Dealing with the problems caused by invasive non-native species costs the British economy in excess of £1.7 billion annually (CABI report, 2010)

What are invasive non-native species?

When the Ice Age ended over 10,000 years ago the ice that covered most of Britain retreated northwards. Following behind this retreating ice were waves of plants and animals that slowly colonised Britain as conditions warmed up. These plants and animals arrived in Britain naturally as there was still a connection attaching us to the European mainland. However as the ice melted, causing sea levels to rise, the connection was flooded. This effectively stopped any more colonisation by species that couldn't cross the water. All these plants and animals – the ones that established themselves in Britain naturally - are called native species.

Man first arrived back in Britain about 8,000 years ago and virtually all new land animals and plants that have become established since this date have been brought here by man. These are all non-native species.

However, we must not think that all non-native species are bad – indeed it is only a minority that has serious negative impacts on our native British species, our health or our economy. These species we call invasive non-native species.

How do they affect us?

The problems caused by invasive non-native species affect us all. They are an economic problem and a well known threat to our environment:

  • Reduction in population of our rarest species e.g. the impact of American mink on water voles
  • Competition with native species e.g. Harlequin ladybird
  • Reduction in biodiversity - invasive plants often form monocultures, taking over an area so that they are the only plant growing there e.g. Rhododendron (Rhododendron ponticum)
  • Impact on our health e.g. skin blisters from Giant Hogweed sap
  • Increased risk of flooding, difficulties with angling and reduced fish-stocks due to clogged waterways
  • Reduction in food availability for insects - non-native invasive plants are often unpalatable to native herbivores like invertebrates
  • Reduction in oxygen and light levels in water bodies as plants spread over the surface

Once a species has been introduced the problems persist and escalate as the species spreads further. Many invasive plants can re-grow from just a tiny fragment of plant matter left in the soil or water meaning it is often impossible to clear an area of unwanted plants in one go - it can take years to put right.

For more infomation go to www.nonnativespecies.org

Of the UK species assessed, over 10% are thought to be at risk of extinction. In England there exists a list (Section 41 of the National Environment and Rural Communities Act, 2006) of all the species thought to be of principal importance to biodiversity conservation. This includes 943 species , all of which require action, and conservation prioritsation to prevent extinction. By focusing on landscape scale habitat conservation we hope that these species will benefit as a result.

 

Principal Species in Berkshire

In Berkshire we a lucky enough to still have a number of these rare and threatened species living among us. They include;

    Adder by Etienne Littlefair free to use e-mail littlefair.ehotmail.com when used
 Lesser Stag Beetle  Otter Adder 
     
 Marsh Frittilary Water Vole  Long-eared Bat 
 Hedgehog BBOWT Andy Fairbairn  
Lapwing
  Hedgehog  

 

Photographs:

Lesser stag beetle by Andy Fairbain/BBOWT,  Otter © Rob Appleby/AntIms, all rights reserved, Adder by Etienne Littlefair, Marsh fritllary by BBOWT, Water Vole by Wildlife Trusts, Long-eared bat by BBOWT, Lapwing © Steve Mendham/ Steviepix 2011, Hedgehog by Andrew Fairbairn.

 

 

In 2013 the UK's wildlife organisations joined forces to undertake a health check of nature in the UK and its overseas territories. They found that:

  • 60% of the UK's species have declined over the last 50 years
  • Of the 6,000 species assessed, more than one in ten are thought to be under threat of extinction in the UK
  • Our ability to monitor the state of nature, and therefore respond, is hampered by a lack of knowledge
  • What we do know about the state of nature is often based upon the efforts from dedicated volunteers
  • Climate change is also having an increasing impact on nature in the UK

There have been a further two triennial reports since then. Click here for the most recent report.

Different habitats support different species, occur in different conditions and can serve many different purposes. Each therefore requires a different management prescription, built on baseline evidence gathered about the habitat and species within it before work commences. Monitoring and evaluation of practices helps ensure that work is having the desired effect and that habitats are protected, enhanced, expanded and safeguarded for the future.

In the UK 45 habitats have been identified as a priority for conservation, 15 of these are found in Berkshire, and can be categorised into the following groups:

Urban

 Towns and villages often contain areas very rich in wildlife, much richer in fact than intensively managed countryside. There are not only diverse parks and gardens, but also remnants of ancient natural systems (such as woodland), pre-industrial landscape (such as meadows) and naturally seeded areas on disturbed ground, which are unique to settlements.

All of these areas harbour wildlife and provide much more opportunity for contact between people and nature than many parts of the countryside.

