Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

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Using the ecosystem services concept to analyse stakeholder involvement in wetland management
Cohen-Shacham, E. ; Dayan, T. ; Groot, R.S. de; Beltrame, C. ; Guillet, F. ; Feitelson, E. - \ 2015
Wetlands Ecology and Management 23 (2015)2. - ISSN 0923-4861 - p. 241 - 256.
water management - israel - hula - typology - basin - lake
Wetland management usually involves multiple stakeholders. This paper describes how the use of the ecosystem services (ES) concept can help to identify the main stakeholders associated with wetland conservation, using the Hula Wetland in the Sea of Galilee’s watershed as a case study. We conducted a stakeholder analysis based on semi-structured interviews. We focused on the management of two semi-natural areas within the larger Hula Wetland area (Hula Nature Reserve and Agamon), in which different management regimes are used and which provide different bundles of ES to different stakeholders. Using the ES concept in the stakeholder analysis, we were able to present the Hula Wetland management in a comprehensive manner. The approach also revealed a lack of coordination between the managing organisations which might lead to competition favouring cultural services (in particular tourism) at the expense of habitat services (i.e. biodiversity conservation) in the future. To test our method we also conducted a stakeholder analysis in the Camargue Wetland in France. The two wetlands have similar characteristics but are embedded in different institutional contexts. The Camargue Regional Park has a multi-stakeholder platform which could serve as an example for the Hula Wetland to improve its management and lead to better coordination and complementarity of ES provided by the two sub-sites. Our study showed that applying the ES concept helps to quickly identify relevant stakeholders and analyse wetland management in a more holistic way and to point towards sustainable solutions for conflicting stakeholder interests.
Lifelines for Ramat Hanadiv : an analysis of the necessity for ecological corridors
Sluis, T. van der; Eupen, M. van - \ 2013
Wageningen : Alterra, Wageningen-UR (Alterra-rapport 2423)
ecologische hoofdstructuur - landschapsecologie - ecologie - modellen - wild - wildbescherming - israël - ecological network - landscape ecology - ecology - models - wildlife - wildlife conservation - israel
This report presents the results of an analysis of the ecological network for Ramat Hanadiv. We used the LARCH Landscape ecological model to assess, first, the long-term viability of the wildlife populations of Ramat Hanadiv, and secondly, to identify where the most important landscape connections or corridors are situated. Analysis shows that almost no species are viable in Ramat Hanadiv alone; almost all require some exchange with surrounding populations. The exchange with surrounding areas is therefore essential for biodiversity in Ramat Hanadiv. Specific de-fragmentation measures are important. The best measure to improve viability is to ensure that a corridor eastward is maintained. The best location for the corridor is most likely through the industrial zone. A potential corridor through the Taninim River would be another option. This would likely require further study and a significantly larger investment of resources.
Characterization of Dickeya strains isolated from potato grown under hot-climate conditions
Tsror, L. ; Ben-Daniel, B. ; Chalupowicz, L. ; Wolf, J.M. van der; Lebiush, S. ; Erlich, O. ; Dror, O. ; Barel, V. ; Nijhuis, E.H. ; Manulis-Sasson, S. - \ 2013
Plant Pathology 62 (2013)5. - ISSN 0032-0862 - p. 1097 - 1105.
soft-rot erwinias - chrysanthemi - population - israel - crops - pcr
Dickeya strains isolated in Israel in 2006–2010 were characterized by dnaX sequence analysis, pulsed-field gel electrophoresis (PFGE), biochemical assays and pectolytic activity, and found to be homogeneous: most of them could be classified as ‘Dickeya solani’. Of the 34 strains isolated from imported seed tubers or potato plants grown from imported seed, 32 were typed as ‘D. solani’ and only two were characterized as Dickeya dianthicola. Biovar typing indicated that all ‘D. solani’ strains were biovar 3. ‘Dickeya solani’ strains were most closely related to Dickeya dadantii subsp. dieffenbachiae according to PFGE and dnaX analyses and both species exhibited high pectolytic activity. Expression levels of two putative virulence genes, pelL (encoding a pectic enzyme) and dspE (encoding a type III effector) were significantly induced in ‘D. solani’ strains isolated from potato plants or tubers grown in hot climates such as the Negev region in Israel, compared to those isolated from seed tubers imported from the Netherlands, France or Germany. Results of this study support the hypothesis that ‘D. solani’ strains isolated in Israel are also clonal; however, they appear to be more virulent than strains isolated in Europe
Virulence of ‘Dickeya solani’ and Dickeya dianthicola biovar-1 and -7 strains on potato (Solanum tuberosum)
Czajkowski, R.L. ; Boer, W.J. de; Zouwen, P.S. van der; Kastelein, P. ; Jafra, S. ; Haan, E.G. de; Bovenkamp, G.W. van den; Wolf, J.M. van der - \ 2013
Plant Pathology 62 (2013)3. - ISSN 0032-0862 - p. 597 - 610.
