Earth's Major Biomes

Chapter 7: Earth's Major Biomes

• Biomes are large regions with characteristic organisms adapted to specific climates
• Temperature defines biomes near the poles, while precipitation is more influential in temperate and tropical regions
• Abiotic factors like fires, floods, droughts, winds, and elevation also affect biomes
• Nine major biomes: tundra, boreal forest, temperate rain forest, temperate deciduous forest, temperate grassland, chaparral, desert, savanna, and tropical rain forest

Tundra

• Treeless biome in the far north with boggy plains covered in lichens and mosses
• Has harsh winters and short summers with limited rain or snow (10-25 cm)
• Tundra soils are nutrient-poor with permafrost, a permanently frozen ground layer
• Primary productivity is low, but species often exist in large numbers
• Dominant plants include mosses, lichens, grasses, and sedges, with stunted trees and shrubs in sheltered areas
• Adapted animals include lemmings, voles, weasels, arctic foxes, snowshoe hares, snowy owls, and musk oxen
• Caribou and bird species migrate north to graze and nest during summer
• Mosquitoes, blackflies, and deerflies emerge in great numbers during summer
• Tundra is slow to recover from disturbances; oil exploration and military use cause lasting damage
• Climate change melts permafrost, leading to conifer trees replacing tundra vegetation
• Conifer trees have lower reflectivity than tundra vegetation, causing additional warming

Taiga (Boreal Forest)

• Coniferous forest region in the Northern Hemisphere, south of the tundra
• Winters are extremely cold and severe, but less harsh than in the tundra
• Precipitation is low, around 50 cm (20 in) per year, with acidic and mineral-poor soil
• Soil has a thick surface layer of partly decomposed pine and spruce needles
• Dominant trees are black and white spruces, balsam fir, and eastern larch, with occasional deciduous trees
• Animals include caribou, wolves, bears, rodents, rabbits, lynx, sable, and mink
• Birds are abundant in the summer but migrate for winter
• Insects are plentiful with few amphibians and reptiles in the southern part
• Boreal forest is source of industrial wood and wood fiber
• Logging, gas and oil exploration, mining, and farming contribute to boreal forest loss

Temperate Rain Forest

• Coniferous rain forest on the northwest coast of North America, southeastern Australia, and southern South America
• High annual precipitation (over 127 cm or 50 in) with condensation from coastal fogs
• Temperatures are moderated by proximity to the coastline; mild winters and cool summers
• Soil is relatively nutrient-poor with high organic content
• Dominated by evergreen trees like western hemlock, Douglas fir, and Sitka spruce
• Epiphytes like mosses, lichens, and ferns cover the ground
• Common animals include squirrels, wood rats, mule deer, elk, birds, and amphibians and reptiles
• Temperate rain forests supply lumber and pulpwood
• Overharvesting old-growth forests can devastate the biome because it takes long periods to develop

Temperate Deciduous Forest

• Characterized by leaf-shedding, broad-leaved hardwood trees and seasonal climate
• Annual precipitation ranges from 75 cm to 150 cm (30 to 60 in)
• Soil is typically a topsoil-rich organic material over a deep, clay-rich lower layer
• Dominated by broadleaved hardwood trees like oak, hickory, and beech in the northeastern and mid-eastern United States
• Broad-leaved evergreen trees like magnolia increase in the southern areas
• Originally contained large mammals like puma, wolves, and bison, but now mostly deer, bears, and small mammals/birds
• Deciduous forests were among the first biomes converted to agriculture
• Intensive agriculture, overgrazing, and deforestation have degraded some agricultural lands

Temperate Grassland

• Has hot summers, cold winters, and uncertain rainfall (25-75cm or 10-30in annual precipitation)
• Grassland soil has considerable organic material
• Dominated by sod-forming grasses with thick, continuous underground mats
• Periodic wildfires help maintain grasses as the dominant vegetation
• Most moist temperate grasslands have been converted into agricultural breadbaskets
• Ideal for growing crops such as corn and wheat

