Ecology - Biomes Chapter 50
What you need to know The role of abiotic factors in the formation of biomes Features of freshwater and marine biomes Major terrestrial biomes and their characteristics
Ecology The study of the interactions between organisms and their environment Biotic factors: living variables Plants, animals, fungi, protists, prokaryotes Feces, detritus Abiotic factors: nonliving variables *Temperature, *water, salinity, sunlight, and soil
Biomes The major types of ecosystems that occupy very broad geographic regions. Types include: Aquatic Biomes (largest part of the biosphere) Freshwater Marine Terrestrial Biomes Defining variables = temperature and precipitation(climate)
Aquatic Biomes Broken into four layers: 1.Photic zone: enough light for PS 2.Aphotic zone: very little light 3.Thermoclines: mid level region with fast temperature change (deeper colder) 4.Benthic zone: bottom of the biome (sand, organic sediments, detritus)
Freshwater Biomes 1.Lakes & Wetlands Littoral zone (shore), limnetic zone (deep water) Oligotrophic lakes (deep lakes, nutrient poor, O 2 rich), eutrophic (shallow lakes, nutrient rich, O 2 poor) 2.Rivers & Streams Defined by current, and divided among head waters and mouth Estuaries are where freshwater rivers and streams merge into the ocean
Marine Biomes Intertidal zone: land meets the water (tidal regions) Neritic zone: shallow water Pelagic Biome: open blue water (most of the ocean) Coral Reef: cnidarians make calcium carbonate shells (coral); among the most productive ecosystems
Climate Annual rainfall Avg annual temperature Sunlight Wind Types: Microclimates: under a log, on your skin, etc. Macroclimate: global and local weather patterns Climate is largely determined by latitude (distance from the equator), but can be modified by mountain ranges, trade wind patterns, and/or altitude
8 Major Biomes 1.Tropical rain forest 2.Savanna 3.Desert 4.Temperate Forest (Deciduous/ broadleaf) 5.Temperate grassland 6.Chaparral 7.Coniferous Forest (Taiga) 8.Tundra High temperature Decreasing rainfall Mid temp Decreasing rf Very low temp
Tropical Rain Forest
Tropical Rainforest Around equator Temperature is warm, rainfall cm/year Little to no seasonal change Photoperiod: hr/day - year round Most complex terrestrial biome, many varieties of vegetation (300 species of trees), highest variety of species Layered: canopy vs. ground Poor soil: rapid recycling rather than accumulation
Savannah
Savannas Temp. warm, rainfall cm year Seasonal droughts Main vegetation: grasses Most abundant herbivores: ants, termites, large herbivores Seasonal drought, fires Fire adapted plants
Desert
Desert Low and unpredictable rainfall, less than 30 cm/year (some none in decades!) Driest terrestrial biome High, extreme temperature fluctuations Deep rooted, water storing plants (CAM), with defense from herbivores (spines) Animal adapted by behavior and excretory systems
Temperate Forest (deciduous/broadleaf)
Temperate Forests Seasonal rainfall 200 cm/year Growing season 5-6 month (spring and summer) Less diversity and density than rainforest High rates of decomposition, but low cycling of nutrients, allows for thick layer of rich soil Many invertebrates (leaf litter), many bird, rodent, deer species Hibernation and migration is common Good regeneration from human impact
Temperate Grassland
Moderate temperatures, 50 cm of annual rainfall Seasonal droughts and fires Large herbivores Nutrient rich (good for agriculture)
Chaparral
Chaparral Mild rainy winter and long, hot, dry summers Midlatitude areas close to cold oceans Dense spiny shrubs, tough evergreens Adapted to fire Animals: grazers, fruit eating birds, rodents, lizards
Coniferous Forest (Taiga)
Taiga Long cold winters, short wet summers Cone shaped evergreens Snow won’t break branches
Tundra
Tundra Long bitter arctic winter, 24 hour photoperiod during growing season Permafrost prevents large root growth Animals adapted by thick coats Grazing migratory herds