What are the three elements that changed the Mediterranean?

The Mediterranean region is relatively small compared with other regions. The basin is calculated to be only around 3,800 km long from West to East and 1,000 km from South to North which is less than 2% of the worlds surface area (Kerstin Sundseth, 2009). A landscape is how the surface of the earth looks like at a particular time and place. We find two types of landscapes which are the natural landscape and cultural landscape. The natural landscape consists of a series of natural forms (landforms), like streams, rivers, mountains and soils and their characteristics vary from one place to another. Human interference such as building dam in a river may change the landscape of that area, for example flooding which may lead to loss of biodiversity and ecosystems. Human activity may also increase the rate of weathering and erosion which by time these processes change the surface of our planet occurring by deforestation. In the past, in the Mediterranean Sea there was a demand for wood used by ships and fuel and over grazing to feed the goats and sheep, this led to an area from a woodland and turned into a garigue. Pollution is also another factor which increases the rate of weathering by adding sulphur oxide in the air which when it rains it changes into sulphuric acid thus dissolving the calcium of the rock which increases the rate of weathering (chemical weathering). Cultural landscape is land which is modified and changed for human interests, such as agriculture and buildings cities (National geographic, n.d.).

In this discussion, we will see how the main elements: which are climate, geomorphology and humans are changing the landscape of the Mediterranean region. Different climates around the world lead to the different types of landscapes result of different types of ecosystems and factors such as precipitation, temperature and humidity. Climate The Mediterranean is distinguished for its mild wet winters and warm to hot, dry summers with almost no rain during summer (Lionello et al., 2006). Climate is an element which shapes and help processes to occur and increases the rate for weathering and even force organisms and vegetation to adopt to that climate, due to the amount of precipitation, temperature and humidity (Roberts, Meadows & Dodson, 2001)
The Mediterranean is known for its dry summers and for it’s natural fires in summers and throughout evolution organisms and vegetation in this area, adapted to live and survive in this type of climate. Most of the plants which are found in this area are normally called ‘xerophytic’ which means drought resistance. The ever-green plants like the olive tree, carob and the oak are known as ‘Sclerophyllous’. They are able to survive since these plants contain small leafs (Mediterranean thyme), thick waxy cuticle found on the surface of the leafs or a thorn leaf like structure to reduce the rate of transpiration stream. The trees and shrubs in this region are also fire resistant which is known as pyrophytic, since its common to have wild fires during hot days in summer a perfect example of a pyrophytic tree is the holm oak (Waugh, 2009) The climate of the Mediterranean is changing thus leading the region to go to desertification, this is visible since drought around the region is increasing and trees are getting replaced by shrubs which are more resistant to heat and drought. In fact in Malta trees cannot grow naturally but all of recent trees are planted since to grow trees naturally the minimum of water needed is 700 mm per year and in Malta the average is 600mm. This is an indication of climate change and it is also shaping and changing our landscape and ecosystems (Quintano, A. Personal communication, January 10, 2016).

Geomorphology

Geomorphology is the study of landscapes which includes landforms and information regarding their purpose and how a typical landscape changed through time, for example how from a small stream turned into a valley (Huggett, 2007). Land is affected by two factors; plate tectonics and weathering. Plate tectonics is a theory which shows how plates moves on the surface of earth leads to changes. The region of the Mediterranean is a result of the movement of the plates. Around 220 million years ago all the continents were connected which made up a super continent called “Pangea. When these continents started to move away from each other a sea was formed which was called Tethys. In the tertiary era, another big upheaval occurred. After millions of years the continents kept drifting apart and this ancient sea started to become smaller. When the Alps started to form the Tethys sea around 5.6 million years ago it got stuck between the Africa and Eurasia, which led to the drought of the Tethys sea which by time it turned into a big dessert covered in salt until a natural wall formed by the Strait of Gibraltar around 5.3 million years ago broke which let water from the Atlantic Ocean flow into this basin after a long period of time without water (CNES, 2000)

Weathering is a process of how rocks break (Huggett, 2007), we find two types of weathering which are physical weathering and chemical weathering. The Mediterranean region consists of warm summers and supporting a big diversity of life which is formed from animals to plants. These two factors lead to three types of physical weathering which are the onion skin weathering (disintegration), biological weathering and salt crystal growing weathering. The onion skin weathering occurs when the rock heats up during a hot day in summer which leads the rock to expand from rays emitted by the sun. At night, temperatures fall, which leads to the shrink causing stress and fractures to the rock. As a result, the surface layer of the rock peels off in a process known as exfoliation. If this process keeps on going it will lead to fragmentation and decomposition of the rock, this kind of weathering is mostly found on the Northern part of Africa. As mentioned before the Mediterranean region is rich in life, leading to another type of weathering which is biological weathering, where organisms’ breakdown rocks for example a wild rabbit borrowing and the growth of roots in weak spots such as the bedding planes when the root grows it will crack the rock. Salt crystals weathering occurs when water moves slowly through fractured rocks contains ions, when it evaporates it leaves crystals behind. When the temperature is high these crystals will expand leaving fractures and pressure on the rock. We also find chemical weathering which occurs when carbon dioxide turns into a weak carbonic acid when rain is falling. When this droplet hits the rock, it will react with calcium making the rock weaker.

Chemical weathering can be also increased by humans’ activities (Waugh, 2009). It can be said that, when the rock is weaker or broken it becomes easier to be eroded away, which change the surface of the landscape and landforms such as slopes, scree and karstic landscapes are formed. Human agency Humans have been habiting this region for thousands of years and with their activity such as deforestation for wood, land for agriculture and for urbanisation this region has very small area left of original full climax. Agriculture was one of the biggest reasons of the landscape we have today such as, terraced fields on hills and low shrubs areas due to over grazing (Waugh, 2009). Since vegetation hold together the soil and deforestation occurred and is still happening the rate of soil erosion increases leading to places from deep soils into places with only pockets of soils, turning them into garigue or even steppe. Deforestation and overgrazing in the uplands leads to soil exposure. Soil exposure combined with torrential rains leads to erosion and as a result sediment is then carried in the rivers downstream thus the flow of river becomes sluggish. Sediment then settles along the river bed and sides. Consequently, the river
level rises flooding the area around the river (Conrad, E. Personal Communication, November 3, 2017). The Coastal areas are being affected by human activities and are being developed and urbanised mostly for commercial use, tourism and trade. This is leading of loss of ecosystems and habitats and putting endemic and indigenous creatures, such the Mediterranean monk seals. Dunes and sandy beaches are also being destroyed due to building roads and hotels next to the coast (Berado, 1999) We could say that the Humans are the most species in the history that changed and transformed this planet.

Conclusion

To conclude we can say that these three elements worked together hand in hand to make the Mediterranean region as we know it today and unique from other regions, by first geomorphological since of its unique history about how it formed and how weathering processes changed the surface of our planet. Secondly climate is an element which shapes and help processes to occur and increases the rate for weathering and even force organisms and vegetation to adopt to that climate, due to the amount of precipitation, temperature and humidity and also how climate change is effecting the growth of trees in the Mediterranean and even the Maltese islands. Finally, in the human aspect deforestation and urbanisation is a key problem which is shaping the landscape and having drastic effects on our environment and on other species which have been on this planet before us.