James and Thibaud Aronson post here the first part of a 3-part report from The Hashemite Kingdom of Jordan, mid-April, 2015.
As part of an epic project undertaken with our very dear friend in France, Edouard Le Floc’h, and now with expert help from our friend Delphine Vinck, we are working on an ambitious book about trees that grow in deserts, their role in ecosystems there, and their not-to-be underestimated role in the vast number of ecological restoration projects and programs waiting to be undertaken in the vast deserts of the world, and on their ‘shores’, the even vaster semiarid regions of the earth.
This trip started with an inspiring meeting attended by James, in Amman, as part of the fourth gathering of the Ecological Restoration Alliance of Botanic Gardens, and a visit for Thibaud in southern Israel to observe, in some awe, the annual south-to-north bird migration along one of the major flyways of the western Palearctic.
And some mammals along the way.
We reunited in Aqaba, to begin a 4 x 4 road trip together with Hatem Taifour, chief botanist at the Royal Botanic Gardens of Jordan. Jordan and Israel form an incredible crossroads where the floras, faunas and cultures of three continents meet, Africa, Asia and Europe.
According to Avinoam Danin (1999), southwestern Jordan is the ideal place for tracing transects as huge variations in climate, geology, flora, and fauna can be seen over short distances, and remarkable Mediterranean relicts and dozens of endemics occur there, far more so than in Israel and Sinai.
Therefore, our goal was to describe ecological transects following gradients of aridity, from relatively wet mediterranean climate regions at high-elevations with cypress, pine, oaks and pistacia, westward to steppe-desert with juniper and other trees of its own, into the hot, tropical desert of the Rift Valley. The Acacia-dominated vegetation found from the Red Sea to the Dead Sea, and the Jordan Valley, from the Dead Sea to the Sea of Galilee, represents a ‘tongue’ of so-called Sudanian flora, rich in trees. To one side is a colder desert with a Saharo-Arabian flora dominated by shrubs. On the other, is a tongue of penetration coming in from the east and the north of the so-called Irano-Turanian steppe, which experiences hot summers and very cold winters.
We began our trip with a morning visit to the justly celebrated archaeological site of Petra (looking at the trees along the way). We then drove up to Dana Nature Reserve – a jewel of the Mediterranean Basin by any standards and full of endemics and relicts of the Mediterranean vegetation that is now rare in the Near East. We visited rich montane Mediterranean forests, with a real canopy of evergreen oaks and Red Juniper, with populations of Atlantic Pistacia and a small, venerable and unquestionably wild population of Mediterranean Cypress – the only one in all the Near East. To our knowledge, its only other wild populations are in Cyprus and Cyrenaica, Libya. Two of these cypress trees are estimated to be roughly 800 years old.
From there, in just 22 km as the crow flies, we descended to semi-arid steppes at 300 m above sea level, where the vegetation was dominated by red juniper and Rhus tripartita.
Then, Hatem led us down a steep dirt road to a site he had discovered, at 100 m.a.s.l., in remote Wadi Hasa, far from any town or garden. Growing there amidst native poplar and willow, we saw a population of Dalbergia sissoo, where we would never have expected to find it. This tree is native to India, Pakistan, southern Iran, Afghanistan and Oman (Tengberg & Potts 1999) and widely cultivated elsewhere. Danin (1999) reports it occurring in oases near the Dead Sea in Israel, and there are reports of it occurring in Sudan. In Jordan, Hatem Taifour has never seen it anywhere except in this location in Wadi Hasa and in one other wadi.
How then did this wind-dispersed tree get here? Is this a relict from earlier times when climate was different and the species was more widespread, and the tree was widely used for a range of purposes and perhaps intentionally introduced throughout the Near East? There is no clear answer to date….But it certainly added spice to our field trip and food for thought for restorationists working in Near Eastern deserts.
Danin, A, 1999. Desert rocks as plant refugia in the Near East. The Botanical Review 65: 93-170.
Tengberg, M. & D. T. Potts 1999. mes.mii-gan-na (Dalbergia sissoo Roxb.) at Tell Abraq [Oman]. Arabian Archaeology and Epigraphy 10:129-133.