WA Environment Minister Albert Jacob says it is too early to say if mass plant deaths at Kalbarri National Park are a sign the region is experiencing the early effects of climate change.
A draft management plan from the State Government's Conservation Commission has proposed more than doubling the size of the WA tourist icon, in part to protect its biodiversity in the face of uncertainty about the impact of climate change.
It also highlighted the need to manage threats such as weeds, introduced animals and fire, and improve plant resilience.
Mr Jacob, who visited the park this month to open a $7.7 million facilities upgrade, said the plant deaths were noticeable.
"It's quite stark," he said. "It's very dry."
He said it was too early to say whether drought conditions were the result of climate change but it would be monitored.
The plan, which has been released for public comment, said a decrease in surface and groundwater for plants had "resulted in mass plant deaths across Kalbarri National Park, especially in banksia species and may be an indicator that the Kalbarri area is experiencing an early effect of climate change".
"Vegetation of the Murchison Gorge is vulnerable, particularly species that are geographically restricted at their range extent or sensitive to fire," it said.
"Accurately determining that a species, community or habitat has been directly and adversely affected by varying climatic conditions is difficult. Further research will be important in gaining a greater understanding of the impacts of climate change at a species and community level and management will be adapted on the basis of these findings.
"Uncertainty about appropriate responses to the effects of a changing climate mean that increasing areas held in conservation reserves and managing other threats may be the best options to protect biodiversity in the immediate future."
The plan identified 239,778ha adjacent to the park that had conservation significance and could become part of the park, significantly boosting its existing 183,000ha.