Succession: how ecosystems rebuild after a change
Grade 9 Science Worksheet - Building Confidence
Circle the best answer.
Read this first
A new lava flow on an island (model data)
question answer what happened a lava flow covered the land ground now bare rock soil on it none Ari reads the site card. Which kind of succession begins here, and why?
- Secondary succession, because people will plant the first species
- Secondary succession, because the rock still holds soil under the lava
- Primary succession, because the new rock has no soil on it
- Secondary succession, because the lava cleared the old plants away
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 the soil is still there for new plants
- Secondary succession, because tall trees are the first to grow back
- 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?
- Primary succession, because farming took the soil away
- Secondary succession, because the field's soil is still there
- A climax community, because the field is already grown over
- 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, grasses, trees
- bare rock, grasses, lichens and mosses, trees
- bare rock, lichens and mosses, trees, grasses
- bare rock, trees, lichens and mosses, grasses
Primary succession on lava rock (model data)
stage what grows 1 bare rock 2 lichens and mosses 3 ? 4 shrubs 5 trees Kira reads the stage table for primary succession. What belongs in the box for stage 3?
- a climax community
- trees
- bare rock
- 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?
- tall oak and hickory trees, then shrubs
- annual plants, then fast-spreading grasses
- shrubs, then small pine trees
- lichens and mosses, which first turn the ground into soil
Milo reads the graph. At year 30, which plant type covers the most ground?
- Trees, at 10 percent
- Lichens and mosses, at 30 percent
- Grasses, at 60 percent
- Grasses, at 40 percent
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 near 80 percent, with small ups and downs
- It stays at 80 percent, with no change
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?
- Pioneer species, the hardy first living things in a new place
- 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
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?
- A climax community, in which nothing changes in any way
- A pioneer stage, in which hardy first species stay the main cover
- An intermediate stage, in which shrubs and small trees take over
- A climax community, steady until the next disturbance
