Week 4 Chapter 16,17,18 (Not chapter 1 & 24)

Week 4 Chapter 16,17,18 (Not chapter 1 & 24)
Univ. of Phoenix SCI/256 Week 4 Chapter 16,17,18 (Not chapter 1 & 24)

Species Diversity and Preservation I Chapter 16 pt1

Factors Affecting Biological Resources
Natural Processes (e.g., fires) Land Use (e.g., urban development) Water Use (e.g., hydroelectric) Climate Change (e.g., global warming) ( Nonindigenous Species Environmental Contaminants (e.g., oil spills) Harvest (e.g., overfishing)

Species Diversity - Terrestrial

Species Diversity

Definitions Extinction: the irreversible loss or ‘death’ of a species.
Endangered species (ESA): a species in imminent danger of extinction throughout all or a significant portion of its range. (What is a species?) Threatened species: a species that is likely to become endangered in all or a significant portion of its range.

Species Diversity

Characteristics of Endangered Species
Extremely small range - lily on single hilltop near SF. Large territories - California condor. (+ issue of Minimum Viable Populations) Living on islands - endemics (living nowhere else); evolved in isolation from predators, disease, and competition. Low biotic potential - blue whales. Specialized breeding areas - green sea turtles. Specialized feeding habitats - pandas and bamboo.

Extinction If extinction is a natural process, why should we be concerned about extinction?

Human-based Extinction:
Human disturbance dominates many landscapes, making the processes of many ecosystems human-dominated.

Species Diversity - Loss of Ecosystems

Effects of Human Population on Diversity

Human-based Extinction:
:We affect species through: 1. Habitat Destruction 2. Hunting and Fishing 3. Predator Control 4. Pollution 5. Genetic Assimilation Diseases Exotic Species Introductions

Species Diversity - Health of Ecosystems

Habitat Destruction: conversion of wilderness into human-based habitat; mainly for farming, range use, and forestry, but also for urban centers. Iowa has lost much greater than 90% of its wetlands. Fragmentation can cause forests (or prairies) to slowly become small islands of wooded area that can be too small to maintain breeding populations. Fragmentation eliminates the core environment, expanding the amount of edge available for weedy species to invade, and eliminates the environment some species need to survive.

Critical Size of an Ecosystem
Amazonia example: Thomas Lovejoy created patches of various sizes (from 1 to 1000 ha and a 10,000 ha 'mainland'). A hectare (ha) = 10,000 sq kilometers or ~ 2.5 acres

Results from Lovejoy’s Amazonia Studies
A guild of insectivorous birds (that feed on insects fleeing swarming army ants) disappeared in 1, 10 hectare, and some 100 ha fragments plots. Pollinators, euglossine bees, would not cross 100 m cleared strips, so population biology of at least 30 plant families dramatically affected.

Rain forest fragments in central Amazonia were experienced a dramatic loss of above-ground tree biomass that was not offset by recruitment of new trees. These losses were largest within 100 meters of fragment edges, where tree mortality was sharply increased by microclimatic changes and elevated wind turbulence. Permanent study plots within 100 meters of edges lost up to 36% of their biomass in the first 10 to 17 years after fragmentation.

Dung and carrion feeding beetles responded similarly to other insects, so the decomposition process slowed. Much of the primate diversity went almost immediately extinct in the isolated fragments. Only 7 of 20 mammal species present in reserve areas persisted in the first isolated fragments, and many of those that persisted were those capable of surviving in disturbed areas or secondary vegetation.

Minimum Viable Populations
Populations that are large enough that inbreeding does not cause the species to go extinct. If Minimum Viable Populations are not maintained, the species cannot survive. (Plus, chance events have a greater likelihood of eliminating a species that is already reduced in numbers.) Greater Prairie Chicken

Planned reserves on an ecosystem basis
Planned reserves on an ecosystem basis. For example, in Yellowstone National Park (for watershed and wildlife resources), more land would have to be added.

Protected Forests

Preservation and Park Usage in the U.S.A.
Habitat destruction does not end just because land is placed into a reserve/preserve/park. Threats to Parks: Islands of nature surrounded by destructive land use. 2. Roads, trails (especially ATVs and off-road vehicles). 3. Visitor impact: Yosemite National Park - 25,000 visitors for a 3-day weekend (cars, laundries, concessions, guest rooms, etc).

