SGCEP SCIE 1121 Environmental Science Spring 2012 Section 20531 Steve Thompson: steventhompson@sgc.edu http://www.bioinfo4u.net/ 1
First, some points from the Planet Earth documentary: The tropical rain forest is the most biodiverse terrestrial biome, e.g. almost half of most species on earth, 80% of all insects! The huge tree falling began a small, localized, very rapid series of secondary succession events. The ecosystem is totally dependent on fungi! All the monkeys eating figs at different times was a case of resource partitioning based on time. The chimps demonstrated very strong territoriality and cooperativity in achieving their collective goals. 2
Wild Species and Biodiversity Or, why it even matters! Attitudes toward wildlife stem from values... Not everyone agrees on the type of protection for wildlife, even if they agree that wildlife should be protected. Some want wildlife protected for hunting. Others feel hunting should be banned. Many think loss of biodiversity is a tragedy. But people in developing countries use wildlife for food or money, often in order to survive. How can different values be reconciled to sustainably mange wildlife? 3
Biological wealth Almost two million species have been examined, named, and classified... Out of 5 30 million species (and most folk don t even consider fungi, protists, bacteria, and archaea, unfortunately, so maybe 100+ million!) Biota: natural species of living things. Biological wealth: biota plus their ecosystems... Makes up most ecosystem capital that sustains humans, and... Represents a major part of a country s total wealth. Biodiversity: richness of living species. 4
Humans have always used wild species. 12,000 years ago, humans started converting forests, savannas, and plains to fields and pastures with the advent of agriculture. As human populations grew and culture developed: Species were exploited to extinction, and... Others disappeared as their habitats were destroyed. Between 1642 and 2001, 631 North American species and subspecies went extinct. We have been drawing down our biological wealth with unknown consequences. 5
We still depend on biological wealth... However, many Americans don t see the connection between everyday life and nature. Contrast that to developing countries: People draw sustenance and income from the natural world they live in; Environmental income sustains them and gives them wealth. But these... People also deplete their biological wealth. The way all peoples regard and value nature is a root cause of the problem. 6
Two kinds of value In the 19th century, hunters slaughtered all sorts of wildlife... bison, passenger pigeons, egrets, and other shorebirds, some to extinction. Appalled naturalists called for ending the slaughter. The U.S. public became sensitized. People saw species as worth preserving. Why shouldn t we hunt species to extinction? Wild species have some value that makes it essential to preserve them. By identifying this value we can assess our moral duties to species. 7
The value of wildlife 1) Instrumental value: a species or organism s existence or use benefits some other entity. Such as... Food, shelter, or source of income. This is... Usually anthropocentric: beneficiaries are humans. That is, we preserve species to enjoy the benefits they provide. Versus... 2) Intrinsic value: something has value for its own sake. It does not have to be useful to us. So... Do non-human animals have rights? Or are they simply property to be exploited by humans? Many people believe only humans have intrinsic value. And that there is no reason to preserve insignificant species. 8
Species value as sources of human food Most human food comes from agriculture. Wild populations have a great amount of genetic diversity with traits for competitiveness, resistance to parasites, tolerance to adverse conditions, etc. However,... Cultivated varieties (cultivars) are clones; highly selected such that they have lost these traits and have minimal genetic variation. Which... Produces outstanding yields in specific conditions, but can not adapt to other conditions (especially disease). Plant breeders comb wild populations of related species for desired traits and introduce them into cultivars by crossbreeding or biotechnology... To maintain vigor and adapt them to specific conditions. These genes can only come from natural (wild) biota. If wild populations are lost, options for improved food plants are greatly reduced. 9
Species value for other foods and for raw materials Animal husbandry, forestry, and aquaculture also select species from nature. Three billion people use wood for heating and cooking, not to mention building homes! Demand for wood is always increasing. Scientists are predicting a timber famine or fuelwood crisis. Many rubbers, oils, nuts, fruits, spices, and gums also come from forests. All are valuable for humans. 10
Species also have value as sources for medicine. For example: Madagascar s rosy periwinkle has revolutionized treatment of childhood leukemia and Hodgkin s disease. And... The Chinese star anise s fruit is used in Tamiflu; and... Paclitaxel from the Pacific yew tree treats ovarian, breast, and small-cell cancers! Therefore,... Ethnobotany: studies relationships between plants and people (especially indigenous peoples). At least... 3,000 plants have anticancer properties! The search for beneficial drugs has helped create parks. And has spanned a whole new field... Bioprospecting: studies indigenous people s use of plants. 11
