The heritage region is also strewn with walking and bike trails for the tourists and locals. Using horses for logging is far less intrusive and destructive than using massive machines.
"I could be working only 50 feet away from the trails and no-one would know unless they spotted me, so there's no noise pollution and the horses don't tear up the paths like a machine would," says Tom.
Since our carbon footprint has become so topical, few could argue that the horse is leaving a big imprint on the environment.
"The forest floor here is full of small trees growing and regenerating the forest," he says. "There are thousands of small oak trees around six or eight-inches high and the horse does no damage to those trees compared to machines.
"Aside from the young saplings, the last thing you want to do is damage any of the standing crop," he adds.
Damage to the bark of an older tree leaves it more susceptible to disease and subsequent death, so flexible and supple horses are less likely to accidentally cause damage.
However, despite his in-depth knowledge of forestry, Tom was originally trained as a farm manager in the heart of Dublin city.
Airfield Trust, a 50ac farm situated in the centre of Dundrum, employed Tom's father Gerry as farm manager in the 1960s and 1970s.
The well-known Overend sisters, Letitia and Naomi, ran a pedigree Jersey dairy herd on the farm.
It was fairly self-sufficient, growing enough corn and grass to feed the cows all year round and the herd regularly featured in cattle shows, including the spring show at the RDS.
In 1980, when his father retired, Tom took over as farm manager and began to develop the horse work on the farm.
Much of the work was being done by an outside contractor and, even though there was a Massey 135 on the farm, there was little in the way of other implements and not enough money in the farm kitty to buy more.
"But all the ploughs, harnesses and carts had been stored away in sheds since the early part of the century," explains Tom.
"So I went into Smithfield fair and picked up a couple of horses to work on the farm," he recalls. The horses were heavy, traditional-type Clydesdales, between 15.1hh and 15.2hh. The Travellers were willing to lend Tom horses on a trial basis from one fair to the next until he found the animals he wanted.
The experiment worked and from then on the majority of farm work was done in the traditional way with horses.
However, Tom's own career took him away from Airfield to another heritage site, this time at the opposite end of the country.
The trustees of Muckross House wanted to develop a traditional working farm in the style of a farm from the 1920s. They advertised the post of farm manager, but by the time Tom applied, the job was filled.
Undeterred, he applied for the position of horseman and when he secured the job, brought four of his own horses to the famous Kerry national park.
The horses were a mix of Clydesdale/Irish Draught crosses and he had built up his own collections of horse-drawn machinery such as harrows, carts and drays.
However, in 1996 he decided to bite the bullet and start working his horses for himself.
He sold off several horses and kept only a pair of Shires that he used for promotional work: fairs, festivals and the like. To supplement his income, he worked for SWS as a farm relief operator.
He set up his own company, Trojan Heavy Horses, in 2004 and focused on gathering more work.
His team of Shires were regularly washed, plaited and spruced up before being hitched up to his Landau carriage for weddings.
"We did a bit of film work too. You can see us in The Wind That Shakes The Barley," he says proudly.
The business grew as the wedding, festival and promotional work began to roll in. Tom also trained horses for other people, as well as buying and selling a few here and there.
Since 2005, he has concentrated on the forestry work that has begun to flourish after an absence of two decades.
"Up to 20 years ago there was hardly a machine in the woods, it was all horses," he explains. "But then horse logging got a bad name."
"The horses were underfed, the harness was rubbish and the horses were asked to do a lot more than they could because they weren't fit enough," he recalls.
"There were some good operators in horse logging, but there were plenty of bad ones," he says.
"Horses were often tied to a tree for the whole weekend with just a hay net to keep them going and there was no-one to oversee what was happening," he says.
"They were paid on the amount of timber they got out of the woods and the only way to get big volumes out was to hammer the horses," he says.
Simon Lenihan from the Limerick/Kerry region was the last real commercial logger in Ireland, according to Tom.
"He left Ireland seven or eight years ago to move to Cumbria with his wife and six sons," recalls the horseman.
"Three of the sons have gone into business with him and they have one of the biggest commercial horse logging companies in the UK now."
Lenihan recently received an award from Prince Charles for his horse logging and is currently working on the Duchess of Cornwall's estate.
Tom's own first horse logging job was for the Irish National Forestry Foundation on the Manch Estate in Ballineen, Co Cork.
"The forestry canopy needed to be opened to allow the natural regeneration from the forest floor without damaging any of the young trees," recalls Tom.
Training a horse to forestry work can begin as early as two years of age but the horses will not be asked to pull full loads until they are at least four.
"I would mouth them and begin training at two but you can't work them too hard or you could damage their joints and even stunt their growth," he says.
"You need a well-trained horse that's responsive, careful and calm, because the terrain you're working in can be very dangerous," he says. "If my foot is caught in a log, I need the horse to turn quickly and easily to prevent an accident. I can't be swinging out of the ropes to get her to turn," says Tom.
He maintains that having an excitable horse in forestry work is akin to giving a child a loaded gun.
"You need a docile animal that listens and obeys your commands instantly, particularly when you're working on steep slopes and around banks and drains," he adds.
Accessibility is one of the major reasons why horses are popular with forestry owners carrying out first and second thinning. Horses take up less room, cause less damage and leave less of an imprint behind.
To say that Nixon is dedicated is an understatement. He travels the length and breadth of the country for jobs and often stays in the lorry until the job is done.
"I can bring three horses and all my equipment in the lorry, so I just bunk down in the lorry until the job's finished. It means I can get longer, more productive working days," he explains.
The work recently took him to join a fellow logger in Dumfries, Scotland on a job for the Scottish National Trust.
Jim Johnson and Tom worked their horses in a special conservation forestry site that contained an ancient defensive trench around Castle Douglas.
"Some of the oak stumps were 1,000 years old and the trench was used for fighting in wars so they had to be maintained," he explains.
It seems time has come full circle for horses in forestry.