Enviro Topic 3- Biodiversity and Conservation

Biodiversity- 

• Broad concept encompassing the total diversity of living systems.

• This is measured through:

  • Habitat/ecosystem diversity

  • Species diversity 

  • Genetic diversity 

Species diversity

• Considers:

  • Richness:

    • Number of species 

  • Relative proportions/evenness:

    • Relative abundance of each species 

• Measured through a diversity index such as Simpson’s 

• Used to draw trends about a community:

  •  more diverse could mean less pollution 

  • Less diverse could mean recently colonized

Habitat diversity

• Range of different habitats in an ecosystem or biome 

  • Often based of plant diversity 

• how many different places an organism can live within an environment 

  • Lots of ways to specialize = lots of niches 

  • Allows for species diversity

Genetic diversity

• Within one species 

• Ex. amongst people 

• Explains distinct populations of a single species (via the range of genetic material present in a population of a species)

Species richness

The number of species

Species evenness

• Relative proportions/evenness:

  • Relative abundance of each species

Endemic

• Lives only in one location 

  • ex) Santa Cruz Island Scrub Jay

Evolution

• development of new species over a very long period of geological time--millions of years

Natural selection

• Occurs because of evolution

• specifically, genetic diversity = natural variation → some individuals fitter than others → more reproductive success)

• Opposite of selective breeding  (nature does the choosing)

• “Survival of the fittest”

  • Ex) smaller organisms need less food consumption 

  • Genetic Variability → (selective pressure) → only some organisms live to reproductive age → next generation has more of favorable trait 

Geographic isolation

• A physical barrier that separates populations of the same species.

• This can lead to speciation when combinded with natural selection

• ex) ice age, land bridge 

Reproductive isolation

• A reproductive barrier that prevents populations from interbreeding 

• No longer interbreed due to changes in behavior or physical structure

• Later they are genetically different and can’t interbreed

• ex) if flowers bloom at different times of year 

Speciation

• formation of new species when populations of a species become isolated and evolve differently

• Occurs due to geographic isolation or reproductive isolation + natural selection = speciation 

Plate Tectonics?* (How in depth?)

• Movement of plates around the surface of the earth is driven by convection of magma 

• Two types of plates:

  • Oceanic 

    • More dense →basalt

    • Less dense → granite 

• Types of plate boundaries:

  • Convergent →←

    • Continental + continental→ mountain ranges (ex. Himalayas)

    • Oceanic + oceanic → island arc (ex.Aleutian Islands, Alaska)

    • Continental + oceanic → subduction → inland volcanoes (ex. Cascade mountain range OR, WA)

  • Divergent ←→

    • On land→rift valleys (ex. Iceland)

    • In ocean → oceanic ridge (seafloor spreading)

  • Transform ↓↑

    • Slide past each other 

    • Pressure builds and is released in earthquake (Ex. San Andres Fault)

Mass extinction 

• 5 previous mass extincitions all caused by asteroids, volcanoes or huge change in climate (ABIOTIC) (every 100ish years). It opens up niches for other organisms.

  • Average time between extinction ≈ every 100 million years

  • Mass extinction event → massive loss of biodiversity →new biodiversity evolving 

    • New biodiversity b/c of new opportunities for surviving populations

    • Adaptive radiation (ancestral species evolve to fill different niches → new species)

Sixth mass extinction

• HUMAN caused (Biotic caused)

• 13,000 years ago → agriculture, 1st major way of change 

• industrial revolution → burning of fossil fuels → pop ↑ b/c food ↑

• Historically, 10-100 species go extinct per year

• Losing 27,000 species per year from rainforest alone

• Evidedence from video: 

  • 45% decline in invertebrates in past 40 years

  • Fossil record shows “background rate” extinction is 1000- 45,000 times higher than before

Causes of mass extinctions

• Five previous mass extinction events (all caused by ABIOTIC factors) (listed from most to least recent)

  • Cretaceous-Tertiary Extinction 

    • likely asteroid 

  • End Triassic

    •  floods of lava from the ocean (geologic activity)

  • Permian-Triassic- The Great Dying 

    • asteroid or volcano

  • Late Devonian 

    • Effect- global cooling followed by global warming 

    • (cause unknown)

  • Ordovician-Silurian  

    • Effect-drop in sea levels then rising sea levels with glacier forming and melting (Ice Age followed by rapid warming)

    • (cause unknown)

Factors causing endangerment:

• HIPPCO 

• Habitat loss/fragmentation

• Invasive species

• Pollution

• Population of humans

• Climate change

• Over-exploitation

Invasive species

• non-native and harmful to environment. They can out-compete native species. Tend to be r strategists and generalists

• New species can parasitize or predate upon residents, hybridize with them, compete with them for food, bring unfamiliar diseases, modify habitats, or disrupt important interactions.