soft-rot erwinias - carotovora subsp atroseptica - plant-pathogenic bacteria - host-range - pectobacterium - israel - extracts
Studies were conducted to explain the relative success of ‘Dickeya solani’, a genetic clade of Dickeya biovar 3 and a blackleg-causing organism that, after recent introduction, has spread rapidly in seed potato production in Europe to the extent that it is now more frequently detected than D. dianthicola. In vitro experiments showed that both species were motile, had comparable siderophore production and pectinolytic activity, and that there was no antagonism between them when growing. Both ‘D. solani’ and biovar 1 and biovar 7 of D. dianthicola rotted tuber tissue when inoculated at a low density of 103 CFU mL-1. In an agar overlay assay, D. dianthicola was susceptible to 80% of saprophytic bacteria isolated from tuber extracts, whereas ‘D. solani’ was susceptible to only 31%, suggesting that ‘D. solani’ could be a stronger competitor in the potato ecosystem. In greenhouse experiments at high temperatures (28°C), roots were more rapidly colonized by ‘D. solani’ than by biovar 1 or 7 of D. dianthicola and at 30 days after inoculation higher densities of ‘D. solani’ were found in stolons and progeny tubers. In co-inoculated plants, fluorescent protein (GFP or DsRed)-tagged ‘D. solani’ outcompeted D. dianthicola in plants grown from vacuum-infiltrated tubers. In 3 years of field studies in the Netherlands with D. dianthicola and ‘D. solani’, disease incidence varied greatly annually and with strain. In summary, ‘D. solani’ possesses features which allow more efficient plant colonization than D. dianthicola at high temperatures. In temperate climates, however, tuber infections with ‘D. solani’ will not necessarily result in a higher disease incidence than infections with D. dianthicola, but latent seed infection could be more prevalent
Israel cultiveren nederlands
Livestock Research, - \ 2012
[S.l.] : YouTube
melkveehouderij - loopstallen - dierlijke meststoffen - cultivateren - onderlaag - compostering - vloertypen - israël - dairy farming - loose housing - animal manures - chiselling - understorey - composting - floor type - israel
Nadat de eerder opgeslagen mest weer wordt uitgereden op de vloer van de Israelische loopstal en met een cultivator met de onderlaag is gemengd, wordt het mengsel bekeken en beoordeeld.
Studiereis vrijloopstal Israel 2008
Livestock Research, - \ 2012
[S.l.] : YouTube
melkveehouderij - loopstallen - dierlijke meststoffen - cultivateren - compostering - israël - dairy farming - loose housing - animal manures - chiselling - composting - israel
Een Israelische boer vertelt dat elke dag op zijn bedrijf de reeds opgeslagen mest op zijn bedrijf wordt uitgereden en met een cultivator wordt gemengd met de grondlaag waar het wordt uitgereden.
EBONE in Mediterranean and desert sites in Israel, with notes on South Africa : report on field tests in LTER sites and habitat monitoring
Olsvig-Whittaker, L. ; Jobse, D. ; Gelder, A. de - \ 2011
Wageningen : Alterra (Alterra-rapport 2260) - 54 p.
habitats - biodiversiteit - remote sensing - woestijnen - israël - zuid-afrika - biodiversity - deserts - israel - south africa
Heritability and repeatability of insect bite hypersensitivity in Dutch Shetland breeding mares
Schurink, A. ; Grevenhof, E.M. van; Ducro, B.J. ; Arendonk, J.A.M. van - \ 2009
Journal of Animal Science 87 (2009). - ISSN 0021-8812 - p. 484 - 490.
