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Drought is perhaps the most complex and least understood of all weather and climate extremes. Despite an increasing drought risk in a future warmer climate, this risk is often underestimated and continues to remain a "hidden hazard." Drought can span timescales from a few weeks to decades, and areas from a few kilometers to entire regions. Impacts usually develop slowly, are often indirect and can linger for long after the end of the drought itself.

Trophic rewilding seeks to rehabilitate degraded ecosystems by repopulating them with large animals, thereby re-establishing strong top-down interactions. Yet there are very few tests of whether such initiatives can restore ecosystem structure and functions, and on what timescales. Here we show that war-induced collapse of large-mammal populations in Mozambique's Gorongosa National Park exacerbated woody encroachment by the invasive shrub Mimosa pigra-considered one of the world's 100 worst invasive species-and that one decade of concerted trophic rewilding restored this invasion to pre-war baseline levels.

An international research team from Germany and France has created structures in which light fields interact with electrons so strongly that the quantum vacuum itself is significantly altered. Using extremely short bursts of light, they interrupted this coupling much faster than the timescale of a vacuum fluctuation and observed an intriguing ringing of the emitted electromagnetic field, indicating the collapse of the vacuum state. Their key achievement could improve our understanding of the nature of nothingness-the vacuum of space itself, paving a way toward photonics exploiting vacuum fluctuations. The results are published in the current issue of Nature Photonics.