Conservation Ecology: Human Impacts Flashcards
(180 cards)
what % is the human population growing per yr?
1.1% (135 million births and 55 million deaths)
major impacts to earths ecosystems resulting from human population growth
habitat loss
what is the most invasive form of habitat loss?
deforestation
which country has the largest density of people per sqr/km
india
which country has the smallest density of people per sqr/km
usa
where has the highest growth rate?
africa, india
when did human population start to ramp up in a hx context?
industrial revolution
_____ and _____ lead to the current huge human popularion
large families, low mortality
methods of deforestation
clear cutting, variable retention, and selective cutting
selective cuttign
removal of single trees by helicoper
- leaves small gaps in the canopy in which seedling develop
- most similar to natural disturbance
- cost prohibitive in most areas
variable retention
leave representative old growth in each cut block (10-30%) retention, low profit margin due to high costs of road contruction
clear cutting
remove all trees in patches up to 2000ha (80yr rotation) - most invasive, most widespread around the globe, greatest profit margin
human population increases by ____ million per year
80
soil and lemur population
- in madagascar forests were comprised for profit
- lateritic soil (leached of silica after deforestation)
- concentration of iron, maganese, aluminum, nickle
- leaked into the ocean and killed coral reefs
- lemurs still exist but will go extinct
amazon deforestation
- deforestation for cattle export
- burned/slashed agriculture
- largest cattle farm in the world, sent cattle to 170 countries (3x export in past 3 years)
what country has the highest rate of deforestation per year?
brazil
- protest by indigenous
- little response by the educated class
Brazil implemented new laws to combat deforestation; however, locals complain that these laws are______and allow those responsible for the main environmental impacts to go ______
ineffective, unpunished
brazils new laws about deforestation
- remission of penalties in landowners who illegally remove native vegetation
- reduce the areas classified as “requiring restoration”
- injustice in the population
- means that insect collectors are charged with high fines but landowners receive no
-punishment for illegal reforestation
what did the ecuadorian government annouce?
- recent signings of 2 new oil concession in yasuni national park
- piplines, wells, drilling platforms, etc
what ecosystem has the greatest biomass/ha?
coastal temperate rainforests
what is remaining of BC’s coastal temperate rainforest?
1/4
on haida gwaii, 70% of the forest is…
gone
loss of forests due to
logging
gribbrell island
- government clearcut river
- was main source of salmon for bears
- 80% reduction of their major protein source for bears