Secondary Succession

Question 1

Reason for secondary succession

Answer 1

established community is suddenly and drastically changed
response to injury
ex. forest fires, wind storms, agriculture

Question 2

Dominance in secondary succession

Answer 2

If changes that cause secondary succession destroy species, there becomes a fight for dominance

Question 3

Process of secondary succession

Answer 3

1. weeds move onto bare earth
2. grasses accumulate and deepen the soil
3. small shrub community develop soil profile
4. large shrub community accumulate organic material
5. small tree species community create deeper, more complex soil
6. large tree species community fully develop soil profile
7. final tree species community have deep, stabilized soil profile

Question 4

forest fires

Answer 4

some ecosystems rely on them
returns minerals to soil
can increase diversity and disease resistance
spread fast and only burn debris
when normal forest fires are prevented, they burn more than debris and harm the environment

Question 5

fireweed

Answer 5

seeds lie dormant until heated by forest fire

Question 6

taiga biome forests

Answer 6

depend on forest fires

forest fires get rid of debris

Question 7

jack pines

Answer 7

only grow after a fire

cones hold seeds until heated by fire

Question 8

land clearing and ecological succession

Answer 8

disrupts stable ecosystem

disrupted ecosystem can return to normal if left alone for long enough due to ecological succession

Question 9

weeds

Answer 9

well adapted to sunny conditions
beginning of ecological succession
grow fast and densely
choke out weak garden plants and take over
"weed" is a subjective term

Question 10

importance of weeding

Answer 10

stops the process of ecological succession

demonstrative of power of ecological succession

Question 11

process of ecological succession in abandoned field

Answer 11

1. colonized by annual species
2. becomes dominated by perennials after a year (this stage lasts 2-5 years)
3. woody species invade through the assistance of small animals and birds spreading seeds
4. pines
5. after 15-20 years the pine canopy closes and sun loving plants and small pines can no longer survive
6. shade loving plants grow and take over
7. after 150 years, climax species establish themselves