dermatitis sweet itch - british-columbia - icelandic horses - culicoides hypersensitivity - summer eczema - ceratopogonidae - diptera - israel
Insect bite hypersensitivity (IBH) is a seasonal recurrent allergic reaction of horses to the bites of certain Culicoides spp. and is found throughout the world. The aim of our study was to estimate the heritability and repeatability of IBH in the Dutch Shetland pony population. A total of 7,924 IBH scores on 6,073 mares were collected during foal inspections in 2003, 2005, and 2006. Mares were scored for clinical symptoms of IBH from June until February by 16 inspectors. Of all mares, 74.4% (n = 4,520) had a single observation, 20.7% (n = 1,255) had 2 observations, and 4.9% (n = 298) had 3 observations in different years. The overall mean IBH prevalence was 8.8%. Heritability was 0.08 (SE = 0.02) on the observed binary scale and 0.24 (SE = 0.06) on the underlying continuous scale. Repeatability was 0.30 (SE = 0.02) and indicates that including repeated observations of the clinical symptoms of IBH will improve the accuracy of breeding values for IBH. We conclude that IBH, based on clinical symptoms, is a heritable trait in the Dutch Shetland pony population. Therefore, the IBH prevalence in this population can be decreased by selection
Laboratory, field and airborne spectroscopy for monitoring organic carbon content in agricultural soils
Stevens, A. ; Wesemael, B. van; Bartholomeus, H. ; Rosillon, D. ; Tychon, B. ; Ben-Dor, E. - \ 2008
Geoderma 144 (2008)1-2. - ISSN 0016-7061 - p. 395 - 404.
diffuse-reflectance spectroscopy - meta analysis - regression - sequestration - validation - matter - sensor - israel
The temporal evolution in Soil Organic Carbon (SOC) content is often used in estimations of greenhouse gas fluxes and is an important indicator of soil quality. Regional estimates of SOC changes can only be obtained by analyzing very large number of samples over large areas due to the strong spatial variability in SOC contents. Visible and Near Infrared Spectroscopy (VNIRS) provides an alternative to chemical analyses. The benefits of this technique include a reduction of the sampling processing time, an increase of the number of samples that can be analyzed within time and budget constraints and hence an improvement of the detection of small changes in SOC stocks for a given area. Carbon contents are predicted from spectra through Partial Least Square Regressions (PLSR). The performance of three different instrumental settings (laboratory, field and airborne spectroscopy) has been assessed and their relative advantages for soil monitoring studies have been outlined using the concept of Minimal Detectable Difference. It appears that ground-based spectrometers give Root Mean Square Errors of Cross-Validation similar to the limit of repeatability of a routine SOC analytical technique such as the Walkley and Black method (± 1 g C kg¿ 1). The airborne spectrometer, despite its greater potential to cover large areas during a single flight campaign, has some difficulties to reach such values due to a lower Signal-to-Noise Ratio. Because of its statistical nature, the method and its potential rely on the stability of the calibrations obtained. It appears that calibrations are currently site-specific due to variation in soil type and surface condition. However, it is shown that PLSR can take into account both soil and spectral variation caused by different measuring campaigns and study areas. Further research is needed to develop regional spectral libraries in order to be able to use VNIRS as a robust analytical technique for precisely determining the SOC content and its spatial variation.
C/N ratio control and substrate addition for periphyton development jointly enhance freshwater prawn Macrobrachium rosenbergii production in ponds
Asaduzzaman, M. ; Wahab, M.A. ; Verdegem, M.C.J. ; Huque, S. ; Salam, M.A. ; Azim, M.E. - \ 2008
Aquaculture 280 (2008)1-4. - ISSN 0044-8486 - p. 117 - 123.
fish ponds - aquaculture - systems - culture - israel
The present research investigated the effect of carbon/nitrogen ratio (C/N ratio) control in ponds with or without substrate addition for periphyton development on production of giant freshwater prawn. C/N ratios of 10, 15 and 20 were investigated in 40 m¿ 2 ponds stocked with 2 prawn juveniles (5.023 ± 0.02 g) m¿ 2 with or without added substrates for periphyton development. The various treatment combinations of C/N ratio and periphyton substrate addition are abbreviated as `CN10¿, `CN15¿, `CN20¿, `CN10 + P¿, `CN15 + P¿ and `CN20 + P¿, P representing periphyton substrate. A locally formulated and prepared feed containing 30% crude protein with C/N ratio10 was applied. Tapioca starch was used as carbohydrate source for manipulating C/N ratio and applied to the water column separately from the feed. Increasing the C/N ratio from 10 to 20 reduced (P <0.001) the total ammonia-nitrogen (TAN), nitrite¿nitrogen (NO2¿N) and nitrate¿nitrogen (NO3¿N) in water column and total Kjeldahl nitrogen (TKN) in sediment. The addition of substrates only influenced the NO2¿N concentration in the water column (P <0.001). Increasing the C/N ratio raised the total heterotrophic bacterial (THB) population in the water column, sediment and periphyton (P <0.001). It also increased the dry matter (DM), ash free dry matter (AFDM), and chlorophyll a content of periphyton (P <0.001). The lowest specific growth rate (SGR), the highest food conversion ratio (FCR), and the lowest protein efficiency ratio (PER) were recorded in treatment CN10 (P <0.05). The addition of substrates did not influence size at harvest (P > 0.05) but improved the survival from 62.8 to 72% (P <0.001). Increasing the C/N ratio from 10 to 20 increased the net yield by 40% and addition of substrate increased the net yield by 23%. The combination of C/N ratio control and substrate addition increased the net yield by 75% from 309 (CN10) to 540 (CN20 + P) kg ha¿ 1 (120 days)¿ 1. This 75% higher production concurred with (1) a lower inorganic nitrogen content in the water column, (2) a higher THB abundance supplying additional single cell protein to augment the prawn production, and (3) an improved periphyton productivity and quality.
