Christmas tree will stay in place until 12 January.
The Vatican's Christmas tree arrived in St Peter's Square on Thursday amid controversy, after an appeal to Pope Francis to spare the 200-year-old fir was ignored.
More than 53,000 people signed an online petition calling for the 30m-high "Gigante verde" or green giant to be left standing in the forests of Val di Ledro, in Italy's northern Trentino region.
Local residents and enviornmentalists had slammed the proposed tree felling as an "anachronistic outrage", urging the pontiff to give a clear signal towards respecting nature in the face of climate change.
Noting that the Christmas tree is "a pagan tradition", the petition condemned "the purely consumerist practice of using living trees for ephemeral use, for mere advertising purposes and a few ridiculous selfies."
However authorities went ahead and chopped down the majestic tree in Val di Ledro, along with a further 39 smaller trees destined to adorn various Vatican offices and buildings.
In an attempt to quell the controversy, Cardinal Fernando Vérgez Alzaga, president of the governorate of Vatican City State, this week defended the choice of the tree as "not only aesthetic but also ecologically responsible".
The cardinal said that removing the tree would "ensure the natural renewal of the forest for the coming decades", adding that the Val di Ledro trees are managed in line with the PEFC sustainable forest management requirements.
Nativity scene
The Vatican's Nativity scene, from Grado in Italy's northern Friuli-Venezia Giulia region, will be installed beside the Christmas tree.
This year the Christmas crib will have a maritime theme and will depict fishermen alongside traditional boats and thatched dwellings together with 3-D renderings of birds.
The Vatican's Christmas tree and Nativity scene will both be illuminated during a ceremony on Saturday 7 December, at 18.30, and will remain in place until 12 January 2025.