3 Part 1: Biomes Biomes Broadly defined life zones Environments with similar climates, topographies, soil conditions, and biological communities Distribution mainly dependent on temperature and precipitation These come due to either latitude or vertical zonation
4 ADD FIG. 5.1
5 Biomes of the World
6 ADD FIG. 5.4
7 Tropical moist forests Abundant rainfall and warm constant temperature. Soil is thin, acidic and poor in nutrients Rich in biodiversity Most nutrients are contained in the biomes of living things
8 Tropical seasonal forests Have wet and dry seasons Temperature is warm throughout the year. seasonal forests tolerant of dry seasons. Soil is richer than tropical moist forests.
9 Tropical savannas and grasslands Low rainfall to support forests Routinely exposed to fire during dry season Plants have adapted to the long drought, fire and heat. They have persistent roots that continue after leave and stem die. Migratory grazers feed on the newly grown shoots
10 Deserts Very low rainfall Temperature could be hot or cold Highly adapted plants live there. Organisms are adapted to conserve water. Water storing leaves and stems, tick epidermal layer Animals could be nocturnal and have minimized water loss
11 Temperate grasslands Grow in midlatitude Moderate rainfall that can support grassland but not forests Rich soil made from organic matter of dead leaves.
12 Temperate shrublands Dry Hot and dry summers and cold and moist winters. Drought adapted shrubs, trees and grass. Common plants include ever green shrubs with thick layers. Open to periodic fire that bring about succession The biome contains a big diversity of unique organisms
13 Temperate forests Evergreen or deciduous Deciduous forests: plentiful of rainfall Broad leafed trees Live in midlatitude Shed leaf in the winter At lower latitude they are evergreen
14 Coniferous Forests Grow in a wide range of temperature and moisture They grow mostly in dry habitats Thin waxy leaves adapted to conserve water They can also grow in wet coasts
15 Boreal forests Northern forest that lies between 50º and 60º north or mountainous area in lower latitude. Forest dominated by conifers, pines and cedar. And some deciduous plants as well.
16 Tundra Temperature below freezing for most of the year. It’s a treeless landscape that occurs at high latitude or on mountain tops Resembles grassland or deserts. Less disturbed by human intervention because of harsh conditions
17 Arctic and Alpine tundra Arctic: has short growing season and so low productivity Has short intense blooming time. Attracts migratory animals, specially birds. It’s important for global diversity specially birds. Alpine: occurs on mountaintops. Have similar environmental conditions as that of the Arctic tundra. Robust plant growth takes place during growing season Plants tend to have deep pigmentation and leathery leaves for protection against UV light.
21 Marine Ecosystem Biological communities in oceans and seas Most marine communities depend on photosynthetic organisms for energy source. Photosynthesis is greater at the coast lines due to accumulation of nitrogen and phosphorous Ocean currents also contribute to the distribution of biological activity by transporting nutrients and phytoplankton Ocean-bottoms depend on the surface organisms for food as they settle down. This could also be brought up to the surface. Vertical stratification is an important parameter. Determines light, temperature, and oxygen contents
22 Marine Ecosystems Open Ocean: has low productivity Current drives nutrients and food that can support life in the open water Deep-sea thermal vent community: chemosynthesis (from sulfur compounds) by microbes that live on the ocean floor.
23 Tidal shores Support rich biological community Coral reefs: Reefs are colonies of minute animals called coral polyps that live symbiotically with photosynthetic algae. The hard skeleton provides shelter for the algae. Coral reefs provide shelter for a lot marine animals as well. They require shallow and clear water. They don’t like nutritious water. Reefs can be damaged by coastal developments, fish, poisoning.
24 Mangroves Salt tolerant trees Grow on warm and calm marine coasts Are source of food for marine and terrestrial animals. Provide shelter for juvenile fish, crabs and shrimps. Have been affected by human developments
25 Estuaries Bays where fresh water and salt water mix Calm, warm, nutrient rich Biologically rich and diverse Emergent plants supported by the muddy bottoms. Different crustaceans Fish depend on them for juvenile development.
26 Tide pool Violent wave blasted shorelines Flooded at high tide and retain some water at low tide Usually rock as wave action prevents sedimentation and plant growth. Cold flood at high tide and hot and dessicating sunshine at low tide makes hard for most species to live Has specialized but diverse plant and animal life.
30 Part 2: Biodiversity Genetic diversity - variety of different versions of the same genes within a species Species diversity - number of different kinds of organisms within an ecosystem Ecological diversity - complexity of a biological community (number of niches, trophic levels, etc.) Biodiversity - the variety of living things - three types essential:
31 How many species are there?
32 Biodiversity Hotspots Most of the world's biodiversity concentrations are near the equator (tropical rainforests, coral reefs).
33 Part 3: How do we benefit from biodiversity? Food Drugs and medicines Ecological benefits Aesthetic and cultural benefits
34 Fig. 5.21
36 Aesthetic and cultural benefits Bird watching and other wildlife observation contribute more than $29 billion each year to the U.S. economy.
37 Part 4: What Threatens Biodiversity? Extinction - the elimination of a species Natural process - one species lost every 10 years Process been accelerated by human impacts on populations and ecosystems E.O. Wilson - we are currently losing thousands of species a year
39 Part 5: Human-Caused Reductions in Biodiversity Habitat destruction and fragmentation Hunting and fishing Commercial products and live specimens Predator and pest control Exotic species introduction Diseases Pollution Genetic assimilation
40 About 200 years ago, the American passenger pigeon was probably the world's most abundant bird. Population: 3-5 billion Over hunting and habitat destruction caused its extinction.
41 Trade in Products from Endangered Species
42 Trade in Wildlife About 75% of all saltwater tropical aquarium fish sold come from coral reefs of the Philippines and Indonesia, where they are commonly caught with dynamite or cyanide.
43 Part 6: Protecting Biodiversity Hunting and fishing laws The Endangered Species Act (ESA) Recovery plans Reintroductions Minimum viable population Private land and critical habitat Reauthorization of the ESA International wildlife treaties