New protocols to assess the environmental impact of pests in the EPPO decision‐support scheme for pest risk analysis*

Assessing the potential environmental impact of alien plants and plant pests is notoriously difficult. New protocols have been developed in the framework of the EC project PRATIQUE to provide guidance on environmental impact assessment in the EPPO pest risk analysis (PRA) decision‐support scheme and enhance consistency between risk assessors and risk ratings for different pests. A set of questions with rating guidance and examples is provided, and individual scores are summarized into final scores, using a hierarchy of risk matrices, to assess current and potential environmental impacts. Two separate protocols are available: for alien plants and for other pests. These protocols could also be used to assess environmental impact in other PRA schemes as well as to assign alien species to regional black lists or to prioritize species for management decisions.     

Amelioration of a hardsetting Alfisol through deep mouldboard ploughing, gypsum application and double cropping. II. Soil-water relations

Deep mouldboard ploughing to a depth of 0.45 m, gypsum (5 t ha⁻¹) and double cropping wheat (Triticum aestivum) with a summer forage crop were applied individually, and in combination, to modify a hardsetting red-brown earth (Alfisol) used for flood-irrigated wheat production. The effects of these treatments upon water infiltration, storage and intake during irrigations, application efficiency, and depletion between irrigations were measured. Gypsum markedly increased saturated hydraulic conductivity (K_s) immediately after being applied in June 1984 but not in 1985. Mouldboard ploughing and double cropping had little effect on K_s. All K_s values were less than 0.5 m day⁻¹. Plant available water content (PAWC) was increased by gypsum application and mouldboard ploughing after the initial irrigation in 1984, and by the three main treatments in 1985. The order in which the main treatments increased PAWC was: gypsum>mouldboard ploughing>double cropping. Water applied and water intake during irrigations were increased by mouldboard ploughing and gypsum during the first irrigation in 1984 by as much as 60 mm. Thereafter mouldboard ploughing, gypsum and double cropping had little effect on water intake, and only gypsum increased the amount of water applied in 1985. The ratio of water intake to water applied during irrigations (application efficiency) was increased by mouldboard ploughing to 59% in 1984; no treatment had values greater than 40% during 1985. Water depletion was significantly increased by mouldboard ploughing in 1984 and by gypsum and double cropping in 1985. Few significant interactions were found between the three main treatments, each of which would improve soil-water relations for crop growth, although the effect of mouldboard ploughing on soil-water relations declined after the first year. Despite substantial improvements after 2 years in some treatments, soil hydraulic properties were inadequate for optimal irrigated cropping.     

An evaluation of controlled traffic with reduced tillage for irrigated cotton on a Vertisol

Where Vertisols are used for the mechanised production of irrigated cotton, the main pre-planting tillage options are ‘direct listing’ (a ‘controlled traffic-reduced tillage’ treatment with retained ridges), deep ripping (0.45 m deep) and chisel ploughing (0.25 m deep). An experiment was established, on a commercial scale under furrow irrigation, to compare the effects of these treatments on the physical properties (aeration, strength and water content) of a frequently irrigated Vertisol over 3 years. The growth and profitability of three cotton crops and one wheat crop were monitored during this period. The soil was well structured when the experiment commenced. Soil measurements showed that whilst the deep ripped treatment had lower resistance to penetration than the direct listed treatment, it provided a less favourable environment for root growth than the direct listed soil due to prolonged waterlogging after irrigation. An excess of water entered the ripped profile under the prevailing irrigation regime. All treatments had a sodic subsoil that was poorly drained. The chisel ploughed treatment generally behaved in a fashion that was intermediate between the direct listed and deep ripped treatments. The direct listed treatment resulted in higher cotton lint yields and lower land preparation costs, in comparison with deep ripping. Profitability increases were of the order of 11% when the lint value was 1.78 Australian dollars kg⁻¹. The deep ripped soil had more stored water than the other treatments throughout each irrigation cycle, but this potential advantage could not be expressed in terms of better crop yield and improved water use efficiency. A supplementary experiment is needed to evaluate the three tillage options where irrigation water is applied less frequently.     

Assessment of seafood processing wastes as alternative sources of Selenium in plant production

Abstract

In some parts of the world, the soil selenium (Se) content is too low to ensure the Se level recommended for human or animal consumption in the crops produced. In order to secure a desired concentration of Se in crops, Se has been applied as mineral fertilizer to agricultural fields. Since only a minor part of the inorganic Se applied is utilized by plants and small increases in Se concentrations in, e.g., drinking water, may be toxic, the method is somewhat controversial. As an alternative to Se-enriched mineral fertilizer, different seafood-processing wastes have been examined as a source for Se in crop production. Both in greenhouse pot experiments and field trials the Se in seafood waste was not plant-available during the first growing season. There was no significant difference between the Se concentration in wheat growing in soil without added Se and in soil receiving Se from seafood waste in amounts ranging from 0.9 to 9 g ha^?1. Neither was any residual effect of Se in seafood waste seen during a second year growth period. Thus, seafood-processing waste cannot be regarded as a potential source of Se in crop production. Possible mobilization of formerly applied Se, as seafood-processing waste or Se enriched mineral fertilizer due to changes in soil redox conditions were examined in a leaching experiment. The mobility of formerly applied Se was generally very low, but the results indicated that under permanently wet soil conditions leaching of Se may occur in plant dormant periods in soils with low organic matter content and high pH.     