Identification of factors associated with the development of insect bite hypersensitivity in horses in the Netherlands
Boom, R. van den; Ducro, B.J. ; Sloet van Oldruitenborgh-Oosterbaan, M.M. - \ 2008
Tijdschrift voor Diergeneeskunde 133 (2008)13. - ISSN 0040-7453 - p. 554 - 563.
paardenziekten - zomereczeem - insectenbeten - allergieën voor geleedpotigen - overgevoeligheid - paarden - horse diseases - sweet itch - insect bites - arthropod allergies - hypersensitivity - horses - dermatitis sweet itch - british-columbia - culicoides hypersensitivity - dermal hypersensitivity - icelandic horses - genetic-basis - ceratopogonidae - diptera - israel - diseases
An Internet-based questionnaire among horse owners was carried out to identify factors affecting the incidence of insect bite hypersensitivity (IBHI) among horses in the Netherlands. Information was obtained for 794 horses of various breeds, but the breed distribution was not representative for the Dutch horse population. Of the horses for which information was available, 56% suffered from IBH and 44% did not. The most common clinical symptoms were pruritus, scaling, and hair loss, occurring mainly at the base of the tail and along the mane. Breed, age, region (and local habitat), stabling, type of bedding in the stable, use of the horse, deworming frequency, and season were associated with significant differences in IBH incidence. Knowledge of the factors influencing the incidence of IBH may make it possible to reduce the number of animals affected and help alleviate symptoms in affected horses.
A new remote optical wetness sensor and its applications
Heusinkveld, B.G. ; Berkowicz, S.M. ; Jacobs, A.F.G. ; Hillen, W.C.A.M. ; Holtslag, A.A.M. - \ 2008
Agricultural and Forest Meteorology 148 (2008)4. - ISSN 0168-1923 - p. 580 - 591.
soil-moisture - negev desert - surface-temperature - western-negev - dew formation - leaf wetness - reflectance - water - simulation - israel
An optical wetness sensor (OWS) was developed for continuous surface wetness measurements. The sensor is an all-weather instrument that does not interfere with the surface wetting and drying process and is unaffected by solar radiation. It is equipped with its own light source with which it can scan a surface and analyse its spectral reflectance. The backscattered radiation is detected around two wave bands: 1.70 ¿m (170 nm waveband) and 1.94 ¿m (80 nm waveband). The optical design is such that the ratio of the two signals is not dependent on the sampling distance, hence making it possible to study leaves under field conditions. Field and lab testing showed that the OWS was also capable of resolving small changes in surface soil water content such as from dew. In addition, the change of leaf water content could be detected (accuracy 5%). The OWS was also capable of measuring small changes in water content in the upper soil layer (
Arid landscape dynamics along a precipitation gradient: addressing vegetation - landscape structure - resource interactions at different time scales
Buis, E. - \ 2008
Wageningen University. Promotor(en): Tom Veldkamp; N. van Breemen, co-promotor(en): B. Boeken. - S.l. : S.n. - ISBN 9789085049463 - 190
droge gebieden - landschap - bodemmorfologie - neerslag - gradiënten - dynamica - watervoorraden - israël - landschapsanalyse - bodem-landschap relaties - arid lands - landscape - soil morphology - precipitation - gradients - dynamics - water resources - israel - landscape analysis - soil-landscape relationships
This research is entitled ‘Arid landscape dynamics along a precipitation gradient: addressing
vegetation – landscape structure – resource interactions at different time scales’ with as subtitle
‘A case study for the Northern Negev Desert of Israel’. Landscape dynamics describes the
interactions and feedbacks among landscape structure, resource flows and organisms. This study
focuses on the Northern Negev Desert of Israel, a semi-arid to arid rock desert with local loess
and sand cover. Climate and humans are important driving factors of landscape dynamics here.
Semi-arid and arid regions worldwide, are vulnerable to land degradation and desertification. A
profound knowledge of the processes in these regions can help to avert land degradation and
desertification. The objective of this thesis is to increase the knowledge on landscape dynamics
and its drivers in semi-arid and arid regions by field and model studies in the Northern Negev
Desert. This study can contribute to a sustainable future for the inhabitants of these areas.
