APES - Biodiversity & Land Use

unit 6

Biodiversity

diversity of life forms in an environment - Genetics - Species - Ecosystem

Genetic Diversity

differences in DNA among individuals in a species - allows for adaptation to disease/climate change/ environmental stress

Species Diversity

variety (abundance/evenness) of different species in an area/ecosystem - dif species provide various essential roles (decomp/pollination/etc.) allow for ecosystem stability

Ecosystem Biodiversity

variety of habitats/communities and ecological processes (nutrient cycles) within a region - allows for species niches - complex interactions that sustain/regulate life

Earth’s Species

2 million identified - 10 million estimated

General Background extinction

average rate at which species go extinct over the long term - 1 species per year

Earth’s Background Extinction

2 million identified species x 5000 extinctions a year due to deforestation/climate change = 10000 species extinct per year

Species Richness

number of species in a given area/ecosystem

• Varies with latitude (+lat = -biod), time/disturbances (+time = +biod), size of habitat (+size = +biod)

species evenness

how equal the relative abundance of a species is - distribution

Most Biodiverse Ecosystems on Earth

Coral reefs and tropical rainforests

Biodiversity ecosystem services

• secure food supply

• clean water / water filtration

• habitable climate

• resilience to climate change

• flood protection

• economic reliance (tourism/trade/food/shelter)

• essential medicines

• Carbon sequestration

• disease control

• job creation (tourism/forestry/agr)

• pollination

• cultural identity

• mental well being

Shanon-Weiner Diversity Index

quantifies ecosystem health by measuring both species richness (number of species) and species evenness (relative abundance) using the formula 𝐻′=−(𝑝𝑖ln(𝑝𝑖))

Theory of Biogeography

the larger the island and closer to the mainland the more biodiversity (+distance from mainland = -biod)

Species Adaptability to Change

• higher chance if environmental change is slow (need generations for mutations)

• higher chance if there is higher genetic variation (more options)

• higher chance if shorter generation times (typical of R species - K species vulnerable)

Range of Tolerance

range of abiotic conditions in which a species can survive in (temp, pH, light, O2)

• have optimum range where they thrive and zones of stress (struggle)

Realized Niche

not the full theoretical range of conditions a species can live in but the actual smaller space a species occupies

Niche Generalists

a species with a broad ecological niche (thrive in diverse environs, eat many foods, tolerate many conditions) - strong adaptability (racoons/cockroaches/rats)

Niche Specialists

narrow ecological niche - specific food sources, habitats, environ conditions - vulnerable to change (pandas/koalas)

Characteristics that make a species vulnerable to extinction

• niche specialists

• single food source

• not highly mobile

• K species (long generations)

• endemic species (1 location)

• scavengers (large area)

• Nomadic species (large area)

Mass extinction

rapid widespread decrease of earth’s biodiversity - a significant percentage (75%) of all species die out in a short geological timeframe (less than 2.8 million years) due to catastrophic events like asteroids, volcanism, abrupt climate change

6th Mass Extinction

5 mass extinctions in earths history due to natural causes - currently in 6th due to human actions - background extinction 100-1000x faster than average

Genetic Diversity Decline

• size of populations decreasing → gene pool shrinking

• Inbreeding depression

• bottlenecks from rapid/drastic decline

• crops & livestock left

Species Diversity Decline

• international union for conservation of nature (IUCN) maintains Red List of threatened species → less than 10% of species have been assessed

• 1/3 of species assessed are threatened with extinction

• 1 in 8 birds

• 1 in 4 mammals

• 41% of amphibians

• 38% of trees

• 38% of sharks

• 1 in 4 freshwater fish

Ecosystem Diversity Decline

#1 cause = habitat destruction

→ leads to loss of ecosystem services (food, medicine, natural products worth Trillions in the economy)

Inbreeding Depression

reduced survival and reproduction (fitness) of a population due to breeding between close relatives → hidden harmful genes - increased homozygosity (florida panthers)

Biodiversity hotspots

region w exceptionally high concentrations of unique/endemic species - under severe threat of habitat loss - provide many ecosystem services (water filtration/pollination)

HIPPCO

H - abitat destruction (fragmentation)

I - nvasive species

P - opulation growth/increased resource use

P - ollution

C - limate change

O - ver exploitation

Habitat destruction

process where an ecosystem is changed so much that it cannot support its native species - #1 threat to biodiversity

• Ex: deforestation clearing rainforests for cattle ranches or draining wetlands to build cities - destroys homes for countless species.

Coral Reef Habitat Destruction

habitat that disappears when corals and their mutualistic algae cant survive bc of warming and acidifying oceans (bleaching)

• contain 25% of all marine life

• 50+% are gone (rapid loss)

• pollution & over exploitation also affect

Habitat Fragmentation

reducing the size and number of habitats

• can be too small for animals that roam (nomads/scavengers)

• decline in genetic diversity → inbreeding depression

• disconnected → cant find mate / seeds cant disperse

• vulnerable to density dependent factors (predation, disease, competition)

Invasive Species Ex.

Introducing non-native organisms, like the zebra mussel in the Great Lakes, which outcompete native species and consume unaware prey - transported thru ballast water

Eradication of Invasives

transported thru ballast water, shipping containers, cargo holds, planes, imports and pet releases - often way past the point of return when we realize they are a problem - very costly (billion/trillions worldwide yearly)

Population growth Ex.

More people demanding more food, water, and energy, leading to greater habitat destruction and resource use

• intensifying all other HIPPCO factors

Pollution Ex.

Water and Air contamination

• Ex: Plastic in oceans, chemical runoff from farms contaminating rivers, or noise pollution disrupting wildlife.

