how long did a crusade usually take?

Usually, a crusade would take 2 centuries. An example of one is the Christians and Muslims fighting over holy lands. Even though an average crusade would last 2 centuries, if would normaly depend though, because some could last for only 1 year while others could last for millions of years so it all depends.

monitor contract compliance and results of forestry activities to assure adherence to government regulations.  

plan and supervise forestry projects, such as determining the type, number and placement of trees to be planted, managing tree nurseries, thinning forest and monitoring growth of new seedlings.  

establish short- and long-term plans for management of forest lands and forest resources.  

determine methods of cutting and removing timber with minimum waste and environmental damage.  

supervise activities of other forestry workers.

by the way there is no video here.