Elm trees suffer from invaders, UK benefits from immigrants

ONS most recent map of non-UK born UK Residents as %, selection most of England & Wales

Looking for old Hunt's Post articles at the Norris Museum, I came across a reference from 1970 to the Huntingdon Elm, mentioning its resistance to Dutch Elm disease. The Huntingdon Elm is an old English hybrid cultivar isolated by nurserymen Wood & Ingram in 1746 from seed collected from an Ulmus × hollandica hybrid in Hinchingbrooke Park. It was resistant to the first strain of Dutch Elm disease which had begun to decimate Britain's Elms. The pest was a mild form that petered out in the UK. Unfortunately, a more aggressive strain came in on an import of Rock Elm from America in 1967 - and decimated the Elm population. The Huntingdon Elm was also affected this time. Currently there seem to be three strategies to grow healthy elms:

1. Hedging elms - as infection occurs when the trees grow taller 5m. This has kept many trees healthy over more than 40 years.
2. Inoculation with a mild strain to induce a resistance - used in the Netherlands
3. Finding resistant native cultivars. There is a current UK project looking at propagating saplings from large elms that survived the last Dutch Elm disease attack - see http://www.conservationfoundation.co.uk/elm

Today saw a brief news spike in the BBC, looking at how attitudes to immigration might have changed since the Referendum. From a morning report on Radio 4 and a TV news report in the afternoon, the indication seemed to be that it was still seen as a big issue. The conservative manifesto restates the desire to reduce net immigration to 100,000 per annum.

An alternative view is presented by Global Future, an independent UK think tank, in their report 'The Case for Immigration'  http://ourglobalfuture.com/2017/05/the-case-for-immigration/. It argues that that the UK is effectively in a state of full employment (recognised as unemployment figures below 5% of working population). It states that simply to meet the requirements of retirement and pension costs, a net migration figure of 225,000 would be required every year for 50 years to increase the working population from 32 to 38 million, according to the Office of Budget Responsibility . Global Future points to the stagnatory effect of the very low immigration levels on the Japanese economy as a possible undesireable similar outcome for the UK.

I was trying to find a good visualisation of the degree of immigration across the UK, and fortunately, the Office for National Statistics (ONS) provides a lot of data on non-UK born UK residents - and a map at:
https://www.ons.gov.uk/peoplepopulationandcommunity/populationandmigration/internationalmigration/bulletins/ukpopulationbycountryofbirthandnationality/august2016,
The overall average is about 13% of the population, with only some areas reaching just over 50%. The map distribution also reflects the observation made last year during the Referendum; those most likely to vote for Brexit were those experiencing the lowest levels of immigration (http://theconversation.com/hard-evidence-how-areas-with-low-immigration-voted-mainly-for-brexit-62138).

Even Tories have apparently been trying to get the Prime Minister to move away from an unrealistic or even unachievable net immigration target of 100,000. However, this being a general election, there seems to be no incentive to do so.