Do Now 4.21 (HW check) OBJECTIVES Define biogeochemical cycle. Identify key carbon cycle processes and the directions in which they move carbon. Identify important processes in the water and nitrogen cycles. Task: What chemical elements are crucial for life on Earth? In other words, if you broke organisms down into elements, which would there be the most of? List 6.

Succession: The gradual, sequential regrowth of species in an area

Succession Types Primary succession refers to the first colonization of new land (e.g. from volcanoes, uplift, etc.)

Succession Happens in Stages

Succession Types Secondary succession refers to the recolonization of land after a disturbance (e.g. fire, clear-cut, etc.)

Pioneer stage / pioneer organisms: The first organisms to establish populations are called pioneer organisms. Quickly growing Minimum requirements (e.g. lichen) Succession Stages Climax community: high biodiversity, slower growing organisms (e.g. trees), more specialization in niches.

Succession Recap What is it? What types are there? What is a pioneer organism? What is a climax community?

Simple Carbon Cycle CO2 C6H12O6 In Atmosphere Respiration & Combustion Photosynthesis C6H12O6 In Organisms

Half a million years of CO2 and Climate Change

Who Cares about Global Warming?

Water & Nitrogen Cycles 4/21 OBJECTIVES: Describe the flow of Nitrogen through terrestrial ecosystems, including NITROGEN FIXATION and EUTROPHICATION. Describe the water cycle, including TRANSPIRATION. TASK: If you wanted to analyze the sustainability of human life on Earth, what particular ecological factors would you have to measure and analyze?

7 Planetary Boundaries E/MSY = Extinctions / million species per year BII = Biosphere Integrity Index

Water Cycle

Nitrogen Cycle

Biogeochemical Cycles The carbon, water, and nitrogen cycles are three systems that are CRITICAL for almost all life on Earth. CO2 input to the atmosphere has increased dramatically as a result of industrial civilization. Global warming is altering climates and ecosystems worldwide. Bacteria capture nitrogen from the atmosphere and convert it into a more useful form.