Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2011
Authors
Felix Herzog Katalin Balázs Peter Dennis Tetyana Dyman Wendy Fjellstad Jürgen Friedel Salah Garchi Philippe Jeanneret Rob Jongman Maximilian Kainz Gerardo Moreno Charles Nkwiine Maurizio Paoletti Philippe Pointereau Jean-Pierre Sarthou Siyka Stoyanova Davide ViaggiAbstract
Farmland biodiversity is an important component of Europe’s biodiversity. More than half the continent is occupied by agricultural lands. They host specific habitats and species, which – in addition to the conservation values they provide – perform vital ecological functions. Indicators are needed to enable the monitoring of biodiversity at the farm level for the purpose of assessing the impacts of farming practices and of agricultural policies. Our research aims at identifying farmland biodiversity indicators which are scientifically sound, operational and relevant for stakeholders. We screened the literature for farmland biodiversity indicators and, in an iterative process with stakeholders, we identified 28 candidate indicators for genetic, species and habitat diversity. Those selected biodiversity indicators, as well as 14 management parameters that are known to relate to biodiversity, were assessed in 12 case study regions across Europe. Each case study region represents a typical production system (i.e. specialist field crops, horticulture and permanent crops; specialist grazing with cattle and other livestock types; mixed crop and livestock farming). In each region, 8 – 20 farms were randomly selected, mostly within the two groups of organic and non-organic farms, to obtain a gradient of farming intensity. Indicators were measured applying standardized sampling procedures and farm interviews. Sampling effort was recorded in order to assess the cost of indicator measurement. For each case study region, biodiversity indicators are presently being evaluated in conjunction with management indicators. Surrogate indicators will be proposed when possible and indicators will be prioritized taking into account their validity, practicality, cost and priority for stakeholders. Based on preliminary results, the presentation will focus on the relation between direct (species and habitat diversity) indicators and indirect (farm management) parameters. Part of this research was funded by the EU FP7 contract KBBE-2B-227161. For more information consult www.biobio-indicator.org
Abstract
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Abstract
Nematodes, commonly known as round worms, are the most common multicellular animals on planet Earth. After 1000 million years of evolution members of the phylum Nematoda have a high bionomic diversity. As habitants of the soil and rhizosphere nematodes are involved en energy fluxes, and affect carbon and nutrient cycles. As plant parasites, either alone or in synergism with other pathogens, nematodes are responsible for plant disease complexes and major crop losses. A growth depression in a field of potato (Solanum tuberosum) cv. Saturna [resistant to pathotype Ro1 of potato cyst nematode (PCN) Globodera rostochiensis], suggestive of potato cyst nematode damage, was detected in Grue, eastern Norway. Analyses of soil samples did not detect PCN, but demonstrated the occurrence of a large number of lesion nematodes Pratylenchus penetrans .Tubers from the depressed part of the field had severe symptoms similar to those caused by the common scab bacterium Streptomyces scabies. Potato yield was reduced by 50% in the affected area of the field. Transect-sampling showed plant growth to be negatively correlated with densities of P. penetrans and suggested a damage threshold of potato to the nematode of 100 specimens per250 g of soil. Common scab (Streptomyces scabies) occurred frequently in the affected area. P. penetrans was present in roots, underground stems, stolons and tubers. Tubers from the depressed part of the field had severe symptoms similar to those caused by the common scab bacterium. In tubers, nematodes were detected inside cross-lesions typical symptoms of common scab, and occurred also in the outermost 0.5 mm tissue associated with such lesions. In pots with sterile sand, micro-tubers of potato cv. Saturna, produced from meristems, were grown in a green-house infected with, P. penetrans, S. scabies, and a combination of P. penetrans and, S. scabies. P. penetrans alone induced tuber lesions similar to those of common scab. Also, the combined inoculation of the bacterium and the nematode seemed to enhance symptom expression. Similar scab symptoms, in connection with lesion nematode infections, have been observed on potato tubers cv. Oleva, which also is relatively tolerant to common scab. Symptomatic tubers cv. Saturna first stored at 4o C for 20 weeks were transferred to pots with sterile sand and grown for 3 months in the green-house. In these cultures P. penetrans was first detected in soil 8 weeks after planting. Examination at harvest of soil, roots, stolons, tubers demonstrated symptoms typical of P. penetrans. Interestingly, P. penetrans survives storage of potatoes, from which new infections may develop. Hence, potato tubers do appear to be an important means for the spread of P. penetrans to new areas. The fact that the symptoms induced by this nematode may be mistaken for symptoms of common scab suggests that the frequency of S. scabies might have been overestimated in regular surveys. Infections by P. penetrans have important implications for scab control. This pertains in particular to recommended maintenance of high soil moisture at and during 4-9 weeks after tuber set. If symptoms are related to nematode infection rather than to the scab bacterium, this recommendation would allow for a rapid build-up of lesion nematodes resulting in a decrease in both yield and marketability of the tubers. Further studies are needed to investigate the extent of this problem.
Abstract
A changing climate will likely influence the selection of tree species in the future, and this may in turn affect the size of the pools and fluxes of carbon. Tree species differ in growth rate, fine-root turnover and quality of litter and tend to produce different types of understory vegetation. In Sweden three tree species (Norway spruce [Picea abies] 43%, Scots pine [Pinus sylvestris] 39% and birch [Betula spp.] 11%) dominate. In the present study we used field experiments in southern Sweden to test if these tree species differed in root distribution and turnover.
Abstract
1. In the face of a rapidly changing environment, long-term studies provide important insights into patterns of vegetation and processes of change, but long-term studies are rare for many ecosystems.2. We studied recent vegetation changes at a fine scale in a Sphagnum-dominated bog in south Sweden by resurveying part of the bog 54 years after the original phytosociological survey. We used an indirect approach to identify changes in vegetation composition in relation to environment because of a lack of permanent sampling units. By applying a weighted averaging technique, we calculated relative changes in species optimum values for different environmental gradients as represented by indicator values for light, temperature, pH, moisture and nutrients.3. Species composition of the mire vegetation has changed significantly over the past five decades, as indicated by significant changes in species frequencies and species optima for the gradients examined. Species with lower indicator values for moisture and light and higher indicator values for nutrients have become more frequent on the mire. In particular, species of trees and dwarf shrubs increased in frequency, whereas typical mire species decreased (e.g. Trichophorum cespitosum (L.) Hartm.) or disappeared fromthe study site (e.g. Scheuchzeria palustris L.).4. Synthesis. Composition of the mire vegetation is found to be dynamic at different temporal and spatial scales. Increased air temperature and nutrient availability in south Sweden over the past few decades may have augmented productivity (e.g. tree growth), resulting in drier and shadier conditions for several species. This study successfully demonstrated the applicability of an indirect approach for detecting long-term vegetation change at a fine scale. This approach is an effective way of using historic and modern phytosociological data sets to detect vegetation and environmental change through time.
Authors
Jutta KapferAbstract
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During a survey conducted in August 2009 in northern Norway, symptoms typical for red band needle blight (1) were observed in four young Scots pine (Pinus sylvestris) stands. The stands, less than 15 years old, were located in humid sites near rivers in Bardu and Målselv municipalities, Troms County. Many of the oldest needles (2- to 3- years-old) in the lower part of young trees were partially or completely brown, but still attached, and red bands could be observed. Aggregations of conidial stromata were often seen in the red bands. Conidia were hyaline, smooth, thin walled, and filiform, 1.9 to 2.6 μm wide and 12 to 36 μm long....
Abstract
No abstract has been registered