Practical Ecology

Nature Switched On

 

 

 

 


in the Pyrenees  the first 10 years

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                         a   S T A M M E R  project              

2007 May 5, 6 & 7, from Saturday to Monday


 This weekend was going to be dedicated to the digging of a pond. Looking through the literature and internet it rapidly becomes clear that there is everything except unanimity about concepts and methods. To name just some polemic topics: while one resource advocates the use of rainwater, the other loathes it; one recommends letting the water settle down and not doing anything for two or three weeks, the other insists on putting oxygenating plants as soon as possible. I decided to go my own way, combine ideas from different authors and give nature itself as much protagonism as possible. These were my starting points:

  • The pond would be at the foot of the biggest terrace where it could collect the rainwater from that terrace and the one above it.

  • The main source of water would have to be rainfall. I will interfere in the beginning with some water from another ecologically healthy pond in order to inoculate the system and perhaps also to offer some relieve during very dry seasons 

  • The pond could be excavated in soil that had already be moved by a bulldozer one year ago so it would be relatively easy to dig without the surprise of big stones or solid rock while at the same time I would not have to face the destruction of a valuable vegetation layer.

  • The pond would be of a decent size and depth to facilitate a stable water ecosystem with a lot of big stones for additional temperature buffering.

  • An important area of the pond would be dedicated to marshland and shallow areas which usually harbours more wildlife than open water.

  • The pond liner would be protected by a 'sandwich' of two layers (4 cm) of fine sand.

  • The pond liner must stick out some centimetres in the vertical to inhibit the suction of water by the surrounding area.

 

 

 

 


WWW   NSO
   
  These SketchUp images illustrate the process with the first showing sizes and the position of some mayor boulders  and the next showing the situation after the filling with pebbles, sandy soil and water.The area at the front is a gently sloping shallow marshy part while the deepest part (80cm) is at the rear, surrounded by boulders to retain the somewhat steeper slopes behind them.

 

 

 

 

Cross section of the pond

   
 

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Armed with these premises I draw an outline of the future pond on paper and then on the field and started to dig. I had a long sunny weekend at my disposal and the soil was relatively loose and manageable, so on Monday morning the digging was done.

The next phase would be introducing a layer of fine sand (fortunately  a big pile of this material was left behind by the previous owner) and installing the pond liner (1.2 mm of synthetic rubber (Butyl, EPDM) at around 8/m2 at the local store) and another layer of fine sand and then filling the pond with a lot of river boulders and some sandy soil in order to create soft slopes and marshy areas. 

 
  The future pond in the eastern part of the terrain. Looking west.
Monday 12:34
 

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Rectification: with some embarrassment I must confess a serious mistake considering the beautiful birdsong we enjoy day and night that I commented on last week. I was already somewhat hesitating about its origin: the birds who produced the song were difficult to spot and when I saw something it looked quite brown with a reddish tail, not really the dark impression of a male blackbird. Also the fact that it sings in the middle of the night should have been an eye-opener: it is in fact a nightingale (Luscinia megarhynchos). In order to offer rehabilitation after the somewhat denigrating comments last week I offer here 1 minute of its beautiful song I recorded with my digital camera.

 
 
 

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Another visiting bird was the Rock Sparrow (Petronia petronia). It felt so at home that it decided to install its nest in a Juniper shrub at 15 metres from our caravan. It honoured its own name by always hipping on some nearby stones before entering its nest, beautifully camouflaged inside the shrub.

 
Nest of the Rock Sparrow in a Juniper shrub
Sunday 19:58
The Rock Sparrow always approaches its nest cautiously via some big stones
Saturday 12:54
 
 

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Needless to say that the terrain was offering a marvellous look at this time of the year, in which I can add 6 or 7 new species per week to the floristic catalogue. I hope to introduce soon a faunistic catalogue to do some justice to all the insects, birds and mammals.

 

 

 
Rosa sp, Euphorbia cyparissias, Papaver rhoeas, Helianthemum violaceum, Bromus diandrus  
Monday 11:06
Overview looking northwest.
Monday 11:11

introduction
floristic catalogue
faunistic catalogue
contact
index
gallery 1: 2006-2012
gallery 2: 2012-

map
>> 2007 May 12 
<< 2007 Apr  28

 

 

 


 

  

 
   

Latest revision on:  14/08/2018