ENVISCI.docx

**SCX 010: ENVIRONMENTAL SCIENCE** **[MODULE 9]** **Sir Arthur George Tansley** -british ecologist -coined the term "ecosystem" in 1935 **Biotic** -include the producers like plants, consumers like animals and decomposers such as bacteria, yeast and fungi. **Abiotic** -are the physical facto...

**SCX 010: ENVIRONMENTAL SCIENCE** **[MODULE 9]** **Sir Arthur George Tansley** -british ecologist -coined the term "ecosystem" in 1935 **Biotic** -include the producers like plants, consumers like animals and decomposers such as bacteria, yeast and fungi. **Abiotic** -are the physical factors and chemical substances that greatly affect the presence and success of the biotic components **Ecosystem Components:** **Producers (Autotrophs):** Capture energy from the sun and manufacture food from organic and inorganic substances. **Consumers (Heterotrophs):** Use the food stored by autotrophs. Consumers are further classified as: **Herbivores** (plant-eaters) **Carnivores** (flesh-eaters) **Omnivores** (both plant and flesh-eaters) **Decomposers:** Bacteria and fungi break down dead matter into inorganic substances. **Biome Hierarchy:**The planet's living environment (Biosphere) is organized into biomes, which are large ecological zones characterized by dominant vegetation and climate. These biomes consist of ecosystems. **Types of Biomes:** **Tundra**: Long harsh winters, short summers. **Taiga**: Little precipitation, poor soil, short growing season. **Temperate Deciduous Forest**: Hot summers, cold winters, rich organic soil. **Tropical Rainforest**: High temperature, abundant soil moisture. **Grassland**: Hot summers, cold winters, good for crops. **Desert**: Low water vapor, dry areas with minimal plant life. **Types of Aquatic Ecosystems:** **Freshwater**: Includes standing water (lentic, like ponds) and flowing water (lotic, like rivers). **Marine**: Includes pelagic (oceanic) environments, subdivided into zones based on depth (e.g., benthic zones). **[MODULE 10]** **Energy Pyramid** **Producers (Base):** These are organisms like plants and algae that capture energy from the sun through photosynthesis. They form the foundation of the pyramid. **Primary Consumers (Second Level):** Herbivores that eat producers. Examples include rabbits, deer, and caterpillars. **Secondary Consumers (Third Level):** Carnivores that eat primary consumers. Examples include foxes, snakes, and owls. **Tertiary Consumers (Fourth Level):** Carnivores that eat secondary consumers. Examples include hawks, wolves, and sharks. **Terminal Consumers (Top Level):** These are the apex predators, often at the top of the food chain. They have few or no natural predators. **Its Key Points** **Energy Loss:** Only about 10% of the energy from one trophic level (level of the food chain) is transferred to the next level. The rest is lost as heat during metabolism. **Decreasing Biomass:** As you move up the pyramid, the amount of biomass (total living matter) decreases. This is because less energy is available at each higher level. **Limited Levels:** There are typically only 4-5 trophic levels in an ecosystem because energy loss limits the number of levels that can be supported. **Food Chain** **Linear Pathway:** A food chain shows a single, direct path of energy flow from producers to consumers. **Example**: Grass → Grasshopper → Frog → Snake → Hawk **Interconnectedness**: Food chains are interconnected to form food webs, which are more complex and realistic representations of energy flow in an ecosystem **Decomposers**: While not always shown in a simple energy pyramid, decomposers (like bacteria and fungi) play a crucial role in breaking down dead organisms and returning nutrients to the ecosystem. **Ecological Balance**: The balance of energy flow and the relationships between organisms in food chains and webs are essential for maintaining a healthy ecosystem. **Grazing Food Chain** A set of interconnected food chains by which energy and materials circulate within an ecosystem is called a food web. **Food Chains:** **Grazing Food Chain:** -Starts with plants (producers) and moves through herbivores (primary consumers) to carnivores (secondary consumers). **Example**: corn -\> caterpillar -\> chicken. **Detrital Food Chain:** -Starts with dead organic matter (detritus) and moves through decomposers (bacteria and fungi) to detritivores (earthworms, woodlice) and then to their predators (carnivores). **Example**: dead leaves -\> earthworms -\> chicken. **Food Webs:** -A network of interconnected food chains where energy and materials circulate within an ecosystem. **Divided into two main categories:** Grazing Web: Begins with plants, algae, or photosynthesizing plankton. Detrital Web: Begins with dead organic matter. **Trophic Levels:** Feeding levels within a food web. **[First Trophic Level:]** Primary producers (plants). **[Second Trophic Level:]** Herbivores (primary consumers). **[Third Trophic Level:]** Carnivores (secondary consumers) that feed on herbivores. **[Fourth Trophic Level:]** Secondary carnivores (tertiary consumers) that feed on other carnivores. **[Decomposers:]** Function as herbivores or carnivores depending on their food source (plant or animal matter). **Energy Flow:** Energy flows from one trophic level to another through the process of eating and being eaten. Plants capture sunlight energy and convert it into chemical energy (carbohydrates). Most of this energy is lost as heat during metabolism and respiration. The remaining energy is stored as biomass and transferred to the next trophic level. Energy loss occurs at each trophic level, resulting in less energy available at higher levels. This limits the number of trophic levels in a food web to typically four or five. **Example of a Food Chain:** **Grazing Food Chain:** Grass -\> Grasshopper -\> Frog -\> Snake -\> Hawk **[MODULE 11]** **Ecological Succession:** -The gradual and predictable change in the composition of species within a community over time. **Driving Forces:** **Pioneer Species**: The first organisms to colonize a new habitat. **Habitat Modification**: Existing species alter the habitat, creating conditions that may be less suitable for themselves but more suitable for other species. **Species Diversity**: Increases as succession progresses. **Biomass**: Total mass of living organisms increases. **Climax Community**: The final, stable stage of succession, characterized by a constant species composition. **Persistence**: Remains unchanged until a major disturbance. **Types of Succession:** **Primary Succession**: Occurs on substrates that have never previously supported life. **Examples**: Rock, lava flows, sand dunes. **Secondary Succession**: Occurs in habitats where existing communities have been partially or completely destroyed. **Examples**: Abandoned cropland, areas after fires, floods, or overgrazing. **(Exercise A)** **[Gap Dynamics in a Forest Canopy]:** Primary Succession (A) **[In Sand Dunes]:** Primary Succession (A) **[After a Nuclear Explosion]:** Secondary Succession (B) **[Plants Arising on Plain Land]:** Primary Succession (A) if truly bare, Secondary Succession (B) **[if some soil exists.]** **[After a Fire]:** Secondary Succession (B) **[MODULE 13]** The Philippines is prone to natural disasters, particularly typhoons, floods landslides, volcanic eruptions, earthquakes; and tsunamis, lying as it does astride the belt, in the active volcanic region known as the "**Pacific Ring of Fire**," and in the geologically unstable region between the Pacific and Eurasian tectonic plates. **Pollution**, the introduction of harmful substances into the environment, is a critical issue. Pollutants can be natural, like volcanic ash, or human-made, like industrial waste and plastic. They degrade the quality of air, water, and land, impacting human health and ecosystems. **Types of Pollution** **1. Water Pollution** -contamination of water bodies (lakes, rivers, seas) by harmful substances. **Sources**: Chemicals, sewage, industrial waste, agricultural runoff. **Effects**: Harm to aquatic life, human health, and the environment. **2. Air Pollution** -contamination of air with harmful gases, particulate matter, and other pollutants. **Sources**: Vehicle emissions, industrial processes, burning fossil fuels. **Effects**: Respiratory problems, cardiovascular disease, other health issues. **3. Noise Pollution** -excessive noise that disrupts the natural balance. **Sources**: Man-made (vehicles, construction, etc.), natural (volcanoes). **Effects**: Stress, sleep disturbances, hearing loss, other health problems. **4. Soil Pollution (Soil Contamination)** -degradation of land due to chemicals or man-made substances in the soil. **Sources**: Pesticides, herbicides, fertilizers, industrial waste. **Effects**: Harm to plant growth, contaminated food sources, human health risks. **5. Light Pollution** -excessive or misdirected artificial light. **Effects**: Disrupted ecosystems, interference with astronomy, energy waste. **6. Plastic Pollution** -accumulation of plastic waste in the environment. **Effects**: Threat to marine life, release of harmful chemicals, long-lasting pollution. **7. Personal Pollution** -contamination of our bodies and lifestyles due to hazardous actions. **Sources**: Toxins in household products, unhealthy habits, lack of physical activity. **8. Radiation Pollution** -release of radioactive substances into the environment. **Sources**: Nuclear accidents, weapons testing, industrial and medical use. **Effects**: Physical pollution of living organisms and their environment. **Point vs. Nonpoint Source Pollution:** **Point-source pollution**: Easily identifiable, originating from a single source, like a factory or sewage treatment plant. **Nonpoint-source pollution**: Difficult to pinpoint, originating from multiple sources, like agricultural runoff or urban stormwater. **[MODULE 14]** **Types of Forests in the Philippines:** **1. Mangrove Forest:** **Location**: Tidal zones along clayed shorelines and river estuaries. **Characteristics**: These forests are characterized by salt-tolerant trees with unique adaptations to survive in flooded, saline environments. They play a crucial role in coastal protection, providing a buffer against erosion and storm surges. **2. Beach Forest:** **Location**: Narrow strips along sandy coastlines. **Characteristics**: These forests are adapted to harsh conditions like strong winds and salt spray. They often feature trees with deep root systems and dense foliage to withstand the elements. **3. Molave Forest:** **Location**: Areas where molave trees (a species with a crooked trunk) thrive. **Characteristics**: Molave forests are known for their drought-resistant trees, which are valuable for timber and fuelwood. **4. Dipterocarp