Explain the important of rock to man

now you can mark brain hope this

clearcutting reproduces a new even-aged stand by completely removing the mature stand.

clearcutting as a silvicultural treatment has several characteristics:

it causes a sudden environmental change

it removes the seed source from the regeneration area

the configuration of the clearcut may affect seed dispersal

it begins a new rotation

it will eliminate some pests that require forest cover

overall, it temporarily removes the forest cover, transforming the forest community and environment.

clearcutting followed by artificial (seeded or planted) regeneration has several advantages:

we can avoid delay in restocking the site

we can introduce a selected species, seed source, and genotype

we can control arrangement and spacing

we can achieve uniformity in the new stand

we can overcome the problems associated with securing sufficient natural regeneration.

the shelterwood method involves the removal of most of the mature stand at the end of the rotation, but a portion of the mature stand is left standing.   the shelterwood method serves three basic purposes:

to prepare the stand for production of abundant seed

to modify the environment in a way that promotes germination and survival of the selected species

to build up the amount and size of advance regeneration to ensure the prompt restocking of the new stand following overstory removal.

the shelterwood method involves a sequence of 3 cuttings:

preparatory cuttings: make the seed trees more vigorous and set the stage for regeneration. see our thinning page for more information.

establishment/seed cuttings: open up enough vacant growing space to allow establishment of the new regeneration.

removal cuttings: uncover the new crop to allow it to fill the growing space.

the residual trees in the shelterwood must:

be sturdy and windfirm

be able to survive exposure

flower and reproduce seed

be the best trees of the mature stand

keep in mind that the shelter trees must not occupy the entire site.   a void must be created in order to make room for the new regeneration. the amount of shelter to leave will depend on the following factors:

species characteristics (seeding and shelter requirements)

the number of cuttings in the cutting sequence (1, 2, or 3)

landowner objectives

the size of the area to be regenerated

the final removal harvest level required to be profitable

the shelter must be removed before it impedes the growth of the new stand or threatens its survival.

in the united states a public policy is an agreed upon way that our federal, state, or local government fulfills its responsibilities, such as protecting the rights of individuals and promoting the welfare of all the people. some public policies are written into laws by legislatures. other policies are contained in rules and regulations created by executive branches of government, the branches responsible for carrying out and enforcing laws.

the following are examples of public policies and the governmental agencies responsible for carrying them out.

school districts are responsible for making policies regarding student behavior and discipline. teachers and school administrators enforce these policies. state legislatures are responsible for making laws that place speed limits on drivers. police officers enforce these laws. city governments often adopt policies that prohibit people from operating liquor stores near public schools. city inspectors and zoning departments enforce these policies.

when people become aware of problems in their communities, they often want government to develop and carry out policies to deal with those problems. these may be problems for which there are

existing policies or laws that do not work well,

existing policies or laws that are not being enforced,

no policies or laws.

as a citizen of the united states you have a right to say what you think government should do about problems in your community. you also have a right to say what you think about problems in your state, the nation, and about international problems. you have the right to try to influence the decisions people in your government make about all of those problems.

to be able to participate effectively, however, citizens need to know which levels of government and which governmental agencies are responsible for changing, enforcing, or developing a specific public policy. for example, state legislatures may direct agencies to enact policies resulting from federal legislation. or, local governments may create policies in order to carry out responsibilities assigned to them through laws enacted at the state or federal level. additionally, as part of the process of developing and implementing policy, governmental agencies must determine if the new policy conflicts with existing legislation or policy.

this project is intended to you learn how to express your opinions, how to decide which level of government and which agency is most appropriate for dealing with the problem you identify, and how to influence policy decisions at that level of government. it calls for you to work cooperatively with others in your class and, with the of your teacher and adult volunteers, to accomplish the following tas

answer; (20%)percent