Evaluating Biodiversity and Vulnerability

Topic 4.2

4.2.1 Identify factors that lead to loss of diversity…….

• You will be allocated a factor from the list on the next few pages…….describe and explain (using real life examples) how biodiversity is affected by your factor:

How do Natural Disasters effect Biodiversity?

By Kieran Harris, Fausti Preysler, and Anil Daryanani

The visible path of a meteoroid that enters the Earth’s atmosphere.

Meteors are otherwise known as shooting stars or falling stars

Destroys the land that each meteor strikes

Meteors:

Cretaceous Period Meteor wiped out all dinosaurs Burned down 50% of forests Caused excessive amounts of carbon to

enter the atmosphere killing most life species on earth

Aqua life much further down in the seas survived as they were unaffected

Turtles survived as well due to their slow metabolisms and aquatic lifestyles

No land animal larger than 23 kg survived

Meteors:

Drought: A long period of no rain Causes extreme heat and dryness Effects on biodiversity

Dries everything up, kills it all Plants dry up and die, leaving no

shelter for other living organisms like bugs, birds, etc.

Drought: Example: Dust Bowl

Caused by severe drought in the American and Canadian prairie land in the 1930’s

Caused by severe drought, plus decades of extensive farming without things such as crop rotation

Nothing to keep soil in place, dried up, turned into dust and blew away into many cities

Volcanoes and Animals:

When volcanoes erupt they release huge amount of ash into the atmosphere, it also spews out molten lava.

The lava destroys the habitats of the animals that are surrounding the volcano, the animals that also live near the volcano would die as well due to this.

Volcano’s and Environments:

The trees and forests around the volcano’s will be destroyed from the magma that seeps down the mountain side onto the ground and they also release a great deal of soot into the air which pollutes the atmosphere.

Volcano’s can also effect the people surrounding the volcano by destroying homes, crops, and there livelihood.

Works Cited Volcano Image: http://www.indianchild.com/images/valcanoe2.jpg

Drought Image:http://4.bp.blogspot.com/_hLV9xP2uHXs/TUtQZGMAhLI/AAAAAAAABCA/NUvH87j6W0I/s1600/drought.jpg

Meteor Image:http://www.pollsb.com/photos/o/217336-huge_meteor_hit_earth_die_dinosaurs_did.jpg

Volcano information: http://library.thinkquest.org/06aug/00886/index_files/Page307.htm

Habitat degradation,

fragmentation and loss.

• Ecosystem degradationLook back at your work on deforestation, desertification, leaching and salinization. (topic 3.4)

Fragmentation definition:The term habitat fragmentation includes five discrete phenomena:1. Reduction in the total area of the habitat 2. Decrease of the interior : edge ratio3. Isolation of one habitat fragment from other

areas of habitat4. Breaking up of one patch of habitat into several

smaller patches5. Decrease in the average size of each patch of

habitat

http://en.wikipedia.org/wiki/Habitat_fragmentation

Ecosystem Fragmentation• Habitat fragmentation as the name

implies, describes the emergence of discontinuities (fragmentation) in an organism's preferred environment (habitat), causing population fragmentation.

• Habitat fragmentation can be caused by geological processes that slowly alter the layout of the physical environment (suspected of being one of the major causes of speciation), or by human activity such as land conversion, which can alter the environment much faster and causes extinctions of many species.

Fragmentation and destruction of Great Ape habitat in Central Africa, from the GLOBIO and GRASP projects

http://en.wikipedia.org/wiki/Habitat_fragmentation

Natural causes and effects

• Evidence of habitat destruction through natural processes such as volcanism, fire, and climate change is found in the fossil record.[1] For example, habitat fragmentation of tropical rainforests in Euramerica 300 million years ago led to a great loss of amphibian diversity, but simultaneously the drier climate spurred on a burst of diversity among reptiles.[1]

http://en.wikipedia.org/wiki/Habitat_fragmentation

Human causes• Habitat fragmentation is frequently caused by

humans when native vegetation is cleared for human activities such as agriculture, rural development, urbanization and the creation of hydroelectric dams.

