Untitled Quiz

Biomes Overview

• Biomes are large ecological areas on Earth, characterized by specific flora and fauna adapted to the environment.
• Biomes play a vital role in sustaining life on Earth, providing habitats, and contributing to the global ecosystem.
• Biomes are categorized by factors like dominant vegetation, climate, geographic location, and other environmental characteristics. Physical factors, including water depth, temperature, and precipitation, greatly influence species' traits within a biome.
• Biomes are broadly categorized into aquatic (water-based) and terrestrial (land-based).

Types of Biomes

• Aquatic biomes are further classified into marine and freshwater.

  • Marine biomes are the largest, covering approximately 70% of Earth's surface, and include oceans, coral reefs, and estuaries.
  • Freshwater biomes, including ponds, lakes, streams, rivers, and wetlands, are characterized by a lower salt concentration.

• Terrestrial biomes are further classified into six sub-types:

  • Forest
  • Grasslands
  • Desert
  • Tundra (Arctic and Alpine)
  • Boreal forest (Taiga)
  • Tropical and subtropical moist broadleaf forests

Terrestrial Biomes

• Terrestrial biomes encompass various ecosystems characterized by distinct vegetation types and climate conditions. Each biome supports unique life forms and contributes to Earth's biodiversity. The dominant vegetation, temperature, and rainfall influence a biome.

Tundra

• Characterized by freezing temperatures, permafrost, and a short growing season.
• Has around 400 varieties of flowering plants and approximately 2000 different species of plants.
• Tundras are among the least inhabited and least disturbed habitats.
• Alpine tundras are high-elevation mountaintops; Arctic tundras are at high latitudes. Permafrost is absent in alpine tundras.

Boreal Forest (Taiga)

• Also known as boreal forests, characterized by moist-cool conditions and more precipitation than the tundra.
• These areas lie between 50 and 65° North latitude.
• Taiga soils have deep litter layers that accumulate due to slow decomposition rates. The soils are acidic and low in minerals.

Tropical and Subtropical Moist Broadleaf Forests

• Known as moist tropical rain forests, characterized by warm temperatures, high humidity, and considerable rainfall.
• This biome is located approximately 10 degrees north and south of the equator. Annual rainfall often exceeds 250 centimeters.
• Characterized by rapid decomposition due to high temperature and moisture, resulting in acidic and nutrient-deficient soils.
• This biome features exceptionally high plant diversity, with as many as 300 different tree species and many other common plant species.

Temperate Broadleaf and Mixed Forests

• Also known as temperate deciduous forests, a temperate climate and broadleaf deciduous trees are characteristic of this biome.
• Deciduous trees shed their leaves in the winter.
• Found in eastern half of the United States, central Europe, Korea, and China.
• Soils in these biomes are rich in nutrients due to the accumulation of organic materials, forming rich humus layers.
• Typical tree species include maple, beech, cottonwood, hickory, basswood, magnolia, oak, elm, and willow, along with diverse shrubs, herbs, and ferns.

Grasslands

• Found in the continental interiors of Eurasia, Australia, and South America. Grassses are the prominent vegetation and are just a few inches above the soil. Other types of flowering plants include composites and legumes, but generally are less significant compared to grasses.
• Soil is often fertile in some areas. In some drier areas, soils can be affected by salinization.
• Animals found in grasslands include smaller burrowing mammals (like prairie dogs, jack rabbits, ground squirrels), and larger running herbivores (bison, pronghorn antelope, elk). Certain carnivores (like coyotes, ferrets, wolves, badgers, cougars) are also present, but their populations are often reduced due to habitat conversion to croplands; some species are nearly extinct.

Deserts

• Typically covered by shrubs with plants distributed sparsely across the land. Deserts usually receive less than 3 centimeters of rainfall annually.
• Found in interiors of continents and between 25 and 35 degrees North and South latitude.
• Litter layers are generally non-existent in deserts. Soil organic content is low, and biomass productivity is also low.
• Evaporation tends to concentrate salts in the soil.
• Plant adaptations include drought-resistance mechanisms and water storage, such as those in succulents like cacti.
• Desert mammals tend to be nocturnal because of the intense heat; cold-blooded life forms thrive in deserts.

Aquatic Biomes

• Marine biomes are characterized by the water depth and the presence of substrate for organisms to attach. Oceans cover about 70% of Earth's surface.
• Crucial components are coral reefs and estuaries. The ocean algae provide a significant part of the Earth's oxygen supply and absorb atmospheric carbon dioxide. The ocean's evaporation contributes to rainfall.
• Ocean zones: intertidal (shore), pelagic, benthic, abyssal

Coral Reefs

• Coral reefs are primarily found in warm, shallow waters as barriers along continents, islands, and islets.
• Coral reefs are rich in diverse organisms, with corals being the dominant organisms.

Estuaries

• Estuaries are areas where freshwater and ocean water mix, creating a unique ecosystem characterized by varying salt concentrations.
• Characteristic flora include algae, macroflora like seaweeds, mangroves, marsh grasses. Diverse fauna exists, including worms, oysters, crabs, and waterfowl.

Freshwater Biomes

• Freshwater biomes consist of ponds, lakes, streams, rivers, and wetlands which are characterized by water depth and whether the water is moving or standing.
• Ponds and lakes are crucial water supplies for agricultural, domestic, and industrial use. They provide a source for drinking water and renewable energy (hydropower, hydroelectric, thermoelectric).
• Ponds and lakes also play important roles in maintaining soil health, supporting biodiversity, and groundwater recharge.
• Streams and rivers are fast-flowing bodies of water with cooler temperatures at their sources, higher oxygen levels, and clear water. They generally decrease in oxygen levels and clarity toward their mouths. Flora diversity tends to be lower in rivers as compared to streams. Certain fishes like catfish and carp are adapted to lower oxygen levels and are common in these areas.
• Wetlands exhibit high species diversity with hydrophytes (plants adapted to moist conditions) such as pond lilies, cattails, and sedges. Many amphibians, reptiles, birds, and furbearers inhabit wetlands.