Chaparral

• Hilly temperate environments with mild winters and abundant rainfall with hot, dry summers
• Occurs in the Mediterranean Sea area, North American Southwest, southwestern and southern Australia, central Chile, and southwestern South Africa
• Soil is generally thin and not very fertile
• Frequent wildfires occur naturally, especially in late summer and autumn
• Dominated by evergreen shrubs, often drought-resistant pine or scrub oak trees (1 to 3 m or 3 to 10 ft tall)
• Common animals include mule deer, wood rats, chipmunks, lizards, and various birds

Deserts

• Dry areas with extreme daily temperatures and limited vegetation
• Present in both temperate (cold deserts) and subtropical/tropical regions (warm deserts)
• Soil is low in organic material but high in mineral content, especially salts
• Plants like cacti, yuccas, and sagebrush have few or small leaves to conserve water
• Desert animals are typically small, remaining under cover during the day and foraging at night
• Humans have altered deserts by driving off-road vehicles, causing erosion and reducing vegetation
• Cacti and desert tortoises are poached
• Houses, factories, and farms in deserts require imported water, dropping groundwater levels

Savanna

• Tropical grassland with occasional trees like acacia
• Found in areas of low rainfall or intense seasonal rainfall with prolonged dry periods
• Temperatures are relatively consistent year-round
• Annual precipitation is 85 to 150 cm (34 to 60 in)
• Soil is somewhat low in essential nutrient minerals due to leaching during rainy periods
• Savannas are converted into rangeland for cattle and other domesticated animals

Tropical Rain Forest

• Lush, species-rich forest biome with warm, moist climate and daily precipitation (200-450 cm or 80-180 in/yr)
• Highly weathered, mineral-poor soil with little organic matter accumulation
• Found in Central and South America, Africa, and Southeast Asia
• Highest species richness and variety of all biomes
• Trees support woody vines and epiphytes like ferns, mosses, orchids, and bromeliads
• About 90% of organisms live in the canopy, excluding soil-dwelling organisms
• Diverse insect, bird, reptile, and amphibian populations
• Rainforest mammals, like sloths and monkeys, live in the trees, but ground-dwelling mammals like elephants exist

Aquatic Ecosystems

• Consist of three main ecological categories: plankton, nekton, and benthos
• Plankton includes phytoplankton (photosynthetic algae and cyanobacteria) and zooplankton (animal-like organisms)
• Phytoplankton forms the base of aquatic food webs
• Nekton consists of larger, mobile organisms like fish, turtles, and whales
• Benthos includes bottom-dwelling organisms that either fix themselves, burrow, or walk on the bottom, such as sponges, oysters, worms, clams, crawfish, and aquatic insects

Freshwater Ecosystems

• Include lakes and ponds (standing water), rivers and streams (flowing water), and marshes and swamps (freshwater wetland)
• Large lakes have littoral, limnetic, and profundal zones
• Littoral zone: shallow-water area along the shore
• Limnetic zone: open water extending as far as sunlight penetrates
• Profundal zone: deepest zone where light does not penetrate
• Eutrophication: nutrient enrichment with nitrates and phosphates due to runoff and sewage; impacts lakes and ponds
• Flowing-water ecosystems have different organisms depending on current strength
• Fast currents: inhabitants have adaptations like suckers or flattened bodies
• Pollution and dam construction are human activities that adversely affect rivers and streams
• Freshwater wetlands: marshes (grass-like plants) and swamps (woody trees and shrubs)
• Wetland soils are waterlogged, anaerobic, and rich in organic materials
• Provide habitat for migratory waterfowl, other birds, beavers, otters, muskrats, and game fish
• Wetlands are threatened by pollution, development, agriculture, and dam construction

Brackish/Estuarine Ecosystem

• Transition zones between freshwater and marine water habitats
• Brakish water pH and salinity varies based on the ocean and rivers present
• Productive ecosystems are full of organic matter and nutrients in the sediments
• Estuarine ecosystems filter water from land, resulting in clearer water flowing seaward
• Act as a natural buffer between the land and the ocean

Chapter 8: Population Ecology

• Population ecology is the study of populations and their interactions with the environment
• Environment influences population: density, distribution, age structure, and size
• Environment limits population growth due to finite resources
• Population is a group of interbreeding individuals of a single species in the same area
• Population density is the number of individuals per unit area or volume
• Factors: birth, immigration, death & emigration affect density
• Population grows when birth rate exceeds death rate and declines vice versa

