Human Impacts on Ecological Systems

Question 1

Average species persistence is every … years

Answer 1

1-10 million years

Question 2

… recognized mass extinctions

Answer 2

five

Question 3

Mass extinction

Answer 3

When more than 75% of species go exist within a 2 million years period

Question 4

IUCN extinction lists

Answer 4

black is extinct white is not evaluated. Red tiny vertical lines show amount of species threatened.

Question 5

Forests Cover … of global land area

Answer 5

31%

Question 6

Intense deforestation has endangered many … species

Answer 6

endemic

Question 7

… forests in the us are less than 10% intact

Answer 7

old growth

Question 8

Some species need …. forests to survive

Answer 8

old growth

Question 9

Fragmentation releases the ratio of

Answer 9

edge to interior (core)

Question 10

Invasive species prevalence increases with more

Answer 10

edges

Question 11

Invasive Species

Answer 11

Not native and has negative effects on economy, environment, or health. Displace native species and alter ecosystems.

Question 12

Invasive Species often have … enemies and … population growth

Answer 12

few, fast

Question 13

Biotic Homogenization

Answer 13

Species invasions and extinctions increase the similarity of species composition in two or more locations over time.

Question 14

Biomagnification

Answer 14

The accumulation of chemicals through food webs.

Question 15

DDT

Answer 15

Insecticide

Question 16

Biomagnification happens because

Answer 16

chemicals are stored in fats and passed up the food chain causing vulnerability for larger birds.

Question 17

Effects of acid rain

Answer 17

Water bodies become toxic. Nutrients leach out of leaves and soils. Plants less able to withstand cold, insects, and disease.

Question 18

Anthropocene

Answer 18

Human altered properties of earth on geologic scale. Must but stratigraphically significant

Question 19

… species endangered/extinct yearly

Answer 19

50,000