The Welsh Government has launched a strategy to control the spread of Phytophthora ramorum, while acknowledging that the tree pathogen cannot be eliminated.
The national strategy divides Wales into two zones: a core disease zone with high levels of infection in larch stands and that has a geographically defined outer boundary; and a disease-limitation zone covering the rest of Wales, where infection is sparse or non-existent.
The emphasis in the former is on effective land management and the fate of infected material. In the latter, statutory plant-health notices will require rapid felling of any infected larch.
Already more than two million trees have been felled in Wales to control the spread of the disease, which has thrived in the wetter west of Britain, particularly on larch plantations, since its appearance in 2002.
Natural Resources Wales chief executive Emyr Roberts said: "Our aim is to develop a more diverse forest estate in the future. We have already started replanting at some locations and our aim is to make our woodlands more resilient to disease, and continue to be a popular attraction for people to visit, as well as maintaining a good supply of wood to the timber trade."
Natural resources and food minister Alun Davies added: "Due to the virulent nature of this disease and the way it spreads, we cannot eradicate P. ramorum from Wales. But we must take action to minimise its environmental and economic impact and this strategy sets out exactly how we will do that."
Trees & Flooding - Report to be published
The Woodland Trust will shortly launch a report, called Trees & Flooding, at the Welsh Assembly.
"Planting the right trees in the right places can be one of the most cost-effective ways to reduce flood risk to homes," Woodland Trust director for Wales Jerry Langford said in a letter to assembly member Alun Davies.
While the trust is keep to help landowners plant more trees, he added: "We cannot do this without some kind of official woodland grant scheme."