unique habitat of ancient olive trees in deir hanna

ברוקשטיין: עופר צילום

Que

rcus

ithab

uren

sis

Olive

3500-

525-

1675-

775+

1750+

BCAD

Canaanite period

Early IsraerliIsraeli period

Persian period

Helenistic period

Roman period

Byzantine period

Arabian periodCrusades

Mamluk period

Ottoman period

British mandateState of Israel

Stormy, cold, and rainy

ויבש חם) שיא ) וגשום קר

ויבש חם

וגשום קר

ויבש חם

וגשום קר

Stormy, cold, and rainy

Hot and dryCold and rainy

Hot and dry

Cold and rainy

Hot and dry

Cold and rainy

Hot and dry

Cold and rainy (include the little ice

age)

Hot and dry

Human history

ברוך" ) פ (1994ע " פ ע פליאואקלים

Issar (2001) ואחרים

Unique habitat as the key factor for the survival and vitality of Deir Hana old olive

treesNir Herr – Forest department, Northern region, KKL-JNF

Deir Hanna old olive trees are well known for their impressive stem. The unique appearance in this local spot was examined.

We have raised and tried to answer questions such as: Why they are growing here, how old are they, and why they had survived

exactly here during dry periods. Is there any guaranty for their future livelihood?

Recently, hydro-mechanical operations intending to increase water flow in the spring below are threatening this rare orchard.

How many people are needed to hug the tree ?

Deir Hanna

Rama formation

Kamon formation

Quercus calliprinos maquis

The ancient oliveThe springThe olive land

ויניקהו דבש מסלע ושמן מחלמיש צור

כגון סיכני וחברותיהמדרש תנאים לספר דברים

ל"ב

The ancient olivesThe maquis

The spring

Rock structure

Yelow Marl

Marly chalk

Reddish sandstone

Breccia

The maquis grows on higher stratigraphic layer relative to the Olive layer

Good hydraulic conductivity, fast flow

Low conductivity, slow flow

Aquitard: very low conductivity, slowly flow

Marly chalk

Marl

Cracked rock

Spring

A schematic draw of the hydrogeological system. Water percolate in and between rock layers with different water conductivity.

Quarrying

310

312

314

316

318

320

322

324

326

0 10 20 30 40 50 60

Heig

ht a

bove

sea

leve

l (m

)

Horizontal distance

Topography and layer section Topography section

Layer inclination

Pipe line

Maquis layerOlive layer

Maquis layer

The site is part of an inclined geological block. The Olives are growing in the soil on the marly chalk, and the maquis is on a layer above it.

Quarry

Deir Hanna olives

The ancient olive trees

Geological, pedological and hydrological factors were studied. The site is located on the fairly rare Rama formation of the Lower Cretaceous era. The unique habitat was comprised of: an aerated soil, inclined layer of marly chalk which serves as a perched aquifer, and a water saturated marl beneath. This specific habitat increased trees vitality and survivorship through the centuries even in dry periods.

The site

The rock-soil system

The hydrogeological system

Oaks

Q. C

allip

rinos

Pist

acia

Years

Pollen amount Climate conditions

The Olive history as reconstructed by pollen research from the bottom of the Sea of Galilee.

Compared to the human periods and climate conditions

A quotation from the “Mishna”:

that Implies on the region olive oil fertility

Deir Hanna olives in the Galilee

A panoramic view of the slopeUpper left – the olive orchard, Bottom right – the spring

Pollen after Baruch, 1994Climate after Issar, 2001 and others

The olive orchard – past, and future?Relying on pollen and Paleo-Climatic research, we assess that the trees were planted around 2,000 years ago, in the Hellenistic and Roman period (as shown in the Figure on the right), in a relative humid climate. At that era olive plantations were at its peak.

Dier Hana Olive trees succeeded to overcome dry periods while olive trees in surrounding lands have not. This is due to their unique habitat

The threat: recently, hydro-mechanical operations were made downward the aquifer, (the quarry) intending to increase water flow in the spring.

This intervention might accelerate the flow in the perched aquifer, reduce the water availability and could risk trees survival in the future.