http://en.wikipedia.org/wiki/Habitat_fragmentation

• Habitats which were once continuous become divided into separate fragments. After intensive clearing, the separate fragments tend to be very small islands isolated from each other by cropland, pasture, pavement, or even barren land. The latter is often the result of slash and burn farming in tropical forests

http://en.wikipedia.org/wiki/Habitat_fragmentation

• In the wheat belt of central western New South Wales, Australia, 90% of the native vegetation has been cleared and over 99% of the tall grass prairie of North America has been cleared, resulting in extreme habitat fragmentation.

http://en.wikipedia.org/wiki/Habitat_fragmentation

Implications• One of the major ways that habitat fragmentation affects biodiversity is

by reduction in the amount of available habitat (such as rainforests, boreal forests, oceans, marshlands, etc.) for all organisms in an ecological niche.

• Habitat fragmentation invariably involves some amount of habitat destruction. Plants and other non- moving or slow moving organisms in these areas are usually directly destroyed. Mobile animals (especially birds and mammals) retreat into remnant patches of habitat. This can lead to crowding effects and increased competition.

• The remaining habitat fragments are smaller than the original habitat. Species that can move between fragments may use more than one fragment. Species which cannot move between fragments must make do with what is available in the single fragment in which they ended up. Since one of the major causes of habitat destruction is agricultural development, habitat fragments are rarely representative samples of the initial landscape.

http://en.wikipedia.org/wiki/Habitat_fragmentation

Farming Practices & BiodiversityMonoculture, Pesticide

use, GMOs

Monoculture• Monoculture is the practice of producing one single

crop over a wide area– Monocultures often kill off all the biodiversity because

the crops are not used to having to share soil with other plants and often kill of the competition

Pesticide Use• Pesticides can be spread through the air

and water into areas which they were not originally intended, harming many other organisms than pests– Some of these chemicals are toxic or lethal to

the organisms they make contact with– But some of the chemicals would also not be

considered directly toxic or lethal, with effects sufficiently impairing populations in these ways:

• Inability to recover from infectious disease due to immunosuppression

• Inability to obtain sufficient food, effectively avoid predators, or apply proper parenting instincts due to neurotoxicological effects

• Development of abnormal sexual anatomy or behavior due to hormone disruption

Genetically Modified Organisms • Genetically modified organisms can

compromise biodiversity in these ways:– Out-crossing: If GM plants pass their traits onto

their wild relatives, then those relatives could be changed in a way that could change their ecological role, which would potentially enable them to out-compete other species

GMOs (continued…)– New traits agreed upon by genetic engineering

could offer advantages that could lead to widespread use of only a few crop varieties, but this means a loss of cultivar biodiversity. (Cultivar is a term used in plant breeding for the differentiation of breeding lines) Reducing the diversity of the cultivars found in agriculture could lead to problems such as raised susceptibility to widespread outbreaks of plant diseases and pests

• Using GMOs doesn’t necessarily mean reducing the diversity of cultivars, but it is still a good idea to keep a close eye on this

Sites to look at:• Monoculture:HERE :D & AND HERE• Pesticides:HELLO & HOW ARE YOU?

• GMOs:BYE

Invasive species – Cane-toad and rabbit, cats and goats

Invasive species affect on biodiversity

• There are two ways for the invasive species to affect biodiversity, out-competing and hybridizing native species.

• The invasive species is one that lessens that diversity by throwing off the natural balance

• Damage life forms effecting the ecosystemHabitat destruction, such as forest clearing

• The more invasive species invading certain levels of ecosystems, the biodiversity would be more threatened

Australia - Rabbits• Rabbits are an invasive species in Australia brought by

Europeans. Since rabbits reproduce very quickly, the population of rabbits quickly increased.

• Native species of animals, such as the Rabbit-eared Bandicoot or Bilby needs a constant supply of carbohydrate-rich seeds and roots. The rabbits graze or degrade vegetation that provides food and shelter for them and other native animals. Rabbits grazing on vegetation also cause erosion and removal topsoil, and thus endangers some native vegetation. If rabbits destroy or eat the native vegetation, the Bilby and other native species are placed under greater pressure, and thus the native species become endangered.

