WHO LIVES HERE?
Which of these is a major component of biological soil crusts?
A. Cyanobacteria
B. Sharks
C. Coral
D. Ferns
Cyanobacteria
What is one major ecological function of biological soil crusts?
A. Increasing soil erosion
B. Stabilizing soil
C. Producing plastic
D. Preventing all rainfall
Stabilizing soil
I’m the long-term environmental stress that can threaten biocrust communities.
Drought
I look like dirt, but I’m alive.
Biocrust
A storm hits bare soil and soil protected by a healthy biocrust. Which is generally more vulnerable to soil loss?
A. Bare soil
B. Biocrust
C. Both equally
D. Neither
Bare soil
I can photosynthesize and, in some cases, fix atmospheric nitrogen. Who am I?
A. Cyanobacteria
B. Earthworm
C. Grasshopper
D. Earthworm
Cyanobacteria
Cyanobacteria can contribute to which important nutrient cycle?
A. Nitrogen cycle
B. Mercury cycle
C. Plastic cycle
D. Petroleum cycle
Nitrogen cycle
A biocrust loses one of its key microbial groups. What happens first?
A. Function
B. Ocean
C. Pollination
D. Migration
Function
“The living skin disappears. Wind suddenly steals the exposed soil. What ecological process has escaped?”
Erosion
A fragile biocrust is repeatedly walked over. What is the most likely result?
A. Degradation
B. Expansion
C. Germination
D. Pollination
Degradation
Name TWO groups of organisms commonly found in biological soil crusts.
A biocrust is destroyed. What is the most likely immediate ecological consequence?
A. Greater soil stability
B. Increased vulnerability to erosion
C. Instant forest growth
D. Increased biodiversity everywhere
Increased vulnerability to erosion
The crust dries out and becomes inactive, but later rainfall brings it back to life. What ability does this show?
A. Dormancy
B. Predation
C. Migration
D. Competition
Dormancy
Which environmental factor would you most likely measure when studying how dryland biocrusts respond to climate change?
Moisture
Imagine the biocrust disappears.
Soil becomes less stable → erosion increases → nutrients are lost → plant establishment becomes harder.
What larger environmental process could this chain eventually contribute to?
A. Desertification
B. Pollination
C. Photosynthesis
D. Succession
Desertification
A scientist removes cyanobacteria from a biocrust. Which ecosystem function could be directly affected?
A. Nitrogen fixation
B. Ocean circulation
C. Pollination by bees
D. Tidal movement
Nitrogen fixation
Which process can biological soil crusts influence during rainfall?
A. Water infiltration and runoff
B. Ocean tides
C. Cloud formation
D. Earthquake frequency
Water infiltration and runoff
“Animals remove vegetation and repeatedly disturb the soil surface. Which human-managed activity is most closely associated?”
A. Overgrazing
B. Irrigation
C. Afforestation
D. Pollination
Overgrazing
Several different organisms living and interacting in the same soil-surface layer form a biological…
A. Population
B. Community
C. Habitat
D. Species
Community
A biocrust is destroyed by disturbance. Years later, the community gradually returns.
Was the biocrust resistant or resilient?
A. Resistance
B. Resilience
C. Competition
D. Succession
Resilience
Which organisms can form a symbiotic partnership between a fungus and a photosynthetic organism?
A. Lichens
B. Earthworms
C. Insects
D. Grasses
Lichens
Why can a thin biological soil crust have effects far beyond its tiny physical size?
A. It interacts with soil, water, nutrients and microorganisms
B. It produces rainfall
C. It controls the climate by itself
D. It replaces all vegetation
It interacts with soil, water, nutrients and microorganisms
The crust isn't directly destroyed but hotter, drier conditions make its survival increasingly difficult. What stress is increasing?
A. Aridity
B. Humidity
C. Fertility
D. Salinity
Aridity
A biocrust organism changes soil conditions, which then affects other organisms. What does this demonstrate?
A. Interaction
B. Isolation
C. Extinction
D. Migration
Interaction
Two biocrust communities experience the same drought.
Crust A: changes very little.
Crust B: loses most of its structure.
What property explains why Crust A withstands the disturbance better?
A. Resistance
B. Recovery
C. Succession
D. Competition
Resistance