Attritional conservation

Seas of Green – UPDATE

Last September we reported on the installation of black plastic sheeting on a couple of ponds in Bilsdale with the aim of shading out the non-native invasive plant species – New Zealand pigmyweed Crassula helmsii – which was accidentally flourishing there. The idea was to give the plant a taste of its own medicine by depriving it of light.

By two months the pigmyweed was becoming etiolated – pale and weakened due to the loss of sunlight – indicting the sheeting was effecting growth.

Crassula helmsii two months after black plastic sheeting applied. Copyright NYMNPA.

The sheeting was left on the two ponds through the winter and spring, and a second survey was carried out this July. The sheeting has killed off 100% of the pigmyweed that was covered, however pigmyweed plants remain around the edges of the ponds, where it was difficult to install the sheeting due to the surrounding vegetation and irregular shape of the pond edges.

One of the ponds covered by the black plastic sheeting July 2017. Copyright NYMNPA.

Contrast between the remaining Crassula helmsii at the edge of teh pond and under where the sheeting where the plant is now dead, July 2017. Copyright NYMNPA.The National Park Authority’s southern Apprentice Team will be spraying off the pigmyweed round the edge with a herbicide. The sheeting will remain on the ponds until at least late autumn to try to finish off this invasive species once and for all in this location, allowing the biodiversity of the ponds to recover.

Other non-native invasive plant species

New Zealand pigmyweed is one of the most common non-native invasive plant species found in England, along with Common rhododendron Rhododendron ponticum, Himalayan balsam Impatiens glandulifera, Japanese knotweed Fallopia japonica, and Giant hogweed Heracleum mantegazzianum. They were all introduced into the UK as garden plants. All of these species are present in the North York Moors to some extent, and work continues to control these particular plant species, without natural competition and predators, that can have such a detrimental effect on the area’s habitats and water quality.

We’re grant aiding the removal of rhododendron from important Plantation on Ancient Woodland Sties (PAWS), to help let in the light and give native ground flora a better chance of survival. Rhododendron can harbour the Phytopthora ramorum pathogen which is a great threat to forest species such as larch.

Himalayan balsam can be pulled out/cut down by hand but this needs to be done before the seeds are setting (August/September) because one shake of a plant can release 1000s of seeds that can travel up to seven metres potentially creating 1000s of new plants. Repeatedly removing the plants from a location before they can seed over a number of years will eventually mean this annual plant no longer regenerates there.

Japanese knotweed is trickier to tackle because it needs to be treated by careful herbicide injection. Repeated treatment can kill the rhizome which is so effective at spreading. The accidental breaking up of live rhizomes can spread the plant expediently. Careful disposal is vital.

We’re currently making best use of four years of funding from Yorkshire Water to tackle Himalayan balsam and Japanese knotweed along the banks of the Rivers Esk, Rye, Seph and Seven, through whole catchments and sub-catchments starting at the top. Both species are particularly menacing to river habitats as they out compete evergreen native species and die back in the winter leaving banks bare and prone to erosion increasing the sediment loads in the water.

Giant hogweed isn’t quite so common as the other plants in this area. It can be dangerous to deal with because its sap can burn skin so it needs to be treated with care. It can be cut down or tackled with herbicides, but like all non-native invasive species repeat control will be necessary to achieve eradication at a site.

There are lots of initiatives now across the country to address the threat of these out of place species, it can sometimes seem overwhelming but concerted repeated local efforts can have an effect.

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

Revitalising the Rye

Tom Stephenson, External Funding Officer

There must be something in the water in the North York Moors, having just started delivering the This Exploited Land of Iron Landscape Partnership Scheme, the National Park Authority and its partners* have also been successful at the first stage of securing a further £2 million of Heritage Lottery Fund money to develop our next Landscape Partnership SchemeRyevitalise.

The River Rye and its tributaries rise on the moorland of the North York Moors, flowing through fast and clear upland becks that carve out steep sided dales until the land flattens and the river slows and broadens taking on the character of the undulating Howardian Hills and the flat lowlands of the Vale of Pickering. The Ryevitalise Landscape Partnership Scheme under development will help appreciate and enhance the Rye’s verdant landscape and clear waters which have been prized for millennia for their beauty and tranquillity resulting in a more natural, better functioning and better understood landscape.

Planned projects will cover four themes:

  • Water Environment, looking at 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 helping people to protect their heritage.

Without wanting to spoil the surprise of future blog posts, below are just some of the particular issues we are aiming to address through Ryevitalise scheme projects if we’re lucky enough to be successful in our Stage 2 application due in October 2018.

The wet…

Water is the major theme of Ryevitalise. Through the Ryevitalise scheme, from the high moorlands to the lowland wetlands, we will identify priority areas of riparian habitat for restoration to ensure existing high-value habitats (and their species) are in positive management and can act as nodes from which to extend outwards by creating ‘stepping stones’ and connections between these habitat sites.

