Evolutionary impact assessment: accounting for evolutionary consequences of fishing in an ecosystem approach to fisheries management

Managing fisheries resources to maintain healthy ecosystems is one of the main goals of the ecosystem approach to fisheries (EAF). While a number of international treaties call for the implementation of EAF, there are still gaps in the underlying methodology. One aspect that has received substantial scientific attention recently is fisheries‐induced evolution (FIE). Increasing evidence indicates that intensive fishing has the potential to exert strong directional selection on life‐history traits, behaviour, physiology, and morphology of exploited fish. Of particular concern is that reversing evolutionary responses to fishing can be much more difficult than reversing demographic or phenotypically plastic responses. Furthermore, like climate change, multiple agents cause FIE, with effects accumulating over time. Consequently, FIE may alter the utility derived from fish stocks, which in turn can modify the monetary value living aquatic resources provide to society. Quantifying and predicting the evolutionary effects of fishing is therefore important for both ecological and economic reasons. An important reason this is not happening is the lack of an appropriate assessment framework. We therefore describe the evolutionary impact assessment (EvoIA) as a structured approach for assessing the evolutionary consequences of fishing and evaluating the predicted evolutionary outcomes of alternative management options. EvoIA can contribute to EAF by clarifying how evolution may alter stock properties and ecological relations, support the precautionary approach to fisheries management by addressing a previously overlooked source of uncertainty and risk, and thus contribute to sustainable fisheries.     

Untersuchungen zur Verticillium-Welke im Hopfenanbaugebiet Hallertau

Verticillium wilt is a devastating disease in hops and causes considerable crop losses. V. albo-atrum is the most widespread species, whereas V. dahliae is rarely found. Due to the survival of the fungus for several years in soil by resting structures and the lack of effective chemical control, a fast detection method is needed. One aim of this study was to evaluate the occurrence of Verticillium spp. in the Hallertau region (Germany). Therefore, 76 hop plants, with or without wilt symptoms, were analyzed using a real time PCR (polymerase chain reaction) assay. V. albo-atrum was identified in 57 bine samples. The pathogen can sporadically appear without showing visual symptoms. The abundance of the fungus inside the plants was analyzed. Furthermore, four beneficial bacteria, Burkholderia terricola ZR2-12, Pseudomonas poae RE*1-1-14, Serratia plymuthica 3Re4-18, and Stenotrophomonas rhizophila DSM14405^T, were evaluated as biological control agents in hops. The colonization competence in the root system, plant growing promotion, and antagonistic effects were assessed. All strains colonized the endorhiza and the rhizosphere. The bacterial strains B. terricola ZR2-12, S. plymuthica 3Re4-18, and S. rhizophila DSM14405^T are promising candidates for further biocontrol strategies. Thus, first steps towards the biological control of Verticillium wilt were presented.     

Fast analysis of sugars, fruit acids, and vitamin C in sea buckthorn (Hippophaë rhamnoides L.) varieties

A fast, one-step gas chromatographic method was developed to analyze trimethylsilyl (TMS) derivatives of sugars, fruit acids, and ascorbic acid in sea buckthorn (Hippoha? rhamnoides L.) berries. The method was applied to berry press juice of sea buckthorn of different origins grown in Finland during the 2003 and 2004 seasons. The method gave reliable results for D-fructose, D-glucose, ethyl-D-glucose, and malic, quinic, and ascorbic acids, which are the major sugars and acids in sea buckthorn juice. For the first time in sea buckthorn and evidently in any berry, the presence of ethyl beta-D-glucopyranoside is reported. The structure of ethyl glucose was verified by high-performance liquid chromatography (HPLC), gas chromatography (GC), MS, and NMR analyses of both the isolated and the synthesized compounds. In the GC method, vitamin C was analyzed as ascorbic acid only, and dehydroascorbic acid was thus not taken into account.     

Short-term effects of retention felling at mire sites on boreal spiders and carabid beetles

Green-tree retention is an integral part of forest management in the boreal zone. Retention of small spruce mires, proposed as ‘key habitats’ for many forest organisms, is recommended while logging, but the efficiency of such practices for the maintenance of forest species is poorly understood. Hence, we studied boreal spiders and carabid beetles at 11 retained mire patches (up to 0.55 ha) in Eastern Finland during 1998–2001. The adjacent surrounding drier forests of the focal mires were clear-cut during the winter of 1998/1999. We evaluated the importance of micro-habitat type (retention, edge or clear-cut plot), time since logging, and retention-patch size in determining the assemblages of spiders and carabids. Following logging, species associated with forests and mires generally decreased both in the retained mire patches and in their adjacent clear-cuts. In a GLMM, the number of standing trees in a retention patch – a surrogate for retention-patch size – had no significant effect on most of the tested species, but plot type (retention patch, its edge or clear-cut) was significant for many species. Semi-open-habitat species and open-habitat specialists increased following logging, especially in the clear-cut plots but even within the retention patches. In contrast, mature-forest and moist-habitat specialists became significantly less abundant in clear-cuts than in retention patches following logging. Spider assemblages showed pre-harvest differences among the mires, their edges and adjacent drier forests, but the fauna of logged plots rapidly diverged from that of mire and edge plots. However, after a 1–2 summers time lag, the spider fauna of mires and edges changed toward clear-cuts. For spiders, the post-harvest sample heterogeneity was significantly lower in clear-cuts than in retention patches, including their edges. Carabid responses were generally ambiguous. Multivariate regression trees showed that the number of trees in a forest patch better determined the spider assemblage structure than study area, study year or micro-site type (retention patch, its edge or clear-cut), indicating a strong impact of logging. For carabids, however, the study area better determined the assemblage structure; the other factors were of minor importance. Our results suggest that, as the spider and carabid faunas of the retention patches had drastically changed following logging, (i) retention patches should be considerably larger than the studied size range to efficiently maintain a ‘mire core’ spider and carabid assemblage; (ii) the effect of logging may take years to appear; (iii) spiders were more sensitive to habitat change than carabids; and (iv) harvesting not only changes the relative abundances of forest- and open-habitat associated species but it may also locally decrease the faunal variation.     

