THE ARID ECOSYSTEMS RESEARCH CENTER

INTRODUCTION:
THE ARID ECOSYSTEMS RESEARCH CENTER (AERC)
Director: Prof. Aaron Kaplan
Tel: 972-2-658-5234
E-mail: aaronka@vms.huji.ac.il
Scientific Coordinator: Mr. Simon Berkowicz
Tel: 972-2-658-4353
E-mail: berkowi@vms.huji.ac.il

Nearly one-third of the world's total land area is arid or semi-arid. Many
developing countries are situated in dry regions where the needs of the rapid
increasing population have often led to misuse of the land. In recent years t
consequences of such misuse have been compounded by drought. Desert ecosystem
are so delicately balanced that once disturbed they may require a lengthy
period of time to recover. In order to improve our understanding of the
structure and function of arid and semi-arid areas, and in view of the ongoin
threat of desertification, the Hebrew University of Jerusalem, together with
the Minerva Gesellschaft of the Federal Republic of Germany, established the
Arid Ecosystems Research Center (AERC) in 1987. The purpose was to encourage
longterm interdisciplinary scientific cooperation for research to be carried
out at field stations in the Negev desert and vicinity.

Due to the strong interactions between abiotic (climatology, hydrology,
pedology, geomorphology) and biotic aspects (botany, microbiology, physiology
zoology), the AERC adopted a multidisciplinary research approach to integrate
them as well as investigate feedback mechanisms. Initially four experimental
sites (Nizzana, Sede Boker, Avdat, Hatzeva) were selected in the Negev desert
to serve as long-term monitoring and experimental stations. The stations were
established in sandy, rocky and loess ecosystems in order to develop our
overall understanding of the desert environment. The bulk of AERC research
activities have focused, however, at two stations - Sede Boker and Nizzana -
primarily as a result of greater interest in these two sites.

The Nizzana station (average annual rainfall about 100 mm) was established in
1988, in a sandy area composed of linear dunes having relatively well-preserv
natural vegetation. Measurements have included meteorological data collection
high-density rainfall measurements, dew, soil moisture, runoff and sediment
removal, dust fallout, seed germination and others.

The Sede Boker experimental station (average annual rainfall about 100 mm),
originally established in 1972 by Prof. A. Yair, had been instrumented for
measuring the spatial and temporal variability of rainfall, wind regime,
hillslope and channel runoff, and soil erosion. It is characterized by a
rocky/loess environment.

Three additional sites were later established. The "Shivta" station lies
halfway between Sede Boker and Nizzana, while the other 2 stations are locat
north of Nizzana along the Egyptian-Israeli border.

The research has resulted in about 175 publications and 45 graduate theses.

The abiotic variables studied have so far included:
Soils: Morphology, genesis, ecology, soil moisture, salinity, permeability,
soil erosion and deposition.

Climate: Temperature, rainfall, hydrological rainfall, rainfall intensity, wi
speeds and wind regime, dew deposition and evaporation, dew collecting, fog a
fog water collecting.

Hydrology: Runoff, rainfall-runoff relationships, spatial variability of runo
along slopes, water harvesting.

The biotic variables studied have so far included:
Plant ecology and physiology: Responses to the stress conditions (studied at
the proteins and gene levels), seed production and dispersal, germination,
establishment, survival, growth, flowering, pollination, and competition.

Biological crust: Characteristics and activities, nature of the organisms and
their physiological/molecular response to hydration/dehydration cycles, the
effect on runoff and erosion, recovery following disturbance.

Animal ecology and behavior: foraging strategies, habitat selection and
preference, bioturbation.

Resources: The availability and predictability of resources (water, nutrients
etc.) and spatial heterogeneity of these resources.

RECENT PUBLICATIONS:
Berkowicz, S.M., Lavee, H. and Yair, A., eds. (1998) Geomorphic Response t
Climate Change. Geomorphology (Special Volume), 23 (2-4), 369 pp.

Beyer, L., Tielb?rger, K., Blume, H-P., Pfisterer, U., Pingpank, K. and
Podlech, D. (1998) Geoecological soil features and the vegetation pattern in
arid dune area in the Northern Negev, Israel. Zeitschrift f?r
Pflanzenernahrung und Bodenkunde, 161: 347-356.

Harrison, J.B.J. and Yair, A. (1998) Late pleistocene and fluvial interaction
in the development of the Nizzana dune field,
Negev Desert, Israel. Sedimentology, 45: 507-518.

Bornkamm, R., Darius, F. and Prasse, R. (1999) On the life cycle of
Stipagrostis scoparia hillocks. J. Arid Environments, 42:
177-186.

Jacobs, A.F.G., Heusinkveld, B.G. and Berkowicz, S. (1999) Dew deposition and
drying in a desert system: A simple simulation model. J. Arid
Environments, 42: 211-222.