• Chapter 1 is the introduction of this thesis and discusses among others the four studied
catchments along a precipitation gradient: Lehavim receives at average 280 mm precipitation per
year, Sayeret Shaked 200 mm yr-1, Halluqim 93 mm yr-1 and Avdat 87 mm yr-1. Of the surface of
Lehavim 53% is covered by vegetation and 15% by bedrock outcrops. The catchment is
intensively grazed by livestock. Sayeret Shaked is covered by a thick layer of homogeneous
loess. Vegetation cover is dense (62%). The catchment is taken out of grazing since 1987. In
Halluqim only 20% of the surface is covered by vegetation. The catchment is very rocky, as
bedrock crops out at 42% of the surface. Avdat, located close by, is much less rocky (7%). Here
22% of the surface is covered by vegetation. Both catchments are extensively grazed.
The thesis can be separated in three parts. In the first part the relationships between landscape
structure and vegetation in the four catchments is studied by statistical analyses. This part gives
insight in the landscape dynamics along a precipitation gradient and provides a system
framework for the remainder of the thesis. The second part focuses on simulating water and
sediment dynamics in the catchments using the landscape evolution model LAPSUS. The model
is adapted to a semi-arid and arid climate, and vegetation cover is incorporated. The interactions
between resource flows and vegetation is studied by model simulations. In the third part the
system knowledge and modelling framework are applied at a longer time scale. Firstly the history
of a valley fill is reconstructed by field observations, after which this valley fill is simulated with
LAPSUS. Additionally the effect of land use on the valley fill development is tested by model
simulations.
Part 1: System framework
• In chapter 2 the controls on functional surface cover types are studied in the four catchments
along the precipitation gradient. First, four functional surface cover types are selected, based on
their unique functionality in terms of water use and redistribution: shrubs, Asphodelus ramosus,
other herbaceous plants and surface crusts (biological and physical). Percentage of surface cover
of these functional surface cover types is estimated, and of bedrock outcrops and loose surface
stones. Additionally, data is collected on soil depth, relative elevation, insolation, slope, profile
curvature and plan curvature. Relations between functional surface cover types and landscape
structure variables are analyzed with descriptive statistics, factor analyses and linear regressions.
The landscape structure variables bedrock outcrop, relative elevation, soil depth and surface
stones explain most of the cover variance in the catchments. In catchments with many bedrock
outcrops, the occurrence of functional surface cover types is best explained by the landscape
structure variables. In catchments with homogeneous soils reaching beyond the root zone,
biological interactions between functional surface cover types are more important. Along the
precipitation gradient the explanatory power of the biological variables decreases with decreasing
precipitation, while the explanatory power of landscape structure variables appears unrelated.
Only in homogeneous semi-arid catchments can regular vegetation patterns develop, in arid and
heterogeneous catchments irregular vegetation patterns dominate.
Part 2: Model framework
• In chapter 3 the process of water redistribution at catchment scale is studied with the landscape
evolution and erosion model LAPSUS. LAPSUS, formerly applied in Mediterranean regions, is
modified to deal with the arid climate of the Northern Negev Desert of Israel. Daily model runs
are used instead of yearly model runs, and the infiltration module is adapted to better represent
the spatial diversity in water availability in an arid catchment. The model is calibrated for
Halluqim and Avdat. First, a sensitivity analysis of the modified LAPSUS was done. Especially
pore volume of the soil appears to have a strong influence on the modelling results. Second, the
capability of LAPSUS to deal with varying surface characteristics was assessed by comparing the
simulated water redistribution patterns in the two catchments with field data. Simulation results
demonstrate that the catchments respond very different to precipitation. Water redistribution is
larger in the dominantly bedrock-covered Halluqim compared to the dominantly sedimentcovered
catchment of Avdat. Consequently, Halluqim has more positions with water
accumulation than Avdat, and can sustain a larger vegetation cover including Mediterranean
species. Finally the modelled infiltration patterns are spatially compared with vegetation cover in
the catchments. The results indicate that there is a broad agreement between infiltration and
vegetation patterns, but locally there is a strong mismatch indicating that part of the involved
processes are still missing in the model.
