutrient cycling. Oligotrophic lakes tend to have steep shorelines, which can contribute to their low nutrient content. Rivers and streams: These are bodies of water that flow from a higher elevation to a lower elevation. They are home to a variety of aquatic  B. Eutrophic - Eutrophic lakes are characterized by their high Watershed: A watershed, also known as a nutrient content and excessive plant growth. drainage basin, is a geographic area that drains into a particular river or stream. Watersheds are KEY FEATURES: defined by their natural boundaries, such as Eutrophic lakes have high concentrations of mountains or ridges. nutrients, such as nitrogen and phosphorus. This excess of nutrients can come from various Drainage basin: This is another term for sources, including agricultural runoff, sewage watershed, referring to the area that drains into a discharge, and atmospheric deposition. specific river or stream. Eutrophic lakes often have extensive shoreline vegetation due to the abundant nutrients available Floodplain: This is the area adjacent to a river or for plant growth. stream that is prone to flooding. Floodplains are In eutrophic lakes, this zone is often characterized often fertile and productive areas, but they can by dense algal blooms, which can reduce light also be vulnerable to damage during floods. penetration and oxygen levels. Eutrophic lakes can have a high fish population, SUMMARY: but the quality and diversity of the fish community - Runoff is the precipitation that flows over land may be affected by the reduced oxygen levels and when it can't infiltrate into the soil, influenced by competition for resources. factors like soil type, slope, and vegetation. This water drains into a watershed, which is the geographic area that feeds a particular river or stream, defined by natural features like mountains Stream Systems or ridges. The term "drainage basin" is often used Runoff: This refers to the water that flows over the interchangeably with watershed, referring to the land surface, typically as a result of precipitation. same area. Floodplains are flat areas adjacent to Runoff can be influenced by factors such as soil rivers or streams that are prone to flooding during type, slope, and vegetation. high water events. When runoff flows into a river, it  can cause the river to overflow, flooding the water, harming aquatic life and degrading water floodplain and connecting these components in quality. the water cycle. 4. Wetland Destruction: Human activities such as urban development, agriculture, and mining often Human Impacts on Wetlands and Streams lead to the destruction of wetlands. This loss not 1. Dams, Diversions, and Canals: Dams and water only reduces biodiversity and disrupts habitats but diversion projects alter natural water flow in rivers also diminishes the natural water filtration and streams. While they can provide benefits like systems that wetlands provide, impacting water hydroelectric power and irrigation, they disrupt quality and increasing flooding risks in ecosystems by changing water levels and surrounding areas. temperatures, affecting fish migration and habitats. 2. Flood Control and Dikes: Flood control measures Things to remember in an ECOSYSTEM like dikes and levees are built to protect human An ecosystem is a community of organisms that settlements from flooding. However, these interact with each other and with the non-living structures can prevent natural flooding, which is components of their environment. essential for replenishing wetlands and Ecosystems are essential for sustainable maintaining their ecological functions, leading to development and adaptation to changing habitat loss and decreased biodiversity. environmental conditions. 3. Pollution and Eutrophication: Runoff from Biosphere: agricultural and urban areas can introduce The biosphere is the combination of all pollutants into wetlands and streams, including ecosystems present on Earth. It encompasses all nutrients like nitrogen and phosphorus. This living organisms and their interactions with the excess nutrient input causes eutrophication, physical environment. leading to algal blooms that deplete oxygen in the Functions of Ecosystem 2 MAIN TYPES OF WATER POLLUTION 1. Rate of biological energy flow: This refers to the SOURCES: movement of energy through an ecosystem, which is influenced by the production and respiration POINT SOURCES rates of the organisms within the community. - Point sources are direct, identifiable, and localized 2. Nutrient cycles: Ecosystems play a crucial role in sources of pollution. These sou