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Drinking from a Cloud

August 17, 2015. Life in Portugal by Jude Irwin

As I took my morning run today, jogging rather ponderously through the cool mist that billows down the wooded hills, I encountered a mystery. The sun had started to burn through, creating patches of vivid blue above me. And yet…I could hear a sound – unmistakable and welcome in this gusty summer of drought and forest fire: It was raining!

Or was it? If it was, why wasn’t I getting wet? Puzzled, I followed the pitter-patter to its source. At once, I understood – and immediately thought of Africa.

For 18 months or so, I lived in Swakopmund, Namibia, a gone-to-seed little town sandwiched between the western Atlantic shore and a vast, heat-blasted, glittering desert. The fog is sometimes so dense you can’t see the other side of the street. It forms a land-hugging coverlet as warm air from inland collides with cold Benguela ocean currents surging up from the far south. Among the lofty dunes of this stark “Skeleton Coast”, sand temperatures can tip 70 Centigrade, and rains are so rare they are hardly worth measuring. You might expect this to be a desolate zone, but the dunebelt’s unique ecosystem actually supports many curious plant and animal stalwarts that hoard and harvest water in remarkable ways.

The fruits of the prickly Nara bush (also dubbed the Bushman’s Football Factory) hold drinkable water – just one of the wonders of Namibian dunes.

One creature in particular came to mind as I stood in the dusty forest track: the Namibian Desert Beetle. When he feels parched, Stenocara gracilipes climbs to the dune’s ridge and practically stands on his head, angling his body at 45 degrees. Poised delicately on long legs like a ballerina en pointe, he faces the prevailing breeze. Slowly, the rolling sea mist pearls into droplets on his knobbly wings, until gravity guides them down waxy channels and into his thirsty mouth.

My mysterious Portuguese “rainmaker” turned out to be something less bizarre – and, frankly, far too common here: a mature eucalyptus. As I watched, its tall canopy was gathering passing clouds of vapour; every long, leathery, slightly-concave leaf pointed downward, funneling water droplets to the ground around its roots in a steady and substantial shower. I checked out neighbouring oaks. They, too, were attempting this self-watering feat, but with less success. Their broader, flattened leaves didn’t act as effective troughs, and sunlight was rapidly evaporating drops on shelf-like foliage. Each broadleaf’s rough, ridged bark also seemed to soak up trickledown moisture before it could reach the earth, whereas the gum tree’s smooth skin sluiced far more to its base.

Desert beetle and “Land of Fire” tree: both have adapted brilliantly to be able to cadge a drink literally out of the blue.

Eucalypts: Love Them or Hate Them.

About 6500 square kilometers of Portugal is covered by various timber and paper-producing eucalypt varieties. Fierce debate has raged for years about whether this is a “good thing” because it makes money for the plantation owners and thereby tax revenue for Portugal’s treasury, or a “bad thing” because eucalypts wreak such ecological damage.

Each eucalyptus prepares its own ‘bonfire’ by shedding lots of bark.

I make no bones about which side I am on. I know that these “interlopers” are superb survivors, as the photos accompanying this piece will testify. But I prefer bio-diverse landscapes to monoculture of any species. I believe forest planning and management should be about more than making money for investors. I believe insects, birds, reptiles and mammals – including humans – deserve a better environment than the one hogged by blue gum bullies, which almost totally exclude other species and deplete the soil till it is good for nothing except erosion. And let’s not forget their tolerance of – or should I say preference for – frequent forest fires.

Survivors: most fire casualties are small trees and shrubs. Large eucalypts blacken, but are essentially unharmed. Wood can be ’cleaned’ for sale.

The “good vs. bad” debate is now tilting worldwide toward reducing big tracts of eucalypts. There are several driving forces. For example, our digital age delivers virtual information on computers and mobile devices. We simply don’t need as many paper-based communications. But the overriding factor here is climate change.

