He wants a royal commission into the laws, which he says prevent him clearing his land.
Mr Spencer began his protest on November 23 on his property outside Cooma and says what he wants now is Vegemite and a poached egg on toast.
His son Aaron Spencer, 33, helped winch his father down from the so-called Tower of Hope because the older Mr Spencer had become too weak to climb down from the 12-metre tower.
Mr Spencer is now expected to be taken Cooma Base Hospital for medical treatment after living on water and vitamin supplements.
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Before Mr Spencer was lowered his 27-year-old daughter Emma told reporters that family members were relieved he had decided to come down, despite not achieving his goal of a meeting with Prime Minister Kevin Rudd.
Close friend Alastair McRobert said doctors warned Mr Spencer he risked long-term damage if he continued his hunger strike any longer.
"His electrolyte levels were out of balance and the doctor said if he stayed there any longer he would cause himself irreparable, permanent damage," Mr McRobert said.
Nationals senator Barnaby Joyce already has plans to take Mr Spencer to parliament when it resumes in February to bring more attention to his concerns.
"We can continue this fight for property rights that have been taken off so many people because of these crazy environmental laws," Senator Joyce told Sky News.
He said it took courage to do what Mr Spencer had done.
Government reaction
The federal government welcomed Mr Spencer's decision to end his hunger strike and said he'd made his point.
Climate Change Minister Penny Wong said the government remained open to a meeting between the grazier and parliamentary secretary for water Mike Kelly.
"Mr Spencer has certainly made his point very clear," Senator Wong told reporters in Adelaide.
"We're very pleased that, given the concerns for his health, that he's made this decision."
Mr McRobert, who has a farm near Cobar and also claims to have been financially devastated by the land-clearing laws, said the protest had been a great success.
"No citizen in this country should have to go to that extent to be heard, but Peter's been denied that right, and denied his property rights," he said.
"But he's been heard and it's out there now, people won't be able to suppress this (issue) anymore."
Mr Spencer said he doesn't plan on giving up the fight and warned bureaucrats he was vocal while on the tower and they could expect more from him now he is down.