• In chapter 4 the interactions between resource flows and vegetation is studied and simulated in
the loess-covered catchment of Sayeret Shaked. In semi-arid areas vegetation is scarce and occurs
often as individual shrubs on raised mounds. The formation process of these mounds is still
debated. In this chapter the hypothesis that shrub mounds are formed in part of the Northern
Negev Desert by erosion and sedimentation is tested. Height and diameter of shrub canopy and
shrub mounds are measured and micro-morphological techniques are used to reconstruct the
formation process of the shrub mounds. The results suggests that shrub mounds are formed by
accumulation of atmospheric dust and sedimentation of eroded material in the vicinity of the
shrub, as well as by erosion of the surrounding crust. Model simulations are done for single
events and longer time scale (100 years). In the simulations, mound formation appears most
prominent at low shrub density and large shrub canopy diameter. Positive and negative feedbacks
between shrubs and resource redistribution results in a meta-stable landscape. Long-term model
simulations of the current climate indicates that initially formation rate of shrub mounds is high,
but stabilized at lower rates. In dryer and wetter climates mound formation is unlikely to happen,
as respectively too little or too many resources are redistributed, causing a stable or highly
erosive landscape. Mound simulation with LAPSUS is successful and simulated shrub mounds
resemble the actual shrub mounds in Sayeret Shaked. Consequently the model may prove to be
valuable for the modelling of ecohydrological landscape processes in semi-arid areas.
Part 3: Long-term application
• In chapter 5 the interactions between climate change, human occupation and semi-arid
landscape dynamics are studied to increase the insight in the effect of climate change and human
land use. A Late Quaternary valley fill in the catchment of Sayeret Shaked is studied. The
aggradation and incision history is reconstructed based on a transect study. The reconstructed
valley fill is put in a temporal framework by correlation with local climate records and optically
simulated luminescence and potsherd dates. Two Late Pleistocene and four Holocene aggradation
and incision cycles are recognized, of which three in the last 2000 years. Contradictory to the
expected positive relation between amplitude of climate fluctuations and cycles of aggradation
and incision, the Late Holocene cycles are stronger than those in the Late Pleistocene and Early
to Middle Holocene. The most significant cycle coincides with the rise and fall of the Byzantine
Empire and appears related to the higher pressure on the landscape due to human occupation
during that time. Human activity appears to have a strongly amplifying effect on aggradation and
incision phases, which are initially triggered by climate fluctuations. This amplifying effect
occurs only when human occupation crosses a threshold and triggers destabilization of the
landscape. It causes collapse of the ecosystem and increases sediment redistribution.
• Chapter 6 aims to quantify the effect of humans on semi-arid catchments, by reconstructing the
infill history of Sayeret Shaked using LAPSUS. First, the infill history of Sayeret Shaked
between about 800 BC and 800 AD is simulated. Second, three land use scenarios are tested to
quantify the effect of extensive grazing, intensive grazing and intensive grazing combined with
rainfed agriculture. Especially intensive grazing combined with rainfed agriculture leads to strong
landscape dynamics. Extensive grazing causes almost no landscape dynamics, resulting in an
almost stable landscape. The results seem to indicate that this catchment is formed by coevolution
of human and natural induced processes. Rainfed agriculture leads to valley
aggradation by tillage translocation, whereas intensive livestock grazing causes gully incision by
increased slope runoff. Humans appear to be the main driven factor of landscape dynamics in this
semi-arid catchment, much more than climate fluctuations. Only a short time period of strong
human land use can irreversibly alter the development trajectory of a catchment. It is thus of high
importance to manage the land sustainable, both in the present and future, to avoid further
degradation of drylands.
• In chapter 7 the results of the different chapters are combined and the most important
conclusions discussed. The four catchments display very different landscape dynamics, caused by
a high variation in climate, land use and landscape structure. In Lehavim and Halluqim the
landscape dynamics is strongly influenced by the landscape structure, because bedrock outcrops
regulate positions for vegetation grow and stimulate water redistribution. In Sayeret Shaked water
redistribution depends mainly on biological surface cover. In Sayeret Shaked interactions
between shrub and crust patches can, under a more intensive grazing regime, lead to regular
vegetation patterns. When grazing pressure is released the herbaceous plant coverage recovers, as
is happening today. Avdat is a divers catchment, with steep rock outcrop, a flat plateau and a
loess covered wide gully. Though the whole catchment is characterized by a high aridity, each
zone experiences different landscape dynamics.
At a larger spatial scale, in the whole Northern Negev Desert, the most relevant interactions and
feedbacks between landscape structure, resource flows and organisms are related to water
availability and redistribution as well. Since the Late Holocene, the main driving factor of
landscape dynamics is human land use, especially tillage and intensive livestock grazing. Climate
fluctuations seem to have much less influence on the region. The influence of humans, even
confined in a small period in time, strongly affects landscape development in the whole Northern
Negev Desert, causing co-evolution and formation of cultural landscapes.
