Practical Ecology

Nature Switched On

 

 

 

 


in the Pyrenees  the first 10 years

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>> 2009 Apr  9
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                         a   S T A M M E R  project              

2009 March 27 to 29, Friday to Sunday


We had some welcome rainfall this weekend. It was a light rain but it fell continuously over a period of almost 12 hours and amounted to about 10 litres. This meant a test case for the roof with the recent load of soil and (temporal) straw. If these layers absorb all this water (what I think they mostly did), the whole roof will have to carry a 500 kg extra.

 


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After the rain.
Looking north-east.
Sunday 15:59

 

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This weight and the roof in general have recently been the focus of some worrying. What has happened is that gradually, and without us noticing until somebody told us, the strawbale walls are showing an inclination to the south-west. We are talking about 2 to 3º and this is not catastrophic of course but it is clearly visible on the photograph on the left. The important thing is that it mustn't get worse.


There are a number of possible causes:

- the irregular shape and weight distribution of the roof
- the long overhangs to the south
- unbalanced tensioning of the cordstraps
- difficult angles in the wall layout (the south wall was originally designed as a rammed earth wall)
- insufficient connection between the horizontal layers of straw with the used bamboo sticks

Corrections are probably difficult to make. I have loosened the white cordstraps on the south side and tensioned the ones on the north side. I also installed three braces under the southern overhang. These direct some of the weight of the roof towards the south wall and at the same time correct another problem: the overhang had substantially lowered under the weight of the soil. A collection of heavy stones was collocated on the east corner of the roof to compensate for the weight of the overhang.
Time will tell what the overall effect of all these countermeasures will be. For the moment we will closely watch the inclination angle. After two weeks with the soil load (and the recent rainwater) on the roof the inclination doesn't seem to be affected, which makes us optimistic.

 

 
The white cordstraps clearly indicate an inclination to the right.
Photograph taken on 22 March 16:52
 
3 extra braces under the overhang.
Looking north.
Photograph taken on 22 March 16:47
 
After installing the braces (with the help of a car jack), the roof line doesn't show any substantial dip.
Looking north.
Photograph taken on 22 March 16:28
The east corner with 9 heavy stones on the roof.
Looking east.
Sunday 12:06
 

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As mentioned at the beginning, the rainfall on Saturday night was a nice test for the roof. The day before I had installed a provisional rainwater harvesting system. It takes the water from the roof to the ponds by gravity through a 150m long hose of polythene. The idea was to make use of my water pump and use the same hose to transport water in the opposite direction and irrigate the vegetable garden and fruit trees with water from the ponds. But the pump didn't have sufficient power and I will have to buy a more dedicated pump. I made the error of adjusting the whole system to this deficient water pump, that is buying 20mm diameter hoses and connections suitable for this pump. But to avoid clogging, a wider diameter (30mm)would have been preferable.

 

 


 

After the rain of Saturday night I didn't detect any puddles on the roof so I suppose some water will have reached the pond but probably most of the 500 litres will have been absorbed by straw and soil.

 
  The temporal straw flakes on the roof, heavy with rainwater.
Sunday 12:02
Rainwater outlet (PVC) connected to rainwater harvesting system (PE).
Sunday 12:09
 

 

 

Faucets to divert water from the ponds to vegetables and fruit trees.
Sunday 11:41

Water still clear in the upper pond after the inlet of rainwater.
Sunday 10:59
 
 

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Straw is abundantly used as mulch in the vegetable garden. I also used straw to fill up the mulch basins around the fruit trees. The basin walls were sown with White clover (Trifolium repens 'Huia') and Bird's foot clover (Lotus corniculatus) to provide for nitrogen fertilization.

I planted potatoes (early; 'Jaerla') under a mulch layer of 30 cm. In theory we will just have to pull up this layer to harvest the potatoes in summer. The same afternoon I saw a potato I had just thrown on an improvised compost heap because it started to rot and it was immediately attacked by mice...