Every year, our seasons shift just a little. Temperatures rise. Rains that used to be predictable and ample are now scant and unreliable in many countries. Aquifers are sinking. Destructive forest fires occur more frequently, and the carbon they spew into the atmosphere pollutes the air we breathe. Blackened ground absorbs more heat and accelerates climate change even more. In the face of impending global disaster, can there be any defensible reason for planting trees that enhance fire risks and suck up so much precious water?

Valuable ground cover like heathers and cistus burn fast, leaving earth exposed, baked hard and friable. It will erode with the first heavy rains.

Just How Much Does a Eucalyptus Drink?

At Kenya’s ICRAF Agroforestry Centre, scientists working in partnership with the University of Western Australia have developed what is undoubtedly the world’s most accurate means of measuring how much water any type of tree consumes. The idea behind it has been around for about 50 years in the literature, but it was only recently that advanced digital technology made a robust, user-friendly and precise system possible.

Briefly, the method uses three digital probes inserted into a tree to measure sap flow both up and down the stem. The top and bottom needles contain heat-sensitive plates, while the middle one develops a uniform heat pulse throughout the depth of the sapwood. All the probes are connected to a 16-bit micro-processor computer that converts analogue readings to a calibrated digital output. To compensate for small variations and inaccuracies, multiple readings are sampled. All the data is then stored in a memory chip and available through ICRAF or its international associates and partners.

Equipped with clear data, scientists can now advise agro-foresters and farmers authoritatively on such matters as the most drought-tolerant types of trees to plant and how much water they will need.

Eucalypts were among the first trees studied by ICRAF, because so many are grown for timber and paper – and frankly, because it was about time to settle the heated question of whether they are light or heavy drinkers. According to Dr. Chin Ong, a leading agroforestry researcher who spearheaded ICRAF-UWA system development, “The eucalyptus is the thirstiest tree of all.” Even on a day when little water is available, each tree will slurp 10 liters per day.

Multiply that by the millions of gums growing in Portugal alone, and it adds up to a staggering use of our dwindling water. Now consider this: in the summer of 2015, Portugal has received only 10% of its usual seasonal precipitation. So where is the water for everyone’s survival to come from? Eucalypts know. They are capable of sinking a taproot however far it takes to reach the underground aquifer; in other words, if there is any water at all underground, you know exactly what species will get it.

Deep ash surrounds lightly-charred eucalypts and the remains of a venerable oak that has been lost forever.

Dr. Chin is advising the farmers of East Africa to remove commercially-grown eucalypts or cease replanting when these are harvested, and to replace them with alternative timber/nut tree crops. It’s advice the Portuguese should heed.

If you use a credit card to shop and you (spend) more than you are earning, you will be in problems. This is the same with the eucalyptus tree, as demonstrated by the sap flow method, as it uses more water than the ecology can provide.” – Dr. Chin Ong, ICRAF, Kenya

Portugal’s ecological credit card is “maxed out”. Our natural world is being bankrupted, and other species (including people) are being robbed of their birthrights to sufficient water, clean air, and reasonable safety from fires. And why? Simply so that individual landowners, big corporates and shareholders can line their pockets. But who pays for the damage they cause?

We do, all of us. Year after year. To everyone who lives near plantations of eucalypts, I say this: If you want this situation to change, don’t stay silent. Speak out. Organise. Form groups, write petitions and tell those with power over forest planning and management: “It’s time for change.” There can be no sitting on the fence over this issue. The damned fence is burning.

A scorched lizard gutted by ants. A week after the fires near Figueiró dos Vinhos, the ground was still hot and deep roots smouldered.

Read more about ICRAF here:

Read about ICRAF’s parent, the Consortium of International Agricultural Research Centres here: and in particular, read this important Institute for Environmental Management and Assessment piece about a project replacing eucalypts in the Algarve.

Photos and text © Jude & Keith Irwin Figueiró dos Vinhos, Portugal 2015. For permission to use any of this material email:




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