Corridors Strips of habitat running between patches of habitat.
Used to allow movement of species from one area to another to help maintain genetic exchange and prevent extinction. However, corridors can also be a risk because they may act as a corridor for disease, invasive species, or as traps for the species you are trying to protect.

Hunting and Fishing Consider the large Pleistocene mammals - extinctions probably caused by human hunting - mammoths, mastadons wooly rhinos, and ground sloths.

Hunting and Fishing In the recent past, whales have been hunted to the brink of extinction. Bison were once in the 10’s of millions, but were reduced to less than 1000 individuals. Passenger pigeons - now extinct; once over 3 billion.

Predator/Pest Control
Involves top predators (keystone species). Wolves, mountain lions, gators. American alligator: top predator - keeps gar populations in check. creates habitat diversity - islands created by nest mounds gator trails - prevent marsh establishment gator holes - provide habitat for other species in drought

Pollution Amphibians as early warning indicators. In North America, and world-wide, amphibian populations have drastically declined and deformities have increased.

Pollution Environmental estrogens: (DDT, PCBs, Dioxins) disrupt hormones; impact fish, reptilian, and amphibian reproduction. Acid precipitation: alters pH of water, thereby affecting species. Ozone depletion (due to CFCs): cause increased UV light penetration and so cause higher mutation rates, thereby affecting populations. Global warming: temperature alterations can cause population declines.

Genetic Assimilation Classic definition is that genes of species at low population numbers are at risk of being swamped if they hybridize with close relatives. With the use of genetically modified (GM) species in farming, for example, could include the assimilation of native species into closely related GM species.

Genetic Assimilation Red wolf: predator control and destruction of mature woodland caused a reduction in range and population size. By 1970s, the species had dwindled to a single population in eastern Texas, and this population is threatened by interbreeding with the close relative, the coyote (Canis latrans).

Disease Dutch elm disease owes its name to the fact that it was first identified in the Netherlands in 1921. Dutch elm disease was first found in the United States in Ohio in It has now spread throughout North America and has destroyed over half the elm trees in the northern United States. Dutch elm disease is caused by the fungus Ophiostoma ulmi which is transmitted by two species of bark beetles or by root grafting.

Powdery Mildew on Dogwoods (Dogwood Anthracnose)
Powdery mildew, which is caused by the fungus Microsphaeria penicillata. Probably introduced into the United States near Connecticut and Washington State simultaneously in the mid-1970s. Although it entered the U.S.A. at two separate points, genetic analysis has shown that the causal organism is the same. However, the origin of this pathogen remains unknown, as it has yet to be identified on any species of dogwood occurring outside the U.S.

Disease American chestnut trees were once 1/4th of all trees in the Appalachian Mountains. Infection by a fungal blight destroyed all chestnuts of reproductive size.

Introduced Species The fungus that destroys the American chestnut was introduced with a shipment of nursery stock from China in 1904, so it was in actuality an introduced exotic species.

Introduced Species

Species Diversity and Preservation II Chapter 16 pt 2

Terminology Alien species - refers to a species that is transported or established outside of its native range. This transport may or may not be intentional. Introduced species - is an alien species that was transported intentionally. Invasive species - is an alien species that disrupts the normal functioning and/or structure of an ecosystem. A naturalized species is one that has become established and is self-sustaining in a new area.

Invasive Species - USA The current environmental, economic, and health costs of invasive species could exceed $138 billion per year, more than all other natural disasters combined. West Nile virus and Purple loosestrife (northeast) Kudzu, water hyacinth, nutria, and fire ants (southeast) Zebra mussels and leafy spurge, (Midwest) Salt cedar, Russian olive, and Africanized bees (southwest) Yellow star thistle, Asian clams, and sudden oak death (California) Cheatgrass, knapweeds and thistles (Great Basin) Whirling disease of salmonids (northwest) Hundreds of species (microbes to mammals) (Hawaii) Brown tree snake (Guam)

Factors that Contribute to Community Vulnerability to Invasion
Vacant niches Escape from biotic constraints Community species richness Disturbance before or upon immigration

Exotic Species Introductions (Biotic Pollution)
Other than habitat loss (and possibly exploitative hunting/fishing practices), the introduction of exotic species has caused the greatest threat to biodiversity. Introduced competitors and predators have a greater negative effect on local organisms than do native competitors or predators because exotic species have not coevolved with those native species. Therefore, the native species have no adaptations to the introduced species. Islands (e.g., Hawaii, Australia) are particularly susceptible to introductions because predators are often rare on islands.

