Ecologisch gericht suppleren, nu en in de toekomst: het ontwerp meerjarenplan voor monitoring en (toepassingsgericht) onderzoek

Zandsuppleties. Het programma “Ecologisch gericht suppleren, nu en in de toekomst” is een onderzoeks- en monitoringsprogramma voor de middellange termijn (2009-2014) met als doelstelling meer inzicht te krijgen of, en in welke mate, zandsuppleties van invloed zijn op natuurwaarden en op welke wijze zandsuppleties in de nabije toekomst kunnen bijdragen aan de opgaven van veiligheid samen met natuurbehoud en -ontwikkeling. Het programma moet leiden tot een optimalisatie van natuurbescherming van het kustecosysteem en een dynamisch beheer en behoud van de kustlijn

Effect of air distribution and spray liquid distribution of a cross-flow fan orchard sprayer on spray deposition in fruit trees

In a 4-year ongoing research programme in the Netherlands, we focus to maximise spray deposition in pome fruit trees and minimise spray deposition underneath the trees on the ground and minimise spray drift. For a cross-flow fan orchard sprayer we therefore measured spray deposition in the tree as an effect of different air settings and nozzle types. Nozzle types chosen were the Albuz ATR lilac (as a reference) and the Albuz TVI8001, both sprayed at 7 bar spray pressure. The orchard sprayer was a Munckhof cross-flow fan sprayer with a 2.75 m high cross-flow construction on top of the axial fan, equipped with 8 nozzles on both sides. At a forward speed of 6.5 km/h the spray volume was 200 L/ha and 290 L/ha, for respectively the Albuz lilac and Albuz TVI8001 nozzles. Air settings were: High air setting - 540 rpm PTO; and Low air setting - 540 rpm, 400 rpm, and 300 rpm PTO. Liquid distributions were measured with an AAMS-Salvarani Vertical patternator with discs, and air distribution was measured with a self-constructed measuring device equipped with ultrasonic anemometers and a handheld vane-anemometer. Liquid distribution in the apple trees (cv. Elstar) was measured in the full leaf growing stage (following ISO 22522). First results show a good correlation between air distribution and liquid distribution. Vertical liquid distribution measured on the liquid measuring device correlates also very good with the liquid distribution at different heights in the tree. However, air distribution and especially air speed of the orchard sprayer showed that decreasing air assistance increased the spray deposition in the fruit trees. Showing that air assistance is an important parameter to be taken up in the advice to fruit growers.In a 4-year ongoing research programme in the Netherlands, we focus to maximise spray deposition in pome fruit trees and minimise spray deposition underneath the trees on the ground and minimise spray drift. For a cross-flow fan orchard sprayer we therefore measured spray deposition in the tree as an effect of different air settings and nozzle types. Nozzle types chosen were the Albuz ATR lilac (as a reference) and the Albuz TVI8001, both sprayed at 7 bar spray pressure. The orchard sprayer was a Munckhof cross-flow fan sprayer with a 2.75 m high cross-flow construction on top of the axial fan, equipped with 8 nozzles on both sides. At a forward speed of 6.5 km/h the spray volume was 200 L/ha and 290 L/ha, for respectively the Albuz lilac and Albuz TVI8001 nozzles. Air settings were: High air setting - 540 rpm PTO; and Low air setting - 540 rpm, 400 rpm, and 300 rpm PTO. Liquid distributions were measured with an AAMS-Salvarani Vertical patternator with discs, and air distribution was measured with a self-constructed measuring device equipped with ultrasonic anemometers and a handheld vane-anemometer. Liquid distribution in the apple trees (cv. Elstar) was measured in the full leaf growing stage (following ISO 22522). First results show a good correlation between air distribution and liquid distribution. Vertical liquid distribution measured on the liquid measuring device correlates also very good with the liquid distribution at different heights in the tree. However, air distribution and especially air speed of the orchard sprayer showed that decreasing air assistance increased the spray deposition in the fruit trees. Showing that air assistance is an important parameter to be taken up in the advice to fruit growers

CATT voor de boomkwekerij - pilotproeven met sierheesterstek en vaste planten laten kansen voor de toekomst zien

