Introduction to Environmental Biology

• Environmental biology integrates biology with ecology to understand organism-environment interactions.
• Sub-disciplines include conservation biology, ecotoxicology, and environmental microbiology.
• The main goal is to address environmental problems using biological principles, while promoting sustainability and biodiversity conservation.

Key Concepts in Environmental Biology

• Ecology studies interactions between organisms and their environment and is the foundation of environmental biology.
• Ecosystems are communities of living organisms interacting with their physical environment.
• Biodiversity, the variety of life, is crucial for ecosystem stability and function.
• Population dynamics studies population changes in size, density, and distribution, influenced by birth rates, death rates, immigration, and emigration.
• Community ecology examines interactions between species, including competition, predation, mutualism, and parasitism.

Environmental Factors

• Abiotic factors are non-living environmental components like temperature, water, sunlight, soil, and nutrients.
• Biotic factors are living environmental components, including interactions like competition, predation, and symbiosis.
• Climate change, due to greenhouse gases, alters temperature, precipitation, and sea levels, impacting ecosystems.
• Pollution, including air, water, and soil pollution, harms organisms and ecosystems.
• Habitat destruction/fragmentation, from deforestation, urbanization, and agriculture, reduces biodiversity and disrupts ecological processes.

Conservation Biology

• Conservation biology focuses on protecting and managing biodiversity and ecosystems.
• Habitat conservation protects and restores habitats for native species.
• Endangered species management prevents extinction and promotes species recovery.
• Protected areas, like national parks, conserve biodiversity and ecosystem services.
• Restoration ecology restores degraded ecosystems to their natural state.

Ecotoxicology

• Ecotoxicology studies the effects of toxic substances on organisms and ecosystems.
• Pollutants enter the environment via industrial discharge, agricultural runoff, and waste disposal.
• Bioaccumulation is toxin accumulation in organisms, while biomagnification increases toxin concentration up the food chain.
• Risk assessment evaluates the potential risks of toxic substances to human health and the environment.
• Remediation strategies clean up contaminated sites and reduce pollution.

Environmental Microbiology

• Environmental microbiology explores microorganism roles in environmental processes.
• Biogeochemical cycles (carbon, nitrogen, phosphorus) are driven by microbial activity.
• Bioremediation uses microorganisms to break down pollutants and clean up sites.
• Microbial ecology examines the diversity, distribution, and function of microbial communities.
• Pathogen detection and control protect human and environmental health.

Ecosystems and Biodiversity

• Ecosystem functions include primary production, nutrient cycling, and decomposition, essential for ecosystem health and stability.
• Ecosystem services are human benefits from ecosystems, including clean air and water, food, pollination, and climate regulation.
• Biodiversity ensures ecosystem resilience, enabling ecosystems to adapt to changes and disturbances.
• Threats to biodiversity include habitat loss, invasive species, pollution, climate change, and overexploitation.
• Conservation strategies protect biodiversity by preserving habitats, managing populations, and mitigating threats.

Population Dynamics

• Population growth is affected by birth rates, death rates, immigration, and emigration.
• Carrying capacity is the maximum population size an environment can support.
• Density-dependent factors (competition, disease) regulate growth based on population density.
• Density-independent factors (natural disasters) affect growth regardless of density.
• Population viability analysis assesses a population's likelihood of persisting, considering habitat, demographics, and variability.

Community Ecology

• Species interactions, like competition, predation, mutualism, and parasitism, shape community dynamics.
• Competition occurs when species need the same limited resource, reducing growth, survival, or reproduction.
• Predation involves predators consuming prey, influencing populations and communities.
• Mutualism is a relationship where both species benefit, like pollination and seed dispersal.
• Parasitism is a relationship where the parasite benefits at the host's expense.
• Keystone species maintain community structure whose removal can have cascading effects.

Human Impacts on the Environment

• Deforestation causes habitat loss, soil erosion, and climate change.
• Pollution harms human health and disrupts ecosystems.
• Overfishing depletes fish stocks and disrupts marine ecosystems.
• Climate change causes rising temperatures, sea-level rise, and extreme weather.
• Invasive species outcompete native species and alter ecosystems.

Sustainability and Environmental Management

• Sustainable development meets present needs without compromising future generations.
• Environmental management uses science to manage and protect natural resources and ecosystems.
• Conservation practices (reducing consumption, reusing, recycling) minimize environmental impacts.
• Renewable energy sources (solar, wind, hydro) reduce reliance on fossil fuels and mitigate climate change.
• Policy and regulation address environmental problems and promote sustainability.