Introduced Species in Hawaii
With the arrival of Captain James Cook in 1778, the environment of Hawaii began to change dramatically. These first European settlers brought a number of new species including; pigs, goats, sheep, and many ornamental and horticultural plants. It is now estimated that an average of new species arrive annually in Hawaii. The subsequent loss of native species has decreased the diversity and produced economic problems.

Introduced Species in the Continental USA
Kudzu: Introduced in the southeastern U.S. in the 1930s as a control for erosion. Has overgrown everything in its path, causing millions of dollars in damage annually.

Purple loosestrife: Cultivated for its beautiful purple flowers, this wetland plant escaped into New England marshes a century ago. It now fills the wetlands across much of the northern U.S. and southern Canada, reducing wetland biodiversity.

Japanese honeysuckle: This aggressive vine seriously alters or destroys the understory and herbaceous layers of communities it invades, including prairies, glades, floodplains, and upland forests.

Cane toads: Bufo marinus is the most introduced amphibian in the world. It outcompetes native amphibians and also causes predator declines because they have no natural immunity to the bufotoxin it secretes.

Great Lakes Introduction of Species

Zebra Mussels Introduced from the ballast water of cargo ships from the Caspian Sea. They glue themselves to any solid surface. These mussels clog intake pipes, cover the bottom of lakes, and invaded the Hudson and Mississippi Rivers. They cost $400 million/year in removal costs, and exclude other, native mussels.

Zebra Mussels The estimated cost to industry, shipping and sport fishing was $5 billion in the Great Lake region alone by the year 2000. Each female can produce one million eggs a year. Being colonial, as many as mussels may be attached as a solid mass on each square meter of substance, encrusting and clogging various utilities like the intake ducts and pipes of power stations and industries, drains, etc.

Lampreys

Lampreys The impact of lamprey on commercial fishing in the Great Lakes.

Protecting Species Habitat Protection:
Placement of habitats into Preserves, Reserves, and National Monuments, can protect both endangered species, as well as provide ecosystem stability. Risks: Multiple use (recreation, timber extraction, grazing use, mineral extraction) can often conflict with preservation of a habitat. “Paper” parks are often logged, farmed, mined, or poached. Poaching is a common practice, even in U.S. protected areas.

Protecting Species Sometimes the protection of a specific habitat (e.g., freshwater river) involves monitoring of other ecosystems (e.g., riparian environment).

Protecting Species Debt for Nature Swaps:
The purchase of debt by organizations at a much lower rate (10 cents on the dollar), and then forgiveness of that debt in return for that countries efforts to make reserves in certain areas. The largest of the “debt for nature swap” organization is the World Wildlife Fund (WWF). Since its inception in 1961, WWF has invested in over 13,100 projects in 157 countries. The annual budget is about $20 million, almost all from private donations.

Examples of Non-governmental Organizations (NGOs) Involved in Defending Species and Habitats
Nature Conservancy Conservation International World Wildlife Fund Environmental Defense Fund Sierra Club Greenpeace.

Protecting Species by Laws
Hunting and Fishing Laws - Limit number of animals that can be ‘harvested’ on a yearly basis. Usually animal populations are monitored so that hunting pressures do not limit the populations. For some animals, such as deer, management practices favor them, so they may be even more abundant than prior to settlement of the U.S. In these cases, the species can be more of a problem for habitat integrity than a species that needs protection.

Zoos, Botanical Gardens, Captive Breeding Programs
Breeding of endangered animals (Cheetahs, other big cats, rhinos, other large game animals), conservation of plant species (sometimes through the storage of seeds in banks), may provide a haven from which to reestablish very endangered species. Costs are prohibitive.

Restoration Ecology Restoration Ecology means to bring back a habitat to a former condition. When overexploited, ecosystems degenerate and services decline. Ultimately we need the capture of renewable resources while sustaining the global ecosystems that convert sunlight into ecosystem services. Principles and Goals: Need to consider several levels - genes, populations, ecosystems at the same time. Ongoing research to collect data on the restored site to monitor changes.

