Wolves were reintroduced to Yellowstone National Park in 1995. This keystone species restored the park’s ecosystem. What is the ecological value of a keystone species? A. They influence the survival of many other species in an ecosystem. B. They prevent the ecosystem from changing and growing. C. They protect land and water resources within the ecosystem. D. They decrease the number of unwanted species in an ecosystem.

answer: national resource conservation services

national resource conservation services is the us. based approach that provides technical and financial assistance for natural resource management. nrcs society in conservation of resources by involving in activities like farmland protection, flood prevention, watershed protection, urban conservation, conserves economic and environmental conditions. it conducts soil surveys and implements the policy of natural resources management on the society.

d. cellulose and starch