FAIRBANKS, Alaska (AP) - A Fairbanks man bulldozed his way through four long-term forest research projects as he cut a trail to property on the Tanana River, state officials said.

The damage may ruin the UAF research projects that have been ongoing for more than 20 years.

David Lace on Saturday created a mile-long trail on state property from the end of Bonanza Creek Road, about an hour south of Fairbanks along the Parks Highway, to the river. The land is near the university's Bonanza Creek Experimental Forest.

Several scientists use the area outside the experimental forest, with state permission, for long-term research projects.

Lace said he tried to avoid the research plots.

"We went out of our way not to disturb anything," he said. "We didn't maliciously do any damage."

Jamie Hollingsworth, site manager for the experimental forest, said Lace was not careful enough.

"There were four projects for sure that were directly impacted," Hollingsworth said. Scientists on Thursday were still assessing damage.

The bulldozer cut a power cable for a weather station. It damaged fences used to keep moose and hares out of research areas. A hare-trapping grid was disturbed and the bulldozer drove through a long-term vegetation plot.

The areas were marked clearly with fiberglass stakes, Hollingsworth said.

The research projects were designed to study vegetation patterns in areas relatively undisturbed by humans.

"That has been altered now," Hollingsworth said. "It's going to be hard to continue because of this."

Lace said he talked to officials at the Department of Natural Resources before he cleared the trail.

"Nobody said anything about a permit," Lace said.

But Frank Maxwell, a DNR manager, said that was unlikely.

The state generally allows property owners to make trails across state land without a permit if the trail is no wider than 5 feet and created using hand tools or chain saws. The path Lace cut with the bulldozer is almost 35 feet wide in places, Maxwell said.

"If he had described what he planned to do accurately, nobody in the office would have told him to go ahead without a permit," Maxwell said.

Maxwell said Lace should have known better. In 1994, Lace applied for a permit to drive large machinery across the same state land to his property, Maxwell said.

"This was more somebody wanting to get from A to B and not going through the proper hoops to do it," Maxwell said. "One of the reasons we require people to apply and get permits is so that they don't destroy a research station or interfere with other resource uses."

Lace said he thought he was doing the right thing. He owns more than 125 acres of property surrounded by state land. He bought the land in the 1960s, he said.

His 75-year-old sister, Wendy Allington, and her husband, Ray, have lived year-round in a cabin on the property for 14 years. In summer, they reach the property by boat. In winter, access is by snowmobile.

"I have a 75-year-old sister that lives down there, and I need some better access," he said. "They're getting older and we just want access to the property."

Maxwell would not comment on any possible penalties Lace might face.