7th Grade Ecological Succession Test Review

An abandoned garden has been cleared of all vegetation, and only a layer of nutrient-poor soil remains. Which of the following will most likely be observed in the garden area first?

• Squirrels building nests in trees

• Butterflies competing for flower nectar

• Beetles feeding on leaves of shrubs

• Weeds sprouting in the soil

In a rainforest ecosystem, some plants are able to grow attached to the sides of the tallest trees. This adaptation benefits these plants by allowing them to better compete for what resources that are limited on the forest floor?

• Sunlight

• Water

• Nutrients

• Air

How might competition for resources explain the sequence of plant growth in succession?

• Weeds do better than other plants early on because they require fewer nutrients to grow.

• Flowering plants appear last because they are unable to compete for pollinators.

• Tall trees appear before flowering plants because their large roots absorb more water.

• Lichens appear after trees since they compete with other plants for shady areas.

If a new species moves into an area what is a possible result.

• Native species and the new species may compete for food.

• Native species began consuming more water to drive out the non-native species.

• Native Species began interbreeding with the non-native species, creating a hybrid.

A large area of forest is cleared of trees that usually provide shade. In response to this change, plants in this environment would be expected to show an increase in traits that allow them to–

• attract insect pollinators.

• develop deep root systems.

• produce wind-blown seeds.

• withstand direct sunlight.

Areas with high biodiversity have?

• High Sustainability

• Low Sustainability

• More rainfall

• Less rainfall

The habitat with the greatest sustainability will be the one that -

• receives the highest annual rainfall.

• has few top-level predators.

• has the greatest overall biodiversity.

• maintains a moderate climate year-round.

The greater a habitat’s biodiversity, the greater will be that habitat’s -

• sustainability over time with varying conditions.

• consumption of energy in the form of sunlight.

• temperature ranges across the seasons.

• distance to the nearest water source.

Over time, a shallow pond fills with plants, such as duckweed and cattails. These plants -

• will die off quickly in the shallow water.

• support ecological succession from pond to marshland.

• will grow into larger trees as they mature.

• eventually will dry out and create a fire hazard.

Why does biodiversity contribute to a habitat’s sustainability?

• The more plants and animals in a habitat, the greater the biomass, which is how habitats store energy.

• The greater the number of species, the more competition there is for food between predators, which sustains their populations.

• Changing conditions that harm one species leave other species to survive and perhaps even thrive.

• Landforms change shape less frequently when there is a greater number of species using the land.