Effects of alternative pesticides on greenhouse whitefly in protected cultivation

The greenhouse trials were conducted to determine the efficacy of environmentally safe insecticides/fungicides with physical mode of action [Agri-50E (propylene glycol alginate, hydrated) and SB Plant Invigorator] against Trialeurodes vaporariorum (Westwood). The efficacy of Agri-50E on adults and nymphs (first, second, third, and fourth instars) was compared to the commercially available standard Boxer 200 SL (imidacloprid) and an untreated control on greenhouse-grown poinsettia. Insecticides were applied by foliar spraying, Agri-50E (2 or 3 ml/l) two times and Boxer 200 SL (1 ml/l) once. Three and 7 days after first application (DAFA), imidacloprid was more effective than both concentrations of Agri-50E in controlling T. vaporariorum adults, whereas 10 DAFA there were no differences between insecticides. Twelve DAFA, imidacloprid was more effective than Agri-50E in controlling first, second and third instars and after 19 days in controlling second, third, and fourth instars. The results obtained from the poinsettia study, indicated that Agri-50E (2 or 3 ml/l) is successful in controlling T. vaporariorum adults and moderately effective against T. vaporariorum immature stages. In the second experiment, the efficacy of Agri-50E on adults was compared to SB Plant Invigorator (SBPI), the standard treatment Calypso 480 SC (thiacloprid), and an untreated control on greenhouse-grown tomato. Agri-50E (3 ml/l) and SBPI (2 ml/l) were applied four times while Calypso 480 SC (0.4 ml/l) was applied twice. The results obtained from tomato study showed that SBPI was the most effective insecticide against T. vaporariorum adults, followed by Agri-50E and Calypso 480 EC. Beside the ecological benefits, the alternative insecticides Agri-50E and SBPI might have an important role to play in future pest management programs.     

NEPTUN,PAPA, Vergleichs- und Demonstrationsbetriebe oder Wer hat da noch den Durchblick?

The Institute for Strategies and Technology Assessment of the Julius Kühn-Institute operates four different networks: demonstration farms on IPM, reference farms for plant protection, panel pesticide applications and NEPTUN farms. All networks deal with the use of plant protection products in agricultural practice. The latter three also have very similar tasks and are closely interlinked. As a result, outsiders have significant problems distinguishing between those four farm networks and assigning the respective activities to the “right” corresponding network.Therefore, the publication aims at presenting comparatively the tasks and objectives of the various networks and to explain to the reader what are they doing, what are the differences, as well as why and how the establishment of these four different farm networks has come about.     

Wirtschaftlichkeitsbewertung von Pflanzenschutzstrategien in E- und A‑Weizen anhand eines Feldversuches in Brandenburg mit sechsgliedriger Fruchtfolge in den Jahren 2004 bis 2016

Plant protection strategies are mostly assessed with respect to their efficacy and yield stability rather than their economic result. Therefore, this study aimed at evaluating the economic excellence of different strategies. Based on a long term field trial, the economics of four plant protection strategies in two different winter wheat quality classes (A wheat and E wheat) were evaluated. The field trial located in Dahnsdorf in Brandenburg comprised a crop rotation with six rotation components which is rather untypical for agricultural practice in that region. The economic analysis was based on field trial data from 13 years between 2004 and 2016 which was supplemented by secondary statistical data. Four plant protection strategies were considered: (S1) harrowing without chemical plant protection, (S2) plant protection in accordance to good farming practice taking into account the general principles of integrated pest management and a reduction of the treatment frequency index by (S3) 25% or rather (S4) 50% compared to good farming practice. By calculating the plant protection and labor cost free revenues for each year and strategy and by transferring these into annuities the four plant protection strategies were compared economically. The results for E wheat (elite wheat) were similar to those of A wheat (quality wheat) in terms of economic performance. A comparison of the plant protection strategies showed, that the abandonment of pesticides (S1) led to considerable economic disadvantages compared to the other three strategies. These three strategies which included the application of pesticides (S2, S3, S4) led to almost equivalent revenues, however, a reduction of the treatment frequency index by 25% compared to the good farming practice resulted in the best economical outcome for both wheat qualities. The applied crop rotation with six rotation components in combination with an intensive monitoring of the plant pests clearly supported the reduction of pesticide use in winter wheat without economic disadvantages. The results suggest, that such crop rotations have the potential to contribute to a sustainable crop production.