Kadmon, R. and Tielb?rger, K. (1999) Testing for source-sink population
dynamics: An experimental approach exemplified with desert
annuals. Oikos, 86: 417-429.

Yair, A. (1999) Spatial variability in the runoff generated in small arid
watersheds: Implications for water harvesting. In: Arid Lands
Management, eds. T.W. Hoekstra and M. Shachak, Urbana-Chicago, University
of Illinois Press, pp.212-222.

Jacobs, A.F.G., Heusinkveld, B.G. and Berkowicz, S. (2000) Force restore
technique for ground surface temperature and moisture content in a dry desert
system. Water Resources Research, 36: 1261-1268.

Littmann, T. and Gintz, D. (2000) Eolian transport and deposition in a
partially vegetated arid longitudinal sand dune area. Z. Geomorphologie,
Supplementband, 121: 71-90.

Tielb?rger, K. and Kadmon, R. (2000) Temporal environmental variation tips th
balance between facilitation and interference in a desert plant
community.Ecology, 81: 1544-1553.

Anand, M. and Kadmon, R. (2000) Community-level analysis of spatio-temporal
plant dynamics. Ecoscience, 7: 101-110.

Hassan, M., Slaymaker, O. and Berkowicz, S.M., eds. (2000)
The Hydrology-Geomorphology Interface: Rainfall, Floods, Sedimentation, La
Use. Intl. Association Hydrological Sciences. Red Series Vol. 261, 326 pp

Prasse, R. and Bornkamm, R. (2000) Effect of microbiotic soil surface crusts
emergence of vascular plants. Plant Ecology, 150: 65-75.

Kidron, G.J. (2001) Runoff-induced sediment yield over dune slopes in the Neg
Desert. 2: Texture, carbonate and organic matter. Earth Surf. Proc.

Land., 26: 583-599.

Kidron, G.J. and Yair, A. (2001) Runoff-induced sediment yield over dune slop
in the Negev Desert. 1: Quantity and variability.

Earth Surf. Proc. Land., 26: 461-474.

Mittler, R., Merquiol, E., Hallak-Herr, E., Rachmilevitch, S., Kaplan, A. and
Cohen, M. (2001) Living under a 'dormant' canopy: A molecular acclimation
mechanism of the desert plant Retama raetam. Plant Journal, 25:
407-416.

Veste, M., Littmann, T., Friedrich, H. and Breckle, S.W. (2001) Microclimatic
boundary conditions for activity of soil lichen crusts in sand dunes of the
north-western Negev desert, Israel. Flora, 196: 465-474.

Veste, M., Littmann, T., Breckle, S.W. and Yair, A. (2001) The role of
biological soil crusts on desert sand dunes in the northwestern Negev, Israel

In: Sustainable Land Use in Deserts, eds. S.W. Breckle, M. Veste, and

Wucherer, Berlin, Springer, pp.357-367.

Yair, A. (2001) Effects of biological soil crusts on water redistribution in
the Negev desert, Israel: A case study in longitudinal dunes. In: Biologic
Soil Crusts: Structure, Function and Management, ed. J. Belnap and O.L.

Lange, Berlin, Springer-Verlag, pp.303-314.

Jacobs, A.F.G., Heusinkveld, B.G. and Berkowicz, S.M. (2002) A simple model f
potential dew-fall in an arid region. Atmospheric Research, 64: 285-29

Merquiol, M., Pnueli, L., Cohen, M., Simovitch, M., Goloubinoff, P., Kaplan,

and Mittler, R. (2002) Seasonal and diurnal variations in gene expression in
the desert legume Retama Raetam. Plant Cell and Environ., 25: 1627-163

Pnueli, L., Hallak-Herr, E., Rozenberg, M., Cohen, M., Goloubinoff, P., Kapla
A. and Mittler, R. (2002) Mechanisms of dormancy
and drought tolerance in the desert legume Retama raetam. Plant Journal,
31: 319-330.

Sharon, D., Margalit, A. and Berkowicz, S.M. (2002) Locally modified surface
winds on linear dunes as derived from directional
raingauges. Earth Surf. Proc. Land., 27: 867-889.

Yair, A. and Kossovsky, A. (2002) Climate and surface properties: Hydrologica
response of small arid and semi-arid watersheds. Geomorphology, 42:
43-57.

Yair, A. and Verrecchia, E. (2002) The role of the mineral component in surfa
stabilization processes of a disturbed desert sandy surface.

Land Degrad. Develop., 13: 295-306.

Berkowicz, S.M., Beysens, D., Milimouk, I., Heusinkveld, B.G., Muselli, M.,
Wakshal, E. and Jacobs, A.F.G. (2004) Urban dew collection under semi-arid
conditions: Jerusalem. Third Intl. Conf. on Fog, Fog Collection and Dew. Oct
11-15, 2004, Cape Town, South Africa, pp. E4: 1-4.

