topic 4

4.2.1 Identify the factors that lead to a loss in biodiversity
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2% of the land w 50-80% of the species

warm and humid always

vertical stratification leads to excess of niches

decompose fast

most of destruction since '50

Brazil has 1/2 of it and at current rate will be gone in 40-50 years

total annual loss 50000-170000 km^2

worldwide 1.5 acres lost per second
about 1.5-10 million species on earth

18000- 50000 lost per year and 1 lost every 20 min

over 50 lost per day

Permian period=(286-248 million years ago) formation of Pangea
terrestrial diversification occurred and 90-95% of marine species became extinct (largest) caused by formation of Pangea, reduced continental shelf area, glaciation, and volcanic eruptions

Cretaceous (144-65 million years ago) 85% died caused by meteor impact in the yucatan, volcanic eruption=climate and atmospheric change
numbers: low=automatic risk

degree of speciation: generalists adapt better than specialists

distribution: widely distributed organisms may migrate out of harms way & dif effects by area

reproductive potential: if low vulnerable

reproductive behaviors: how complex or picky

tropic level: higher are more vulnerable to to bio magnification and tropic cascades
organisms are classified for conservation purposes

2 traditional groups

1. endangered: so few individuals that it could become extinct over all of its natural range

2. threatened: still abundant in range but declining in numbers

categorized by many different factors including Pop size, reduction of pop size, number of mature individuals, geographic range and degree of fragmentation, quality of habitat, area of occupancy, probability of extiction
extinct: passenger pigeon
ecological pressures from clearing of virgin forests
slow reproduction: 1 egg per year
economic pressures: easy to capture
ecological role: once most numerous bird on planet
consequences: linked to spread of Lyme disease

endangered: elephants

1. ecological: shrinking habitat
2.economic pressures: poaching for ivory
3.ecological role: keystone species, maintains grassland community by removing trees
4.consequences: loss of a ecosystem type

recovered: american alligator
1. ecological pressures: shrinking habitat
2. socio political: alligator nuisance, sustainable use, tourism
3.economic:hunted for skins bc confused w crocodile
4.ecological role: keystone predator, Everglades, top carnivore
5. consequences: loss of fish and bird pops and change whole Everglades structure
Amazon rainforest

covers over a billion acres (Brazil, Venezuela, Columbia, eastern Andean region of Ecuador and Peru)

if it was a country it would be the 9th largest

"lungs of our planet"

over 20% of world O2

more than 10 million species

1/5 of fresh water in basin

one hectare may contain 750 types of trees and 15000 species of higher plants

1/3 of destruction from shifting cultivation/ rest cleared for pasture

in just Brazil European colonies have destroyed more than 90 indigenous tribes since the 1900's
1. ethical
2. aesthetic: more beautiful than development
3.genetic resources: unique combos for disease resistance, chemical production, etc.
4.commercial: many products come from biotia support: plants give O2, soil gives means for food, organisms cycle and purify water
ecosystem: all connected
established 1961
to conserve the natural environment and ecological processes
promoting awareness and conservation of wildlife
wildlife conservation, work w companies like Nike to reduce co2, aid
media use
stays current
international law and coordination
limited, no real governmental power, but broad passive influence

exists bc fragile earth deserves a voice, needs solutions, needs change, needs action
nonprofit in 40 countries
does not accept government donations
campaign to stop climate change, protect ancient forests, save the oceans, stop whaling, say no to genetic engineering
started protesting nuclear testing

UNEP: United Nations environment program
established in 1972
negotiate, monitor, implement treaties
focuses on consumption issues, energy, food, youth
limited media use
slower response
underfunded and undersupported
4.3.4 named reserve successEverglades south Florida once 100 km wide knee deep sheet of water moving from leech over to fl since 48 most water has been diverted4.3.5 evaluate species based approach1975CITES 152 countries 900 endangered 29000 regulated as threatened enforcement difficult, consequences weak, choice