 

 

 

 

 

 

 

Mulch basin with a diameter of 2m for a Kaki tree.
Looking north-east on the lowest terrace.
Sunday 11:44

White clover is also sowed in most vegetable beds. Here massively germinating in a bed of perennial Welsh onion (Allium fistulosum; not germinated yet).
Sunday 11:29
 

 

 

 


Mice nibbled at this discarded potato.
Saturday 14:53
 

Potato planted under a bed of 30 cm straw.
Saturday 15:00
 
 

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The growing season has just begun but some of the hazards that unnerve the gardener have already presented themselves. It is precisely straw that can have some adverse side effects. One of them is the obstacle it can form for the earth to radiate its warmth to plants at night, which are in this way more exposed to frosts. This is exactly what happened to 3 kiwis whose leaves didn't survive a light frost. I hope the stalks did.

 

 

 



 

 

Exceptionally early and having no problems with any frost is this Buffalo currant (=Clove currant; Ribes odoratum=R. aureum). It has a very pleasant spicy fragrance that permeates the whole garden. In the Netherlands it is nominated for an official neophyte as it is spreading naturally, partly because of climate change.


A Kiwi plant spreading joyously its leaves...
Photograph taken on 21 March 9:20

Leaves and flowers of the Buffalo currant are weeks ahead of other Currants.
It is often grown for its scent and beautiful colours in spring and autumn, and less for its berries with many pips.
Sunday 11:36
..and one week later, after some light frost.
Saturday 14:56
 

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The almost weekly inspection on the bulb front: on many places but in few numbers come the Grape hyacinths (Muscari neglectum). Very promising is the appearance of Gladiolus illyricus on many new places; not completely spontaneous because I helped the reproduction somewhat, sowing some harvested seeds last summer. Completely spontaneous is the proliferation of the Lady orchid (Orchis purpurea) which is appearing also on many new places.

 
Grape
 hyacinths.
Photograph taken on 21 March 17:02
Dozens of emerging Gladiolus illyricus on the central terrace.
Sunday 10:38
   
 

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Of the 10 planted Wild tulips (Tulipa sylvestris) 9 started to flower. They have got a nice smell and apparently attract the first bees.

An intriguing spectacle is the emergence of Turk's cap lily (Lilium martagon). Only one specimen (the bulbs are quite expensive) but one  plant can have up to 50 flowers and the seeds are dispersed by the wind so perhaps the reproduction is prolific. It is native in Aragon in the higher Pyrenees on relatively humid soil.

 
Tulipa sylvestris with a honey bee.
Friday 15:19
 
  Lilium martagon.
Sunday 13:52
 

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The Creeping Cinquefoil (Potentilla reptans) started to flower on relatively dry areas.
In the pond Marsh marigold (Caltha palustris) showed its flowers but its leaves are remarkably undersized, probably an indication of the poor nutrient conditions of the (rain) water.
Sparganium erectum has extended its territory in the pond, probably with broken-off pieces of rhizome.

 

 

 

 

 

 

I detected about 10 plants of a new species: Field Gromwell (Lithospermum arvense). It is an annual species, typical for disturbed, lime-rich soil. It  became so rare in the Netherlands that it was introduced on the red list.

 
Potentilla reptans on the central terrace. The graminea at the back isn't reed but the short Brachypodium retusum.
Looking north-east.
Photograph taken on 22 March 16:34
 
Caltha palustris in the upper pond.
Looking east.
Photograph taken on 21 March 17:06
 
Sparganium erectum spreading.
Saturday 15:13
  Lithospermum arvense on the central terrace.
Saturday 14:47

introduction
floristic catalogue
faunistic catalogue
contact
index
gallery 1: 2006-2012
gallery 2: 2012-
map
>> 2009 Apr  9
<< 2009 Mar 14

 

 

 


 

  

 

 

 

 

 

Latest revision on:  01/08/2018