Restoration Ecology Curtis Prairie in Wisconsin:
In 1934, seeds were collected from remnants along railroad right-of-ways and in pioneer cemeteries and cultivated in an old field. Periodic fires helped to establish the prairie; it now serves as a seed source for other prairies. Restoration Ecology

Restoration Ecology Guanacaste National Park (Tropical dry forest):
In an attempt to restore a tropical dry forest in Costa Rica, used existing livestock to germinate seeds, fire control to help establish forests, and intensive labor to eliminate weedy plants.

Restoration Ecology Rivers - The Army Corp of Engineers straightened and drained naturally occurring meanders in rivers. Now, after realizing the value of wetlands along rivers as a flood control (and for groundwater recharge), they are trying to restore wetlands.

Endangered Species Act of 1973.
Regulate activities involving endangered species, including taking, selling, or transporting any endangered animal. Protecting these species often involves preserving habitats that are also endangered, as well as the other unidentified species using that habitat. Recovery Plans: Several success stories, 1. American Alligator, which was overhunted for meat and skin 2. Eagles, hawks, and falcons which were decimated by DDT.

Definitions Resulting from Endangered Species Act
Federal Endangered - animal or plant species, subspecies or varieties in danger of extinction throughout all or a significant portion of their range. These are considered "Federally-listed" or "listed" because a final rule was published in the Federal Register. Federal Threatened - species, subspecies or varieties likely to become endangered within the foreseeable future throughout all or a significant portion of their range.

Policy Responses Population:
Governments can help to create the conditions where having fewer children will make sense, and where people have the means to reach their desired fertility. And if fertility can be reduced, there will usually be environmental benefits.

Policy Responses Consumption:
Realistic approach is to divert consumption into channels with lower environmental costs, while ensuring that people still enjoy the end products or services they need for dignity and comfort. The balance of taxes and subsidies can be shifted so as to make environmental "bads" like excessive car or fossil-fuel use less attractive to consumers, and environmental "goods" such as energy-saving technology more attractive.

Policy Responses Technology:
The heaviest burden will fall on the technology element of the equation. If, as is quite likely, the scale of the world economy triples by 2050, then technological changes will have to reduce the environmental impact of our activities by two thirds - just to prevent the present rate of damage from increasing.

Land and Food Resources I Chapter 17/18 pt 1

The Tragedy of the Commons
Giving it a try…

Ecosystem Services of Natural Areas:
Wildlife habitat (protect species) Flood and erosion control Soil formation/maintenance Groundwater recharge Recycle wastes (nutrient cycles) and break down pollutants

Pasture and Open Rangeland
Predominantly grasses with a fibrous root system. Rangelands occupy about 26% of the world’s land surface.

Pasture and Open Rangeland
There is twice as much permanent grazing land as area given to agricultural crops in the world. Much of the western Great Plains and the Prairie provinces of Canada fall in this category.

Pasture and Open Rangeland:
Carefully managed, grazing can be sustained in grasslands (with the loss of a few grazing-intolerant plant species), because most species are tolerant of being grazed. For the U.S., rangeland/prairies have more species of plants, and more threatened species of plants, than any other biome type.

Benefits of grazing include: Hooves create seed-to-soil contact Natural grazers break soil crusts that keep seeds from growing Grazers trample standing vegetation into mulch Grazers act like living compost piles, turning vegetation into high-quality fertilizer By pruning stale growth, they keep forage plants at peak production

Effects of overgrazing grazing include: Compacting soil thus preventing seeds from germinating and water from seeping into soil. Overfeeding on plants not allowing them time to recover and adequately root.

Overgrazing Overgrazing is when plants are consumed such that the plant community does not quickly recover. 1/3rd of the world’s range is severely degraded by overgrazing, making it the largest cause of soil degradation.

Overgrazing The first symptom of overgrazing is the loss of palatable species of herbs and grasses. Continued overgrazing compacts the soil, strips the ground bare, and leads to erosion.

Desertification Continued degradation leads to a fertile land becoming more desert-like. Without plants to hold soil moisture, surface runoff increases, wells dry, the microclimate becomes inhospitable for plants, and deserts occur.

Desertification In Africa, deserts have increased by 50 million hectares, and humid or semiarid lands have decreased by that amount. Is human activity responsible?

