Because there is an intermingling of two ecosystems, such as land and water, or forest and grassland, the edge between these places has greater biodiversity than either of the two ecosystems does.
The biodiversity here includes the species that are found in both of the ecosystems, as well as unique species that can only be found in the transition zone between the two ecosystem edges.
Examples of the Edge Effect
1) Thick Growth in the Woods
The USDA Forest Service states that, “… a mature forest can support a variety of life forms and several layers of vegetation, including shrubs, flowering plants, and trees,” which creates a diverse and natural ecosystem.
However, this diversity is not found in the edges of the forest, where the trees grow very thick and the area is sparse. This canopy is created by the tree branches, which overlap and cover the sun, preventing plant growth.
2) Diverse and Rich Grassland
Studies have shown that grassland diversity increases in areas that have a mix of grass, shrub, and trees.
The variety of plants and the different amounts of sunlight affect the habitat, from the species that are present to the number of bird species, which is why the transition area between barren and grassy lands is more diverse.
3) Edges of Ponds
Studies have shown that the edges of ponds have greater biodiversity than the middle. Fish and aquatic plants prefer the edges of ponds because of the variety of water depth, sunlight, and a better source of food.
Four to 20 times as many fish species can be found in the edges of ponds compared to the middle or center of the ponds.
4) The Forest-Grassland Transition
The edge between the forest and the grassland has greater biodiversity than the forest or the grassland alone. This is because the landscape has more opportunities for different species to find the right habitat.
The forest-grassland edge has more plants, more nest boxes, more small mammals, more fungus, and more unpalatable plants.
The edge between a forest and grassland gives rise to diversity in interesting ways.
5) Man-Made Structures
The edge of a man-made structure, such as a highway, is where insect communities thrive, like the dragonfly.
The edge of the highway is a habitat for butterflies and dragonflies, as well as other insects like bees, which benefit from the human disturbance of the area.
This is because people use the highway, and their movements, such as vultures, can affect the development of the area.
Types of Edges
In general, an edge is a transition between two interstices. One type of edge can be classified into two types of ecosystem. For example, the edge between a grassland and a forest is different than the edge between two different types of grassland, such as prairie and savanna.
The diversity of the area depends on the type of ecosystem it is. Different types of ecosystems can have an edge between them, and this causes a mix of diversity and a mosaic of different ecosystems.
For example, the grassland-forest edge has more plant species than either ecosystem has alone, so the grassland-forest edge is extremely diverse.
There are many examples of the edge effect, whether natural or human-made. The ecosystem and the biodiversity of the area can be affected by the environment around it, and the various landforms affect the natural rhythm of the surrounding ecosystem.
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