Selection of roosting habitats by Nyctalus noctula and Nyctalus leisleri in Białowieża Forest—Adaptive response to forest management?

Tree dwelling bats select cavities in large, old, dying or dead trees. This inevitably brings them into direct conflict with the interests of forest managers, who are trained to fell such trees. Therefore the identification of forest stands providing optimal roosting opportunities for bats is crucial, in order to provide appropriate guidelines for forest management. It is also important to identify the extent to which the roosting ecology of bats changes in response to habitat modification. Bia?owie?a Forest (BF) offers a unique opportunity, in the temperate zone, to observe differences between areas with no direct human intervention and managed areas and in particular to reveal the effect of forest management on the roosting ecology of forest dwelling bat species. We used GIS techniques to evaluate bats’ spatial response to changes in forest structure and to test the hypotheses that the forest dwelling bats Nyctalus noctula and Nyctalus leisleri prefer roost sites within old deciduous or wet woodlands over young and coniferous ones and that roost site preferences reflect the extent to which dead and dying trees are removed. There was a significant difference in the selection of roosting habitat between the managed and pristine areas of the forest. Within the pristine forest, both species displayed a strong preference for roost trees located within old deciduous stands (>100 years), whereas in the managed part of the forest old wet woodland was preferred while all medium and young forest stands were avoided. Our data reveal a high degree of lability in the selection of roosting habitat by bats. It appears that bats are able to respond to changes in their environment by changing their roost site preferences and could therefore occupy habitat previously considered less suitable.     

The UK Plant Health Risk Register: a tool for prioritizing actions

Following unprecedented publicity concerning pest threats to UK trees in 2012, a review body recommended that a UK Plant Health Risk Register (RR) be developed to assist with the prioritisation of actions to reduce the threats posed by the major pests of plant health importance. The RR that has been developed assigns relative risk ratings to pests according to appropriate scenarios, e.g. introduction for pests that are absent. The ratings were based on rules created to summarise the likelihoods of occurrence and impacts taking into account information on the pests and factors such as their pathways, hosts, distribution, spread and impacts. Expert judgement was used where information is lacking. A score referred to as ‘the value at risk’ was obtained from economic and environmental data to produce risk ratings that reflect the value of the host sector to the UK. Risk ratings in the absence of mitigations (risk management actions) were compared with those that take existing actions into account to identify species that are priorities for additional actions, e.g. to enhance regulation or conduct pest risk analyses. The RR is now used routinely to support decision making and further developments are planned.     

Development of pecking damage in layer pullets in relation to dietary protein source

1. In recent years, the UK egg industry has become increasingly dependent on plant protein sources, in particular soyabean meal, and it has been suggested that this trend (and/or the concomitant absence of animal protein in layer diets) might be causally related to increased feather pecking and cannibalism. 2. This study examined the development of pecking damage in relation to dietary protein source, by rearing 12 groups of 12 layer pullets to 24 weeks of age on diets based on 'animal' (fishmeal) or 'plant' (soyabean meal) protein. 3. Damaging pecking began at 6 weeks of age, in three groups (one plant and two animal). Injurious pecking began at 18 weeks of age, and affected four groups (two plant and two animal). 4. Greater numbers of vigorous pecks/pulls were observed in plant protein groups throughout the experiment, although they were significantly higher only between 13 to 16 weeks of age. Pecking damage scores did not differ between treatments. 5. Dietary protein source did not affect plasma oestradiol, progesterone or egg production. 6. These results do not support the notion that inclusion of fishmeal in laying hen diets prevents or alleviates feather pecking and cannibalism.     

Communication of direction by the honey bee

In the presence of controls for site- and path-specific odors, observer and food-source scents, Nasanov gland and alarm odors, visual cues, wind, and general site taxis, recruited bees were able to locate the food source indicated by the dances of returning foragers in preference to a food source located at an equal distance in the opposite direction. This was true even when foragers were simultaneously dancing to indicate two different stations. Recruitment in the absence of dancing was very low, while in the absence of foraging it was virtually zero. Thus, under the experimental conditions used, the directional information contained in the dance appears to have been communicated from forager to recruit and subsequently used by the recruit.