IUCN

• IUCN=International Union for Conservation of Nature 

  • It is an IGO (intergovernmental organization)

• It manages the IUCN red list 

Red List

• An inventory of all threatened species

• Highlights plants and animals facing higher risk of global extinction

• The list goes from least concern → extinct

Red list criteria 

• Population size: 

  • lower diversity when pop smaller 

• Reduction in pop: 

  • recent reduction in pop (trends)

• Trophic level:

  •  higher is more susceptible to endangerment

    • Dependent on food chain

    • Fewer to begin with

    • Tend to be hunted 

• Degree of specialization: 

  • Ex) pandas (very specialized and very at risk)

  • More specialization → more at risk

  • Specialists are more at risk than generalist

• Geographic range:

  • Restricted to certain habitat

  • Habitat specialization

• Degree of fragmentation:

  • Fragmentation of pop (separation of gene pools)

  • Ex) mountian lion divided by freeways 

• Reproductive potential/behavior:  

  • Long gestation period with fewer offspring 

  • Ability to find a mate 

  • R-strategists vs k-strategists

• Quality of habitat: 

  • Pollution, melting ice

Degree of Specialization

Ex) pandas (very specialized and very at risk)

• More specialization → more at risk

• Specialists are more at risk than generalist

Geographic range

• Restricted to certain habitat

• Habitat specialization

Distribution?*

Degree of fragmentation

• Fragmentation of pop (separation of gene pools)

• Ex) mountian lion divided by freeways

Biological Hotspot

• HIGH BIODIVERSITY and UNDER THREAT

• Ex)Tropical rainforests 

• Large numbers of species (often endemic)

• Under threat:

  • 1 football field of rainforest lost every 4 seconds

• Not easily recoverable:

• Thin, nutrient-poor soils make regrowth difficult

Aesthetic reasons/Intrinsic value

• Intrinsic value = everything has a “right to life”

• Aesthetic reasons 

  • cool/pretty

NGOs

• Non-governmenal organizations 

  • Ex)World Nature Organization (WNO)

  • World Wide Fund for Nature (WWF)

  • Greenpeace

IGOs

• Intergovernmental organizations

• Ex)

  • United Nations Environment Programme (UNEP)

  • International Panel on Climate Change (IPCC)

  • International Union for Conservation of Nature (IUCN)

Compare and contrast of NGOs and IGOs 

• IGO:

  • More “red tape”

  • Slower-more people need to agree

  • Political influence

  • More power

  • Gov/national budgets 

• Both:

  • Use media to effect decision making

  • Local and global operations

  • Publish articles and reports for education

• NGO:

  • Faster-few people are involved

  • More focused 

  • Private donations 

Species based conservation

• Two types:

  • In situ and ex situ

In situ conservation

• on site (within natural habitat-ex) within national park)

• ex)  gorrillas in Virunga 

• Needs local support 

• Can have captive breeding programs on site (ex island foxes)

Ex situ conservation

• Offsite (ex. zoo)

• ex) gorrillas in LA zoo

• necesary if the habitat is threatened

• Easier for smaller animals

• Can be used to generate $

• Can use captive breeding programs

Edge effects

• edge of area are more exposed (to abiotic factors like wind or heat or humidity and biotic factors like other species outside of protected area-->competition)

• Closer to round = more area away from the edge = less edge effect

Animal corridor

• overall =good (used to link reserves). 

• Pros: Allow gene flow, seasonal movement, fewer collisions w/ cars, fewer/no roads in corridors (no fragmentation).

•  Cons: allows for poachers to move undetected, large edge effects b/c narrow, invasive species from connected reserves,...)

Buffer zone?*

CITES

• The Convention on International Trade in Endangered Species of Wild Fauna and Flora

• aim is to ensure that international trade in specimens of wild animals and plants does not threaten their survival

  • is an international agreement between governments.

  • Species based conservation strategy

  • This is the one that has banned ivory

  • works by subjecting international trade in specimens of listed species to certain controls. 

  • require that all import, export, re-export and introduction from the sea of species covered by the Convention has to be authorized through a permitting system.