Australia - Rabbits

• Rabbits are an invasive species in Australia brought by Europeans. Since rabbits reproduce very quickly, the population of rabbits quickly increased.

Australia - Rabbits

Native species of animals, such as the Rabbit-eared Bandicoot or Bilby needs a constant supply of carbohydrate-rich seeds and roots. The rabbits graze or degrade vegetation that provides food and shelter for them and other native animals. Rabbits grazing on vegetation also cause erosion and removal topsoil, and thus endangers some native vegetation. If rabbits destroy or eat the native vegetation, the Bilby and other native species are placed under greater pressure, and thus the native species become endangered.

Sources

http://www.environment.gov.au/biodiversity/invasive/ferals/index.html• http://www.environment.gov.au/biodiversity/i

nvasive/ferals/index.html• http://www.pbs.org/wgbh/nova/nature/impact-

invasive-species.html • http://curiosity.discovery.com/question/

invasive-species-affect-biodiversity

Pollution and Biodiversity

Kei and Christine

Biodiversity Decreasing• The IUCN has reported that about 5,200 species of animals currently are

threatened with extinction, including: * Close to 1,100 species of mammals, one-quarter of the total number of mammals.

• Over 1,100 birds, 11% of the 9,600 known species of birds. • Over 2,000 species of freshwater fish, 20% of the total number

identified. • 253 species of reptiles, 20% of the total number surveyed. • An estimated 124 species of amphibians, 25% of the total number

surveyed

• Plant species are not faring well, either. Of the 270,000 known species of higher plants, 34,000 are endangered. In the US nearly 30% of the 16,000 known plant species are at risk of extinction. View these statistics here:

https://online.uas.alaska.edu/online/portfolio/CJOHNSON9/Courses/Fall-2008/Introduction/Pollution__Life?behavior=UAS;

Pollution Increasing

• Since the industrial revolution in the 1800’s, we’ve been relying on environmentally detrimental methods of creating materials and products.

• Factories and waste help our industrial development but hinder our biodiversity development.

How does one affect the other?

WATERToxic discharges

This includes metals, organic chemicals, and suspended sediments usually found in industrial and municipal effluents that are discharged directly into waterbodies. Toxic discharges can inversely impact the biota (living organisms) in an ecosystem by killing them, weakening them, or affecting their ability to carry out essential biological functions (feeding, reproducing, etc.).

Bacterial contaminationFor example, fecal coliforms that come from human waste are found in municipal effluent discharges. Potable water is treated to destroy fecal coliforms which can make people ill if ingested.

How does one affect the other?LAND

Area PollutionArea pollution prevents a specific region from having nutrient buildup, which is ultimately an disadvantage to species such as lichen. But it helps stimulate rapid growth of algae and aquatic plants.

How does one affect the other?

AIRAcid Rain

Acid precipitation is the air pollutant that has the most significant impact on biodiversity in Canada. Despite legislation aimed at reducing acid rain and acid loading, it is predicted that we will lose fish, mollusk and amphibian populations in thousands of lakes because they will not be able to survive in acidified conditions. This is of particular concern in the Canadian Shield region of Quebec, whose countless lakes are sensitive to acidification because their drainage basins cannot neutralize acid inputs the way they can in more southern Quebec regions.

These information is mostly based on the St. Lawrence watershed in the southwest and northeast of North America and Canada.

Read more at: http://redpath-museum.mcgill.ca/Qbp/3.Conservation/impacts.htm

Researchers say that pollution affects plant diversity more than animal diversity

• Air pollution affects lower life forms more than higher life forms. Plants are generally more affected than animals on land.

• Plants constantly take up atmospheric gases i.e. air everyday to sustain their biological processes. Vegetation growing under optimum conditions is most susceptible to air pollution. As air pollution is for the most part man-made, we are the main source of this phenomenon. Pollution can be derived from two kinds of sources namely, stationary and multiple point sources.

