The formation of the vegetation in Alonim-Shefar'am hills and Ramat Menasheh includes herbaceous societies, batha, garrigue, woodland,

and maquis. Quercus ithaburensis woodland generally exists on chalky rock hills, covered with a Nari hardpan and a shallow Brown

Rendzina soil, with scattered soil pockets up to 1.5 m deep. On marl covered with Nari the trees look smaller, reach higher water tension

values, and exhibit an earlier fall exfoliation. In this area forests do not exist on cracked limestone infrastructures, and the formation of flora is

usually from herbaceous to shrubs. Quercus calliprinos maquis exists in the region on more unified and soft chalky rocks with a few soil

pockets.

A previous research showed that the hydraulic traits of the rock-soil system, expressed mainly in rock storativity, hydraulic conductivity and

water retention, are the main factors affecting the establishment and survival of trees. Following examination of environmental factors, it

seems that the dynamics of the water regime in the tree, rock, and soil system dictates the growth rate of the trees and the nature of the

growth cycle process.

The research area and its characteristics – The present study focused in Alonim-Menasheh syncline. The syncline border was determined

by a structural map. The region is characterized by a syncline with defined borders between two anticlines with a cross elevated hinge line,

probably an ancient anticline ("The cross altitude"). The syncline is divided by the Carmel-Yokne'am fault and the Izra'el Valley with several

fault lines within the area, especially in its northern parts. The Izra'el Valley was not included in the research, since the rocky layers are

covered with a deep soil, a situation beyond the aims of the research.

The hypothesis was that the structure of the rock-soil system and its hydraulic characteristics are the main factors that dictate the general

distribution of Quercus ithaburensis and Quercus calliprinos in the Mediterranean region and especially in the Alonim-Menashe region. The

difference between the various habitats is expressed particularly in the water regime, determined mainly by the storativity of the rock and the

soil and the water flow that exist in them, which affect the composition of the tree species of trees and their physiological reaction. It was

expected that studying the dynamics of the water system in the habitat, once we distinguish the structure and characteristics of the habitat,

would enable us to understand the active processes that sustain the formation of vegetation in each habitat, including the composition of

species and their establishment prospects.

The research goals were: (1) to understand the processes that occur in the habitats of Alonim-Menashe region, which affect the distribution

and the development of vegetation, especially the woodland and maquis forms; (2) to find the relationships between the geological structure

and the structure of rock and soil system and the formation of vegetation, the composition of the species, and their development in the

Alonim-Menashe region; (3) to study the moisture pattern, the changes occurring in it, and trends of water movement in the rock, soil, and

plant throughout the year and to calculate the water balance; (4) to reach a comprehensive understanding of the rock-soil-water-tree

interrelationships, namely to find the factors affecting the optimal growth of the main species in the woodland and maquis in the region; (5) to

determine development principles in woodland and maquis, which could be pertained to similar habitats in the Mediterranean region of Israel.

Rock-soil system and water regime dynamics in the habitat as the main ecological

factors of Quercus ithaburensis and Quercus calliprinus in Alonim-Menashe region (Israel)

Nir Herr– abstract

(Herr N. 2008. PhD thesis, Hebrew univ. of Jerusalem [in Hebrew with English abstract]

Methods - (1) Mapping of topographical, geological, soil, and vegetation conditions; Comparison of the various mappings

was done in a geographic information system (GIS) and a some other programs. (2) Establishment of experimental

stations, after preliminary surveys, to study the underground in them and drilling 4.5-8.5 m deep boreholes system. (3)

Studying of the underground system and the relations between tree roots and the infrastructure, by description,

documenting and photographing many rock sections in the area, scanning with ground-penetrating radar (GPR) in the

experimental stations, core drillings, video filming in the borehole, and digging a 3.5 m deep pit inside the station, from

which samples of rock and soil sample were taken. (4) Examination of soil and rock characteristics in the laboratory:

moisture, density, insoluble residues, and retention curves. (5) Measurement of rock and soil moisture in the experimental

stations by neutron prob, borehole antennas radar, and continues measurements with gypsum blocks. (6) Measurement

of the hydraulic conductivity in the sampling pit by flooding and following the infiltration and percolation of water. (7)

