Chapter 30 Flashcards
Biodiversity
Biological diversity: the amazing variety of living organisms that inhabit Earth. Conservation Biology to improve the well being of life on Earth and maintain its diversity.
What is conservation biology?
Is the branch of biology dedicated to understanding and preserving Earth’s biological diversity.
Conservation Biology: -Seek to conserve biodiversity at different levels:
Genetic Diversity is
The success and survival of a species depend on the variety and relative frequencies of different alleles in its gene pool. Genetic diversity may be crucial for a species to adapt to changing environments.
Conservation Biology: -Seek to conserve biodiversity at different levels:
Species Diversity is
The variety and relative abundance of the different species that comprise a community are important for the integrity and sometimes even the survival of the community.
Conservation Biology: -Seek to conserve biodiversity at different levels:
Ecosystem Diversity is
Ecosystem diversity includes the variety of both communities and the nonliving environment on which the communities depend. Diverse communities protect ecosystems by providing services such as providing shade, degrading wastes, and generating oxygen.
Conservation Biology: -Seek to conserve biodiversity-
What is required to maintain ecosystem function?
Genetic and species diversity, and the resulting diversity of community interactions.
Why is Biodiversity important?
Ecosystems, both directly and indirectly, support us.
Why is Biodiversity important? Practical uses for Biodiversity:
-What is an ecosystem services?
Are the processes through which natural ecosystems sustain and enhance human life. Ecosystem services include purifying air and water, replenishing oxygen, pollinating plants, reducing flooding, providing wildlife habitat, Generating soil and improving its fertility, detoxifying and decomposing wastes, controlling erosion, controlling pests, and providing recreational opportunities. (these services sustain human life)- Difficult to measure - we can’t pay for it -
Why is Biodiversity important?
- Economic Benefits
$33 trillion in benefits to humanity is contributed from ecosystem services every year. (twice the world’s national gross national product.)
- A report resulting from a 4 year effort by 1300 scientists concluded that 60% of all Earth’s ecosystem services were being degraded or used in an unsustainable manner.
Why is Biodiversity important? People use some Ecosystem Goods directly -
- Purchase of wild-caught fish that thrive from a healthy marine environment. - Hunting for food and sport is good for the economy of many rural areas. - Africa uses animals are used to harvest food, and they provide an important source of protein for a growing and poorly nourished population.
- In less developing nations: residents rely on wood from local forests for heat and cooking - Rain forests provide valuable hardwoods such as teak for consumers worldwide.
- Medicines used by 80% of the population of the world derived from plants , 3/4 of them prescribed in the US contain active ingredients that are now- extracted from natural resources (plants)
Why is Biodiversity important? Ecosystem Services Benefit people Indirectly -
Indirect services provided by healthy, diverse ecosystems make a greater contribution to human welfare than do goods harvested directly from nature. Example: ->
Why is Biodiversity important? Ecosystem Services Benefit people Indirectly -
SOIL FORMATION
It can take hundreds of years to build up a single inch of soil. THe rich soils of the Midwestern US accumulated under natural grasslands over thousands of years. Farming has converted these grasslands into one of the most productive agricultural regions in the world.
- Soil: with its diverse community of decomposer and detritivore organisms ( bacteria, fungi, worms, many insects, and others) - plays a major role in breaking down wastes and recycling nutrients.
- Rely on soil for waste decomposition
- Soil serves as a water purification plant, nitrogen-fixing bacteria in soil converts atmospheric nitrogen into a form that plants can use.
Why is Biodiversity important? Ecosystem Services Benefit people Indirectly -
EROSION AND FLOOD CONTROL
Plants block wind that blows away soil. Their roots stabilize the soil and increase its ability to hold water, reducing both soil erosion and flooding.
- Massive flooding is caused by conversion of the natural riverside forests, marshes and grasslands to farmland; thus greatly increased the runoff and accompanying soil erosion int the wake of heavy rains.
Why is Biodiversity important? Ecosystem Services Benefit people Indirectly -
CLIMATE REGULATION
Shade, reducing temperature, and serving as windbreaks, plant communities have a major impact on local climates.
- Forests influence water cycle by returning water to the atmosphere through respiration (evaporation from leaves). Amazon: 1/3rd to 1/2 of the rain comes from water transpired by leaves. Extensive clear-cutting of rain forests can cause climate to become hotter and drier, making it harder for the ecosystem to regenerate and damaging nearby intact forests as well.
- Forests affect global climate: They absorb carbon dioxide from the atmosphere, storing the carbon in their trunks, roots, and branches. 15% of the carbon dioxide produced by human activities results from deforestation; as trees are decomposed/burned they releases CO2, which contributes to global warming.
Why is Biodiversity important? Ecosystem Services Benefit people Indirectly -
GENETIC RESOURCES
Crop plants, like corn, wheat, and apples have ancestors that humans have selectively bred to produce modern domestic crops. Most food is supplied by 12 crops.
- Researches have identified genes in wild plants that might be transferred into crops to increase their productivity and to provide greater resistance to disease, drought, and salt accumulation in irrigated soil.
Why is Biodiversity important? Ecosystem Services Benefit people Indirectly -
RECREATION
- National parks, wildlife refuges and state parks
- Many rural areas, the local economy depends on money spent by visitors who come to hike, camp, hunt, fish , or photograph nature. WOrldwide, the economic value of outdoor recreation has been estimated to be $3 trillion annually.
- Ecotourism : Tropical coral reefs and rain forests, The Galápagos Islands, African Savanna, and Antarctica. (more than 100,000 people visit the Monarch Biosphere Reserves in Mexico per year.
What causes extinction? Class notes
Habitat change and destruction
- prehistoric habitat change have had a significant effect on the evolution of organisms
- human activities are the primary cause of present - day habitat destruction
- clearing the rainforest could lead to loss of up to half …
Biomes
Large land areas with similar environmental conditions
Biome: Tropical Rainforest
Average temp 7 - 86 degrees f
- rainfall 100-160 per year
- much of the animal life in rain forests is arboreal.
- highest biodiversity (total # of species within a given region) of any biome on Earth.
Biome: Tropical Rainforest
Being destroyed at rapid rate for
- lumber, burned to clear land for ranching or farming
- over 50% of the world’s rain forests are already gone.
Major Biome: Temperate Rain Forest
- Relatively rare, located on the US Pacific Coast, the southeastern coast of Australia
- Conservation issues: old growth forest (not disturbed place)
Major Biome: Temperate Deciduous Forest
Eastern region of North america; also found in EU and eastern Asia
- rainfall averages 30- 60 inches/yr, much of which occurs in summer,
- water freezes during winters,
- Trees shed leaves to conserve water and remain dormant through the winter.
Human Impacts
Hunting and habitat loss have reduced numbers of large predatory mammals,
- black bears, bobcats, and mountain lions,
- wolves have been eliminated.
Prey species overabundant because of lack of predators; clearing for lumber, agriculture and housing.
Major Biome: Taiga
Largest terrestrial biome on Earth, stretching across North America, Scandinavia, and siberia, nearly encircling the globe
- Also called the northern coniferous forest or boreal forest
- Long, cold winters and short growing seasons
- 16-40 inches of precipitation occurs annually, largely as snow, confers are the dominant tree
- Large and small mammals ; black bears, moose, deer, wolves, wolverines, lynxes, foxes, bobcats, and snowshoe hares
- Breeding grounds for many of North America’s species
HUMAN IMPACT: Clear- cutting for paper making and construction ; natural gas extraction, damming rivers to generate hydropower, logging old-growth forests.
