The QCC project was launched in 2015 during the 24th Commonwealth Heads of Government Meeting (CHOGM) in Malta.
An appeal was made to all 53 Commonwealth nations to contribute areas of indigenous forest to be preserved in infinity to mark the queen's lifetime of service to the Commonwealth.
Since then, around 35 Commonwealth countries have dedicated forestry projects or are planting new forests, with another ten countries in the process of finalising their submissions.
The pronouncement of support to the Mau Forest conservation efforts was conveyed to President Kenyatta in a letter from the queen on Wednesday.
It comes at a time when the complex is facing tremendous human-induced pressures and destruction.
This has contributed to related environmental disasters, loss of livelihoods, drought, water crisis, food shortage, reduced river flows, poor land productivity among others.
The Maasai Mau Forest (MMF) block (water tower) is the most threatened and degraded of the 22 forest blocks.
By offering the MFC to be supported under the QCC, Kenya hopes to accelerate the revival of the most extensive ecosystem and the most critical water tower in Kenya covering approximately 455,000 hectares of land.
The MCF is home to 22 forest blocks with 12 feeding into major water lakes in Kenya and parts of Western Kenya.
Mau’s admission to the QCC will heighten efforts to protect, restore and rehabilitate some of its degraded areas while improving the general status of the water towers as well as creating and promoting alternative livelihood options to the surrounding communities.
The admission also presents an active link to the climate action agenda, falling between the Climate Action Summit 2019 and the Climate Change Conference (COP 26) to be held in Glasgow, Scotland, from 9 to 19 November 2020 under the presidency of the UK government.
"This is great news. The admission of MMF to the QCC is a clear confirmation by Her Majesty The Queen of Mau's importance as a vital ecological and biodiversity asset , not just for Kenya and the Region , but for the whole World," Environment Cabinet Secretary Keriako Tobiko said.
The first country to offer a QCC dedication was Singapore which dedicated six hectares of rainforest in the Singapore Botanic Gardens and 163 hectares of Singapore’s Bukit Timah Nature Reserve forest in 2016.