Biomes and Ecosystems

Concept of Ecosystem

• German Biologist Ernst Haeckel gave the meaning of the word ecology in 1869
• Ecology derives from two Greek words:
  • OIKOS meaning house
  • LOGUS meaning study of
• Ecology denotes the relationship between organisms and their environment.
• An ecosystem is a geographic region where plants, animals, other organisms, weather, and landscape interact to form a bubble of life.
• Ecosystems contain biotic (living) and abiotic (non-living) parts.
• Biotic factors consist of plants, animals, and other organisms
• Abiotic factors consist of rocks, temperature, and humidity
• Every factor in an ecosystem is directly or indirectly dependent on every other factor.
• A temperature change in an ecosystem will affect what plants grow there.
• Animals that depend on plants for food and shelter must adapt, move, or perish
• Ecosystem size varies.
• Complete tiny ecosystems exist in tide pools, which stay behind when the tide recedes.
• Tide pools have seaweed, a kind of algae that uses photosynthesis
• Abalone, a herbivore, consumes seaweed.
• Carnivores such as sea stars consume clams and mussels in the tide pool.
• Tide pool ecosystems rely on ocean water level changes.
• Seaweed thrives in an aquatic environment, when the tide is in and the pool is full.
• Hermit crabs cannot live underwater and depend on shallow pools from low tides.
• Biotic parts of the ecosystem are dependent on abiotic factors.
• The earth's surface comprises connected ecosystems.
• Ecosystems connect within biomes: large regions of land, sea or atmosphere.
• Forests, ponds, reefs, and tundra are types of biomes
• Biomes are generally plants and animals within them
• Each forrest, pond reef and tundra have various different ecosystems
• The Sahara Desert's biome contains various ecosystems.
• The biome is characterized by arid climate and heat
• The Sahara contains oasis ecosystems with palm trees, freshwater, and crocodiles.
• Sahara has dune ecosystems, as the landscape shifts from the wind
• Snakes and scorpions can survive for long periods in sand dunes.
• Biomes with similar sounds have different ecosystems.
• Sahara Desert is very different than the Gobi Desert in Mongolia and China.
• Gobi is a freezing cold desert, with snowfall and freezing temps
• Gobi ecosystems are based on rock, not sand.
• Some grasses can grow in the cold, dry Gobi climate.
• Gobi ecosystems have grazing animals such as gazelles and the endangered takhi.
• Gobi's cold desert ecosystems are distinct from Antarctica's freezing desert ecosystems.
• Antarctica's ice sheet covers a dry, bare rock continent where only mosses grow.
• A few birds such as skuas are supported.

Classification of Ecosystems

• Ecosystems are classified into various types based on several factors
• Can be classified as natural or artificial.
• Artificial ecosystems are natural regions with human interferences, artificial lakes, reservoirs, townships, and cities.
• Natural ecosystems: aquatic and terrestrial ecosystem.
• Ecosystems further classifications:
  • Natural vs Artificial
  • Aquatic vs Terrestrial
• Types of aquatic ecosystems
  • Fresh water (lotic and lentic)
  • Marine
    • Wetlands
    • Upwelling regions
    • Open oceans
    • Coastal areas
• Terrestrial ecosystems
  • Grassland
  • Desert
  • Forest
• Study areas for classifying ecosystems
  • Autecology: examines individual species of organisms with species ecology
  • Synecology: examines communities regarding composition, behavior, and their environment
    • Synecology sub-types
      • Population ecology
      • Community ecology
      • Ecosystem Ecology
• The most biodiverse ecosystem globally is the Coral Triangle in Southeast Asia.
• The Coral Triangle extends from:
  • The Philippines in the north.
  • Solomon Islands in the east.
  • Indonesia and Papua in the west.

