It can get a little depressing writing about the problems that we all have with Invasive Alien Species…so how about some good news for a change? There are positive factors about alien species – you just have to think a little outside the box. If you look closely there are only about 20 or so plants which provide the staple ingredients for our diet – thus these 20 plants are the major contributors to world food supply – without which much of the world population would starve.
These plants are often grown far from their places of origin and are thus – ‘alien species’ – but these are not ‘invasive alien species’ but rather ‘alien species’ that have been purposefully transported and moulded through selection. These plants have developed through years and years of selection and now fit the local conditions in the most productive manner providing high yield food crops which suit the farmer in his quest for maximum return for every acre that they plant.
Alien species abound in our parks and gardens providing feature plants in some of our most famous of landscapes. The Victorian gardeners thought they were ‘masters of the universe’ and brought plants from all over the world to grace their estates and parklands. Landscape Architects have used exotic species within planting schemes for years – with many plants being used in so called habitat or wildlife gardens being exotic and alien.
The recently released ‘field Guide to Invasive Plants and Animals in Britain’ lists various exotic trees and shrubs which are now considered to be potentially problematic. As a Landscape Architect I used nearly all of them in my early planting schemes….! …but please don’t think it was just me…these were plants that were recommended as being either ‘hardy’, ‘ornamental’….or just plain ‘available and cheap’! Many of the plants that we Landscape Architects used 30 years ago were used because they could be grown easily on a commercial basis – and were reliable in terms of rapid growth and establishment….not unlike Japanese Knotweed!
This year at the Chelsea flower show there has been a call for the use of native plants to be used rather than exotic ‘alien’ species – some of the gardens have contained nothing but ‘alien plants’ which, whilst interesting – do not encourage the typical British gardener to plant indigenous species. It is easy to forget what is …and isn’t ‘native’, Sycamore for example is a non-native invasive species – yet if one were to fell/eradicate all of the sycamore trees in the UK …this would leave some major holes in our landscape?
What about the new pests and diseases that we have to contend with? If Ash die back decimates our native Ash trees (as it is forecast to do)…. then should we looking at an ‘alien’ ash species sourced from Europe that may be able to withstand the virus?
Would you rather have no trees..? or ‘Alien trees’ that will survive????
When I was younger I always used to think everything was black and white – I made quick decisions based on a simplistic view of the world. As I have got older I realise that most situations are more about ‘shades of grey’ ….rather than yes or no …it is about multiple variables and realising that not everybody thinks in the same way.
Some people advocate accepting ‘invasive non-native species’ as part of the ‘natural order’ – and believe that we should accept a change in our habitat as invasive species spread. Others point to the associated loss of bio-diversity which they consider vital to the longevity of the planet.
I can see both points of view and in certain cases will sit on both sides of the fence.
In and around Swansea and South Wales I consider the growth of Japanese Knotweed to be so extensive that I don’t believe that current methodologies will ever get on top of the plants extensive growth….so…maybe just maybe…. we should accept this?
Other areas where Invasive plants are just beginning to establish should (I believe) be where we spend our time and effort in trying to preserve the natural order.
From what I understand – the newly introduced ‘Species Control Orders’ seem to take a similar line, plants that are well established will NOT be getting served notice to remove …whilst NEW arrivals will be hit hard and fast and removed….
The message in this blog has got a little confused – but the key point that I’m trying to get across is that it’s not all ‘bad news’….things do change – and it is natural for our environment to evolve. Some changes should perhaps be accepted and even welcomed – whilst others should be challenged and actions taken …
There are some interesting decisions to be made.