Biogeochemical Cycles: Carbon and Nitrogen

• Biogeochemical cycles describe the movement of elements between reservoirs like the atmosphere, hydrosphere, lithosphere, and biosphere.
• These cycles are essential for maintaining ecosystem balance and supporting life.

The Carbon Cycle

• Carbon is the fundamental building block of life, found in DNA, proteins, and fossil fuels.
• Plants absorb CO2 during photosynthesis to produce oxygen and glucose.
• Organisms release CO2 back into the atmosphere through respiration.
• Decomposition involves the breakdown of dead organisms, releasing carbon.
• Burning fossil fuels increases atmospheric CO2 through combustion.
• Reservoirs include the atmosphere, oceans, land ecosystems, and Earth's crust.
• Fossil fuel combustion increases CO2, contributing to climate change.

The Nitrogen Cycle

• Nitrogen is essential for proteins, DNA, and plant growth.
• The atmosphere is 78% nitrogen, but it is unusable by most organisms until converted.
• Nitrogen fixation is when bacteria converts atmospheric nitrogen (N2) into ammonia (NH3). This can be biological (bacteria in soil/roots), industrial (Haber-Bosch process), or atmospheric (lightning).
• Nitrification is when bacteria converts ammonia into nitrates (NO3-).
• Assimilation is when plants absorb nitrates to form proteins.
• Denitrification is when bacteria convert nitrates back into N2 gas.
• Excess fertilizers lead to eutrophication like algal blooms and dead zones.
• Burning fossil fuels releases nitrogen oxides, causing air pollution and acid rain.

The Sulfur Cycle

• Sulfur is crucial for proteins and enzymes in plants and animals.
• Sulfur is found in rocks, oceanic sediments, and the atmosphere.
• Sulfur enters the atmosphere through volcanic eruptions, fossil fuel combustion, and decay.
• It returns to the Earth through precipitation as sulfuric acid (acid rain).
• Plants absorb sulfur and it gets transferred through the food chain.
• Burning coal and oil releases sulfur dioxide (SO2), leading to acid rain.
• Acid rain damages ecosystems and structures.

The Phosphorus Cycle

• Phosphorus is essential for DNA, RNA, ATP, and cell membranes.
• The phosphorus cycle has no gaseous phase; it mainly moves through rocks, soil, water, and organisms.
• Weathering of rocks releases phosphate into the soil.
• Plants absorb phosphates, and animals obtain it through consumption.
• Decomposers return phosphorus to the soil.
• Phosphates reach oceans, settle in sediments, and eventually return to land through geological processes.
• Excess phosphorus from fertilizers causes eutrophication.
• Mining and agricultural runoff disrupt natural phosphorus balance.

Environmental Concerns & Sustainable Practices

• Reduce fossil fuel use and increase forest conservation for the carbon cycle.
• Limit fertilizer use and improve wastewater treatment for the nitrogen cycle.
• Use cleaner energy sources to prevent acid rain for the sulfur cycle.
• Recycle organic waste and use fertilizers efficiently for the phosphorus cycle.

Conclusion: Biogeochemical Cycles

• Understanding and maintaining balanced biogeochemical cycles is essential for environmental health and sustainability.
• Human activities significantly impact these cycles, necessitating responsible management practices.

Introduction to Biodiversity

• Biodiversity refers to the variety of life forms in an environment.
• It is an important indicator of environmental health.
• The Philippines is a biodiversity hotspot and faces significant threats.

Levels of Biodiversity

• Ecosystem diversity is the variety of ecosystems in a region (forests, coral reefs, mangroves, etc.).
• Species diversity is the variety of species within an ecosystem.
• Genetic diversity is the variety of genes within a species, crucial for adaptation and survival.

Unique Biodiversity of the Philippines

• The Philippines is home to over 7,000 islands, with diverse habitats like rainforests and coral reefs.
• The Philippines is one of 18 megadiverse countries globally, containing 70%-80% of the world's plant and animal species.
• The Philippines ranks 5th in the world for plant species diversity and maintains 5% of the world's flora.
• The Philippines has high endemism: 60-70% of plants, 75% of amphibians, 70% of reptiles, and 44% of birds are endemic.
• Key Biodiversity Areas (KBAs) include national parks, wildlife sanctuaries, and marine reserves.

Importance of Biodiversity

• Ecosystem services provide clean water, air, and food.
• Human well-being supports health, livelihoods, and sustainability.
• Genetic diversity ensures adaptability to environmental changes.
• Food security ensures crop and livestock resilience.
• Cultural and aesthetic value inspires art, literature, and tourism.
• Scientific research advances knowledge in ecology and medicine.
• Climate regulation means that forests absorb CO2 and release oxygen.
• Moral responsibility: an ethical duty to protect biodiversity.

Threats to Philippine Biodiversity

• Habitat loss includes deforestation, urbanization, and agricultural expansion which reduce natural habitats.
• Pollution includes industrial waste, plastic pollution, and agricultural runoff which harm ecosystems.
• Overexploitation is overfishing and poaching which threaten wildlife populations.
• Invasive species are non-native species that disrupt ecosystems and outcompete local species.
• Climate change includes rising sea levels, extreme weather, and ocean acidification which damage habitats.

Conservation Efforts

• Protected areas are national parks, marine reserves, and wildlife sanctuaries.
• Sustainable practices are responsible fishing, eco-friendly farming, and reduced pollution.
• Ecotourism promotes conservation through responsible travel.
• Community-based conservation are local communities playing a key role in protecting biodiversity.
• Traditional ecological knowledge is indigenous knowledge which helps manage ecosystems sustainably.
• Government and NGO initiatives are conservation programs to protect endangered species and habitats.
• Research and innovation are efforts to study species and ecosystems to improve conservation strategies.