Flagship species

• Animal used as the face of an organisation 

  • ex) WWF panda 

  • Charismatic species

  • Designed to appeal to public...end up helping other species in that same area

  • High profile/iconic

  • Attention → $ → conservation

Keystone species

• Ecosystem cannot survive without this species 

• ex) wolves in yellowstone

How plate activity has influenced evolution

• Create mountain ranges, oceans, seas, and rift valleys → geographic isolation → speciation

• Plate movement can create new habitats or destroy old ones

Be able to use multiple different types of arguments (NOT just multiple examples of ecological arguments)

• Ethical: Responsibility and “Right to Survive”(intrinsic value), don’t want to deprive future generations

• Athsetic: cool/pretty

• Economic: video, ecotourism

• Ecological: 

  • High biodiversity = more stable

  • May contain endemic species

  • More likely to provide ecosystem services like flood prevention, pollination, or act as a carbon dioxide sink

  • Role in food chain

  • Keystone species

• Cultural value/ historical significance

Strengths and limitations of ecosystem-based or species-based conservation?*

• Ecosystem based:

  • Needs community support (tourism influences this)

  • Adequate funding (tourism influences this)

  • Research based methods

  • Laws and the ability to enforce them 

• Species based:

  • In situ and Ex situ

  • Strengths and limitations on the next

• Strengths and limitations of in situ (ex. Habitat based) or ex situ (ex. zoos) conservation ?*

In situ conservation

• on site (within natural habitat-ex) within national park)

• Needs local support 

• Can have captive breeding programs on site (ex island foxes)

Ex situ conservation

• Offsite (ex. zoo)

• necesary if the habitat is threatened

• Easier for smaller animals

• Can be used to generate $

• Can use captive breeding programs 

• Criteria used to design and manage protected areas

• Size- SLOSS? (single large or several small)

  • if habitats are far apart, several small may be needed. Otherwise, bigger=better (large area better supports big pops and top carnivores). Also, more protection against fire/disease, etc. also less edge effects

  • Several small? Close preferred to isolated b/c easier to disperse. 

  • Clumped > spread out

• Edge effects

  • edge of area are more exposed (to abiotic factors like wind or heat or humidity and biotic factors like other species outside of protected area-->competition)

• Shape

  • circle best b/c less edge effect. Reality? Whatever is available

• Corridors 

  • overall =good (used to link reserves). Pros: Allow gene flow, seasonal movement, fewer collisions w/ cars, fewer/no roads in corridors (no fragmentation). Cons: allows for poachers to move undetected, large edge effects b/c narrow, invasive species from connected reserves,...)

• Proximity to potential human influence

• How to evaluate the success of a named protected area

• What is going right?

• What is going wrong?

• Discuss the case histories of three animals--one that became extinct due to human activity, one that is critically endangered, and one whose conservation status has been improved by intervention

• one that became extinct due to human activity

  • California Grizzly 

    • 1922- last hunted grizzly killes

    • 1924- last seen in CA

    • They were hunted by rancheros and vaueros 

    • The fact that it lived in lowlands, not just mountains, made it come into more contact with ranchers and people in general

    • “Doomed by loss of habitat, food, and slow reproduction” 

• one that is critically endangered (also counts as improved by intervention)

  • California Condor 

    • Victim of habitat destruction, powerlines, poaching, lead posioning

    • Extinct in the wild in 1987 →all remaining 27 put into LA and SD zoo for captive breeding 

    • Reintroduced in 1991  

    • Currently critically endangered 

• improved by intervention

  • Island fox

    • Human efforts helped the fox pop

      • Killing of the pigs

      • Removal of golden eagles and reintroducttion of bald eagles 

      • Vaccination

      • Captive breeding programs

Be able to give

• Named protected areas

• Named biological hotspot

• Named extinct and endangered species

• Named IGO

• Named NGO

Reminder to review this

Be able to 

• Describe the threats to biodiversity from human activity in a given natural area of biological significance or conservation area.

• Evaluate the impact of human activity on the biodiversity of tropical biomes.

• Discuss the conflict between exploitation, sustainable development, and conservation in tropical biomes.

• Range of arguments in favor of the conservation of biodiversity

Reminder to review this

• Evaluate the impact of human activity on the biodiversity of tropical biomes.

• Discuss the conflict between exploitation, sustainable development, and conservation in tropical biomes. ?*

Some examples:

-Clearing b/c: world demand for tropical hardwoods increases & land is cleared for agriculture. 

-tropical soils = thin --> farmlands have short lived productivity.

-Huge forest fires (started to try to clear land during a dry year) devastated large amounts of tropical rainforest in Indonesia and Brazil in 1997/98.

-The construction of roads- In areas with very high rainfall, there is an increased risk of erosion and loss of topsoil. Also, habitat fragmentation.