Module 6: Terrestrial Biomes and Aquatic Biomes

1. A biome is a large-scale ecosystem defined by its climate (temperature + precipitation) and its characteristic plant and animal life. Climate determines biome — not the other way around.
2. Tropical rainforests: near equator, warm year-round, high rainfall (>200 cm/yr), most biodiversity on Earth, dense canopy, thin nutrient-poor soil (nutrients locked in biomass).
3. Savannas: tropical grasslands with scattered trees (acacia), distinct wet and dry seasons, large herbivores (wildebeest, zebra), periodic fire maintains the ecosystem.
4. Deserts: less than 25 cm/yr rainfall, extreme temperature swings, sparse vegetation with waxy or spiny adaptations; hot deserts (Sahara) and cold deserts (Gobi) both qualify.
5. Temperate deciduous forest: four seasons, moderate rainfall (75–150 cm/yr), broadleaf trees that shed leaves in autumn; dominant biome of eastern North America and Western Europe.
6. Boreal forest (taiga): subarctic, cold winters, coniferous trees (spruce, fir, pine), low biodiversity, large carbon store in soil; the world's largest land biome.
7. Freshwater biomes: streams/rivers (moving water), lakes/ponds (standing water), wetlands (saturated soils). Wetlands are among the most productive ecosystems and provide flood control.
8. Marine biomes: estuaries (nurseries for fish; mix of fresh and salt water), coral reefs (most biodiverse marine ecosystem; built by cnidarians), open ocean (pelagic zone, least productive per area but largest by volume).

Discussion post

1. Name the biome where you grew up and describe one abiotic factor that shaped the plants you saw every day.
2. Pick one biome you have never visited. What climate characteristic defines it, and what would you need to survive there that you do not need where you live now?
3. Connect to Course Outcome 3: how has human land use changed the biome you grew up in? Be specific — what replaced what?
4. Reply to two classmates: compare your home biome to theirs. What is the biggest ecological difference?

Netiquette from the syllabus: address ideas, not people. Complete sentences, correct spelling. Personal matters go to email, never the board.

Ask at home: If the climate in Maryland became as dry as a desert, what biome would replace the deciduous forest here — and how long would that transition take?

En español: Si el clima de Maryland se volviera tan seco como un desierto, ¿qué bioma reemplazaría el bosque caducifolio aquí — y cuánto tiempo tardaría esa transición?