Introduction:The typical definition of eutrophication is 'decrease in the levels of oxygen in the water bodies due to effects of excessive use of chemical fertilisers.' This statement clearly tells us all about the cause of the problem of eutrophication.
Oak is a common wood, yet many people arenât aware that there are two distinct species â red oak and white oak. Between the two, there are only subtle differences when it comes to durability, hardness, and cost. Color and grain pattern are the distinguishing features that set red oak and white oak apart.
Oaks have spirally arranged leaves, with lobate margins in many species; some have serrated leaves or entire leaf with smooth margins. Many deciduous species are marcescent, not dropping dead leaves until spring. In spring, a single oak tree produces both male flowers (in the form of catkins) and small coon flowers. The fruit is a nut called an acorn, borne in a cup-like structure known as a cupule; each acorn contains one seed (rarely two or three) and takes 6â18 months to mature, depending on their species.