Perman was appointed to the role by the chairman of the governing boards of the two institutes. SCRI governing board chairman Peter Berry said: "I look forward to working with Ray over the next year to establish the world-class new institute, which is our vision for this merger of two great Scottish scientific institutions."
Macaulay governing board chairman Michael Gibson added:"I am very proud that Macaulay is going to be a founding partner in what will be one of Europe's foremost scientific institutes and that it will be based here in Scotland."
Perman said: "These two institutes already have international reputations for the quality of the work they do. By coming together they are recognising that the problems the world faces demand cross-disciplinary solutions.
"The new organisation will have a tremendous amount to contribute to Scotland and the world and I feel privileged to be asked to play a small part in its formation."
In October 2009, the SCRI and Macaulay announced that they had agreed in principal to unite and form a new institute which would be the first in Europe to carry out research into food, land use and climate change.
The organisations are now looking for a scientist to be chief executive officer for the new institute.