Species have recreational, aesthetic, and scientific value Species provide recreational and aesthetic interests... ya think! Things like... Hunting, fishing, hiking, boating, camping, bird-watching. In 2001, 202 million Americans were involved in some form of outdoor recreation. Their... Attitudes reflect interest in and concern for the environment. And... Contact with the outdoors sensitizes people. Broad public support for wildlife and habitat largely stems from this sort of aesthetic and recreational enjoyment. 12
Values support commercial interests Recreational and aesthetic values also support commercial interests. For instance,... In 2006, 87.5 million U.S. adults participated in wildlife-centered recreation (e.g., bird-watching, hunting). Which generated 2.6 million jobs and $108 million! Ecotourism: tourists visit a place to observe wild species or unique ecological sites; this is a huge factor! It is the largest foreign exchange-generating enterprise for many developing countries. 13
And scientific value! We learn basic laws of nature by studying... The way ecosystems and the biosphere work. Biota provides the nature we study,... But much scientific work is done to gain medicines, agricultural benefits, and other outcomes. Though pure science is pursued by many. 14
But, a cautionary note Using wild species and biodiversity can cause problems. For instance... Little money from the rosy periwinkle s success went back to Madagascar, a very poor country. Large companies have patented ancient herbal remedies... But indigenous people may not benefit. Ecotourism may bring money to poor countries. However, it increases pollution, harms wildlife, and changes cultures. Other examples... Whale-watching boats disrupt whale feeding; Tourist boats frighten flamingoes and reduce their feeding. 15
Species have value on their own sake The usefulness (instrumental value) of species is obvious. But it s not enough to protect many species. Some species have no obvious value. Another strategy: emphasize the intrinsic value of a species. The existence of a species means it has a right to exist. All living things have ends and interests of their own. Humans have a responsibility to the natural world. It is the ethical thing to do! 16
Biodiversity and its decline Biodiversity includes genetic diversity in species as well as the diversity of species, communities, and ecosystems. Two measures calculate biodiversity: The number of species; and... How even those species are distributed. A habitat has low biodiversity if it is dominated by one species with only a few members of other species. Diversity is higher if dominance of any one species is low. 17
The decline of biodiversity Biodiversity is dramatically declining in the United States as well as the rest of the world. Endemic species: are found only in one habitat; and... They are especially at risk. Some areas are very vulnerable to species loss. These are the focus of special conservation efforts. North America, although well-studied, is still not well-known. For example... At least 500 species (100 vertebrates) have gone extinct. And... One-third of species are vulnerable, imperiled, or extinct, especially in freshwater habitats. 18
The state of U.S. species 19
Global outlook The global loss of biodiversity is even worse! The background (past) extinction rate is less than one extinction every thousand years for mammals; Except for the five great extinction events. Current extinction rate = 100 1,000 times greater than past rates. For example... For mammals and birds = 20 25 species per 100 years; Rates for all groups = 850 species over 500 years; 23% of mammal species and 12% of bird species are threatened. 20
Species extinction rates 21
Most threatened species are in the tropics The tropics have almost unimaginable biodiversity. 43 species of ants occur on one tree in Peru! This is... Equal to all ant fauna of the British Isles. 300 species of trees on a 1-ha (2.5-acre) plot, and... 1,000 species of beetles on one tree species, all in Panama. Tropical forests are also experiencing the highest rate of deforestation. The species inventory is so incomplete it s almost impossible to assess extinction rates. 22
Reasons for the decline Past mass extinctions were caused by climate change, plate tectonics and asteroid impacts. Current threats to biodiversity are described with the acronym HIPPO, i.e. 1) Habitat destruction 2) Invasive species 3) Pollution 4) Population 5) Overexploitation 23
Biodiversity loss in the developing world Future losses in biodiversity will be greatest in the developing world. This is where... Biodiversity is greatest. But... So is human population growth. Asia and Africa have lost two-thirds of their original natural habitat! Due to... People s desire for a better life; Desperate poverty; and... Global market for timber and other resources. 24
