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Non-introduction Policy

Shropshire has long had a non-introduction policy, following a conference organised by Shropshire Wildlife Trust in the early 1980s, where it was decided that planting and introducing things is not wise. This has been generally respected by most of the conservation organisations acting in the county and, as a consequence, ShropshiVenus Poolre probably has had far fewer deliberate introductions than most counties. It can be argued that this has helped to make Shropshire’s wildlife more natural and wild than in many other places.

Evidence shows that it is better to manage sites and habitats well and allow species to respond in a natural way, than it is to try to put plants and animals in the places where we think they should be. This is because attempting to maintain a natural ecosystem gives the species concerned a better chance of survival than simply putting them there. You can grow almost any plant in a carefully tended piece of soil, but once you stop gardening that area it will quickly disappear under tall herb and scrub. Whereas if you manage a site by grazing or hay cutting, for example, the plants (and animals) that naturally occur there will persist as long as you continue to undertake this simple and effective management. That is the difference between

Meadows at Venus Pool - example of a habitat creation exercise.

‘gardening’ and ‘managing’ for wildlife.

Scientific studies of introductions  (e.g. Dalrymple et al., 2011) tend to support the view that most introductions are poorly planned, inadequately documented and destined to failure.

What should a nature conservationist do?

You should implement long-term landscape scale management practices that are effective and affordable. These could include hay cutting in meadows, coppicing in woods, using livestock to graze grasslands, or allowing trail bikes to maintain open habitat. Such management should be general and not specifically targeted at one species (although it might be devised with the intention of benefiting certain species). The key thing is to continue the management regime for long periods, as this maintains the conservation-worthy habitat in a landscape that all too often suffers from disruption and incontinuity.

What should a conservationist not do?

Never put a particular species directly in a particular place. This includes planting out a particular species of plant that has been grown in a pot or cultivated for that purpose. Similarly, do not introduce a population of butterfly caterpillars to a site or release other wild animals. Leave nature to move things around - animals and plants are surprisingly adept at finding suitable places to live, as is shown by the natural recolonisation of the county by otters, peregrines and pine martens in the last few decades.

Any exceptions?

Certain types of conservation improvement make sense, because waiting for natural processes might take a very long time. So, for example, strewing green hay from an adjacent site is simply speeding up what would occur anyway. But strewing hay from a very distant site is far less desirable, and sowing wildflower seed from a packet is clearly wrong. Such seeds are often of very different and sometimes exotic species.

In woodland management people often plant trees. It would be interesting to know if this really makes sense for nature conservation, as one often comes across places where the planted trees are being overwhelmed by self-sown wild trees that are more suited to the soils and conditions than the planted ones are. If your woodland is not for timber production, it is probably best to let natural regeneration take place at its own rate, but an argument could be made for scattering nuts from adjacent woods, for instance.

What has happened in Shropshire?

It would be good to have documented evidence of any introductions or conservation interventions of this sort, to see what we can learn from them and find out if they have worked. Unfortunately, this rarely happens and some introductions even take place in secret. Here are some instances of where introductions are known to have occurred, and perhaps they could be documented more fully one day.

  • In the 1970s Bryan Fowler, the BSBI Recorder for Staffordshire, engaged in numerous translocations of rare plants in Shropshire when they were threatened with destruction from agricultural improvement. It is thought that most his introductions failed within a few years but, to his credit, he documented what he had planted where, and you can read about them here.
  • An area of Brown Moss was seeded with heather brash from the Stiperstones in about 2000, as a heathland recreation exercise. Some plants such as cross-leaved heath appeared, possibly as a consequence of this.
  • Prees Heath has been sown with heather brash from Cannock Chase and the Stiperstones, and heather plants have been planted out in their thousands since about 2008. The experiment is struggling but continuing.
  • The fields around Venus Pool have been seeded with hay from various sites, including ones outside Shropshire. It is believed to have introduced Anacamptis morio (Green-winged Orchid) and Cirsium dissectum (Meadow Thistle) - probably from Little Stocking Meadow and Mottey Meadows, respectively. This experiment has been documented by Ian Trueman.
  • Hundreds of trees of Populus nigra ssp. betulifolia (Native Black Poplar) were given out by the Environment Agency in about 2000 for landowners to plants in their sites. Their whereabouts are only partially documented, and the fate of many of these trees is unknown. It is not known what likely benefit was expected from this work.
  • Llynclys Quarry has been planted and sown with rare species in recent years. The introductions are documented in this report by Dan Wrench.
  • Many hedges are planted under conservation schemes or otherwise with a mixture of species in them. Often these include non-native equivalents of native species, such as exotic hawthorns (Crataegus spp.) which are not easy to tell from the native plants. Many hedges contain unsuitable species such a Viburnum lantana (Wayfaring Tree) and Japanese Rose, sometimes even planted in nature reserves using conservation grants. One species that has particularly benefited from hedge planting is Prunus cerasifera (Cherry Plum), which is now frequent along roadsides. This is not against the non-introductions policy, as it is a native plant being introduced to an unnatural situation - you have to plant something, so this is as good as any.