Review For Test 2 PART 1 - Biomes Chap 6
Biomes Terrestrial Desert Grassland (prairies) Tropical rainforest Temperate deciduous forest Tiaga (coniferous forest) Tundra Savannah Chaparral/ Scrublands Tropical Dry Forest Mountain Polar Ice caps
Factors which determine the type of biome: Climate major factor a. Temperature b. Rainfall
Biome terrestrial (land) community that covers a major geographical area Deserts = yellow
Desert
Types of Terrestrial Biomes Desert - <10 inches of precipitation/year, harsh environment, rain =short intense storms, evaporation is high, short growing season, windy; large temperature swings animals - reptiles, snakes, camels, Numerous species = few in number and very specialized to conserve water plants - cactus, Joshua trees SW US, N Africa, Australia
Desert Human impact on deserts: Modern technology allows for the transport of water to the desert. This has resulted in the development of cities in some desert areas and some limited agriculture as a result of irrigation.
Saudi Arabia
Store Water Water can be stored by animals in fatty deposits in their tails and other tissues (e.g., in the gila monster's tail). Water can be stored in the roots, stems, and/or leaves of plants (plants that do this are called succulents). Dissipate Heat Get rid of body heat by evaporation through long appendages (legs, ears, etc.), or small "bodies" that radiate heat.
Most desert animals are active at night and gain moisture through the food they eat Plants have small leaves or prickly spines like cactus and can store water in roots or spongy parts of the plant
Temperate Grasslands
Grasslands Fig. 6.7
Grasslands, prairies or steppes - temperate environment; minimal water, windy, hot summer, mild to cold winter; fire is important in preventing trees soil = ultra-rich farmland, US and Asia animals - migratory animals, buffalo, wildebeests, Lots of insects plants - 60-90% grass, Very few trees
Grassland Human impact on grassland: Most of the wet grasslands of the world have been converted to agriculture. Most of the drier grasslands have been converted to the raising of grazers like sheep, cattle, and goats. Little undisturbed grassland is left
This to This
SAVANNAS Savanna
Types of Terrestrial Biomes Savanna -50-150 cm of precipitation/year, uneven distribution, heavy rain then drought animals migrate across the savannas following the rain/ water plants = grasses with drought resistant trees Africa, South America and Australia
Large herds of grazing animals Large Carnivores such as Lions, Leopards Large herbivores such as elephants, Zebra Many insects, reptiles, rodents, birds
Savannas Have more trees than grasslands Climate change may allow more trees to invade these areas
Human Impact Many African animals hunted to extinction, or close to it Areas have been converted to farmland Areas overgrazed by livestock Some areas have been designated as a wildlife refuge
Mediterranean Scrubland (Chaparrals)
Mediterranean Shrublands (Chaparral) shrubby woody plants.
Mediterranean Shrublands (Chaparral) near oceans = shrubby woody plants. Their climate = wet, cool winters and hot, dry summers. 16-40 inches annual precipitation. the Mediterranean coast, coastal southern California, parts of Africa, Chile, and Australia. Fire is a common feature.
Many birds, reptiles, insects, mammals, rodents
Mediterranean Shrublands (Chaparral) Human impact: Very little undisturbed Mediterranean shrubland still exists. Agriculture (often with the aid of irrigation) Major cities are located in this biome.
Tropical Dry Forest
Tropical Dry Forest Annual precipitation ranges 20-80 inches. monsoon climate (several months of rain followed by a long dry season) Plants have developed special adaptations to survive drought. (some drop leaves during dry season to conserve water)
Tropical Dry Forest
Animals similar to other tropical forests- just less in number
Tropical Dry Forest Human impact: Some forests occur in areas of very high human population. Harvesting of wood for fuel and building materials Many of the forests have been converted to farming or the grazing of animals.
Tropical Rainforest
Tropical Rain Forest
Types of Terrestrial Biomes Tropical rainforest -80+inches( up to 200) of precipitation/year, rains every day warm, constant temperatures, no frost, at equator numerous diverse animals plants,= multi-layered canopy.
Multi - layered Canopy
Tropical Rainforest Human impact logging and agriculture. Clear cutting areas = loss of animal habitat Brazil Area cleared for Agriculture (on Left) Rain forest (on Right)
scientists have not been able to research and explore most of the rainforest plants to find all of the possible medicines and species of plants and animals.
Deciduous Forest
Deciduous Forest
Temperate Deciduous Forest four seasons-trees lose leaves moderate climate with evenly distributed precipitation animals - birds, reptiles, deer plants - trees that lose their leaves, maples, oak Europe, eastern US, Canada
Deciduous Forest Human impact: cleared for farming. logging. Large cities were built in these forest areas = original forests are gone
Fig. 6.16c
Coniferous Forest= Tiaga
Types of Terrestrial Biomes Coniferous Forest, (Taiga or Boreal) - snow,= soil freezes in the winter Short summers, hard winters, snow animals - migratory birds, deer, moose, wolves plants - evergreen pines, soil is poor and acidic, used for wood northern Canada, Russia
Coniferous Forest (Taigas) The trees are adapted to winter conditions: Needle-shaped leaves prevent water loss. Flexible branches
Human impact: Human impact = Climate Change Logging is common. Herding of reindeer occurs in northern Scandinavia.