Habitat change: conversion The greatest source of biodiversity loss (36%) is due to... Conversion, fragmentation, simplification, and intrusion Species are adapted to specific habitats. So,... When the habitat changes, the species goes with it. This includes conversion of natural areas to farms, housing, malls, marinas, industrial centers, etc. Global forest cover has been reduced by 40%! North American songbird declines are due to loss of winter habitat and fragmentation of summer habitat. Croplands that replace grasslands support few species. 25
Habitat change: fragmentation Natural landscapes have large patches of habitat connected to other similar patches. Whereas human-dominated landscapes consist of a mosaic of different land uses. The patches contrast with neighboring patches. Species cannot migrate across them. Fragments of habitat support small numbers and populations of species. Species become vulnerable to extinction. Species that require large areas, grow slowly, or have unstable populations are also vulnerable. 26
Habitat change: simplification and intrusion Simplification: humans simplify habitats. Such as... Removing logs and trees changes forest microhabitats. And... Streams are channelized (straightened), reducing fish and invertebrate species. Plus... Intrusion: human structures are built. For example... Millions of migrating birds crash into telecommunication towers; Cell phone tower lights affect birds migrating at night; and... Up to a billion birds die each year by crashing into windows. 27
Invasive species (again) An exotic (alien) species: one that is introduced into an area from somewhere else. When this happens... Most don t survive or don t become pests. But... Invasive species: those that thrive, spread, and can eliminate native species by predation or competition. I mentioned some before. Here s more. Accidental introductions: the brown tree snake... Entered Guam on cargo ships. Within 50 years, it eliminated 9 of 12 bird species. It has no natural enemies. 28
Other introductions... Species have been deliberately introduced; e.g.... Kudzu: to reclaim eroded or degraded lands; and... Saltcedar (tamarisk) in the American southwest to control erosion. Horticultural desirables: the Brazilian pepper in Florida has fundamentally changed the Everglades. And aquaculture: the farming of shellfish, seaweed, and fish. Has inadvertently... Introduced parasites, seaweeds, invertebrates, and pathogens into ecosystems. Plus... Species escape and enter nearby waterways. 29
Furthermore, over time... Humans have transplanted species throughout history. European colonists brought weeds and plants to America. Many of these became established, such that... Field, lawn, and roadside plants are often invasives. Animals have been introduced to North America; e.g.... House mouse, Norway rat, wild boar, starling, horse. The house cat is one of the most destructive! It... Kills 1 billion small mammals and hundreds of millions of birds every year. And... Species transplanted from North America cause problems. For example... Gray squirrels outcompete red squirrels in Europe. 30
Pollution kills or reduces populations; e.g.... Agricultural nitrogen and phosphorus enter the Mississippi River, creating a 10,000 square mile dead zone in the Gulf of Mexico. Pollution destroys or alters habitats. For instance... Oil spills kill seabirds and sea mammals; Pesticides travel up the food chain and become more concentrated in higher consumers; Sediments kill species in lakes, rivers, and bays; Climate change is already impacting species. 31
Human population Human populations put pressure on species: Direct use, habitat conversion, pollution. Large numbers of humans use resources wild species need; Even if each person uses small amounts of resources. A small group of people can overuse resources. People with highly consumptive resources have a disproportionate effect on the environment. Different levels of consumption and numbers of people drive tensions between countries. 32
Overexploitation & exotics trade Overexploitation: overharvest of a particular species. In other words, removing individuals faster than they can reproduce. This... Overuse of species harms ecosystems. No duh! It is driven by greed, ignorance, desperation, and poor management. For example,... Overharvesting forests, grazeland, wild game. Plus, huge trade in exotics: much of it illegal! Illegal trade generates $12 billion/yr, the third largest source after drugs and guns. Wow! Consumers pay huge prices for these luxuries (e.g., polar bear rugs), so the demand is huge. 33
Consequences of losing biodiversity Biodiversity is essential for ecosystem goods and services. Some examples include... Mangroves and coral reefs buffer against storms; Ecotourism depends on biodiversity. Energy flow and nutrient cycling are driven by species. Keystone species: species whose role is vital to survival of other species. Including... Predators control herbivores; and... Umbrella species: larger animals that need unspoiled habitat (wolves, elephants, tigers, moose, etc.). 34
K-strategists are at most risk Many declining species are K-strategists. Remember long-living, large, older at first reproduction, high parental care. Vulnerable to rapid environmental change. Can decline even if they are common. R-strategists are less likely to be harmed by humans. Because they are... Widely distributed, small, rapid reproduction, low parental care, often with the ability to migrate. Therefore, they... Are likely to become pest species. 35
