Miller-Levine - 4.3: Ecological Succession

Which statement best defines ecological succession in ecosystems?

• A random cycle of seasonal migration events

• A permanent halt in community change over time

• A sudden replacement of species after one day

• A gradual sequence of predictable community changes

What makes primary succession distinct from secondary succession?

• It begins on newly exposed bare rock with no soil

• It starts after a small storm leaves soil intact

• It occurs only in oceans after coral bleaching

• It happens when farms are abandoned with soil

After the 1883 eruption, Krakatau was barren. Which early step most likely occurred first in its recovery?

• Development of complex food webs with top predators

• Establishment of a mature hemlock-spruce forest

• Arrival of large mammals that disperse tree seeds

• Colonization by pioneer species forming initial soil

A retreating glacier leaves exposed rock. Predict the sequence that will most likely lead to a forest over a century.

• Trees immediately, then shrubs, then grasses and lichens

• Grasses only for centuries with no shrubs or trees

• Top predators first, then herbivores, then all plants

• Lichens and mosses, then grasses, then shrubs and trees

Tags

NGSS.MS-LS2-4

NGSS.MS-LS2-1

Which claim is best supported by evidence from Krakatau and glacier-exposed sites?

• Succession stops once grasses appear on bare ground

• Only animals drive succession while plants remain constant

• Disturbances always reduce species numbers permanently

• Biodiversity tends to increase as succession proceeds

Tags

NGSS.MS-LS2-4

NGSS.MS-LS2-5

Which statement best describes a pioneer species in ecological succession?

• Late-arriving plant that dominates stable ecosystems

• Top predator that regulates trophic cascades in forests

• Species that replaces climax communities after disturbances

• First colonizer of barren areas with few resources

What role do lichens most directly play at the start of succession on bare rock?

• Increase shade and lower forest floor temperatures

• Fix nitrogen and help form initial soil layers

• Disperse seeds widely through animal interactions

• Consume organic matter and release stored minerals

Which situation most likely leads to secondary succession rather than primary succession?

• A new island emerges from tectonic uplift

• A glacier retreats leaving exposed bedrock

• Volcanic lava cools to create new oceanic rock

• A forest regrows after a low-intensity surface fire

As secondary succession proceeds in an abandoned field, which sequence is most reasonable?

• Grasses colonize, shrubs establish, young trees grow

• Mature trees die, bedrock forms, lichens arrive

• Top predators arrive, algae spread, soil erodes

• Lichens appear, mosses thrive, soil is removed

Tags

NGSS.MS-LS2-3

A land manager wants to accelerate recovery after a hurricane. Which action best aligns with how succession naturally rebuilds communities?

• Introduce large predators to control herbivore numbers

• Remove all remaining vegetation to start from scratch

• Protect surviving plants to provide seeds and shade

• Apply herbicides to prevent early colonizing grasses

Tags

NGSS.MS-LS2-4

NGSS.MS-LS2-1

NGSS.MS-LS2-5