Going with the flow

Anne-Louise Orange – Ryevitalise Programme Manager

Following the success in securing Heritage Lottery Fund money to support the development of our Ryevitalise programme, the team are now in place and working towards a Stage 2 application*.

The Heritage Lottery Fund’s Landscape Partnerships programme is for schemes led by a partnership of local, regional and national interests which aim to conserve specific areas of distinctive landscape character.

River Rye at Lower Locker, Snilesworth - copyright Liz Bassindale, HH AONB.

The Ryevitalise landscape incorporates the main upper Rye catchment, made up of the upper valleys of the Rye including the River Seph and the River Riccal. The Ryevitalise programme aims to protect and enhance the area’s natural and cultural heritage, resulting in a more natural, better functioning and better understood landscape.

River Rye in Duncombe Park - copyright NYMNPA.

We’ve got a remarkable abundance and variety of priority habitats and wildlife; a number of rare and priority species are strongly linked to the river valleys, including one of only three known UK populations of Alcathoe bat. The catchment is also a national hotspot for veteran trees – iconic and irreplaceable features of both our natural and cultural heritage.

River Rye - crow foot beds in the Vale of Pickering - copyright.

Ryevitalise projects will cover four themes:

  • River Riccal at sunset - copyright Rosy Eaton, Natural England.Water Environment, investigating aquatic habitats of the Rye and rare and threatened species;
  • Water Quality, working with land-owners and managers to reduce pollution;
  • Water Level Management, working alongside our delivery partners to harness natural processes to manage the sources and pathways of flood waters; and
  • Reconnecting People, improving the understanding of the river landscape by telling the story of its evolution and encouraging people to protect their heritage.

The new team – that’s me and Alex Cripps, Catchment Restoration Officer – are keen to hear from anyone with an interest in the Rye catchment. We will be consulting with partners, local landowners and wider communities over the coming months as we develop the projects we want to deliver, ensuring we incorporate peoples’ ideas and knowledge under the four themes. We look forward to meeting with/talking to as many people as we can as we develop our Stage 2 application.

Aerial view of River Rye and Nunnington Hall - taken by NEYEDC.

*The Stage 2 application will be submitted to Heritage Lottery Fund in the autumn of 2018.

Heritage Lottery Fund logo

Seas of Green

Simon Hirst – River Esk Project Officer

New Zealand pigmyweed (Crassula helmsii) was introduced to Britain from Tasmania in 1911. By 1927 it was being sold as an “oxygenating plant” for garden ponds and aquariums by Perry’s Hardy Plant Farm in Enfield. The first recorded occurrence of pigmyweed in the wild was at Greensted Pond in Essex in 1956. It spread widely and rapidly due to the increasing availability of the plant at garden centres and aquatic nurseries.

This non-native invasive plant is now listed under Schedule 9 of the Wildlife and Countryside Act 1981. It is an offence to plant or otherwise cause this species to grow in the wild. The plant is now also banned from sale in the UK, which is a significant environmental step forward.

Crassula helmsii - copyright NYMNPA.

Crassula helmsii grows around the damp margins of ponds and in water up to three metres deep. It starts as a small light green tussock on sediment. The tussocks grow and spread rapidly to form a dense mat of vegetation. Severe oxygen depletion can occur below dense growths. The dense mat out-competes all other aquatic vegetation, eliminates native flora and creates a poorer ecosystem for invertebrates and fish.  The plant grows throughout the year and has no dormant period. Thankfully the pigmyweed does not produce viable seed in the UK but it can re-grow from small stem fragments.

New Zealand pigmyweed is very hard to eradicate when it has become well established. The plant is tolerant of shade for long periods, tolerant of frost and dessication, and it cannot easily be tackled by any existing method of environmental control.

Recently New Zealand pigmyweed was discovered growing in two ponds in Bilsdale which are both adjacent to the River Seph. The river is one of our key wildlife corridors. Working with our Apprentice team, we came up with a plan to carry out a programme of control which will hopefully result in eradication of this invasive plant.

One of the ponds in Bilsdale covered in Crassula helmsii - copyright NYMNPA.

One of the ponds in Bilsdale covered in Crassula helmsii - copyright NYMNPA.

We’ve covered the ponds with black plastic sheeting in order to prevent sunlight reaching the pigmyweed. This will prevent the plant photosynthesising, and should eventually kill it. The unsightly but purposeful plastic sheeting will need to be left on top of the ponds for six months, and we will be reviewing the situation next Spring!

Depriving the Crassula helmsii of light - copyright NYMNPA.

Depriving the Crassula helmsii of light - copyright NYMNPA.

Temporary black plastic over the top of one of the ponds - copyright NYMNPA.

Along the riverbanks

John Beech – Land Management Adviser

A couple of weeks ago a demonstration event was held in Bilsdale, organised through the new (Yorkshire) Derwent Catchment Partnership*.

The event, kindly hosted by Mr and Mrs Lang, was held in order to share knowledge and experience when it comes to managing watercourses for wildlife benefits.

Demo Day 9 September 2015 - copyright NYMNPA

Initial discussions between landowners and Partnership organisations focused on  practical application. The Wild Trout Trust led on the practical demonstrations in the river. This included realigning some of the woody debris found in the channel in order to re-direct water flows. There was a lot of talk around the question of responsibility for trees in rivers, and when and where to remove or leave or realign them.

