The Tasmanian Minerals Council says the intergovernmental agreement on the state's forests represents a "direct attack" on the mining industry.
Prime Minister Julia Gillard and Tasmanian Premier Lara Giddings signed the $276 million forestry deal last weekend, designed to move the ailing industry out of native forests.
At least 430,000 hectares of high-conservation-value (HCV) forests will be protected in informal reserves and placed in national parks once verified independently, with the commonwealth to provide $7 million a year for the management of those areas.
The federal government will fund $85 million to struggling contractors and their families affected by the downturn, and $45 million to assist workers to leave the industry.
Once legislation is passed to put the forests into reserves, a further $120 million over 15 years will go towards diversifying the economies of affected towns.
The Tasmanian Minerals Council said the creation of national parks or world heritage areas would prevent mineral exploration from taking place.
In a letter to members of the state's Legislative Council on Friday, Minerals Council executive director Terry Long said the mining industry faced a period of economic deterioration because of the agreement.
"If the mineral explorers are precluded from searching for ore bodies through exclusionary land tenure, it is also self-evident that the ore bodies will not be found and there will be no mines to replace those which become uneconomic or mined out," Mr Long said.
"The Minerals Council regards this agreement between the governments as a direct attack upon the minerals industry and it very much clouds its future within the state."
But Tasmanian Resources Minister Bryan Green said the independent verification process would ensure that exploration could go ahead.
"This will not mean an end to mining in Tasmania," Mr Green said.
"The independent verification process will determine areas of high conservation value as well as consider what competing uses such as mining should be protected.
"Any mining proposal will be subject to the well-established stringent environmental approvals process."