The Department of National Parks, Wildlife and Plantation (DNP) has begun verifying the number of Karen people living in the Bang Kloi community in the Kaeng Krachan National Park in Phetchaburi.
The department ordered a committee to run a verification process.
This comes after an unusual increase of occupants in the forest was detected by officials. It is possible that ethnic Karen people are expanding their farms to over 1,100 rai of forest land around the community, they say.
Prakit Vongsrivattanakul, the deputy chief of the department, said the DNP is working with stakeholders to determine who are the members of the original families that settled in Bang Kloi.
About 300 families first settled in the community. The number has now risen to around 1,000 families, according to a recent survey.
The surge in population is attributed in part to poor birth control and migration to the community by ethnic Karen people from elsewhere.
The expanded population has caused more forest land to be encroached upon, Mr Prakit said.
Originally, 500 rai of forest land was allocated to the Karen people who agreed to be relocated away from fertile forest reserves in the past 30 years.
"What are we going to do next is create better understanding and cooperation on living with the forest in a sustainable way," Mr Prakit said. "They [the Karen people] need to learn about multi-crop farming that is within the limits of their land."
"Today, we don't need large tracts of land for farming," he said, adding the department will not tolerate further encroachment.
"The enforcement of the law is lenient to people living in the forests, which at times can contribute to shrinking forest land," the DNP officials said.
Mr Prakit added the Environment Ministry is working to secure more water sources for the Karen people's farms.
Also, the ministry is reportedly installing solar cells in every Karen household in the community to generate electricity, which is important for Karen children pursuing their education.
Mr Prakit said a forest inspection team is currently stationed in a freshly-encroached zone in the national park, which is a three-day walk from the Bang Kloi village.
He said the team is tasked with finding culprits responsible for illegal forest encroachment and illegal occupation of the forest land under the National Park Act 2019.
The department has taken legal action against 22 Karen people under the forest law.
They have now been remanded at a provincial police station. Police have also fined 27 others.
A Karen group last month launched a campaign for their return to the fertile forest reserve, claiming the land originally belonged to them.
However, a satellite image obtained by the department shows no trace of human activity for a long time.
The group said they need the forest land for farming to feed their families.
The land that was allocated by the authorities in exchange for vacating the fertile forest is not arable.
They also insisted they want to preserve their traditional way of life and the practice of slash and burn farming method, which they say is good for the environment.
Activists have raised concerns over the need to protect and preserve the largest forest zone in the country for the ethnic people.
Charges of forest encroachment have been pressed against Karen people as well as some members of the NGOs who may be behind the Karen people's movement to resist the authorities' efforts to straighten out the forest land issue.