Harel, Y., Ohad, I. and Kaplan, A. (2004) Activation of photosynthesis and
resistance to photoinhibition in cyanobacteria within biological desert
crust.Plant Physiology, 136: 3070-3079.

Heusinkveld, B.G., Berkowicz, S.M., Jacobs, A.F.G. and Willen, W. (2004)
Development of a Load Cell for use as a weighing micro-lysimeter to measure
dew. Proc. Third Intl. Conf. on Fog, Fog Collection and Dew. Oct 11-15
2004, Cape Town, South Africa, pp.E1: 1-4.

Jacobs, A.F.G., Heusinkveld, B.G. and Berkowicz, S.M. (2004) Dew and fog
collection in a grasslands area: The Netherlands. Proc. Third Intl.

Conf. on Fog, Fog Collection and Dew. Oct 11-15, 2004, Cape Town, South Afric
pp.F2: 1-4.

Mileta, M., Muselli, M., Beysens, D., Milimouk, I., Berkowicz, S.M.,
Heusinkveld,B.G. & Jacobs, A.F.G. (2004) Comparison of dew yields in four
Mediterranean sites: Similarities and differences. Proc. Third Intl. Conf. on
Fog, Fog Collection and Dew, October 11-15, 2004, Cape Town, South Africa,
pp.E2: 1-4.

Heusinkveld, B.G., Jacobs, A.F.G., Holtslag, A.A.M. and Berkowicz, S.M. (2004
Surface energy balance closure in an arid region: Role of soil heat flux.

Agriculture and Forest Meteorology, 122: 21-37.

Ohad, I., Nevo, R., Brumfeld,V., Reich, Z., Tsur, T., Yair, M. and Kaplan, A.

(2005) Inactivation of photosynthetic electron flow during desiccation of
desert biological sand crusts and Microcoleus sp.-enriched isolates. J.

Photochemistry and Photobiology, 977-982.

Heusinkveld, B.G., Berkowicz, S.M., Jacobs, A.F.G., Holtslag, A.A.M. and
Hillen, W.C.A.M. (2006) An automated microlysimeter to study dew formation an
evaporation in arid and semi-arid regions. J. Hydrometeorology, 7,
825-832.

Jacobs, A.F.G., Heusinkveld, B.G., Wichink Kruit, R.J. and Berkowicz, S.M.

(2006) Contribution of dew to the water budget of a grassland area,
Netherlands. Water Resour. Res., 42, W03415, doi:10.1029/2005WR004055.

Beysens, D., Muselli, M., Milimouk, I., Ohayon, O., Berkowicz, S.M., Soyeux,
E., Mileta, M., Ortega, P. (2006) Application of passive radiative cooling fo
dew condensation. Energy, 31: 1967-1979.

Beysens, D., Milimouk, I., Nikolayev, V., Berkowicz, S.M., Muselli, M.,
Heusinkveld, B.G. and Jacobs, A.F.G. (2006) Comment on "The moisture from the
air as water resource in arid region: HOPES, doubt and facts" by Kogan &
Trachtman. J. Arid Environ., 67: 343-352.

Berkowicz, S.M., Rautenbach, H. and Olivier, J., eds. (2008)
Proceedings. Third Intl. Conf. on Fog, Fog Collection and Dew, Oct
11-15, 2004, Cape Town, South Africa. Atmospheric Research, vol.87.

Littmann, T. and Berkowicz, S.M. (2008) The regional climatic setting. In:
Arid Dune Ecosystems - The Nizzana Sands in the Negev Desert, eds. S.W

Breckle, A. Yair and M. Veste, Ecological Studies, Vol. 200,
Berlin-Heidelberg-New York, Springer, pp. - (in press).

Veste, M., Heusinkveld, B.G., Berkowicz, S.M., Breckle, S.-W., Littmann, T. a
Jacobs, A.F.G. (2008) Dew formation and activity of biological soil crusts. I
Arid Dune Ecosystems - The Nizzana Sands in the Negev Desert, eds. S.-

Breckle, A. Yair, and M. Veste, Ecological Studies vol.200,
Berlin-Heidelberg-New York, Springer, pp.305-318.

Jacobs, A.F.G., Heusinkveld, B.G. & Berkowicz, S.M. (2008) Passive dew
collection in a grassland area, The Netherlands. Atmospheric Research,
87: 377-385.

Heusinkveld, B.G., Berkowicz, S.M., Jacobs, A.F.G., Hillen, W.C.A.M. and
Holtslag, A.A.M. (2008) A remote optical wetness sensor using spectral
reflectance spectroscopy. Agric. Forest Meteorology, 148: 580-591.