Green tree reservoir
Encyclopedia
Green tree reservoirs consist of bottomland hardwood forest
land which is shallowly flooded in the fall and winter.
Studies have shown that the availability of flooded bottomland hardwood timber from late fall through early spring is critical to the breeding success of birds such as the mallard duck. The ducks are attracted to green tree reservoirs to feed on mast
such as acorn
s under the water, and invertebrates that live in there also. Many of these were founded in Arkansas, USA in the 1930s. Initially when these GTRs were first established it was thought that the flooding would enhance the trees' growth. However, recent information indicates these GTRs are increasing the mortality of trees and decreasing the trees' health there.
The hydrograph of flooding in the GTRs now shows a pattern that does not fully mimic nature. Floods in these areas where GTRs are made were typically flooded more in the late winter and spring. However, the timing of the floods are now developed around waterfowl migrations in the fall and winter. Also these flood events are frequently too long in duration and too deep. Water is also not removed in a timely manner, allowing the water to possibly become stagnant. Floods do not naturally occur each year. Flooding these GTRs repeatedly year after year may be one of the more deleterious management methods used. At least in one case at Felsenthal National Wildlife refuge located at the lower end of Arkansas near the Louisiana border, flooding is brought about by damming the Ouachita river. Water is impounded behind the lock and dam and is held at a minimum of 65 feet mean sea level (msl). Of course impounding water and holding it at the 65 feet msl has permanently killed thousands of acres of bottomland forest. The bottomland forest above 65 feet is subject to still subject of man induced flooding almost yearly and natural flood events that occur when there is excessive rainfall or there is a backwater caused by high water in the Mississippi River.
Bottomland hardwood forest
The Bottomland hardwood forest is a type of deciduous hardwood forest found in broad lowland floodplains along large rivers and lakes. They are occasionally flooded, which builds up the alluvial soils required for the Gum, Oak and Bald Cypress trees that typically grow in this type of biome...
land which is shallowly flooded in the fall and winter.
Studies have shown that the availability of flooded bottomland hardwood timber from late fall through early spring is critical to the breeding success of birds such as the mallard duck. The ducks are attracted to green tree reservoirs to feed on mast
Mast (botany)
Mast is the "fruit of forest trees like acorns and other nuts". It is also defined as "the fruit of trees such as beech, and other forms of Cupuliferae". Alternatively, it can also refer to "a heap of nuts"....
such as acorn
Acorn
The acorn, or oak nut, is the nut of the oaks and their close relatives . It usually contains a single seed , enclosed in a tough, leathery shell, and borne in a cup-shaped cupule. Acorns vary from 1–6 cm long and 0.8–4 cm broad...
s under the water, and invertebrates that live in there also. Many of these were founded in Arkansas, USA in the 1930s. Initially when these GTRs were first established it was thought that the flooding would enhance the trees' growth. However, recent information indicates these GTRs are increasing the mortality of trees and decreasing the trees' health there.
The hydrograph of flooding in the GTRs now shows a pattern that does not fully mimic nature. Floods in these areas where GTRs are made were typically flooded more in the late winter and spring. However, the timing of the floods are now developed around waterfowl migrations in the fall and winter. Also these flood events are frequently too long in duration and too deep. Water is also not removed in a timely manner, allowing the water to possibly become stagnant. Floods do not naturally occur each year. Flooding these GTRs repeatedly year after year may be one of the more deleterious management methods used. At least in one case at Felsenthal National Wildlife refuge located at the lower end of Arkansas near the Louisiana border, flooding is brought about by damming the Ouachita river. Water is impounded behind the lock and dam and is held at a minimum of 65 feet mean sea level (msl). Of course impounding water and holding it at the 65 feet msl has permanently killed thousands of acres of bottomland forest. The bottomland forest above 65 feet is subject to still subject of man induced flooding almost yearly and natural flood events that occur when there is excessive rainfall or there is a backwater caused by high water in the Mississippi River.