NATURE

 

Picture: busy bee.  

start > gb > nature > nature reserve "het zwin"

Knokke

Damse Vaart
Domain Ryckevelde
Leopoldcanal
Schipdonkcanal
NR town walls of Damme
NR fortress Saint-Donaas
NR Platte Kreek
Batreserve
Birdlife
NR Zwin

Nature reserve "Het Zwin"

This old nature reserve is not in Damme but in the neighbouring community of Knokke-Heist.  Since the history of Damme is closely linked to the Zwin, we can mention it also here.  And now and then we you can see one of the residents of the Zwin in Damme: the stork.

History of "het Zwin". 

If we have to stick an age to "het Zwin", then we can go back in time as far as we wish.  In the soil, traces have been found that take us back to the Eocene (begin Tertiary, roughly 30 to 40 milion years ago).  Let's keep it a little bit more contemporay and start with Tacitus, who described the landscape for Julius Ceasar.  The coastal area here was a vast and practically impenetrable freshwater marsh in which the tribe of the Morines ruled.  The Romans with their heavy equipment wisely stayed out of the swampy area.  Dunes separated the sea and the marshland. 

One very important event for the region was the seatransgression of Dunkirk.  It is most easily described as a series of massive invasions of the sea, flooding the lower lands during a longer period.  When the sea retreated, sediments were deposited that form the actual soil of the fertile polders. 

A first invasion took place in the 2nd century BC and was not radical.  The second one however (4th century), broke through the girdle of dunes more or less where the Zwin is right now.  The seawater streamed inland and reached a small place that would later become one of the largest seaports in the world: Bruges.  From the 8th century drainage started and slowly the sea was pushed back.  The third phase of the transgression (10th century) was of utmost importance for Bruges, which had already become a major trade town.  A storm in 1134 created a large channel that came very close to Bruges.  On this place, Damme was founded.  A canal was dug to link Damme with Bruges.  In the 12th century, drainage of the grounds restarted.  This created more land for farming but also narrowed the natural channel.  It even influenced the working of tide and the strength of the current in the Zwin.  Since the currents were less strong, more sediments were deposed which made the waterstream silt up which made Damme more and more difficult to reach for larger vessels.  As a result, in the 14th centuy the center of trade shifted more towards north, making Sluis more and more important. A last period of drainage happened at the end of the 19th century.  In 1872 the last piece of land was drained.  Up till that moment the sea still reached Sluis. 

A few historic data: 
* Sea battle of 1340: English king Edward III, sinks the French fleet at the mouth of the Zwin.
* 80-years war (1568-1648): the Spanish use the port of Sluis as a base against the Geuzen (religious warriors).  Spanish galleys rule the Zwin until 1604.
* The fall of Sluis (1604): Prince Maurits of Nassau captures Sluis and closes the Zwin, depriving Bruges of its link with the sea.
* 1811: Napoleon disembarks in Retranchement
* 1813: the harbour of Aardenburg is dammed and closed
* 1831: the sea battle at the Hazegrassluis. Two Dutch gunboats are put out of action by a single Belgian cannon.
* 1953: inundations in Zeeland cause hundreds of casualties.  After the storm, the dikes at the Zwin were made higher and stronger.

The Zwin at present

The Zwin is the only place on the Belgian coast where you still have the natural sequence of sea - beach - dunes - marshland - grassland.  This combination is the base for a large diversity of plant- and wildlife.  A still quite substantial girdle of dunes separates the nature reserve of the Zwin with the seaside community of Knokke (le Zoute).  This area is accessible for cyclists and stollers (stay on the paths though!).  The Zwin itself is partially located on Dutch and partially on Belgian territory.  It consists of a birdpark, a part of the reserve that is accessible to the public and a protected area (nesting grounds etc.).  The reserve has an acreage of about 150 ha. 

Flora

The composition of the soil in the Zwin is very variated: salty marshland and dry grounds.  A hard environment to survive, even for plants.  A number of species however are very well adapted and only thrive here and nowhere else in Belgium.
For the amateurs a number of plants you can find here:
- Marsh-daisy (Statice Armeria);
- Buck's-Horn Plantain (Plantago Coronopus);
- Sea Lavender (Limonium Vulgare);
- Black Saltworts (Glaux Maritima);
- Sea spurrey (Spergularia Media);
- Common seablite (Suaeda Maritima);
- Ragwort (Senecio Jacobaea);
- Sea wormwood (Artemesia Maritima);
- Pickleweed (Salicornia Europaea);
- Sea plantain (Plantago Maritima);
- Sea arrowgrass (Triglochin Maritima);
- Sea aster (Aster Tripolium).
- etcetera...

Birdlife

The Zwin is most known for its rich diversity of birds.  More than half of all the species recorded in Belgium can be found here.  The reasons for this are multiple.  Here you have a transition between sea and land housing both sea- as landbirds.  The sea deposits large quantities of food (plankton, molluscs, crustaceans,...) on a daily basis; the higher areas are an ideal nesting ground safe from predators and water.  You have to take into account that a lot of the birds are migratory birds, so their presence depends on the time of the year.  The most well-known flying friends of the Zwin are the storks (Ciconia Ciconia).  This beautiful big bird was extinct in the area but due to a successful breeding programme, they can often be noticed again.
For the amateurs some of the bird species you can see here:
- Avocet (Recuvirostra avosetta)
- Godwit (Limosa Limosa)
- Oyster-catcher (Haematopus Ostralegus)
- Various species of ducks and geese
- Coot (Fulica atra)
- Blue heron (Ardea Cinerea)
- Curlew (Numenius Arquata)
- Lapwing (Vanellus Vanellus)
- Herring gull (Larus Argentatus), Seagull (Larus Ridibundus)
- Various kinds of pigeons
- Skylark (Alauda Arvensis)
- Tern (Sterna Hirundo), Little tern (Sterna Albifrons)
- Fighting cock (Philomachus Pugnax)
- Redshank (Tringa Totanus)
- Cormorant (Phalacrocorax Carbo)
- Spoonbill (Platalea Leucorodia)
- Stork (Ciconia Ciconia)
- The number of birds of prey is rather limited to some types of owls and the locally common species. 



 Damme
 Den Hoorn
 Hoeke
 Lapscheure
 Moerkerke
 Oostkerke
 Sijsele
 Vivenkapelle

 

 

 

 

 

Hendrik De Leyn - www.damme-online.com