Pulpwood and oil palm concessions cover millions of hectares in Indonesia. For some, fire was used to illegally clear the land in the past and many have cleared forest areas on drained peatlands, which are highly flammable.
Local communities often surround the concessions and many larger pulpwood concessions have large areas set aside for communities and for conservation zones that also make them vulnerable to fires started inside and outside their concessions.
Fires by illegal loggers add to the problem.
Singapore-based Asia Pulp and Paper (APP) is Indonesia's largest pulp and paper firm, with concessions covering 2.6 million ha in Indonesia. At present, more than 300 fire alerts have been recorded on APP concessions in Sumatra over the past week.
"The majority of the fires - more than 90 per cent - come from outside the concessions," Ms Aida Greenbury, APP's managing director of sustainability, told The Straits Times yesterday.
"I have people putting their lives on the front lines for the past two weeks making sure our forests are protected," she added.
But the problem was the lack of commitment from those who own the lands outside APP's concessions, she said.
"APP takes fire as an issue very seriously and we recognise that as a responsible business we have a responsibility both to tackle the fires that are burning in our concession areas and to work with other stakeholders on finding long-term solutions," she said.
"Fire is a hugely complex issue, involving the rights of local communities, illegal activity by small enterprises often with political links and fundamental complexities over land use rights, maps, ownership and protection."
She pointed to APP's policy of zero deforestation, zero burning and a newly announced programme of improved peat land management.
"If the rest of the landscape do whatever they want, build whatever drainage canals and burn lands wherever they want, we will be affected. And that's why we have so many hot spots in our operations."