Ecosystem Degradation

• Ecosystems face threats.
• For thousands of years cultures developed around ecosystems.
• Native American tribes of North America lived a complex lifestyle based off local plains ecosystems.
• Human population growth has overtaken ecosystems.
• The tallgrass prairie of the Great Plains became farmland.
• Tropical rain forests in the Amazon River contain many ecosystems with canopies, understories, and forest floors to support food webs.
• Human activities threaten rain forest ecosystems like the Amazon.
• Ecosystems can however recover from distruction.
• South Pacific coral reefs are at risk due to rising ocean temperatures and decreased salinity.
• Corals bleach, or lose bright colors, in warm water or die if the water isn't salty enough.
• The ecosystem collapses with algae, seagrass, fish, snakes, and shrimp disappearing.
• Ecocide is the term for the destruction of entire ecosystems by humans.
• The Great Barrier Reef of Australia is biodiverse, with marine plants and animals.
• Over the last three decades the reef's health has declined significantly due to:
  • Coastal developments.
  • Pollution.
  • Human interferences.
• Mass coral bleaching events due to global warming also threaten the Reef

Keystone Species

• Some species if removed seriously affect the ecosystem; termed a species.
• Ecologist Robert Paine disrupted a patch of Washington State coastline in the in the 1960s
• Paine removed of a food web starfish species in Makaw Bay; in a single area.
• As a result the ecosystem species changed
• Keystone species fulfill vital environmental functions that no other species can.
• EXAMPLES of Keystone Species:
• Star fish by keeping mussel and barnacle populations in check; ensure healthy populations of seaweed which supports communities.
• Sea otters are Top predator in the nearshore marine ecosystem.
• Beavers build dams that make ponds/lakes to help animals thrive.
• Wolves regulate prey populations, ensuring survival of other species.
• Bees enable growth/genetic diversity of plants thru cross-pollination.
• Humming birds aid in plant life/ pollination.
• American Alligators modify environment via high level food consumption.
• Tiger Sharks; are a top ocean predator controlling primary consumer populations

Food Chain

• The food chain describes who eats whom in the wild.
• A food web is all of the food chains in an ecosystem.
• Food chains form different habitats and ecosystems.
• Trophic levels categorize organisms in food chains.
• Trophic levels
  • producers (first lvl)
  • consumers (second, third, fourth lvl)
  • decomposers

Energy Flow in the Ecosystem

• Energy flows through ecosystems as matter stays within them.
• Organic molecules power cellular respiration (producing heat) or are stored as biomass for producers.
• Next energy and matter moves up successive trophic levels in the food chains.
• Decomposers transform matter into inorganic forms for recycling.
• Energy enters an ecosystem as sunlight and exists as heat.
• The atoms in an ecosystem recycle in different ways.
• Nutrients transported back and forth using biogeochemically
• Biogeochemical cycles move nutrients between biotic versus abiotic factors.
• Biogeochemical keep essential elements available.

Carbon cycle

• Carbon recycles in the atmosphere, at the surface and in the Earth's crust.
• The Carbon Cycle consists cycles dealing with rapid carbon exchange among organisms
• Additional cycle dealing with the long-term cycling of carbon through geologic processed.

Nitrogen Cycle

• All organisms need nitrogen for nucleic acids, proteins, and other molecules.
• Nitrogen molecules (N₂) have inert properties.
• Input of substantial energy is required to seperate Nitrogen molecules atoms
• Nitrogen fixation converts nitrogen gas into ammonia (NH3), which becomes ammonium (NH4+).
• Ammonium is located in soil and water bodies.

Oxygen Cycle

• Biological oxygen cycle regulates oxygen levels by traveling through the atmosphere, lithosphere, and biosphere.
• This is a biogeochemical that studies the movement of oxygen gas within the atmosphere, ecosystem, biosphere, and lithosphere.
• the oxygen cycle and the carbon cycle are interconnected.
• Lithosphere and earth's crests contain the most oxygen.

Biodiversity

• Biodiversity is the different kinds of life an area-the variety of animals, plants, fungi, and even microorganisms.
• Species and organisms maintain balance in ecosystems.
• Ecosystems can be resilient if you manage resources.

Explore the interconnectedness of biomes and ecosystems, highlighting differences between deserts like the Sahara and Gobi. Understand key survival characteristics in dune ecosystems and the impact of human activities on the Great Barrier Reef. Discover the significance of keystone species and ecosystem degradation.