In dit project hebben we het perspectief voor CATT-behandelingen (Controlled Atmosphere Temperature Treatment) voor boomkwekerijgewassen onderzocht. Deze methode combineert een CA-behandeling (gewijzigde luchtsamenstelling door aanpassing van CO2-en O2-condities) met een temperatuurbehandeling. Hiervoor wordt het plantmateriaal gedurende een bepaalde periode in een gasdichte cel bewaard. CATT-behandelingen zijn een duurzame vorm van plaagbestrijding omdat er geen chemische middelen aan te pas komen en omdat er geringe kans is op resistentieontwikkeling van de plaagorganismen. Bovendien kan deze methode zeer snel in praktijk worden geïmplementeerd omdat deze geen wettelijke toelating behoeft. Zo zijn in korte tijd CATT-behandelingen ontwikkeld voor het bestrijden van plagen in aardbei, die nu succesvol in praktijk worden toegepast. In dit project hebben we twee sierheesters in de stekfase (Buxus sempervirens en Ilex altaclerensis) en vier soorten vaste planten in de winterbewaring (Astilbe japonica, Geranium sanguineum, Phlox paniculata, Paeonia officinalis) behandeld en vergeleken met onbehandelde controles

Integration of micro-gravity and geodetic data to constrain shallow system mass changes at Krafla Volcano, N Iceland

New and previously published micro-gravity data are combined with InSAR data, precise levelling and GPS measurements to produce a model for the processes operating at Krafla volcano, 20 years after its most recent eruption. The data have been divided into two periods: from 1990 to 1995 and from 1996 to 2003 and show that the rate of deflation at Krafla is decaying exponentially. The net micro-gravity change at the centre of the caldera is shown, using the measured Free Air Gradient, to be -85 μGal for the first and -100 μGal for the second period. After consideration of the effects of water extraction by the geothermal power station within the caldera, the net gravity decreases are -73 ± 17 μGal for the first and -65 ± 17 μGal for the second period. These decreases are interpreted in terms of magma drainage. Following a Mogi point source model we calculate the mass decrease to be ~2 x 1010 kg/yr reflecting a drainage rate of ~0.23 m3/s, similar to the ~0.13 m3/s drainage rate previously found at Askja volcano, N-Iceland. Based on the evidence for deeper magma reservoirs and the similarity between the two volcanic systems, we suggest a pressure-link between Askja and Krafla at deeper levels (at the lower crust or the crust-mantle boundary). After the Krafla fires, co-rifting pressure decrease of a deep source at Krafla stimulated the subsequent inflow of magma, eventually affecting conditions along the plate boundary in N-Iceland, as far away as Askja. We anticipate that the pressure of the deeper reservoir at Krafla will reach a critical value and eventually magma will rise from there to the shallow magma chamber, possibly initiating a new rifting episode. We have demonstrated that by examining micro-gravity and geodetic data, our knowledge of active volcanic systems can be significantly improved

Report of the Working Group on the Effects of Extraction of Marine Sediments on the Marine Ecosystem, WGEXT, 31 May-4 June 2010, Djurönäset, Sweden

ICES WGEXT Report 201

Report of the Working Group on the Effects of Extraction of Marine Sediments on the Marine Ecosystem, WGEXT, 11-15 April 2011, Delft, the Netherlands

ICES WGEXT Report 201

Changes in North Sea macrofauna communities between 1986 and 2000

This paper is chapter 5.2 of the ICES CRR “Structure and dynamics of the North Sea benthos” (ICES 2007) compiled by the ICES Study Group on the North Sea Benthos Project 2000. The North Sea Benthos Project 2000 (NSBP) was initiated as a follow-up to the earlier 1986 ICES North Sea Benthos Survey (NSBS). One major aim of the NSBP 2000 was to compare the outcome with that of the 1986 NSBS, in order to identify any significant changes in the community structure and their likely causes. In general, the spatial distribution of the macrofaunal communities in 2000 was rather similar to that in 1986. But changes were found within communities which were addressed to changes in the hydroclimate caused by changes in the North Atlantic Oscillation influencing changes in currents and sediment structure as well as food availability