Tundra
Types of Terrestrial Biomes Tundra - permanently frozen soil, very harsh environment poor soils animals - migratory birds, musk ox, caribou, plants - no trees, short plants, moss, grass northern Canada, alpine tundra - tundra found above timber line
Animals have adapted to survive in cold weather
Tundra Human impact: Biggest threat= Climate Change Local native people often rely on hunting for food. Because of the very short growing season, damage to this kind of ecosystem is slow to heal, so the land must be handled with great care.
Polar Ice Caps = covered by snow and ice year around
The biggest threat is from global warming and oil and gas exploration Global warming is decreasing year- round ice and snow
Many animals need the ice to reproduce and hunt for food Polar bears hunt their main food source, seals, primarily while on sea ice. Changes in the ice are driving the bears to spend more time on land, where they have to go longer without eating and rely on fat reserves.
As the ice melts, walrus crowd together on the shoreline, making the spread of infection easier, and increasing the dangers of trampling for the young. Credit: Joel Garlich-Miller/U.S. Fish and Wildlife
Caribou may be affected by changes in their food sources, as a result of the warming climate, and increased human activity along shipping routes may affect their migration
Alpine/ Mountain Biomes A mountain biome is very cold and windy. The higher the mountain, the colder and windier the environment. There is also less oxygen at high elevations.
Alpine/ Mountain Biomes Many of the animal species are similar to those that would be found in taiga Alpine animals have to deal with two types of problems: the cold and too much high UV wavelengths. This is because there is less atmosphere to filter UV rays from the sun. And they must adapt to the rocky areas Alpine animals adapt to the cold by hibernating, migrating to warmer areas, or insulating their bodies with layers of fat and fur. Their bodies tend to have shorter legs, tails, and ears, in order to reduce heat loss. Alpine animals also have larger lungs. Mountain goats have special pads on their hooves which are both cushioned (to absorb the shock of jumping from rock to rock) and slip resistant
Mountaintop plants must survive very dry conditions (water runs off mountaintops quickly, the soil may have little ability to hold water, and the air may be dry with a constant wind). Many high mountains plants are succulents, with water stored in thick leaves. Flagging; where tree limbs only grow in the direction the wind blows (right).
POPULATIONS A population is a group of individuals of the same species inhabiting the same area.
Population Principles Current World Population is 7.5 Billion By the year 2025 (or before) the population will be 8 Billion
Birthrate - number added to a population through reproduction (natality) Population Principles Death rate - number of deaths (mortality)
Birthrate and Death rate depend on: 3. Population Density - number of plants or animals in an area changes occur in density because of overcrowding (lions), war, famine, drought, and politics,
Carrying Capacity: number of individuals of a species that can be supported in an area over an extended time Scientist predict the earth may reach this somewhere near 2050
Carrying Capacity: limiting factors - combination of all environmental influences that tend to keep a population stable: A. availability of raw materials, water, food B. availability of energy, sunlight
Limiting Factors C. accumulation of waste products and their disposal, bacteria Carrying Capacity D. interaction among organisms, man or predator
Human Population Growth: 1000 s of years to reach 1 Bil 130 years to reach 2 Bil 45 years to reach 4 Bil 51 years to reach 8 Bil We are increasing in population by 93 Mil/yr, Annual increase of 1.2, double population in 58 yr.
World population is growing A key to controlling worldwide environmental problems is to SLOW population growth!
Human Population Issues Most increases will be in Africa, Asia, and Latin America - they have 82% of the world s pop. (by 2050 they will have 86% of the world s population)
Human Population Issues The impact of a society on the environment depends on: a. population size b. population density - number of people per unit of land area, available resources for population c. technological development - higher development uses more resources, called the ecological footprint
Consequences of Population Growth War, Famine, Disease Pollution increases from agriculture and waste Destruction of habitats to make way for farms, mismanaged agriculture and ranching destroys land, called desertification Decreased resources more competition for resources
Human Population Growth A major reason for the increasing human population growth rate is an increase in medical care, and a decrease in death rates. people live longer mother s care is better before birth
The ecological footprint is a measure of the land area required to provide the resources and absorb the wastes of a population. The most important factor influencing the rate of human populations grow is related to how many women in the population are having children and the number of children each woman will have. When level of education increases, birth rates fall. Financial independence leads to marriage later in life. Better-educated women are more likely to have access to and use birth control. Early marriages = high birth rate
What Does the Future Hold? 1. Available raw materials not limited to the amount of food available. dependence on technology. Our lifestyles are tied to use of other resources such as irrigation water, genetic research, and antibiotics. 2. Available energy Need of raw materials. Increases in energy efficiency and the development of renewable fuels can reduce dependence on fossil fuels.
What Does the Future Hold? 3. Waste disposal Pollution is the waste product of human activity. Lack of adequate sewage treatment and safe drinking water causes large numbers of deaths. 4. Interactions with other organisms We are not the only species of importance. Converting land to meet our needs displaces other species from their habitats. What today seems like an unimportant organism may one day be seen as an important link to our own survival.
What Does the Future Hold? If the world continues to grow at its current rate, population will surpass 12 billion by 2060. The human population will ultimately reach a carrying capacity and stabilize.