Sustainable forestry: seeks to conserve forests for the long-term commercial harvest of timber and non-timber forest products by maintaining a mix of forest trees, by age and species, rather than imposing a monoculture. due to the complexity of goals, is most effective when it involves cooperation among environmentalists, loggers, farmers, indigenous peoples, and local, state, and federal governments. approaches vary from one forest ecosystem to another, in response to different environmental, cultural, and economic conditions. is all of the above.

Yes, it is all of the above.

Explanation:

Yes, all the above statements are necessary for sustainable forestry because trees and other wild plants of the forest are necessary for all farmers, loggers, environmentalists, indigenous peoples and for the governments. The environmentalists study on these plants to find out the impact of these different plants on the environment, the farmers cultivate trees and plants to get money by selling it, the employment of loggers also related to these forests and the indigenous peoples also gain benefits by gaining food as well as medicines from it. This forest also fulfill the needs of wood and other products of the country.

sheep is a herbivore animal whereas grasshopper belongs to the class chordates but both of them feed on greens.  

if grasshopper and sheep feeding on a pasture land, i do not think both of them will have any impact on each other. however, the number of the species can make difference. since sheep feed on greens, there is a possibility there left no pasture land for the grasshoppers or they may get extinct.