Transcript Chapter 4
Unit 3 Ecosystems Topic 3, part 2: Aquatic Biomes Abiotic Factors Wind Nutrient availability pH Depth Temperature Types of Aquatic Biomes Streams and rivers Ponds and lakes Wetlands Streams and Rivers Flowing fresh water that may originate from underground springs or as runoff from rain or melting snow. Streams are typically narrow and carry relatively small amounts of water Rivers are usually wider and carry larger amounts of water. Biotic adaptations for moving water Rooted vegetation Encrusting algae Benthic life styles Burrowing Heavy or flat bodies Webbing/netting Nile River Longest river in the world (4,130 miles) At widest point, 4.7 miles Amazon River 2nd longest (3,977 miles), but greatest output Watershed > 7 million sq mi River mouth = 50 miles wide Unique fauna Mississippi River 4th longest (2,530 miles), 10th biggest Watershed includes 32 states (1,245,000 sq mi) Lakes and Ponds Standing water with areas too deep to support emergent vegetation. Size and depth differentiate the two. Lake and Pond Zonation Seasonal turnover The Great Lakes Together, 21% of unfrozen surface (fresh) waters Lake Baikal Oldest lake (25 million yrs) 20% of unfrozen surface fresh waters The Rift Lakes Very diverse 14% of all freshwater fish species in the world Started forming 40 million years ago on the divergent boundary Periods of drought African Rift Lake Cichlids Model of Cichlid Fish Diversification Freshwater Wetlands Soils submerged or saturated by water for all or at least part of each year, but shallow enough to support emergent vegetation Vegetation have adaptations that make them water tolerant Soils are hydric Freshwater wetlands: Swamps Wetlands with emergent trees Freshwater wetlands: Marshes Contain mostly reeds, sedges, grasses, and rushes for vegetation Freshwater wetlands: Bogs Acidic wetlands containing sphagnum moss, wild cranberry (New England), and spruce trees on the edges Freshwater wetlands: Plants Adapted to life in water-logged soils Aerenchyma Freshwater wetlands: Ecosystem services Recreation/aesthetics Absorption of excess water Methane source Water supply Agriculture Groundwater recharge Freshwater wetlands: Ecosystem services Water filtration Natural waste-water treatment Freshwater wetlands: Human impacts Draining/filling to convert to land for other purposes Urban runoff Waste disposal Water diversion Invasive species (introductions)