Grondbehandeling met hete lucht als alternatief voor methyl bromide
Runia, Willemien - \ 2007
plant protection - soil treatment - tillage - plant parasitic nematodes - meloidogyne - marrows - nematode control - hot air treatment - agricultural research - israel - cyprus
Trade opportunities for Dutch agribusiness in Turkey and Israel
Berkum, S. van; Kelholt, H.J. - \ 2007
The Hague : LEI (Report / LEI : Domain 5, Chains ) - ISBN 9789086151950 - 82
agrarische economie - agrarische handel - handelsrelaties - landbouwindustrie - export - investering - turkije - israël - nederland - agro-industriële ketens - agricultural economics - agricultural trade - trade relations - agribusiness - exports - investment - turkey - israel - netherlands - agro-industrial chains
This study analyses the agricultural trade relations of the Netherlands with Turkey and with Israel, and investigates the present market positions of the Dutch agribusiness in the two countries. Based on a review of market and agri-food supply chain developments, opportunities for expansion of trade and strengthening of Dutch positions in these two countries are evaluated. The study points at the many export and/or investment opportunities in Turkey for Dutch agribusiness in food products and input supplies and services. At the same time, basic conditions in Israel are not conducive to booming export prospects for Dutch agribusiness companies. The study, conducted at the request of the Ministry of Landbouw Natuur en Voedselkwaliteit, may help the Ministry's desk in Ankara prioritising its activities in Turkey and Israel.
Description of plant communities on the Red Sea costal plain of Sudan
Woldewahid, G. ; Werf, W. van der; Sykora, K.V. ; Abate, T. ; Mostofa, B. ; Huis, A. van - \ 2007
Journal of Arid Environments 68 (2007)1. - ISSN 0140-1963 - p. 113 - 131.
vegetation-soil relationships - locust schistocerca-gregaria - saudi-arabia - ecology - regime - israel - jedda - negev
The coastal plains of the Red Sea constitute an important breeding area for the desert locust, Schistocerca gregaria. Vegetation analysis was undertaken in the coastal plain of Sudan to provide a frame of reference for studies on desert locust ecology and distribution. Vegetation relevés (>60 in any season) were made at peak vegetation cover during three subsequent winters, 1999¿2002. Four plant communities were distinguished by Two-Way Indicator Species Analysis. They are named by the dominant plant species: Suaeda monoica Forssk., Heliotropium spp., Panicum turgidum Forssk., and Acacia tortilis (Forssk.) Hayne. These plant communities reflect underlying differences in elevation, soil texture, water availability and land use. The spatial extent of these plant communities is mapped. The resulting vegetation classification is easy to use under field conditions and can be used for ecological studies and practical monitoring of the desert locust
Identification of environmental factors affecting prevalence of insect bite hypersensitivity in Shetland ponies and Friesian horses in the Netherlands
Grevenhof, E.M. van; Ducro, B.J. ; Heuven, H.C.M. ; Bijma, P. - \ 2007
Equine Veterinary Journal 39 (2007)1. - ISSN 0425-1644 - p. 69 - 73.
icelandic horses - sweet itch - culicoides - sickness - viruses - israel
Reasons for performing study: It is expected that climate and habitat factors influence the prevalence of culicoides and, therefore, the prevalence of insect bite hypersensitivity (IBH), but very little is described in the literature to prove the association of these factors. Prevalence varies widely from 3% in certain areas of Great Britain to 60% in certain parts of Australia. Objectives: To describe the influence of environmental factors on the prevalence of IBH in Shetland ponies and Friesian horses in the Netherlands. Methods: Data on 3284 Shetland and 2824 Friesian mares (n = 6108) were collected in the Netherlands, based on 90 regions, according to postal codes. The climate components, amount of rainfall, number of warm days, number of cold days, and habitat components of soil type and type of vegetation were collected for each region. Results: Prevalence of IBH varied widely from 0-71.4% per region. The results showed that the environment with low IBH-prevalence had high rainfall, many cold days and few warm days per year. Habitats with a low IBH-prevalence were based along the coast line. Habitats with increasing prevalence of IBH had soils of clay with heather and woody vegetation. Friesian mares had a higher IBH prevalence than Shetland mares, which could indicate an effect of genetic background or an effect of year. Conclusions: There is an environmental effect on IBH prevalence within the Netherlands, which is caused by climate and habitat factors. Potential relevance: The results provide a more accurate description of environmental factors and their impact on development of IBH; and should help better to understand habitat and climate effects, and to distinguish these from other effects, such as animal factors (genetics, age or sex).