Calibration of the measuring equipment by comparing the measuremens to the moisture data and the rock and soil

characteristics in the sampling pit and in the boreholes and the drilling cores. Creation of calibration curves after statistical

analysis, by using the combined parameters obtained with the various devices. (8) Constant measurements of rock and

soil temperature up to 4 m depth, air temperature, leaf temperature, relative humidity, precipitation, wind, and solar

radiation. (9) Measurement of the transpiration by the heat pulse method and calculation of the tree conductivity by the

vapor pressure deficit (VPD). Porometer was used to measure the transpiration and stomata conductivity, and the water

tension in the leaf was measured with a pressure chamber. (10) Determination of tree dimensions and phenological

follow-up after dates of badding and exfoliation and estimation of the amount of foliage and acorn yield.

Results: Comparative mapping – A comparative geobotanical mapping was conducted to examine the hypothesis that

various formations of vegetation, the woodland, the understory vegetation, and the maquis, appear on certain layers and

rock types, on which different habitats have developed. The question whether there is constancy in the appearance of

vegetation in accordance with the changes in the nature of the rocks. A high agreement was found between changes in

the vegetation and the gradual transitions between rock layers in and between geological formations throughout the

length and width of the Ramat Menashe, and also in several sites that were examined in the Alonim-Shefar'am region.

There is a tendency of reduced rock density and increased capillary porosity in the ascension of the stratigraphic column

in the Adolam formation and Maresha formation above it. A similar tendency was found in the transition from the syncline

edge to its center in the one rock layer. Accordingly, gradual differences in the vegetation were found, in accordance, from

herbaceous to batha societies, the woodland of Quercus ithaburensis with its accompanying vegetation, and aventually to

Quercus calliprinos maquis, with increasing coverage rate from medium to dense.

Studying of the rock-soil structure and rock characteristics – The many rock sections documented and described in the various

quarries in the woodland, the maquis, and other vegetation formations provided significant additional information on the structure of the

rock-soil system in the various habitats. In the Quercus ithaburensis woodland there are different phases of chalk or marly chalk rocks

covered with a Nari hardpan in various developmental stages and soil pockets, some of which are continuous and some are in expanded

rock cracks or between rock layers. The data obtained contained the rock and soil density, the insoluble residue, and the clay rate in the

rock, which were compared to the detailed description of the rock sections. The density was also used to calculate the volumetric

moisture from the gravimetric moisture. A large horizontal variability was obtained within the measuring stations, and the rock

characterization data were used as a basis for the understanding of the characteristics of the various habitats. The obtained retension

curves were characteristic to the soil, the Nari, and the chalky rocks in different depths, and curves were prepared to various rock

appearances characterized by amplitude values measurements of the boreholes antennas, that mainly reflect the composition of rock

clay. The highest moisture saturation in the rock was obtained in marly chalk from 3 m depth and more.

Calibration and the calculation equations – The common methods to determine the moisture by borehole radar antennas (according to

Topp equation) and water tension by gypsum blocks were examined and verified under the local area conditions and an improvement in

the calculation of gypsum blocks' data was introduced by mediating the temperature. Calibration of the neutron probe was done by the

amplitude parameter obtained by the concomitant measurements with the borehole antenna radar. The calibration curve of the neutron

probe, which showed a high significance, is a model of covariance that includes 8 amplitude levels of the borehole antenna waves.

Interpretation of the GPR scanning under the research area conditions was also done with the aid of borehole antenna data, by which the

distinction between the Nari horizons, chalk, limestone and the soil pockets was studied.

