Page 2: Ecosystems

• An ecosystem is a community of living organisms in conjunction with the nonliving components of their environment

• There are three major classes of ecosystems: freshwater ecosystems, terrestrial ecosystems, and ocean ecosystems

Page 3: Freshwater Ecosystems

• Relatively small in area (~1.8% of Earth's surface)

• Support many species of life including fish, amphibians, insects, and plants

• Base of the food web is found in fresh water plankton

• Rivers and streams change greatly from headwater to mouth

• Lakes and ponds have three zones: littoral zone, limnetic zone, and profundal zone

• Experience thermal stratification depending on depth

Page 4: Marshes, Swamps, and Estuaries

• Marshes and swamps are lands that shallow, fresh water covers for at least part of the year

• Estuaries are where freshwater and saltwater mix, creating a highly variable environment

Page 5: Terrestrial Ecosystems

• There are seven major types of terrestrial ecosystems

• Location usually dependent on latitude and amount of precipitation

• Examples include tropical rainforests, savannas, deserts, deciduous forests, temperate grasslands, coniferous forests, and tundra

Page 7: Ocean Ecosystems

• Very large amount of Earth is covered by ocean (~75%)

• Three types of oceanic ecosystems: shallow ocean waters, deep ocean water, and deep ocean surface

• Photosynthetic plankton is the base of the food chain

• No photosynthesis can occur in deep ocean because light cannot penetrate deeply into water

Page 8: Abiotic and Biotic Components

• Abiotic components include basic elements, minerals, water, CO2, soil, and other compounds found in the environment

• Biotic components include producers (green plants and trees), consumers (herbivores, carnivores, and top carnivores), and decomposers (bacteria and fungi)

Page 10: Carbon Cycle

• Carbon is fixed in organic matter in the bodies of plants and animals

• During respiration, carbon dioxide is released into the atmosphere or water

• Plants utilize CO2 for food production

• Upon the death of plants and animals, their bodies are decomposed, releasing carbon again

• Some carbon stays in the soil or in bodies of water, acting as a reservoir

• Organic sediments in the oceans and soil can form coal and oil, returning carbon to the atmosphere

Page 11: Nitrogen Cycle

• About 78% of the atmosphere is made up of nitrogen gas

• Nitrogen-fixing bacteria convert nitrogen in the atmosphere to nitrates

• Nitrates can be utilized for the synthesis of proteins by plants and animals

• Lightning also aids in the fixation of nitrogen in the atmosphere

• The amount of nitrates available to plants is determined by bacteria in the soil and water

Page 12: Phosphorus Cycle

• Phosphorus is a major constituent of ATP, DNA, RNA, cell membrane, shells, bones, and teeth

• Sources of phosphorus include phosphate rocks, guano, and fossil bone deposits

• Rain dissolves phosphate out of these reservoirs, releasing it into the soil

• Plants absorb phosphorus and use it in the synthesis of cell parts

• Animals get phosphorus from plants and use it in the formation of their bones and teeth

• Decomposition and excretion return phosphorus to the soil

• Major geologic upheavals can bring back phosphorus settled as sediments in the seas

Page 13: Relationships between Organisms

• Parasitism: one organism feeds on another organism

• Mutualism: both organisms benefit from each other

• Commensalism: one organism benefits while the other is not affected

• Predation: one organism hunts another organism for food

• Competition: occurs when multiple organisms need the same resources

Page 14: Biodiversity Conservation

• Ex-situ conservation: species are removed from natural habitats and placed in safer areas under human control (e.g., botanical gardens, zoos, germ plasm banks)

• In-situ conservation: protection of species within their natural habitats (e.g., wildlife sanctuaries, national parks, biosphere reserves)

Page 17: World Heritage Sites

• World Heritage Sites are places of special cultural or physical significance listed by UNESCO

• Examples include Baynunah Camel Site, Baynunah Fossil Site, Jebel Hafeet Tombs, Mleisa Elephant Trackway, Umm an-Nar, Maqta Conservation Area, and Hili Archaeological Site

Sustainable Use of Resources (Page 18)

• Sustainable use means using resources at a rate in which they can be replaced or recycled while preserving the long-term environmental health of the biosphere.

• Increase in human population growth increases the need for natural resources.

• Biodiversity of an ecosystem contributes to its sustainability.

  • High biodiversity = more sustainable

  • Low biodiversity = less sustainable

• High biodiversity means a great variety of genes and species in an ecosystem.

Saving Individual Species (Page 19)

• Captive breeding programs aim to breed species in captivity and reintroduce them into native habitats.

• Example: Pandas were first bred in captivity in China in 1955, and the first captive-bred giant panda was born in 1963.

Saving Germplasm (Page 20)

• Saving genetic material (seeds, eggs, DNA) for possible future use.

Endangered Species in UAE (Page 21)

• Hawksbill turtle: Found in Saadiyat Island in Abu Dhabi.

• Arabian Leopard: Found in Sharjah.

• Arabian Tahr: Found in Wadi Wurayah in Fujairah.

Endangered Species in UAE (Page 22)

• Socotra Cormorant: Found in Marawah and Al Yasat in Abu Dhabi.

• Houbara Bustard: Found in Arabian Heritage and Culture.

• Arabian Oryx: Story from Oman.

Biodiversity Hotspots (Page 23)

• Some areas of the globe are richer in species than others.

• Endemic species are found only in one place, so protecting them requires preserving their habitats.

• Conservation International has identified 34 hotspots, which represent 2.3% of Earth's land surface and are home to a significant number of endemic plant and vertebrate species.

International Day on Biological Diversity (Page 24)

• There is an international day dedicated to celebrating and raising awareness about biological diversity.

Endemism (Page 25)

• Endemism refers to the confinement of a particular species, genus, or groups of plants and animals to a specific area.

• Types of Endemism:

  • Neo-endemism: Taxon is evolutionarily young and not yet spread over the new area.

  • Palaeo-endemism: Taxon is now restricted but was once widely distributed.

  • Epibiotics or Relic endemics: Plants belong to fossil groups and are restricted to a few pockets due to favorable climate or lack of competition.

Characters of Endemics (Page 26)

• Endemics are localized in distribution due to their narrow ecological amplitude.

• They lack the potential to migrate and have saturate genomes.

• Real endemics never migrate, while neoendemics have the potential to migrate.

• Dispersal propagules are not able to sustain during migration to other areas, possibly due to physical barriers.