Wednesday 9 September 2015

Removing Water Primrose from the Cher

Since last Wednesday an Agglo Tours boat has been pulling out Water Primrose Ludwigia spp (Fr. jussie) along a 4 kilometre stretch of the river Cher. The work is being done in conjuction with the Anglers Federation. (Agglo Tours is a local authority for the city of Tours and surrounding communities, officially known as Tour(s)plus these days)

Water Primrose on the banks of the Vienne between the road and rail bridge at Chinon.
Viewed from the foot bridge it's like watching an abundant harvest being brought in. It's a result of the exponential growth of this North American invasive alien aquatic plant in the last few years. It is now preventing native plants from growing. In 2010 the Anglers Federation sounded the alarm with a report to the Prefecture (the equivalent of County or Shire). The Prefecture acknowledged the situation but did nothing with the data provided. Finally it was the Agglo that intervened, first under their climate change policy and then applying the EU Freshwater Directive. Last year the Agglo bought a boat and barge for €180 000. This year the equipment is being used to gather up the Water Primrose at 7 locations along the river between the weir at Savonnières and the railway bridge at Tours. The locations are those frequented by anglers or riverside residents. The 4 towns on this stretch of river are Savonnières, Ballan-Miré, Joué-lès-Tours and Tours. The Water Primrose will be disposed of at the municipal composting station at Chanceaux sur Choisille.

 Water Primrose, making an impenetrable mat for animals and native plants.
The Anglers Federation is totally behind the eradication of this weed and there is no question that there is a need for the intervention to control it. Volunteer members work on the bankside to pull the plant out by hand then it is loaded onto the boat which ferries it out to the barge. The Anglers Federation have given €60 000 to the project. They note that nearly 60% of the river bank has been invaded by the plant. They recognised that the state would have had difficulty managing the task alone, both financially and in terms of other resources such as labour, so they have taken on some of the responibility. They have previously dealt with 7 kilometres worth of riverbank in 10 communities, where 80 tonnes of Water Primrose have been removed.

The Anglers Federation hope that by setting an example they will encourage other organisations with a vested interest in the river to join in the programme of destruction. They say they will only stop once the plant is beaten, but as it grows and multiplies all the time they look to be in it for the long haul.

There is an article in the local newspaper about this project. It's in French of course, but worth looking at for the pictures even if you don't read French.
Loire Valley Nature: A photo of Ivy Broomrape Orobanche hederae has been added to the Broomrape Orobanche spp entry. This is a confirmed identification for a species in a difficult group.
A photo of a hypochromatic Bee Orchid Ophrys apifera has been added to the entry for this species. The flowers are white and yellowy green because they have a mutation which has caused the pink pigment to be missing.
An entry for Identifying and Surveying Mosses and Lichens has been started. This will be added to over time.
A photo of Honey Bees foraging in a sunflower crop has been added to the Eurasian Honey Bee Apis mellifera entry.
A photo of the striking red and black flower longhorn beetle Stictoleptura cordigera on Wild Parsnip has been added to the entry for the beetle species. These are reasonably large beetles and with their black heart shape on red background pattern I usually can't resist photographing them.
A photo of the pale and pretty Heath Spotted Orchid Dactylorhiza maculata subsp. ericetorum has been added to the entry for this species.  These orchids are not all that common here as they don't like limestone or chalk.
An entry has been added for Yellow Brain Fungus Tremella mesenterica. This jelly fungus doesn't look much like a brain, but it does look like yellow jelly.


Le Pré de la Forge said...

"The Water Primrose will be disposed of at the municipal composting station at Chanceaux sur Choisille"....
So, indirectly, it is an abundant harvest.
Two nice pix... especially the impenetrable mat one...
the other, to the tourist or passer-by, would look very nice...
the damned plant is attractive...
that, unfortunately, is why it got into the garden centres in the first place!!

chm said...

Tim says, the damned plant is attractive..., so is its name in English! In French, not so much!

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