Remember the Tragedy of the Commons
Any commonly held resource becomes degraded or destroyed because the narrow self-interests of individuals tend to outweigh the public interests.

U.S. Rangelands Bureau of Land Management (BLM): 200 million acres
U.S. Forest Service (USFS): 50 million acres 60% of rangeland is privately owned. 55% of public rangelands are in poor condition (sage, mesquite, cheatgrass, and cactus). Grazing fees: grazing permits on BLM or USFS land was $1.35 per animal. It costs them $3.21 per animal to administer grazing. This equals a loss of of $32 million. Few people hold most of these permits = welfare for rich cattlemen.

Forests and Forest Products
The amount of fuel wood consumed by each person in developing countries is roughly equal to that used as paper products by each American. Demand for fuel wood will be twice the available supply in just 25 years.

The Rates of Deforestation Are Increasing
Consider Costa Rica, an environmental success story. Lost 75% of its primary forests in the last 60 years due to timber harvest, Del-Monte plantations, cattle grazing (mostly for export).

Costa Rica (the “Green Republic”)
Costa Rica contains more biological diversity than all of North America combined. Costa Rica encompasses only.03% of the world’s landmass, but it contains and supports 5-6% of the entire world’s biodiversity.

Costa Rica Policies Costa Rican Government has been a front runner in conservation policy - 90% of its remaining forest is protected, and it has the largest percentage of land dedicated to national parks in the world. Emphasis has been on sustainability. Along with a strong conservation policy, the Costa Rican Government has enacted incentive programs to promote reforestation projects. These incentive programs include such things as residency status and various tax exemptions.

Causes of Tropical Rainforest Destruction
Commercial Logging: tropical forests harvested for timber. Subsistence agriculture: “slash and burn tactics” (also called swidden or milpa agriculture). Cattle ranching: After commercial harvesting or after subsistence agriculture, or on its own.

“Slash and Burn” (Swidden or Milpa Agriculture.
Farmers clear a small plot (2 acres), burn the dried plants to provide a burst of nutrients (and ash is basic, increasing the release of minerals from clay). On field, they practice polyculture (using some perennials). Banana/plantain, papayas, cassava and sweet potato (root crops), beans (increase nitrogen), and maize (plots hold the soil because there is a variety of roots). In time, the plot is given over to encroaching forest because the fertility has decreased, and the farm begins in a new area.

Milpa Agriculture Depends on land to rotate through. If the farm remains long term, the productivity of the land declines. Higher populations are increasing the pressure on the land and not allowing enough time for recovery.

Cattle Ranching Ranching often introduced after commercial harvesting or after subsistence agriculture, or on its own. Tropical soils are Oxisols and ultisols - soils that are highly leached and nutrient poor. Minerals are locked up in the vegetation; if vegetation is lost, minerals are lost. So, it is hard to go from a pasture back to a forest again.

Logging in the U.S.A. Kinds of cutting:
Clear cutting: removal of all wood in a compartment. Strip cutting: harvesting strips within a compartment on a rotational basis. Selective cutting: planned removal of individual trees or small groups of trees within a forest stand.

Clear Cutting: Cost effective because large machines can be used, making it easier to fell, trim and skid logs. But: 1. Eliminates almost all habitat 2. Increases soil erosion greatly 3. Favors early succession tree species and deer (game) 4. Increases soil and water temperatures. Sometimes seed trees or nurse plants left

Clear Cutting:

Strip Cutting 1. Reduces erosion compared to clear cutting
2. Provides seed sources for establishment, But strip cutting still favors early successional tree species and edge animals.

Selective Cutting Favors the more shade-tolerant trees like red spruce, sugar maple and hemlock because the shade is not broken. 2. Provides a continuing supply of food and cover for wildlife throughout the life of the forest. 3. An uneven-aged stand is particularly favorable to birds.

Selective Cutting Need intensive skilled management to prevent degradation of the remaining stand (genetically superior trees are likely to be removed). Management and skidding costs are likely to be higher, road construction and maintenance must be more extensive. High grading - taking out the few choice trees for profit and leaving the rest. Lowest impact, but requires other skidding techniques.

Land and Food Resources II Chapter 17/18 pt 2

Review of Logging Methods

Menominee Forestlands as a Model
Menominee tribal people once controlled about 1 million acres of land in Northeast Wisconsin and Michigan's Upper Peninsula; treaties in the 1850s confined the tribe to their current Reservation lands, totaling 235,000 acres. Longest running operation for sustained-yield forestry in the nation. Densest, most diverse forests in Great Lakes.