Grassland

There are 3 different types of priority habitat grassland in Berkshire:

  • Lowland Meadows
  • Lowland Dry Acid Grassland
  • Lowland Calcareous Grassland

Grasslands are rich, diverse habitats supporting a wide range of plants and animals. They have very high conservation value in terms of contribution to overall biodiversity but also have significant aesthetic, historic and recreational value.

Woodlands

Woodlands represent the greatest area of any priority habitat in Berkshire. They cover 18,000 ha of which 9,160 ha (7% of the county) is priority habitat. Woodlands have been well recorded over the last few centuries and are an integral part of our cultural heritage. They vary from the wooded valleys and wet woodlands of the river corridors to traditional Hunting Forests and parkland.

Windsor Great Park is an internationally important site, which deserves special mention for the sheer number and age of its veteran trees, some of which date back to the time of William the Conqueror. The park holds more ancient oaks than Belgium, Luxembourg and the Netherlands put together. There are further large estates and associated parkland throughout the county and this habitat adds to the local distinctiveness of county as well as supporting an important mosaic habitat for assemblages of invertebrates, birds and fungi.

There are three different types of priority woodland habitat in Berkshire:

  • Lowland mixed deciduous woodland
  • Wet woodland
  • Wood-pasture and parkland

Wetland

Rivers and associated wetlands contain habitats that support a rich variety of plants, mammals and invertebrates as well as often defining our landscapes. They are important in terms of both culture and recreation. The main river catchments that occur in Berkshire are the Thames, Kennet, Lambourn, Pang, Loddon and Colne, although there are great differences in gradients and geology within these lowland rivers. Ponds are another important habitat both regionally and locally and have now been added to the UK priority habitat list. These wetlands have a range of uses and, as a result, there can be conflicts between tourism, recreation, industry and biodiversity.

The priority wetland habitats found in Berkshire are:

  • Rivers (including Chalk Rivers)
  • Lowland Fens
  • Reedbeds
  • Floodplain Grazing Marsh
  • Eutrophic Standing Waters

Heathland

Lowland Heathland is a UK habitat of principal importance. The majority of the Berkshire heathlands are on the acid free draining soils and gravels of the south eastern edge of the county and at Greenham Common in West Berkshire. This has become a highly fragmented landscape and undergone significant decline with only a reported 2% of the county's heathland left, compared the national average of 5%. The principal threat, historically, has come from development pressure. However, the areas that remain support rich assemblages of invertebrates, specialist bird species and native reptile species. Thames Basin Heaths Special Protection Area (SPA) is an important network of heathland sites which overlap into Berkshire; they provide critical habitat for rare ground-nesting bird species. The SPA is protected by law and developments must mitigate any likey adverse affects on the SPA using Suitable Alternative Natural Greenspace (SANG) measures.

Orchards

Traditional Orchards are a long established and widely distributed habitat and make a significant contribution to biodiversity, landscape character and local distinctiveness across the UK. There are many regional variations on this theme, including apple, pear, cherry, plum, damson and walnut orchards. Although cobnuts (a type of hazelnut) and management varies from fruit tree orchards and has affinities with coppice woodland, they are also included in the definition of this principal habitat.

In Berkshire we aim to maintain the extent of our Traditional Orchards, but to do this we need to know where they are.The People's Trust for Endangered Species have used aerial maps to identify potential traditional orchards in Berkshire although this data requires ground-truthing to confirm its accuracy. The Traditional Orchard dataset is available as a GIS layer from the MAGIC website.

Hedgerows

Hedgerows are important for wildlife, landscape, farming and archaeological reasons. Hedgerows are important for butterflies, moths, farmland birds, bats, and dormice. They provide food and shelter and act as wildlife corridors for species including reptiles and amphibians allowing movement and dispersal between other habitats.

How are they threatened?

  • Agricultural development and monoculture have seen many hedges removed to increase agricultural yields.
  • Increase in urban development has seen tracts of hedgerows removed or dissected.
  • Inappropriate hedgerows often become 'gappy', and can result in the hedge degrading into a few isolated trees.
  • Use of herbicides, pesticides and fertilisers right up to the base of hedges, leads to nutrient enrichment and a decline in species diversity.

Further information about the value of hedgerows for wildlife, together with information on managing hedges can be found on the Hedgelink website. 

Nature is a complex, interconnected system. Population growth, increased living standards, technological developments, globalised consumption patterns, and climate change all put pressure on our delicate natural environment.

As much as 30% of the services we receive from the aquatic and terrestrial habitats in the UK have been recently assessed as declining, often as a consequence of long-term reduction in habitat extent or condition.

The previous global target to reduce the rate of loss of biodiversity by 2010 was not met. In England, species and habitats are still declining.

 

  1. Climate Change