Rock moisture and its changes with time and space – A seasonal wetting and percolation models were obtained, in which the time of

the peak of moisture in depth occurs at the time when the soil and upper Nari horizon were in a drying stage. Six different sites were

determined in the Quercus ithaburensis woodland. For example, in an average habitat of Nari covered with marly chalk, rain in the

beginning of the winter wets the soil pockets and continues to percolate slowly. The percolating water reaches depths of 1.5-2.5 m during

the spring and accumulates there. The rains in midwinter and in the spring, reach depths of 0.35-1.25 m that are immediately taken up by

the trees and the understory vegetation. Excess water that does not taken up continues to percolate downward, and the peak zone of the

uptake migrates downward during the summer. The water accumulated in the spring in depths of 1.5-2.5 m are probably the main source

of water uptake during the summer. The uptake at the beginning of the spring is from the soil pockets, and in the summer from the rock

media. At the beginning of the summer water from the rock are taken up mainly in the upper 1 m, in a distance of about 35 cm from the

roots, where a 25 cm depth section contributes a daily flux of more than 0.1 mm. At the end of the summer of a rainy year (2002) the

uptake took place mainly between 1 to 2 m, where according to the habitat and the root depth the uptake distance of the roots in the rock

was 35-120 cm. In an exeptionally rainy year (2003) water was taken up from a depth of 275 cm in the rock, probably due to deep water

availability and a relatively high hydraulic conductivity up to 175 cm distance from the roots. Under these conditions, a depth section of 25

cm from the bottom of the absorption area contributes about 0.01 mm water per day. The amount of annual precipitation also affects the

annual rate of uptake.

In the Quercus calliprinos maquis, stages of accumulation and uptake were observed in the upper wetting-dryness range, up to

2-3 m depth. Uptake from these depths was about two thirds of the total uptake. It seems that in this habitat the uptake occurs up

to 4 or 5 m depth. Changes in moisture in higher depths only express percolation. Roots in this habitat penetrate thin rock joints

up to depths of several meters. the movement distance of water from the rock to the roots in this habitat is probably short.

Transpiration – Models of water transpired by the trees were built throughout the year. In Quercus ithaburensis, three stages

were distinguished in the annual transpiration process. In the first stage the rate of transpiration increases constantly from the

beginning of budding in mid-February until the beginning of May and reaches a rate of about 1.3 mm per day. In the second

stage the control system of the tree balances the water uptake, that remains constant until about the end of June. In the third

stage there is a gradual decrease in the rate of transpiration until it stops with the exfoliation at the beginning of the winter. In dry

years in a relatively arid area, the uptake rate decreases immediately after its peak at the beginning of May, and the total annual

transpiration is lower.

In Quercus calliprinos, two stages were observed in the transpiration behavior. In the winter the water requirements of the

evergreen tree are very low, and the transpiration rate increases gradually in the spring until the beginning of May, when it

reaches to about 1 mm per day. Immediately after that there is a gradual decrease to the low winter level. It was possible to

determine various types of trees during measurements of individual tree conductivity, which differed in their conductivity and in

response to daily and seasonal draught under specific conditions in their habitat. Comparison between years, indicated that in

dry years transpiration in Quercus calliprinos maquis was significantly lower than that in the Quercus ithaburensis woodland.

Water balance – The average amount of precipitation in the four years of measurements was 644 mm (112% of the average

perennial amount – 577 mm). The average water uptake according to sub-soil measurements in the Quercus ithaburensis habitat

was 221 mm, which according to the water balance calculations is 34% of the annual amount of the rain during this period. Of

this amount 33% were related to evapotranspiration from the sub-forest, 28% to runoff water, and only 4% to percolation to the

underground water. In the Quercus calliprinos maquis, the total uptake was between 152 mm in a dry year to 197 in a rainy year.

Research innovations – The research innovations included: adaptation of methods of moisture measurements in the rock;

adaptation of the calibration of the neutron probe in the rock, characterized by a great spatial variability, by the aid of borehole

antenna radar measurements; agreement between the vegetation dispersal and geology, and understanding the spatial

constistency in the investigated region; understanding the dynamics of percolation, water accumulation and uptake in depth and

in time of oak trees in the various habitats, mainly in chalk; presentation of the water regime in two major Mediterranean

formations, woodland and maquis, in Israel; outlining principles that enable implementation of the research results in other

regions, considering the type of rock, the structure of the rock-soil system and the climatic and microclimatic conditions.