Tribe recognized that their future depended on the forest and embarked on a course of sustained yield management to avoid forest exploitation and preserve Tribal existence. In order to survive off of their limited land base, the Tribe decided that it must harvest timber, but must maintain and perpetuate the forest resources for future generations.

The basic concept used was to harvest timber from one end of the reservation to the other in such a manner that when done, the first areas cut would be ready for cutting again. Long-term yields: 1. Maintain the mix of hardwoods (sugar maple, beech, hemlock, basswood). 2. Mimicking fire-succession. 3. Cutting the worst first.

Tribe considers itself a part of the ecosystem and the Tribe's survival depends on managing and protecting the forest ecosystem. The Tribe's land ethic and management philosophy contain the 3 components of a sustainable system. It must be sustainable for future generations. Must cut trees across the Reservation at a rate that there will always be timber ready to cut. The forest must be cared for properly to provide for the needs of people. Must conserve the productive capacity of the land in order to sustain the Tribe's economy. Keep all the pieces of the forest. Must maintain diversity.

U.S. Forest Service (USFS)
USFS supplies cheap logs to the nations timber industry. Charges for timber sales have not been enough to repay management costs, cleanup of logging debris, and replanting of forests. In 1997, the net loss on U.S. Forest Service timber sales was $1.2 billion. (This estimate includes road-building costs.) Of 104 National Forests, 83 lost money on timber sales.

U.S. Forest Service (USFS)
In the past 40 years, USFS has made 340,000 miles of roads (10 times the interstate highway system). Value of Road-less Areas: 1. Supply clean drinking water 2. Decreases habitat fragmentation (lynx, wolverines, and marten, pygmy owls, trillium). 3. Provide habitat that is resistant to invasion by exotic species. 4. Provides unique recreational opportunities.

National Protected Areas

Butterfly Habitats

Pacific Northwest - Temperate Rainforest
Include Redwoods, Red Cedar, Douglas fir, Hemlock, and Sitka spruce. Forests are complex and diverse. Vaux’s swift and marbled murrelet live nowhere else. Now, less than 10% of the forest remains, with 80% scheduled to be cut. In 1989 environmentalists sued, using the Endangered Species Act and the Spotted Owl as their defense.

150,000 people in Pacific Northwest are employed because of forest products.
Logging jobs are disappearing (recreation jobs may provide more jobs). Loss mainly due to mechanization, shipping of raw lumber to Japan mill, and harvested of 90% of forests.

Wetlands are transitional areas between terrestrial and aquatic ecosystems.
Wetlands provide not only habitat for wildlife but also aid in the recharging of the groundwater and reducing the effects of changes in river level by providing flood zones. Wetlands

Wetlands and Forests

Wetlands - Economics Wetlands are important from an economic standpoint. It is estimated that the bottomland hardwood and cypress swamps of the Southeastern part of the United States are worth over $8 billion. Waterfowl hunters spend over $600 million annually in pursuit of wetland-dependent birds, with a large percentage of this money going directly to wetland habitat protection.

Wetlands – Flood Control
Wetlands play an important role in flood control. It is estimated that storm and flood damage exceeds $1 billion annually in the United States. Wetlands intercept storm waters, thereby moderating sharp runoff peaks to slower discharges over longer periods of time. Wetland vegetation serves to stabilize landforms and protect development.

Wetlands – Water Quality
Wetlands have been shown to remove organic and inorganic nutrients and toxic materials from the water that flows across them. Wetlands remove sediments, and remove or filter excess nutrients. These wetlands improve water quality just as a water treatment plant costing millions of dollars to build.

Wetlands - Destruction
Wetlands are most endangered by agriculture, fossil fuel exploration and exploitation, construction of energy projects (e.g., dams), and development. Wetlands are shrinking in the USA at about 117,000 acres per year. About 75% of remaining USA wetlands in private ownership.

How is Land Distributed Globally?
Not that long ago, natural areas were considered essentially limitless. Now, emphasis is on preservation of natural areas. How much of that 37% is enough?

