Science & Tech · Science & Environment · 9 hrs ago
Papua New Guinea study finds tree deaths rose after El Niño drought
Researchers tracked more than 21,000 trees in a Papua New Guinea rainforest before, during and after the 2015-17 El Niño drought.
They found that more trees died after the drought than during it, even after rainfall returned.
This suggests drought can leave trees weakened, though the study could not establish exactly why they died later.
Valley trees recovered quickly, while deaths among trees on ridges rose after the drought and remained high.
The difference may be linked to water: valleys can hold more water, while exposed ridges may lose it through erosion.
The findings matter because climate change is making droughts more common and severe, and delayed damage makes forest responses harder to predict.
The researchers’ measurements covered the drought and the two years after it, but no further research or next steps are specified.
A study of more than 21,000 trees in a Papua New Guinea rainforest found that tree mortality was significantly higher after the 2015-17 El Niño drought than before or during it.
The research was conducted at the 50-hectare Wanang Forest Dynamics Plot in northern Papua New Guinea.
Trees on ridges had their highest mortality after the drought, while valley trees recovered quickly.
The findings suggest drought effects can continue after rainfall returns, though the study could not determine the exact cause of the delayed deaths.
- Who
- Researchers studying more than 21,000 trees at the Wanang Forest Dynamics Plot, led by Hayden Wagia.
- What
- The study found tree mortality was significantly higher after the 2015-17 El Niño drought than before or during it.
- When
- Researchers measured mortality before, during and two years after the drought.
- Where
- Wanang Forest Dynamics Plot, a 50-hectare research site in northern Papua New Guinea.
- Why
- The study examined how forests respond to drought, a concern as climate change makes droughts more common and severe.
This story does not have two clearly opposing sides.
Researchers measured tree mortality before the drought at the Wanang Forest Dynamics Plot.
The El Niño drought brought a substantial reduction in rainfall to the Wanang forest.
Researchers measured tree mortality, including relatively high mortality among valley trees.
Researchers found mortality was significantly higher than before or during the drought, with ridge-tree mortality elevated.
- Study site
- Wanang Forest Dynamics Plot, northern Papua New Guinea
- Area studied
- 50 hectares (124 acres)
- Trees studied
- More than 21,000
- Drought period
- 2015-17 El Niño drought
- Dry-season rainfall share
- 5.2% during the drought, compared with 13.1% before and 9.6% afterward
What people are saying
It was after the drought, the post-drought period, that you could actually see those trees dying
If they’re so sensitive to this dry season rainfall, it’s telling me that that little bit of rain they get in those months, even though it’s [little] compared to the rest of the year, is really important to keep the water balance of the system