Spori otkucaj srca drveća

Noću, u potpunoj tišini, znanstvenici su uperili lasere u redove stabala i čekali. Ono što su našli manje je nalikovalo biljci, a više usnuloj životinji: spor, ravnomjeran puls koji raste i pada svakih nekoliko sati i prolazi kroz cijelo stablo odjednom.

At night, in complete stillness, scientists pointed lasers at rows of trees and waited. What they found looked less like a plant and more like a sleeping animal: a slow, steady pulse, rising and falling every few hours, moving through the entire tree at once.

Grane su se pomicale gore i dolje za otprilike centimetar, ritmično, kao da cijelo stablo polako diše. Istraživači sada vjeruju da se samo deblo možda aktivno steže i pomaže gurati vodu kroz unutarnje cjevčice koje se zovu ksilem, umjesto da se oslanja samo na pasivno upijanje. Za razliku od ljudskog srca, koje kuca oko sedamdeset ili osamdeset puta u minuti, stablu za jedan ciklus može trebati nekoliko sati.

Branches shifted up and down by roughly a centimetre, rhythmically, as if the whole tree were gently breathing. Researchers now believe the trunk itself may be actively squeezing, helping push water up through internal tubes called xylem rather than simply relying on passive absorption. Unlike a human heartbeat, which repeats around seventy or eighty times a minute, a tree's pulse can take several hours to complete a single cycle.

Čudna je to pomisao: vrt pun stabala, a svako od njih pulsira po svom vlastitom, izrazito sporom rasporedu, posve nevidljivo, osim ako se slučajno ne nađeš ondje u mraku s pravim instrumentom.

It is a strange thought: a garden full of trees, each one quietly pulsing on its own private, extremely slow schedule, completely invisible unless you happen to be watching in the dark with the right kind of instrument.