Factors Affecting Population Dynamics

• Resource abundance: availability of food, water, and space
• Life-history patterns: reproductive strategies such as r-selection and K-selection
  • r-selection: rapid growth, small body size, early reproduction, high mobility, short lifespan (e.g., mosquitoes)
  • K-selection: slow growth, large body size, late reproduction, few offspring, long lifespan (e.g., mammals)
• Environmental conditions: seasons, climate, water and light availability
• Organism interactions: limit population sizes below environmental capacity

World Population Milestones

• Neolithic Revolution (11,500-5,000 years ago): Development of agriculture for more abundant/reliable food, and supported population growth
• Industrial Revolution: Use of fossil fuels and improved supply chains supported population growth (half million to a billion in a span of 200 years)
• Medical revolution (1800s): Causes of infection were discovered, sanitation/hygiene were improved, high birth rate & liberated from infectious disease increased the population
• Green revolution: New agricultural technologies to increase worldwide production, a solution for worldwide salvation
• Environmental revolution: Proactively switching from unsustainable practices shift to efficient and clean green technology

Chapter 9: Air and Air Pollution

• The Earth's atmosphere is a gas mixture of about 78% nitrogen, 21% oxygen, 1% argon, carbon dioxide, water vapor, and trace gases
• Oxygen for respiration & carbon dioxide for plants is necessary for life
• Air pollution causes health and environmental problems

Air Pollution

• Degraded air quality due to harmful substances, particulate matter, and biological agents
• Point sources: stationary, readily identified pollution sources (e.g., factory smokestacks)
• Nonpoint sources: diffused, not easily identified pollution sources (e.g., cars) Air pollution is affected by the pollution source, emission rate, wind, and topography/location

Types of Air Pollutants:

• Primary pollutants: from point/nonpoint sources like carbon monoxide, sulfur dioxide, nitrogen oxides, hydrocarbons, particulate matter & toxic substances like chlorine gas, hydrogen sulfide etc.
• Secondary pollutants: Form from primary pollutants reactions
• Sulfuric acid (H2SO4) from sulfur dioxide is very harmful, and breaks down the NO2 from sunlight

Outdoor Air Pollutants:

• Combustion of fossil fuels emits carbon, sulfur, and nitrogen oxides, and heavy metals (e.g., lead, mercury, uranium)
• Airborne pathogens such as viruses can cause common cold, influenza, SARS, coronavirus
• Particulate matter consists of small solid/liquid droplets
• Photochemical smog results from triggered chemical reactions and involves ozone, a harmful pollutant
• Ozone depletion is caused by chlorofluorocarbons (CFCs)
• Acid deposition/acid rain is harmful to plants, animals, humans, and infrastructures

Health Effects of Major Air Pollutants:

• Particulate matter: Aggravates respiratory illnesses/long term is bronchitis
• Sulfur oxides: Irritate the respiratory tract
• Nitrogen oxides: Irritate respiratory tract, aggravate asthma and chronic bronchitis
• Carbon monoxide: Reduces oxygen transport in blood, headaches & fatigue
• Ozone: Irritate eyes and respiratory tract, chest discomfort, aggravate respiratory asthma and chronic bronchitis

Controlling Air Pollutants:

• Use electrostatic precipitators, fabric filters, and scrubbers in smokestacks
• Careful land-excavating activities
• Measures to increase efficiency -Use of smaller or compact cars -Installation of catalytic converters to automobiles -Modification of furnaces and engines to provide more complete combustion
• Careful handling of petroleum products
• Republic Act No. 8749 is the Philippine Clean Air Act

Indoor Air Pollution

• Dust mites trigger allergic reactions such as allergic rhinitis
• Environmental tobacco smoke increases risks of cancer and cardiovascular diseases
• Volatile organic compounds (VOCs) cause headaches and respiratory issues
• Combustion products cause lung problems and fire hazards
• Chlorinated chemicals are carcinogens and may cause nerve disorders
• Asbestos causes asbestosis, asbestos fibers are embedded in the lungs.

Chapter 10: Global Atmospheric Changes

• There's evidence for Earth's warming, such as ice-melting in the Denman Glacier, sea levels would rise almost 5 feet
• The biggest problem is increased carbon dioxide & global changes such as ozone depletion.

