biologe

Blog and online journal with editorial content about science, art and nature.

Tag: geomorphology

Berlin Forest Grunewald and River Havel-Waterside

River Havel

 

The river Havel has its source in the Mecklenburg Lake Plateau and after 94 km flows in the area of the border between the federal states Brandenburg and Sachsen-Anhalt into the big river Elbe.

Havel runs besides the already mentioned states Brandenburg and Sachsen-Anhalt also through Berlin, the capital city of Germany. On its way, the river passes several bigger and smaller lakes, which serve as water reservoirs, even in hot summers, in which many german rivers and lakes from low water levels.

In its most parts, Havel is navigable, and weirs and locks regulate water levels and water supply.

Historically, Havel since at least 928 of our Western calculation played importent roles as natural border and water route. Through the middle ages up to times of the GDR wetlands as important ecosystems were stepwise drained. In more recent times the protection of unique nature refuges is proceeding. In 2004 for example, the Naturfreunde Deutschlands and the German Fishing Federation elected the Havel area as River Landscape of the year.

In 2005 the Federal Agency for Nature Conservation (BfN) and the Nature Biodiversity Conservation Union (NABU began the land restoration to create refuges for rare bird species , beaver, river lamprey, otters and other animals and plants.

The footage of my video was captured close to the bathing beach area „Lieper Bucht“. Visible are the Havel islands Lindwerder and Schwanenwerder as well as edges of the forest area „Düppeler Forst“.

River Havel and Forest Grunewald in Berlin, quadcopter footage. Copyrights Stefan F. Wirth, December 2018. Please like my video also on youtube, in case you like it.

 

Forest Grunewald

 

Adjacent to the Lieper-Bucht area, the huge urban forest Grunewald extends over 3000 hectare between the Berlin districts Charlottenburg and Zehlendorf.

It was elected as Forest Area of the Year by the Union of German Foresters in 2015. The Grunewald ecologically has a specific mosaic of ecosystems: heathlands, neglected grasslands, dunes, dandpits and marshlands. They all bear a remarkable biodiversity of rare animal and plant species.

Geomorphologically the Grunewald area was formed by galcio-fluvial processess during the Weichselian glaciation , which endet about 11600 years ago. Glacio-fluvial sands cobver the area in layers up to 20 meters and more.

The footage of my video also shows the so called Grunewald Tower. The memorial for the German Emperor  William I was planned in 1897 and finally built up by the architect Franz Schechten. The tower was finally inaugurated in 1899 and renovated between 2007 and 2011.

The footage was captured with a DJI Mavic pro quadcopter in mid December 2018.

 

 

Berlin, December 2018. Copyrights Stefan F. Wirth

Lake Teufelssee in Berlin as part of a glacial meltwater lead

Lake Teufelssee in the Berlin urban forest Grunewald is known since ancient times, but is even much older. This is unlike the adjacent hilly landscape, which is named Teufelsberg („Devil’s Mountain““, referring to the nearby lake). It represents an area of mounds of rubble, built up with debris of the destroyed Berlin after the Second World War. Teufelssee („Devil’s Lake“) however is part of a glacial chains of lakes, a result of a supraglacial stream from the period of the Weichselian glaciation.

Air-view footage of lake Teufelssee in Berlin. Copyrights Stefan F. Wirth, please like my video also on youtube,in case you like it.

 

Geomorphology of Berlin, lake Teufelssee and glaciofluvial sands

 

Berlin itself represents geomorphologically a push morain from the Weichselian glacier times (until 11.600 years ago). This until today explains the uniform and scarce vegetation in and around Berlin, which is due to specifically sandy ground conditions. Sand layers with a thickness of at least 20 m date back to glaciofluvial sands, being a result of the advance of a glacial tongue.

 

Vegetation and climatic zone

 

The stock of trees in the Grunewald area is dominated by oaks and pines, being well adapted to this ground composition and the Berlin geomorphology. The climate of the Berlin area is characterized as part of the temperate climate zone in the transition between maritime and continental climate. Aspects of the continental climate are predominant, which is why snowy winters as typical for the Southern parts of Germany are rare.

Instead winters are often very cold and with low precipitation unlike the hot summers, where most rainfall occurs. The winter 2018 to 2019 is following an unusually warm summer with long periods of heat and without rainfall. As a result, water bodies Germany-wide carried less water than usually. But in which intensity lake Teufelssee was or is still concerned is unknown to me. Differences to former years are not obviously visible.

 

Berlin recreation areas and the ancient origin of the term „devil“

 

Teufelssee and Teufelsberg represent local recreation areas and offer enthusiasts and families with children a popular playground in summer, and in case the lake is frozen, also in winter.

The appearance of the German word for „devil“ in Teufelssee and Teufelsberg is assumed to refer to an ancient place of worship in this area.

 

Copyrights Stefan F. Wirth, Berlin December 2018