Scientists covered an Amazon plot with 6,000 panels to block rain; biomass fell by a third

Deep in the Caxiuanã National Forest in northern Brazil, a patch of rainforest the size of a football pitch tells the story of what a drier Amazon might look like. Since 2002, scientists have suspended nearly 6,000 transparent plastic panels above one hectare of pristine forest, diverting roughly half the rainfall away from the soil below and channelling it into gutters instead. It is the longest-running drought experiment of its kind anywhere in the tropics. For years, the trees coped, drawing on deep roots and even absorbing water through their leaves. Then, around eight years in, the resilience gave way. Large, old-growth trees began collapsing at far higher rates than their smaller neighbours and the forest tipped from storing carbon to releasing it. More than two decades on, researchers have traced the full arc of that transformation from collapse to an unexpected, and only partial, recovery.Why did scientists block half the rain in an Amazon rainforestResearchers found that trees employed a range of coping strategies, including redirecting roots to access deeper water reserves and, in some cases, absorbing moisture directly through their leaves. Lucy Rowland, an ecology profe...