In calls made by the owner of Luss Estates, Sir Malcolm Colquhoun, the 'act of wanton vandalism’ which damaged the trees has left a 'blight on the landscape’.

Others say the alleged damage caused by Scottish Natural Heritage (SNH) will not be restored for decades – with demands made to find out why the trees were poisoned.

In response, SNH claims the condition of the woodland has been affected by 'a lack of regeneration, a lack of dead wood and the spread of non-native plants’.

An agreement was made in 2013 between SNH and the tenant of Inchtavannach Island to remove rhododendron from the island, which also allowed mature beech trees to be gradually felled over a five year period.

However, the trees have been poisoned, with a 'dead’ canopy being created in the process.

Sir Malcolm said: “I am outraged and shocked at this act of wanton vandalism, and the resulting blight on the landscape of Inchtavannach Island. “It will take years and indeed generations for the canopy to recover and this beautiful view to be restored.

“I simply cannot understand why the supposed guardian of our natural heritage has killed off these wonderful trees for no apparent reason.” He said Luss Estates had requested 'immediate explanation’ from SNH.

Ian MacEachern, convener of Luss and Arden’s community council, said that local residents are 'appalled’.

He told the Advertiser: “To say we are annoyed is an understatement. The mature beech trees on Inchtavannach added greatly to the visual impact of Loch Lomond, for residents and visitors, particularly in the autumn.

“This act of vandalism is a travesty and tragically cannot be restored in our lifetime.” Simon Miller, chief executive of Luss Estates, said if the felling of the mature beech trees had been carried out as provided for in the agreement, the estate would have immediately sought to re-negotiate the agreement.

He said: “Regrettably we didn’t give sufficient consideration to the impact of the proposed felling of the mature beech trees on the island when our consent was sought. “If we had appreciated this, we would certainly have withdrawn our consent.” Mr Miller has also asked SNH if it had a felling licence to kill the mature trees from Forestry Commission Scotland.

He added: “We want to know what measures SNH proposes to undertake to replace the tree cover on the island, having killed such a large number of mature native beech trees.

“We are assessing the scale of the destruction, valuing the trees killed and instructing a tree surveyor to assess the public liability risks and remedial costs. “We expect SNH to foot the bill for this work.” A spokeswoman for SNH said it consulted Luss Estates, and as work progressed it was agreed it would be more effective to inject the tree stems rather than fell them She told the Advertiser: “Inchtavannach is internationally important for its oak woodland but the condition of the woodland has been affected by a lack of regeneration, a lack of dead wood and the spread of non-native plants. “We have worked with Luss Estates and the tenant over a number of years to improve the condition of the woodland and our latest five year management agreement with the tenant in August 2013 included measures to remove non-native beech and rhododendron from the island. “We consulted the estate about this agreement. “As this work progressed, we agreed with the tenant and contractor that it would be more cost effective to control the beech by injecting the stems rather than felling. “We didn’t appreciate the impact that this would have on the landscape of the island and we are now in discussion with the estate and tenant regarding felling of the dead trees to reduce this impact.”