Climate Change Ex.

Rising global temperatures causing coral bleaching, changing migration patterns, and more extreme weather events.

• ex: polar bears losing habitat due to global warming - melting of the arctic

Over exploitation Ex.

when a population’s reproduction cannot keep up with its depletion - overfishing (bottom trawling), unregulated hunting/ poaching elephants for ivory (pet trade)

CITES

Convention on International Trade in Endangered Species of Wild Fauna and Flora, an international agreement regulating trade in threatened wildlife to prevent extinction

Red List

IUCN List of Threatened Species, a global standard assessing extinction risk, categorizing species from Least Concern to Critically Endangered (Endangered, Vulnerable, Extinct in the Wild, and Extinct)

Convention on Biological Diversity

a key UN treaty from the 1992 Rio Earth Summit that aims to conserve biodiversity, promote its sustainable use, and ensure fair sharing of benefits from genetic resources

Endangered Species Act

U.S. law providing broad protection for species (plants, fish, wildlife) at risk of extinction, requiring federal agencies to conserve them and their critical habitats, prohibiting harm ("take") of listed species, and implementing recovery plans (U.S. Fish and Wildlife Service (FWS) and NOAA Fisheries (NMFS). 

Marine Mammal Protection Act

U.S. law protecting all marine mammals, establishing a moratorium on taking and importing them, and aiming to prevent species depletion by human activities, managed by NOAA Fisheries and the U.S. Fish & Wildlife Service

Conservation techniques

• captive breeding

• ecosystem restoration

• conservation of biodiversity hotspots

• promotion of ecotourism

• habitat corridors (land bridges)

• SLASS

Tragedy of Commons

tendency of a shared, limited resource to become depleted because people act from short term self interest

Externality

cost or benefit of a good or service that is not included in the purchase price - ex: smell of a bakery

Maximum Sustainable Yield

maximum amount of a renewable resource that can be harvested without compromising the future availability of that resource

Public Lands

1. Strict Nature Reserve & Wilderness Areas

2. Managed Resource Protected Area

3. Habitat / Species Management Areas

4. National Parks

5. Protected Landscapes and Seascapes

6. Natural Monuments

Strict Nature Reserves & Wilderness Areas

public land protected from ALL human impact

Managed Resource Protected Area

public land managed for the use of its resources in a sustainable way. The resources are generally biological, like harvesting trees, or minerals.

Habitat / Species Management Areas

public lands managed to ensure that species/environments present do not disappear, due to hunting, recreation, etc. The species or habitats are conserved, but not preserved.

National Parks

public land managed for recreational, scientific, and educational uses. Protection of species is involved, but alongside tourism, which create some human impacts.

Protected Landscapes and Seascapes

public land where the interaction of people and nature has created a distinct character, protected for ecological and cultural values.

National Monument

public land managed to protect culturally and/or historically significant areas. Mount Rushmore in the U.S. is a great example.

Rangeland

dry open grasslands used mostly for cattle grazing - managed by the Bureau of Land Management (BLM) → subsidize grazing with some federal money.

Rangelands Pros

• ecological benefits

• biodiversity

• wildlife habitat

• economic viability

• land restoration

• livestock health

Rangeland Cons

• environment/soil degradation

• requires lots of management

• invasive species

• infrastructure

• need monitoring

National Forests

Lands managed for the steady, sustainable use of timber

National parks

land managed for educational, recreational, scientific and scenic reasons (victims of their popularity)

National Wildlife refuges

the only federal public lands with the #1 purpose of protecting biodiversity

Wilderness Areas

the only land with preservation (not conservation) as the goal, very limited human use allowed

Top 3 US Land Uses

1. Pasture (35%)

2. Forest (23%)

3. Croplands (20%)

Fish and Wildlife Services Purpose

wildlife conservation, hunting and recreation

Bureau of Land Management Purpose

grazing & mining primarily - some timber harvesting and recreation too

US Forest Service Purpose

Timber harvesting primarily, some grazing and recreation too

National Park Service Purpose

recreation and conservation

Clear-Cutting Pros

• economic efficiency

• high timber yield

• simple management

• uniform crops

Clear-Cutting Cons

• increases wind erosion

• increases water erosion

• soil loss

• nutrient depletion

Pros of Forest Fires

• nutrient cycling → soil enrichment

• improved biodiversity

• pest and disease control

• plant reproduction for fire adapted species

National Environmental Policy Act (NEPA)

A very major, but vague sounding, national act was established in 1969. This was at the “birth” of environmental science and environmentalism in our country. This act led to the establishment of the EPA in order to manage all natural resources.

• need to research the effects of development and use of resources before their use/change

Environmental Impact Statement

outlines the scope and purpose of a project - describes environmental context - suggests alternatives and calculates impact

Environmental Mitigation Plan

Under NEPA, how the developer will address the projects environmental impact - can withhold funds/permits until completion

Urban Sprawl

the creation of urbanized areas that spread into rural areas and remove clear boundaries btwn the two → driven by increased automobiles & highway construction, living costs, urban blight & government policies

Urban Blight

as people move away from a city to suburbs/exurbs the city deteriorates causing more people to leave - positive feedback loop - people using the city without living/paying taxes there to keep it nice

Zoning

planning tool developed in 1920s to separate industry and business from residential neighborhoods → creates quieter/safer communities

• can have multi-use to combine retail, light industry and high density residential developments to create walkable communities

Smart Growth

urban planning & transportation theory that concentrates new development in compact, walkable urban centers to avoid urban sprawl

• mixed land use

• preservation of open spaces

• transportation options

• Infill