Mapigo ya Polepole ya Moyo wa Miti

Usiku, katika ukimya kamili, wanasayansi walielekeza mionzi ya leza kwenye safu za miti na kusubiri. Walichokiona kilifanana kidogo na mmea na zaidi na mnyama aliyelala: mpigo wa taratibu na wa kawaida, ukipanda na kushuka kila baada ya saa chache, ukipita katika mti mzima kwa wakati mmoja.

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.

Matawi yalipanda na kushuka kwa takribani sentimita moja, kwa mdundo, kana kwamba mti mzima ulikuwa ukipumua taratibu. Watafiti sasa wanaamini kwamba shina lenyewe huenda linakamua kwa nguvu, likisaidia kusukuma maji juu kupitia mirija ya ndani iitwayo xylem, badala ya kutegemea unyonyaji wa kawaida tu. Tofauti na mpigo wa moyo wa binadamu, unaorudia karibu mara sabini au themanini kwa dakika, mpigo wa mti waweza kuchukua saa kadhaa kukamilisha mzunguko mmoja tu.

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.

Ni wazo la ajabu: bustani iliyojaa miti, kila mmoja ukipiga kwa ratiba yake binafsi ya polepole mno, isiyoonekana kabisa isipokuwa ukibahatika kutazama gizani ukiwa na kifaa kinachofaa.

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.