Objectives of the Lesson

• Distinguish between weather and climate -Weather is the conditions in the short-term -Climate is the long-term changes
• List main greenhouse gases (water vapor, carbon dioxide, methane, nitrous oxide, etc)
• Describe enhanced greenhouse effect
• Discuss the effects and give strategies to mitigate/adapt to the global climate change.
• Describe the importance of the ozone layer

Air Pollution Factors

• Solar energy sustains life along with biogeochemical cycles and gravity.
• Absorption and emission of energy keeps heat in balance.
• Greenhouse gases absorb infrared light emitted from earth (water vapor, carbon dioxide, etc)
• Cause: Lessning carbon sinks due to deforestation, halocarbons in the air, growing human production demand.

Effects of Climate Change

• Health effects
• Loss of natural resources
• Indirect threats to life and property
• Changes in natural habitats and food supply
• Ocean chemistry/acidification

Responses to Climate Change and ozone depletion,

Mitigation is postpone climate change, and adaptation is in response to changes to global climate change.

• Reduce energy use, by driving less
• Improve energy efficiency, by driving better cars
• Price energy strategies and taxes for carbons
• Plant and grow forests to create more oxygen
• Insulating buildings to reduce heating and cooling needs, improving agricultural soils

Ozone Lyer depletion

caused mainly by manmade chemicals

• Chlorofluorocarbons and halogenated substances in the polar ice
• Fragile shield, caused by ozone molecules form in the atmosphere.

Chapter 11: Freshwater Resources and Water Pollution

• Three-fourths of Earth surface is covered but less than 1% is available (humans having only 2.6% gal per day)
• 97% of it is salty. Distributed unevenly and water experts say one-third of humans will live in areas where there isn't any irrigation

Introduction

• Humans depend on water. 90% of humans are body weight
• Serious water supply regional issues and water experts predict population to be in areas of drinking irrigation by 2025

Objectives

• Discuss structure of molecule and hydrogen bonds form by water molecule
• List unique properties of water
• Relate problems caused by overdrawing soil and depletion of aquifers
• Define sustainable water and give its importance
• Give examples of water conservation in agriculture, and individual homes

The Hydrologic Cycle

Has two important components: Rain and evaporation

Water Resource Problems

Three types of water resources:

• Too much water (flooding causes plants to get water absorbed from their soils, construction of buildings on floodplains occurs) & overdrawing surface waters and soil
• Too little water (arid ecosystems are fragile & semiarid soil is more receptive but prone to frequent droughts)
• Poor quality water, a change domestic and industrial waste cause major water dumping that harms people
• Farmers produce water over the areas with irrigation

-Aquifer depletion

• Human removes too much underground with water table going dry
• Causing subsidence or sinking from above There are 421 river basins in watershed areas. 18 said to be major Locally, the Balili River, which has excessive and often causes excessive pollution.

Main goal of water management is to provide and sustain the water supply

Sustainable water reduces costs when water is wasted

3 ways water supplies are obtained

-building dams, diverting water, removing salt from seawater Conservation of water is made by: - Recycling, reusing, and improving water for efficiency

Main cause for too little water:

• Irrigation leads to bad water use, can cause plants absorb only 40% of all supplies for the soil
• Water evaporates, seeps underground, turns onto sediments
• Microirrigation is made through convey by holes

Municipals

They use gray water with is found in sinks, showers - often recycled in lawn water but are treated because they were redistributed.

• Pollution control provides incentives to industries so that they can conserve water. A physical, biological, the main issue is to get clean water

Chapter 12: The Ocean and Fisheries

• Fisheries (Overfishing) is when we harvest fast fishes than we can reproduce
• If ocean pollution and fishing are not controlled then fish populations could collapses by 2048

Global Climate

• Two of most common the water affects the land
• Water flows affect by air, heat, pressure is due to El Nino

Objective

• Discover ocean and its signs affect life, El Nino and la Nina
• Earth water cycle helps our lives, what is what in sea and oceans
• Intertidal zones and oceans affect tides

Oceans divided to three types

• Pelagiic, Nertic, oceanic province zones
• Benthic zone
• Oceans divided the epielagic is stretched and hadopelagic zone.
• Pelagic organisms adapted to oceans because oceans have high impact
• Marine ships cause impact such as dumping etc, which make human pollution which affect movements with the oceans