Chalky limestone

Bata (low shrubs)

or herbaceous

Q. Calliprinos maquis

Q. Ithaburensis

woodland

0

-1.0-

- 2.0 -

- 3.0 -

- 4.0 -

- 5.0 -

Depth

(m)

Soft chalk Med. chalk Hard chalk Dolomite & Limestone

Limestone and dolomite in Judea gr.

Timrat formation, limestone facies

Timrat formation chalk facies Maresha formation

On a limestone transition to soft chalk of the Avdat Group (Eocene era) in Alonim-Menashe Syncline (Israel)

habitatsOak

Water reservoir in the porosity chalk

Other habitat: On karstic

dolomite and limestone of Judea Group

Terra rossa Brown Rendzina

Q. Calliprinos

maquis

Roots

כיס קרקע

Leaf tension 30-40 Bar at noon

0

50

100

150

200

250

300 Nov Oct Sep Aug Jul Jun May Apr Mar Feb Jan Dec

Lower friable Nari

Upper Nari hardpan

Chalk or marly chalk

Spring rain

Horizontal uptake at the end of the summer

Vertical u

ptake at

th

e end

of th

e su

mm

er

קליטה סמויה

Early summer uptake

Water regime dynamics in Q. ithaburensis habitat. Changes in depth and time of uptake, percolation and evaporation

5 mm deeper

percolation

Time axis. Yearly month

Dep

th (cm

)

Evapotranspiration of understory

Runnoff 28%

Winter rain

At spring the uptake is from the soil pocket

Root tension 20 Bar

Tension 0.75 Bar

Yearly uptake 230 mm

225 mm

Multi-year average 570 mm

Subsoil properties as the main factors in drying and mortality of Pinus halepensis at the Yatir forest, northern

Negev, Israel

Nir Herr1, Yakir Preisler2, Eyal Rotenberg2, Noam Greenbaum3

•KKL-JNF, Forestry Department and Northern region, POB 45, Kiryat Haim, Israel

•Weizmann Institute, Department of Earth and planetary Sciences, Rehovot, Israel

•Haifa University, Department of Geography and Environmental Studies, Haifa, Israel

nirh@kkl.org.il

In Yatir forest - the largest forest in Israel, located at the southern edge of the dry Mediterranean region (280 mm mean

annual), a patchiness mortality pattern of pines was observed after continuous droughts. The forest was planted in the 1960’s-

70's, with Pinus Halepensis - a native tree, reputed as relatively drought resistant, as the main tree in the forest.

The objective of the study was to identify the environmental factors that caused the mortality of the trees exposed to ongoing

dry climatic conditions at the background. The study aims at understanding the mortality phenomenon in order to implement

the conclusions in establishment and management of forests in the Mediterranean Region.

An updated aerial photo and a detailed survey in the forest were used to locate plots with patches of both dead and living

trees. At each patch, the trees were documented using regular forestry criteria.

In 11 plots, a trench was dug in each patch to a depth of 1.5 m into the soil and the underlying bedrock. The roots were

measured, stoniness was estimated and the rock-soil-root-tree system was documented in detail. Soil and rock were sampled

at depths of 20, 50, 80, 110 cm and deeper according to site-specific soil depth. Water content, mechanical composition,

salinity, SAR, calcium carbonate content, and rock density, were analyzed in the lab. In addition, locations of dry trees in the

forest were examined in relation to the soil and rock exposure relationships.

The main results are:

• The living trees are located mainly over slopes of chalky rock overlain by shallow, stony lithosol.

•This chalky bedrock determines the development of the shallow soil and its stony and calcareous nature.

•The porous chalk serves as a water reservoir. The shallow soil enables close contact between the roots and the rock. The

stones help to hold moisture throughout the dry season and therefore serve as preferred zones for roots development.

•The soil in this environment contains tolerable levels of salinity and sodium. Their influence is minor compared to the water

gain from the chalk and the importance of this habitat to the tree water system.

Our results suggest that the preferable environment for planting pines in this region is chalk overlain by shallow and stony soil.

Storage of water in this rock-soil system is the key factor affecting the survival and success of the forests in this semi-arid

Mediterranean Region.

Abstract of lecture in MedPine5, Forest Sciences center of Catalonia, Spain, Sept. 2014