An automated microlysimeter to study dew formation and evaporation in arid and semiarid regions
Heusinkveld, B.G. ; Berkowicz, S.M. ; Jacobs, A.F.G. ; Holtslag, A.A.M. ; Hillen, W.C.A.M. - \ 2006
Journal of Hydrometeorology 7 (2006)4. - ISSN 1525-755X - p. 825 - 832.
north-western negev - desert system - sandy soils - israel - water - crust - photosynthesis - simulation - dunes - trap
The development of a simple and low-cost portable weighing microlysimeter that makes use of a load cell for automated recording and for studying daily dew formation, rate of accumulation, and subsequent evaporation in arid or semiarid regions during rainless seasons is presented. The sampling cup is 3.5 cm deep, with the load cell itself situated at 20-cm depth to minimize temperature effects. The device was tested in a sand dune experimental station situated near Nizzana, northwest Negev Desert, Israel, during which extensive micrometeorological measurements were collected. One microlysimeter was placed in a playa and a second was installed on the stabilized midslope of an adjacent linear sand dune. To assess the performance of the load cell microlysimeters (LCM), one pair of manual microlysimeters was installed next to each LCM. A third pair was installed at a point between the LCMs and a fourth pair above the midslope LCM. Sixteen overnight measurements were carried out within a 6-week period. The LCM could measure dew with an error of ±0.02 mm. The daily dew variation in the samples during the 16 overnight measurements ranged up to 0.2 mm on stable dune slopes but up to 0.4 mm on the playa. This difference is attributed to the playa¿s high silt and clay content and salinity. Dew formation and accumulation were found to occur long before the soil-surface temperature reached the dewpoint temperature of the air. The cost of building this microlysimeter, excluding labor, is about $175 (U.S.).
Long-term accumulation of atmospheric dust in rocky deserts
Goossens, D. ; Offer, Z.Y. - \ 2005
Zeitschrift für Geomorphologie 49 (2005)3. - ISSN 0372-8854 - p. 335 - 352.
topographic scale models - wind-tunnel simulations - aeolian dust - negev desert - southern nevada - eolian dust - field verification - deposition - israel - soils
The spatial pattern of long-term (hundreds to thousands of years) accumulation of dust in rocky deserts was investigated in the northern Negev Desert of Israel. The concentration of dust in the desert subsoil was measured at 41 locations in a 53 ha test area for which detailed information exists on contemporary dust deposition and dust erosion rates. Results show that the spatial pattern of the long-term accumulation is strongly affected by topography. Highest accumulation occurs in the valleys, especially those having a large catchment area, and on flat surfaces in a plateau position. Less, but still important, accumulation is observed on concave windward slopes and also, but still less, on concave lee slopes. Moderate accumulation occurs where the curvature of windward slopes changes from concave to convex, and also on slopes parallel to the wind. Little accumulation is observed on the convex windward slopes. Finally, the least accumulation occurs on convex lee slopes. The dust accumulation pattern in the test area reflects the effects exerted by aeolian as well as hydraulic processes. The pattern is clearly hydraulic in the valleys, especially on the valley floors (which are characterised by thick water-supplied deposits), and also, but not always, on the lower valley slopes (where colluvia may occur). Outside the valleys and the lower slope sections the dust pattern is merely aeolian.
Effect of organic nitrogen and carbon mineralization on sediment organic matter accumulation in fish ponds
Jiménez-Montealegre, R. ; Verdegem, M.C.J. ; Dam, A.A. van; Verreth, J.A.J. - \ 2005
Aquaculture Research 36 (2005)10. - ISSN 1355-557X - p. 983 - 995.
water-quality - ammonia - budget - decomposition - consumption - management - excretion - culture - israel - algae
In aquaculture, ponds with high loads of organic inputs, organic matter accumulates at the bottom over time. Uneaten feed, senescent phytoplankton and faeces are the principal sources of accumulated material, but quantifications are scarce. The sedimented organic matter develops into a flocculent layer in which different processes transform the material into inorganic forms. A better understanding of factors influencing organic matter accumulation/decomposition in the sediment is needed to better understand and manage the dynamics of nitrogen in fish ponds. In this study, the rate of mineralization of organic nitrogen and the nitrogen flux between the sediment and the water column were measured. Organic matter accumulation in fish ponds was quantified, and the data were used to construct, calibrate and validate a dynamic simulation model of organic matter deposition/decomposition in fish ponds. The accumulating material consisted of dead phytoplankton, fish faeces and uneaten feed. Through model calibration, the proportion of these materials in the total accumulated organic matter was determined. In the model, gross photosynthetic rate was estimated from an empirical relationship with feed input. After calibration, the model was validated using independent data. The model simulated well the concentrations of organic carbon and nitrogen in the sediments but it may be developed further, especially by considering the effects of resuspension
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