What Is To Be Done? Encourage reassessment of taxes on private agricultural land near urban centers. Require thorough public review and planning of land use. Review procedures of long-standing. Balance interests in management of Federal lands. Wise-use movement Environmental movement

Food Crops and Biodiversity
Human beings have used about five thousand species of plants as food, but only 150 or so have entered world commerce. Fifteen crops provide most of the world's food, and three crops - wheat, rice, and maize - account for roughly 60 percent of the calories and 56 percent of the protein that humans consume directly from plants.

Food Crops and Biodiversity
Forty percent of an estimated 2,300 species of cultivated plants belong to just four families: Graminae (grasses), Leguminosae (legumes), Rosaceae (apples, pear, etc.), and Solanaceae (potatoes). The grass family - including such crops as wheat, rice, maize, barley, sorghum, millet, oats, and rye - provides some 80 percent of calories consumed by humans.

Origins of Major Food Crops
Many of the major food crops originated in regions that are not particularly species rich. Crops were domesticated in warm temperate and subtropical zones and in tropical mountainous regions. Wheat and barley were first grown in the steppes and woodlands of southwestern Asia, and the origin of maize has been traced to the seasonally dry central highlands of Mexico. The highlands of Peru contributed the tomato and potato (though the tomato was probably first cultivated in Mexico).

Most important food crops appear to have originated where seasons are pronounced. In part this is due to the tendency of plants in seasonal environments to store nutrients during the growing season. Often, these reserves are what human eat. Much of the world's agriculture is based on introduced crops.

In developing countries in the Americas, only 32 percent of production is of crops of American origin. The comparable figure for African developing countries is 30 percent of crop production is native plants. Only in Asian developing countries is most production - 70 percent - by native species.

Dependence on introduced species reaches its extreme in Australia, the Mediterranean, northern Europe, northern Asia, and the United States and Canada. In these regions, more than 90 percent of production is derived from introduced species. None of the world's fifteen most important food crops are native to Australia or to North America north of Mexico.

World Food Issues Amounts (famine) Distribution Poverty
Types of food available (malnourishment compared to undernourishment)

Grain Production Conclusion – at the moment supply keeping up with population growth.

World Production Major Food Crops

Regional Differences in Food Production

Regional Differences in Food Availability

Distribution of Food Most of the 183 countries of the world are now to some degree dependent on food imports. These imports come from cereal surpluses produced in only a few countries that have a relatively low population density and intensive agriculture. For instance, in the period , the United States, Canada, Australia and Argentina provided about 81% of net cereal export on the world market

Differences in Food Usage
Rice, which has origins in either India or China, is the eighth most important crop in the developed world (by weight). However, rice is by a factor of two the leading crop in the developing world, and it is the most important source of calories in tropical developing countries.

Differences in Food Usage
Similarly to rice, cassava (manioc) - native to tropical America - is not grown in developed countries but is the fourth most important crop in the developing world (by weight) and provides more than half of the caloric requirements for over 420 million people in 26 tropical countries. Cassava is a high-yield, starchy, low protein (<1%) staple.

Food Resources - Figures
Over the past 20 years World food production has increased by 2.1% per year. There is enough food globally to give everyone 2,700 calories per day. The minimum requirement is 2,100 calories per day and malnourishment is considered to be anything lower than 1,800 calories per day. In the developing countries of the world one in five people do not have enough food to meet their daily requirements.

Global food production outstrips the population!!!!!
Take Home Message Global food production outstrips the population!!!!! Yet, 800 million people are malnourished!!!!! One person dies each and every second from starvation and its related diseases. Three-quarters of those are children under the age of five. Three children died in the time it took you to read this short paragraph.

Number of Undernourished People (1969-1997)
Undernourished people (millions) Sub-Saharan Africa 89 126 164 180 Near East & North Africa 45 22 26 33 East & South-East Asia 504 406 283 241 South Asia 267 338 299 284 Latin America & Caribbean 54 46 59 53 Industrialized countries n/a 9 8 Countries in transition 20 TOTALS 959 938 860 825 Source: FAO (1999)

Distribution of Malnourishment

Farming

General Types of Agriculture
In highly developed countries the main type of agriculture is high-input agriculture (i.e., lots of energy, fertilizers, pesticides) which produces high yields. In developing countries practice subsistence agriculture, which does not produce enough surplus crops to sell or to store for later need. USA Grain Yields