Demo Day 9 September 2015 - copyright NYMNPA

The practical demonstrations also included using natural materials to help stabilise banks in order to lessen erosion. One of the main issues with the Rivers Rye and Seph in Bilsdale is siltation which smothers river gravels and therefore inhibits spawning areas for fish with a knock on effect on fish populations. Riverside fencing and resulting buffer strips can have a significant effect in lessening agricultural run-off into a watercourse and so improve water quality. Creating 6 metre wide grass buffer strips along banks can not only help halt run off and help stabilise the banks with vegetation but also provide excellent habitat linkages adjacent to the river and so enhance connectivity along the river corridors running through a landscape.

Over this summer the National Park Authority has lead on another round of Himalayan balsam control, this time on behalf of the Partnership. This is the 8th year of this programme aimed at eradicating this particular invasive non-native plant at the top of the Rye catchment. Where the programme started, right at the top reaches of the the River Seph, the aim of eradication has almost been achieved, but repeat surveying and the pulling up of any individual plants that remain is vital to make sure this can be finally realised. Himalayan balsam can grow pretty much anywhere but it is particularly rife along watercourses where seeds are effectively spread downstream by the moving water. The main threat of the plant to a riparian habitat is that it tends to out compete native vegetation and then dies back in the winter leaving banks uncovered and subject to erosion.

Himalayan balsam (Impatiens glandulifera) - copyright NYMNPA

Enhancing the river for wildlife is a key goal for all members of the new Partnership. What is essential for delivery is the engagement of landowners and the identification of common objectives, and this kind of event can help with that.

*The Derwent Catchment Partnership includes the East Yorkshire Rivers Trust, Environment Agency, Forestry Commission, Natural England, Yorkshire Wildlife Trust, North Yorkshire County Council, East Riding of Yorkshire Council, City of York Council, Howardian Hills AONB, and the North York Moors National Park Authority.

 

Pink peril

Kirsty Brown – Conservation Project Assistant

Himalayan balsam (Impatiens glandulifera) - NYMNPA

Himalayan Balsam (Impatiens glandulifera) in the UK can be a contentious plant – some people like it and some people loathe it. From a water quality point of view, it’s bad news.

Now in the winter months the detrimental effects of the species are obvious on bare unvegetated river banks where the invasive plant has died back and where it suppressed other vegetation during the summer which could have stabalised the bank, and so the soil from the banks crumbles and slips into the water and chokes the river habitat.

Because of this, the National Park has been tackling Himalayan balsam in Bilsdale, in the west of the North York Moors, since 2008. It’s a long term task.

A targeted top-down approach is being taken which started with the River Seph in the north, with the objective of eliminating Himalayan balsam from the uppermost reaches of the catchment by repeat control over and over again, and expanding slowly downstream and onto the River Rye. It’s this targeted concerted effort that can make a difference as it is the abundant seed released each year and carried downstream that means the balsam is so prolific and recalcitrant.

Over the last seven years contractors, land managers, volunteers and apprentice teams have been tackling the plant. Hand-pulling and strimming have been the only methods of control used, due to the proximity to the watercourse. Permission from the land owners and land managers along the banks has been vital, and the local Bilsdale Beacon newsletter has been used regularly to keep the wider local community informed.

The work is proving effective – in 2014 only a few Himalayan balsam plants were found along the River Seph and were easily hand pulled by our apprentices, at the same time the banks are becoming revegetated with native meadowsweet and willowherb. This is very encouraging and makes the aim of the project to eradicate Himalayan balsam from the Seph catchment and the stretch of the Rye catchment that lies within the National Park, seem actually possible. The efforts over the past seven years have made great inroads into achieving this aim, but there is still work to do.

River Rye in Duncombe Park - where Himalayan balsam is being tackled through a Higher Level Stewardship agri-environment agreement

 

More invasives

Alex Cripps – Conservation Graduate Trainee

As well as controlling Himalayan balsam along the River Rye and River Seph in the west of the North York Moors, the National Park Authority is continuing to tackle invasive plant species in the River Esk catchment in the north of the Park too. We concentrate our efforts along rivers and watercourses because this is where invasive plants are most problematic. Increased sedimentation in the Esk caused by invasive plant species is particularly threatening for the important protected species found there like the freshwater pearl mussel.

Himalayan balsam control work has been going well over the last few years in the upper Esk catchment so this year work effort has moved downstream and is now being concentrated in the Sleights and Ruswarp area near Whitby.

There has been a lot of help from landowners and members of the public letting us know where the balsam is growing. With a big concerted effort from our Mussel Volunteers and local contractors, coordinated by Simon Hirst our River Esk Project Officer, a huge amount of balsam has been pulled up this season. It is really important to hand pull or strim the balsam early, before the seed pods develop, as the seed pods explode catapulting hundreds of seeds up to 8m from the parent plant.

Seeds are transported by waterways and can stay viable in the soil for a few years, so it is going to be important to continue monitoring sites every year. It usually takes atleast 2 – 3 years to eradicate Himalayan balsam at a site. The plant can also be controlled by spraying it with pesticide (using a pesticide approved aquatic use when working near water) but this method is only used for areas with a dense coverage of balsam to ensure we’re not affecting other plant species.

Japanese knotweed is another non-native invasive plant found in the Esk catchment. Like Himalayan balsam it too creates large monocultures, shading out other plant species. Japanese knotweed does not produce seeds but instead it spreads vegetatively and can regrow from fragments of stems or rhizomes. It’s incredibly tenacious. So it cant be strimmed or mowed because that will just spread the plant and this makes it incredibly hard to eradicate.

The best method of control is by stem injection, whereby stems are injected with a pesticide. This is obviously very labour intensive but it is a very effective method and does not affect non-target plants. Spraying Japanese knotweed using a knapsack sprayer is also another method our contractors use, but this can only be done on a dry, calm day.

Hand pulling HB