Wetter still, we will assess the geomorphology and key features of the aquatic environment and target areas where aquatic habitats could be improved by creating changes to the channel through creating gravel bars, by placing debris to create slacks or by making changes to river bank profile. This work will include a survey of the habitats and species of the oxbow lakes in the lower Rye, and also the collecting and analysis of sediment cores to look for valuable paleoecological data which might shed light on how the local landscape formed.

The dry…

We have previously reported on the problems that fluctuating water levels in the River Rye
in Duncombe Park has on the White-clawed crayfish, the only native crayfish in the UK, White-clawed crayfish - during 2016 rescue in Duncombe Park. Copyright NYMNPA.which is suffering from a “perfect storm” of threats. Ryevitalise will prioritise protective measures for the existing population and carry out a feasibility study to identify where potential local ark sites might be located. Ark sites for White-clawed crayfish would allow populations to become established in isolation, separated from the threat of non-native crayfish and the crayfish plague they can carry.

The small…

Alcathoe bat. Copyright Cyril Schonbachler.One of the Rye catchment’s smallest inhabitants is the Alcathoe bat. Relatively new to science, having been first identified in 2001 and only recently becoming the latest addition to the UK bat family, this little creature has only been found at two other sites in the UK so far. Ryevitalise will seek to establish a deeper knowledge of where colonies of the Alcathoe bat and other key bat populations are, along with the requirements to support their survival.

The tall…

At the other end of the size spectrum and intrinsically linked to bats are some of the Rye catchment’s largest residents – its ancient and veteran trees. The area is a national hotspot for these giants that not only give an air of majesty to the landscape as living witnesses to history but also provide important habitat for many invertebrate species as well as providing important roosting sites for Rye bat populations.

The old…

Not only is the Rye catchment home to iconic built heritage like Rievaulx Abbey, Rievaulx Terrace, Duncombe Park and Nunnington Hall but it also contains a wealth of less obvious heritage that traces vernacular land use and tells the story of the working River Rye. Working with local history groups, Ryevitalise will record the remaining evidence of man’s relationship with the river over the centuries, surveying and recording the traces of the former agricultural and industrial settlements along the river banks. Accurate 3D models will be produced of the principal remaining watermills, iron working sites, water races and leats. Essential conservation and consolidation work will be identified from the surveys carried out.

The new…

Meanders in Rye near Sproxton - can see the water crowfoot beds within the river, September 2016. Copyright North East Yorkshire Ecological Data Centre.Like a lot of watercourses, it is not practical to access the river in its entirety at ground level. So as part of the Ryevitalise scheme an Unmanned Aerial Vehicle flight will record the entire 50km main river from its moorland origins all the way downstream to where it
meets the River Derwent. This will produce an invaluable record and will provide an insightful journey along the river for local communities, highlighting how this vital artery connects them all. Tailored sections of flight data will be made freely available to local schools, businesses, and community groups as a community resource; it will also form part of the scheme’s wider education programme.

We are all really excited about the next steps in developing the Ryevitalise scheme; the opportunity to make the most of the wealth of habitats, species and history surrounding the river; the potential to make a lasting difference to this wonderful landscape, and the chance to create a real splash.

HLFNL_2747

* Partners currently include East Yorkshire Rivers Trust, English Heritage, Environment Agency, Forestry Commission, Howardian Hills AONB, National Trust, Natural England, North Yorkshire County Council, Ryedale District Council, Woodland Trust, Yorkshire Wildlife Trust, as well as local communities.

Patience and perserverance

We’ve launched a new concerted effort against two of the most threatening non-native invasive plant species in the North York Moors, bolstered by funding from Yorkshire Water over the next four years. We’re chasing down Himalayan balsam (Impatiens glandulifera) and Japanese knotweed (Fallopia japonica) in the River Esk and River Rye catchments.

As well as damaging existing ecosystems and decreasing diversity, both these species tend to overwhelm other plant species along river banks and the danger from this is that during the winter when these non-natives die back the banksides are left bare of vegetation so subject to erosion which increases the sediment getting into watercourses and smothering the water habitat.

Both plants are vigorous growers and virulent spreaders. Himalayan balsam disperses thousands of seeds per plant through exploding seed pods that can propel the seeds metres from the original plant. If the plants are next to watercourses the seeds can be carried downstream to colonise new areas. Japanese knotweed spreads through its underground rhizomes which are so effective that all remnants of the plants need to be carefully disposed of because even a small fragment of rhizome if given the chance to re-root will form a new plant.

The only way to have any real impact on the plants is to tackle them systematically starting at the top of catchments and moving downstream, and repeating the control year after year to remove any vestiges of the plants. This new funding will provide a much needed boost to efforts made over the last few years.

Himalayan balsam (Impatiens glandulifera) - it has a sickly, sweet smell, pink flowers and a bright green hollow stem. It can grow up to two meters tall. Copyright - NYMNPA.

Japanese knotweed grows to around three metres tall and has large alternate heart shaped leaves and a characteristic zigzag stem covered in purple speckles. Its flowers, which appear in late summer, consist of clusters of tiny creamy-white flowers. Copyright - NYMNPA.

