Question

as vegetation recovered, beaver populations rebounded, constructing dams that restored wetland, improved water quality. these wetlands provided niches for fish, amphibians, insects, and waterfowl, increasing overall biodiversity. songbird populations rose as nesting habitat became more available, and bears benefited, as berry - producing shrubs flourished in recovering forests. the return of wolves stabilized food webs, strengthened ecosystem resilience, and restored ecological complexity.

1. what two key things happened when the wolves were reintroduced to the ecosystem?
2. what happened to the willow, aspen and cottonwood trees when the wolves were brought back? choose a sentence from the paragraph to support your answer.
3. ecologists reintroduced wolves into the ecosystem because they predicted it would help to restore the damaged ecosystem. create a claim about the effectiveness of the wolf reintroduction program in restoring the ecosystem. use at least 2 pieces of evidence from the text to support your answer.

claim:
evidence #1:
evidence #2:
keystone species and ecosystem stability
wolves illustrate the role of a keystone species—having a much greater effect on ecosystem stability than their numbers would suggest. by regulating elk numbers and behavior, wolves maintained the balance between herbivore populations and plant communities. this balance preserved the carrying capacity of the ecosystem, ensuring that resources such as vegetation, soil, and water could sustain a diversity of organisms.

1. based on the information given, summarize the importance of a keystone species within an ecosystem.

the yellowstone case study underscores a central concept in ecology: ecosystems are dynamic networks of interactions. removing or restoring a keystone species can profoundly alter population sizes, biodiversity, and the stability of the entire system.

Explanation:

1. The text mentions that the return of wolves stabilized food - webs and strengthened ecosystem resilience. Also, as vegetation recovered due to wolf - related changes, beaver populations rebounded and constructed dams which improved water quality and increased biodiversity.
2. The willow, aspen and cottonwood trees likely benefited as the wolves regulated elk numbers and behavior, reducing over - grazing. A supporting sentence could be "By regulating elk numbers and behavior, wolves maintained the balance between herbivore populations and plant communities."
3. Claim: The wolf reintroduction program was effective in restoring the ecosystem. Evidence #1: Vegetation recovered, which led to beaver population rebound and dam - building, improving water quality and increasing biodiversity. Evidence #2: Songbird populations rose as nesting habitat became more available, and berry - producing shrubs flourished, benefiting bears.
4. A keystone species like wolves has a disproportionately large effect on ecosystem stability. They maintain the balance between herbivore and plant communities, preserve the ecosystem's carrying capacity, and their presence or absence can profoundly alter population sizes, biodiversity, and the stability of the entire ecosystem.

Answer:

1. Wolves stabilized food - webs and strengthened ecosystem resilience; vegetation recovery led to beaver population rebound and related positive effects.
2. The trees likely benefited as wolves regulated elk. Supporting sentence: "By regulating elk numbers and behavior, wolves maintained the balance between herbivore populations and plant communities."
3. Claim: The wolf reintroduction program was effective in restoring the ecosystem. Evidence #1: Vegetation recovered, beaver populations rebounded, water quality improved and biodiversity increased. Evidence #2: Songbird populations rose and berry - producing shrubs flourished, benefiting bears.
4. Keystone species maintain ecosystem balance, preserve carrying capacity and greatly affect population sizes, biodiversity and ecosystem stability.