Types of Subsistence Agriculture
Slash and burn (aka shifting agriculture) Nomadic herding - mainly in the areas of Northwest Asia, the Middle East, North Africa and the Arctic Tundra. Polyculture

Genetic Diversity in Food Crops
Genetic diversity can enhance crop production. Several varieties can be planted in the same field to minimize crop failure, and new varieties can be bred to maximize production or adapt to adverse or changing conditions As important as genetic diversity is to increasing yields, it is at least as important in maintaining existing productivity because of factors like coevolution. Over 400 species of pests now resist one or more pesticides, and the proportion of U.S. crops lost to insects has approximately doubled - to 13 percent - since the 1940s, even though pesticide use has increased.

History of Plant Breeding
For several thousand years, farmers have been altering the genetic makeup of the crops they grow. Human selection for features such as faster growth, larger seeds or sweeter fruits has dramatically changed domesticated plant species compared to their wild relatives. An Assyrian relief carving from 870 B.C. showing artificial pollination of date palms.

Genetically Modified (GM) Crops
Most new genetic engineering techniques initially involve single-gene modifications of species, and in many cases such modifications are less useful than the multiple-gene changes that result from traditional breeding programs. Maize Maize genetically modified to produce Bt protein Bt protein kills the corn borer insect

Biodiversity of Food

Risks of High-Yielding Crop Varieties
Whereas traditional mixed farming systems produce modest but reliable yields, planting a single modern crop variety over a large area can result in high yields but the crop may be extremely vulnerable to pests, disease and severe weather. The results may be substantial loss of yield (e.g., the 1970 loss of more than 15% of corn crop to a fungus). Single crop agriculture has a history of producing famines when an organism of opportunity destroys that crop.

Loss of Crop Diversity

Problems with Genetic Uniformity
Genetic diversity provides the variation within species that allows populations to adapt to changes in climate and other local environmental conditions. Without a constant infusion of new hardy genes into our crop species, pests and diseases could quickly get out of hand. Already more than 400 species of crop pests have developed resistance to one or more of the pesticides used to control them.

National Plant Germplasm System (NPGS)
NPGS is a cooperative effort by public (State and Federal) and private organizations to preserve the genetic diversity of plants. The NPGS acquires, preserves and distributes crop germplasm. There is also a National Animal Germplasm Program under development.

Sources of Food Approximately 99% of the world food supply is derived from terrestrial ecosystems with the percentage from aquatic systems shrinking. The availability of arable land at world level is less than 0.27 ha per capita, lower than it has ever been in history, and much less than the average of 0.7 ha per capita in the United States. Note that 0.5 ha per capita has been suggested as the minimum requirement for a diverse diet of animal and plant food products

Fisheries Basic problem with ocean fisheries is the issue of the tragedy of the commons. No single nation may legislate or enforce policies.

Fish Farms (Aquaculture)
Are fresh water and marine water facilities. Approximately 1/3 of the shrimp consumed globally are from aquaculture sources. More than 50% of salmon consumed is raised on fish farms.

Fish Farms (Aquaculture)
Farmed fish are frequently fed on meal made from wild-caught fish. In 2000, Goldburg co-authored a paper revealing that 1.9 kilograms of wild fish were on average required to produce every 1 kg of fish farmed in 1997.

Summary Development must meet sustainability criteria
Earth has a carrying capacity Earth’s productivity and resources limited Renewable resources need sufficient protection to be reusable Resources are distributed unequally and the quality of life is unequal We are part of and dependent on the web of life and must conserve diversity (ecosystem services enable us to survive)

Summary We must change our personal attitudes and practices to produce the collective activities which will balance of standard of living with sustainability Success of society will depend upon personal activities, economic costs, and political will. Ultimately, global considerations will need to supersede the interests of individual countries or limited alliances

You can make a difference!!!
GET INVOLVED You can make a difference!!! Think before you consume or dispose of wastes. What can I do to help cut down on resource utilization and make sure we efficiently utilize the resources necessary for human survival. Baby Steps!

the end Now it’s your turn to highlight the things that matter…

Week 4 Chapter 16,17,18 (Not chapter 1 & 24)

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Week 4 Chapter 16,17,18 (Not chapter 1 & 24)

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Presentation on theme: "Week 4 Chapter 16,17,18 (Not chapter 1 & 24)"— Presentation transcript:

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