Cycling of Matter in the Biosphere PDF

Cycling of Matter in the Biosphere (Lessons 1.1–1.3) Key Concepts Biogeochemical Cycles: o Water Cycle: Evaporation, condensation, precipitation, infiltration, transpiration. o Carbon Cycle: Photosynthesis, cellular respiration, combustion,...

Cycling of Matter in the Biosphere (Lessons 1.1–1.3) Key Concepts Biogeochemical Cycles: o Water Cycle: Evaporation, condensation, precipitation, infiltration, transpiration. o Carbon Cycle: Photosynthesis, cellular respiration, combustion, decomposition. o Nitrogen Cycle: Nitrogen fixation, nitrification, assimilation, ammonification, denitrification. Energy Flow in Ecosystems: o Producers (Autotrophs): Convert sunlight into chemical energy (e.g., plants). o Consumers (Heterotrophs): Rely on other organisms for energy. o Decomposers: Break down dead organisms, recycling nutrients. Trophic Levels: o Energy decreases as it moves up trophic levels (10% Rule). o Food chains and food webs represent energy transfer. Population Dynamics (Lessons 1.4–1.5) Key Concepts Carrying Capacity: o The maximum number of individuals an environment can support sustainably. Limiting Factors: o Density-Dependent: Competition, predation, disease. o Density-Independent: Natural disasters, climate changes. Ecological Community Dynamics (Lessons 1.6–1.7) Key Concepts Species Interactions:  o Mutualism (+/+): Both species benefit (e.g., bees and flowers). o Commensalism (+/0): One benefits, the other is unaKected (e.g., barnacles on whales). o Parasitism (+/-): One benefits, the other is harmed (e.g., ticks on dogs). o Competition (-/-): Species compete for the same resources. o Predation (+/-): One species feeds on another. Niche Concept: o Role an organism plays in its environment, including its habitat and interactions. Succession: o Primary Succession: Starts on bare rock (e.g., volcanic islands). o Secondary Succession: Occurs in areas with existing soil after disturbance (e.g., forest fire recovery). Changes in Ecological Communities (Lessons 1.8–1.9) Key Concepts Ecosystem Disturbances: o Natural (e.g., hurricanes) or human-caused (e.g., deforestation). o Impact depends on the scale and resilience of the ecosystem. Ecosystem Resilience and Stability: o Ability of an ecosystem to recover after a disturbance. o Biodiversity increases resilience and ecosystem health. Biodiversity: o Variety of species, genetic variation, and ecosystem types. o Higher biodiversity = Greater stability and resistance to disturbances.