Saving wild species Conservation biologists are at the front lines of protecting biodiversity. They know what is out there and what is declining. Stopping biodiversity losses requires national and international laws and their enforcement. People need to look at the big picture. Conservation biology: focuses on protection of populations and species. It uses the techniques of... Captive breeding, telemetry, and tracking devices. Taxonomy: the cataloging and naming of species Understanding species and identifying those in trouble A lack of experts makes it hard to find solutions 36
Hunting and conservation Managers use hunting and trapping fees to enhance habitats. It s a good thing. Organizations raise funds to help species they want to hunt. Defenders of hunting argue that their prey lack predators, and this is often true. Increased prey eat crops, collide with cars, etc. Hunters may think species are declining, but others think numbers are too high. Many want to end hunting and trapping. And, indeed... Some practices (e.g. leghold steel traps) are cruel. Predators would restore natural checks and balances, but this is often impossible. 37
Endangered Species Act Endangered species: in imminent danger of becoming extinct if it is not protected. This... Includes genetically distinct subpopulations (subspecies). Threatened species: in jeopardy but not yet endangered. An officially recognized endangered or threatened species has protection... Fines are levied for killing, trapping, uprooting (plants), or engaging in commerce with it. Administered by the U.S. Fish and Wildlife Service and the National Oceanic and Atmospheric Administration Fisheries Service. 38
Some endangered species... 39
Elements of the Act Listing: by the appropriate agency, individuals, groups, state agencies. This is... Based on the best available information; It does not include any economic impact of listing. Critical habitat: areas where a species is or could spread as it recovers. And this... Includes privately held lands. Recovery plans: designed to allow listed species to survive and thrive. These are... Developed by the appropriate agency. 40
Alternatives and roadblocks By August, 2008, 1,327 species were listed for protection. Of these... 1,170 have recovery plans. And... 526 species have designated critical habitats; plus... 253 other candidate species are waiting to be listed. However,... Political battles have prevented reauthorization of the act. Timber, recreational, mining, and other groups oppose it, because they believe it limits their property rights. Congressional allies sponsor legislation to weaken or abolish the Endangered Species Act. 41
Future legislation Many political and commercial groups want to weaken the Endangered Species Act. In 2006, 6,000 scientists signed a letter to the Senate urging them to maintain and strengthen the act. The Endangered Species Act formally recognizes the importance of preserving species... Regardless of their economic importance. Species have legal rights to protection! Tax breaks and incentives to landowners may help, but the opposition is fierce. 42
Seeing some success Some species have successfully recovered. Like... The gray wolf has done well (mostly). And... Birds of prey have recovered. For example,... Both the bald eagle and peregrine falcon had thinner eggs due to the pesticide DDT. But... Once DDT was banned in the U.S. and Canada, numbers have steadily increased. And they are protected by law. The whooping crane has had full-time monitoring and protection. It was almost extinct! From 14 cranes in 1939, 266 cranes now exist. The migratory flock flies between Texas and Canada. A nonmigratory flock has been established in Florida. 72 birds make up a new Florida-Wisconsin migratory flock. They were taught their migratory path by following an ultralight aircraft, but the flock is still extremely vulnerable. 43
The spotted owl Critics of the Endangered Species Act say it goes too far to protect a species. They often incite... The northern spotted owl, which was used to save a few remaining old-growth forests in the Pacific Northwest. But... it may have worked! The remaining 2,400 pairs are found only in these forests. And they seem to be hanging in there. The Northwest Forest Plan (1994) uses ecosystem management to set aside federal land for the owl. It prohibits logging trees older than 80 years. But, because of threatened lawsuits, pro and con, it took the Fish and Wildlife Service until 2008 to finally release a recovery plan. 44
Protecting biodiversity internationally Efforts are being made worldwide to protect species... Especially in the tropics. But it... Requires immense cooperation among local, state, and federal authorities. International partnerships create treaties to... Monitor species, share information, and find solutions to the needs of people when they clash with those of other species. 45
Biodiversity hot spots Hot spots are 34 regions making up 2.3% of Earth s land surface, But containing 75% of the most threatened species. 46
Next time... Resource management... how we can cope with the problems and use and restore ecosystems intelligently. And then the first test after that! 47