Next year's planted forestry area is set to be the lowest since 1947 unless the capital expenditure budget for forestry is increased, the Association of Irish Forestry Consultants (AIFC) has warned.
Planting levels will fall back to 1,800-2,500ha next year, unless funding is increased by €25m, the AIFC has claimed.
Planting levels have not fallen that low since 1947, when 2,350ha were planted.
AIFC chairman Seán Lenihan said €89m has been allocated for forestry in 2011, but €80-82m of this is required for existing commitments, leaving just €7-9m for new planting.
"This will be a disaster for the forest industry and the country, and will affect the livelihoods of many people employed in forestry, mainly in rural Ireland," Mr Lenihan insisted.
"If there is no change to the proposed budget, there will be major job losses in the industry, which currently employs 12,000 people, and our carbon emissions bill will increase as we need to plant 15,000ha a year to maintain the carbon sequestration potential of our forests," he added.
Uncertainty about annual budgets has caused falling planting levels in recent years. In the early 1990s, the annual average was more than 16,000ha, but this has fallen closer to 7,000ha. However, Mr Lenihan maintained there was potential to achieve annual plantings of 10,000-12,500ha or more if there was a sufficient budget in place.
Fine Gael agriculture spokesman Andrew Doyle accused the Green Party of forfeiting its own forestry targets.
"A year ago, the Green Party announced renewed forestry commitments to facilitate the attainment of the target of 17pc forestry cover by 2030 and contribute to meeting our climate change commitments," he said.
"Now that capital spending has been slashed, it is clear that the Green Party expended all of its energy in fighting for a ban on stag hunting and has nothing left in the tank to secure spending for its own forestry commitments."
Mr Doyle said economic and environmental impacts of abandoning the 10,000ha per annum planting target was significant because reaching that target would result in a saving of €46m to the exchequer in climate change mitigation.
Meanwhile, the president of Engineers Ireland said the potential of forestry in this country was not being realised.
Martin Lowery, who is a former chief executive of Coillte, said tree growing was one of the few areas in which Ireland had inherent competitive advantage due to our temperate climate.
"It is the undisputed best use for more than 17pc of Irish land," he said. "Forestry cover is currently just over 9pc, so it has potential to almost double in size and could spawn a pulp/paper industry if better use was made of this land."