Forest:** **Location**: Covering the largest area of forest in the Philippines, from coastal flats to altitudes of approximately 800 meters. **Characteristics**: Dipterocarp forests are dominated by tall, hardwood trees, making them a significant source of lumber for the country. They are also home to a rich biodiversity of plants and animals. **5. Pine Forest:** **Location**: High plateau regions, typically at altitudes ranging from 700 to 800 meters above sea level. **Characteristics**: These forests are characterized by coniferous trees, primarily pines, which are adapted to cooler temperatures and drier conditions. **6. Mossy Forest** **Location**: Found along mountain slopes at altitudes of around 1200 meters or higher. **Characteristics**: These forests are named for the abundance of mosses that thrive in the moist, cool climate of high elevations. They are often shrouded in mist and fog, creating a unique and enchanting atmosphere. **Natural Causes of Deforestation** ** Forest Fires** ** Volcanic Eruption** ** Typhoon** **Effects of Deforestation** 1\. Denuded upland 2\. Degraded watershed 3\. Serious water shortage 4\. Heavy soil erosion 5\. Flooding 6\. Silting of rivers and dams 7\. Destruction of corals along the coast 8\. Illegal logging 9\. Greenhouse effect 10\. Extinction of thousands of species. 11\. Food shortage **Importance of Philippine Forests:** **Biodiversity Conservation**: They are home to a wide range of plant and animal species, many of which are endemic to the Philippines. **Water Regulation**: Forests play a crucial role in regulating water flow and preventing soil erosion. **Climate Regulation**: They absorb carbon dioxide and release oxygen, contributing to climate regulation. **Economic Benefits**: Forests provide timber, fuelwood, and other resources that support local communities and the national economy. **Conservation Efforts:** Despite their importance, Philippine forests face threats from deforestation, illegal logging, and habitat loss. Conservation efforts are crucial to protect these valuable ecosystems for future generations. **[MODULE 16 ]** **Levels of Biological Diversity** **Species Diversity**: The variety of different species within a given area. **Genetic Diversity**: The variety of genetic information within a species. **Endemic Species in the Philippines:** -endemic species are found only in a specific geographic area. They are often vulnerable to extinction due to habitat loss, poaching, and other threats. Here are some notable endemic species in the Philippines: **[1. Tamaraw (Bubalus mindorensis):]** This small, dwarf buffalo is endemic to the island of Mindoro. It is critically endangered due to habitat loss and hunting. Conservation efforts are underway to protect this iconic species. **[2. Dwarf Pygmy Goby (Pandaka pygmaea):]** One of the smallest fish in the world, reaching only 1.5 cm in length. Found in freshwater habitats in the Philippines. Its small size makes it vulnerable to habitat degradation. **[3. Philippine Tarsier (Tarsius syrichta):]** A nocturnal primate with large eyes and a long, slender tail. Found in the southeastern Philippines, including Bohol, Samar, Leyte, and Mindanao. Threatened by habitat loss and the illegal pet trade. **[4. Philippine Mouse-deer (Tragulus nigricans):]** Also known as the Balabac Mouse-deer, it is found on the island of Balabac. Its small size and shy nature make it vulnerable to predators and habitat loss. **[5. Philippine Eagle-owl (Bubo philippensis):]** A large, powerful owl found in lowland forests throughout the Philippines. Classified as vulnerable due to habitat loss and hunting. Its role as a predator helps to maintain the balance of the forest ecosystem. [**6. Philippine Crocodile (Crocodylus mindorensis):**] A freshwater crocodile found only in the Philippines, known for its relatively small size and broad snout. **[7. Hoya Obscura:]** A fast-growing hoya species with distinctive veined leaves that change color depending on sunlight exposure. **[8. Paphiopedilum Fowliei:]** An orchid species native to Palawan, threatened by habitat loss. **[9. Rafflesia Philippensis:]** A parasitic plant species found only in a specific mountain range in Luzon. **[10. Waling-Waling (Euanthe sanderiana):]** An orchid species endemic to Mindanao, considered the "Queen of Philippine flowers" and revered by the Bagobo people. **[11. Kris Plant (Alocasia sanderiana):]** An ornamental plant with distinctive V-shaped leaves, native to the Philippines. **[12. Cebu Cinnamon Tree (Cinnamomum cebuense):]** A cinnamon species endemic to Cebu Island, discovered in the 1980s. **Importance of Endemic Species:** **Ecological Balance:** Endemic species play crucial roles in their ecosystems, such as pollination, seed dispersal, and predator-prey relationships. **Scientific Research:** They provide valuable insights into evolution, adaptation, and biodiversity. **Tourism and Economy:** Endemic species attract tourists and contribute to the country's economy. **Conservation Efforts:** **Protected Areas:** Establishing protected areas helps to safeguard habitats and endemic species. **Education and Awareness:** Raising awareness about the importance of biodiversity and the threats to endemic species is crucial. **Sustainable Practices:** Promoting sustainable practices in agriculture, forestry, and fishing helps to minimize the impact on biodiversity.