We’ll be surveying the current extent of the plants and then resurveying each year to monitor the effects of the control. We’re using tried and tested control methods – hand pulling the Himalayan balsam before it gets the chance to seed and propogate, and treating individual Japanese knotweed plants with directly administered glyphosate injections to carry the chemical down into the rhizomes. We’ll be using contractors and volunteers to carry out the work coordinated by National Park staff.

Controlling and hopefully eradicating non-native invasive species in an area takes a long time. Simon, our River Esk Project Officer, is a real enthusiast for non-native invasive species control because he sees the detrimental effects the plants have on the river environment and on his beloved Freshwater pearl mussels. He can see the years of attrition starting to pay off as native vegetation starts to recolonise sites where invasive species have been removed.

“The secret of success is constancy to purpose” — Benjamin Disraeli

Another crustacean crisis

Due to the sustained period of dry and hot weather recently an emergency rescue was required last week. We’ve blogged about similar operations in the previous two years, where the River Rye in Duncombe Park, Helmsley tends to dry up during summer months because of numerous natural sink holes. This leaves large numbers of fish and other water-dependent creatures stranded in shrinking pools. This year the crisis was particularly acute with no effective quantities of rain in the short term weather forecast.

The River Rye is one of only a few rivers in the North East of England which supports a population of White-clawed crayfish (Austropotamobius pallipes). The species are “Globally Threatened” according to the IUCN’s Red List of Threatened Species. They are the only native crayfish in the UK, and the majority of populations here are declining due to competition from introduced crayfish species, crayfish plague and water pollution.

So last week, alerted by the local fishing club, staff and apprentices turned up in force under the supervision of Simon our River Esk Officer (because he has a licence to handle the protected crayfish). Using gloves and buckets everyone scooped up what creatures they could and then relayed the buckets upstream to where the collected creatures were released back into the River Rye, safely above the sink holes. Over 500 White-clawed crayfish were rescued along with a variety of fish species – Bullhead (250+), Brown Trout (20+), Stone Loach (20+) and Brook Lamprey (50+).

White-clawed crayfish rescue, River Rye, July 2016. Drought conditions. Copyright NYMNPA.

White-clawed crayfish rescue, River Rye, July 2016. Drought conditions. Copyright NYMNPA.White-clawed crayfish rescue, River Rye, July 2016. Bucket collection. Copyright NYMNPA.White-clawed crayfish rescue, River Rye, July 2016. Cooling buckets to adjust water temperature before releasing. Copyright NYMNPA.White-clawed crayfish rescue, River Rye, July 2016. Releasing White-clawed crayfish (adult). Copyright NYMNPA.White-clawed crayfish rescue, River Rye, July 2016. Releasing White-clawed crayfish (female carrying young). Copyright NYMNPA.The translocated fish and White-clawed crayfish will inevitably recolonise the dried up section once the flows return to normal. The habitat here is ordinarily really good, the only down side being the disastrous disappearing water phenomenon during the summer.

The future for local White-clawed crayfish is somewhat uncertain. Further survey work is needed to establish the location of populations in the Rye, in order to help direct and prioritise effective measures to bolster the populations and make them more resilient to climate change risks like flash flooding and drought crisis. Rescue events may need to become a regularised occurrence.

We have no current evidence that the introduced Signal crayfish, which are such a threat to the White-clawed crayfish, have made it into the River Rye yet. Elsewhere in the country ark sites have been established, away from river networks, where populations of White-clawed crayfish can be introduced and kept in blissful isolation. If feasible here this could be a useful additional safety measure, but the first priority is keeping the Rye White-clawed crayfish populations in the river for as long as possible and conserving this particular element of our local natural heritage.

Catchment Trilogy – Part 3: wildlife wonderland

Gallery

This gallery contains 10 photos.

Alex Cripps – Catchment Partnership Officer I’m the Catchment Partnership Officer for the Esk and Coastal Stream Catchment and I love rivers! A big part of my role is surveying along the River Esk and its tributaries. I get to … Continue reading

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

 

Emergency rescue

Alex Cripps – Conservation Graduate Trainee

A couple of days ago Simon, Emily, Sam and I carried out an emergency crayfish rescue on the River Rye.

Crayfiah rescue  (1)

The Rye and the Upper Derwent (which both rise in the North York Moors) are two of only a few rivers in the North East of England which still support a population of the globally threatened White-clawed crayfish (Austropotamobius pallipes).

White-clawed crayfish are incredibly important as they are the only native crayfish in the UK, but unfortunately populations are declining due to competition by introduced crayfish species, crayfish plague and pollution.

The recent sustained period of dry hot weather had caused crayfish and fish to become stranded in small pools as the river dried up. Working under a Natural England licence we managed to collect the stranded crayfish and a number of small fish and move them upstream, using buckets and a small car, to a safer haven above the limestone swallow holes.

Crayfiah rescue  (2)Crayfiah rescue  (7)Crayfiah rescue  (6)

Along with the Environment Agency we will be continuing to monitor the river levels over the summer and will be ready to leap back into action if further rescues are required.

We recorded a quick film of a White-clawed crayfish that we’d just released (click on the image above). Look out for the juvenile crayfish in the top left corner about half way through – you can also see a small Bullhead darting about too!

 

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