• Multiple point sources are usually mobile and include automobiles and other vehicles. The vehicles are the most important source of atmospheric pollutants as they release carbon monoxide. This is followed by industrials sources which release sulphur oxides, steam and electric power plants, space heating and lastly refuse burning. Agricultural chemicals also form part of air pollution.

• The uptake of pollutants depends on the concentration gradient between the ambient air and the absorptive sites within the leaf. It also depends on the conductance of the stomata. The toxic effect of a pollutant may thus be almost directly related to the functioning of the stomata.

• Because of the higher susceptibility of dying off as a result of pollution in plants, their biodiversity is at a greater threat. But sometimes, the biodiversity of plants can affect the biodiversity of animals as you’ll see in the next slide………..

Read more at: http://bcb705.blogspot.com/2007/03/air-pollution-lethal-injection.html

Example: The Pollination Crisis

• Since 2006, honeybee colonies in the United States have been suffering from a widespread phenomenon known as colony collapse disorder (CCD), in which adult worker bees abandon an otherwise-healthy hive.

• Air pollution interferes with the ability of bees and other insects to follow the scent of flowers to their source, undermining the essential process of pollination, a study by three University of Virginia researchers suggests.

• Their findings may help unlock part of the mystery surrounding the current pollination crisis that is affecting a wide variety of crops.

• Scientists already knew that scent-bearing hydrocarbon molecules released by flowers can be destroyed when they come into contact with ozone and other pollutants.

• Most bees have poor eyesight, which makes scent particularly important, the researchers wrote.• This phenomenon triggers a cycle, the authors noted, in which the pollinators have trouble finding

sufficient food, and as a result their populations decline. That, in turn, translates into decreased pollination and keeps flowering plants, including many fruits and vegetables, from proliferating.

• "We know that ozone levels continue to be high and go well beyond EPA standards for public health," Tear said. "What's been pretty consistent is the more we look at air pollution's impacts on natural resources, the more we find those impacts to be.”

• Tear and his colleagues have recently completed a survey of how atmospheric pollution is affecting biodiversity in the Eastern United States and concluded that high levels of ozone can decrease forest growth by as much as 30 percent.

Read more at: http://www.washingtonpost.com/wp-dyn/content/article/2008/05/04/AR2008050401737.html

Hunting, collecting and Harvesting

Hunting

• Most extinction over the past several hundred years are mainly due to over-harvesting for food, fashion, and profit

• Commercial hunting, both legal and illegal (poaching), is the principal threat.

• For Example Rhino Horns for $40,000 to $100,000 per horn

• The pet and decorative-plant trade falls within this commercial hunting category, and includes a mix of legal and illegal activities. The annual trade is estimated to be at least US $5 billion, with perhaps one-quarter to one-third of it illegal.

Hunting (continued)

• “Sport or recreational hunting causes no endangerment of species where it is well regulated, and may help to bring back a species from the edge of extinction. Many wildlife managers view sport hunting as the principal basis for protection of wildlife.”

• http://www.fathom.com/course/21701785/session2.html

Harvesting/Collecting

• Conversion of Forests into agriculture for harvesting – Lessens habitat, which in turn lessens species diversity.

• Harvesting removes certain foods or areas of nutrition for animals• Overharvesting any area is a direct threat to a biodiversity• Habitat loss and overharvesting often occur simultaneously

“The problem with biological resource extraction is when the rate of increase in demand for the resource far outstrips the reproductive rate of the population - demand outstrips supply”http://redpath-museum.mcgill.ca/Qbp/3.Conservation/impacts.htm

• “The recent expansion of road networks into previously remote tropical forests enables the bush meat trade resulting in what some conservationist describe as ‘empty forests’ as more and more wild animals are shot for food.”

• Link to a table which shows the affects of overharvesting in comparison with the other factors.

• http://www.fathom.com/course/21701785/session2.html

Harvesting/Collecting(continued)

Overharvesting (3 points)

“The unsustainability of biological resource extraction has, at its root, three main problems

a) too many people want the resources, b) the short-term profit goals of extractors c) Lack of information about the ecology and

about the life-histories of the populations being harvested.”

http://redpath-museum.mcgill.ca/Qbp/3.Conservation/impacts.htm