Succession: how ecosystems rebuild after a change
Grade 9 Science Worksheet - Building Confidence
Circle the best answer.
Read this first
A forest after a fire (model data)
question answer what happened a fire cleared the forest ground now ash on the soil soil on it still there Bo reads the site card. Which kind of succession begins here, and why?
- Secondary succession, because tall trees are the first to grow back
- Secondary succession, because the soil is still there for new plants
- Primary succession, because the fire left the ground with no soil
- Secondary succession, because someone must plant the new forest first
A field that is no longer farmed (model data)
question answer what happened the farmer stopped farming and left the field alone ground now bare soil years since farming stopped 1 Esme reads the site card. Which kind of succession begins here, and why?
- Secondary succession, because the field's soil is still there
- A climax community, because the field is already grown over
- Primary succession, because farming took the soil away
- Secondary succession, because crops must be planted first
Table
Stage cards for new lava rock (model data), 4 rows. Columns: stage card. Row 1: trees. Row 2: bare rock. Row 3: lichens and mosses. Row 4: grasses.
Jun puts the cards in order for primary succession, first to last. Which list is right?
- bare rock, lichens and mosses, trees, grasses
- bare rock, lichens and mosses, grasses, trees
- bare rock, grasses, lichens and mosses, trees
- bare rock, trees, lichens and mosses, grasses
An oak and hickory forest after a fire (model data)
question answer what happened a fire cleared the forest soil on it still there, with ash Luz reads the card. In this secondary succession, which plants usually grow back first?
- lichens and mosses, which first turn the ground into soil
- shrubs, then small pine trees
- annual plants, then fast-spreading grasses
- tall oak and hickory trees, then shrubs
Milo reads the graph. At year 30, which plant type covers the most ground?
- Lichens and mosses, at 30 percent
- Grasses, at 40 percent
- Grasses, at 60 percent
- Trees, at 10 percent
Noah reads the graph. Which plant type is the first to show any cover?
- Trees, at year 10
- Grasses, at year 10
- Lichens and mosses, at year 10
- Grasses, at year 20
Pia reads the graph of an old forest. What does the line say about the tree cover?
- It keeps rising, so the forest is still young
- It keeps falling, so grasses are taking over
- It stays at 80 percent, with no change
- It stays near 80 percent, with small ups and downs
Lichens on new lava rock (model data)
question answer site new lava rock year 3 living things lichens soil none yet Ren reads the card. What are the lichens called in succession?
- Intermediate species, the shrubs and small trees in the middle stages
- Permanent species, the first plants that stay the main cover for good
- Climax species, the steady group of species at the end of the stages
- Pioneer species, the hardy first living things in a new place
Lichens and mosses on lava rock over 20 years (model data)
year what is there 0 bare rock and no soil 20 lichens and mosses and a thin layer of soil Tala reads the card. How did the first soil on the lava rock start to form?
- The pioneers helped break the rock down, and their remains added to the soil
- Rain alone made the soil, and the pioneers had no part in it
- Trees dropped leaves on the bare rock, and the leaves became soil
- People carried soil in and planted the first species on it
A forest long after a fire (model data)
question answer years since the fire 150 species mix like the forest before the fire change now steady, with small changes in counts Zee reads the card. What is this stage of succession called?
- An intermediate stage, in which shrubs and small trees take over
- A climax community, in which nothing changes in any way
- A climax community, steady until the next disturbance
- A pioneer stage, in which hardy first species stay the main cover