Anders Bryn
Forsker
(+47) 930 39 782
anders.bryn@nibio.no
Sted
Ås - Bygg O43
Besøksadresse
Oluf Thesens vei 43, 1433 Ås (Varelevering: Elizabeth Stephansens vei 21)
Biografi
Sammendrag
Purpose Treelines and forest lines (TFLs) have received growing interest in recent decades, due to their potential role as indicators of climate change. However, the understanding of TFL dynamics is challenged by the complex interactions of factors that control TFLs. The review aims to provide an overview over the trends in the elevational dynamics of TFLs in Norway since the beginning of the 20th century, to identify main challenges to explain temporal and spatial patterns in TFL dynamics, and to identify important domains for future research. Method A systematic search was performed using international and Norwegian search engines for peer-reviewed articles, scientific reports, and MA and PhD theses concerning TFL changes. Results Most articles indicate TFL rise, but with high variability. Single factors that have an impact on TFL dynamics are well understood, but knowledge gaps exist with regard to interactions and feedbacks, especially those leading to distributional time lags. Extracting the most relevant factors for TFL changes, especially with regard to climate versus land-use changes, requires more research. Conclusions Existing data on TFL dynamics provide a broad overview of past and current changes, but estimations of reliable TFL changes for Norway as a whole is impossible. The main challenges in future empirically-based predictions of TFLs are to understand causes of time lags, separate effects of contemporary processes, and make progress on the impacts of feedback and interactions. Remapping needs to be continued, but combined with both the establishment of representative TFL monitoring sites and field experiments.
Sammendrag
The Norwegian area frame survey of land cover and outfield land resources (AR18X18), completed in 2014, provided unbiased statistics of land cover in Norway. The article reports the new statistics, discusses implications of the data set, and provides potential value in terms of research, management, and monitoring. A gridded sampling design for 1081 primary statistical units of 0.9 km2 at 18 km intervals was implemented in the survey. The plots were mapped in situ, aided by aerial photos, and all areas were coded following a vegetation type system. The results provide new insights into the cover and distribution of vegetation and land cover types. The statistic for mire and wetlands, which previously covered 5.8%, has since been corrected to 8.9%. The survey results can be used for environmental and agricultural management, and the data can be stratified for regional analyses. The survey data can also serve as training data for remote sensing and distribution modelling. Finally, the survey data can be used to calibrate vegetation perturbations in climate change research that focuses on atmospheric–vegetation feedback. The survey documented novel land cover statistics and revealed that the national cover of wetlands had previously been underestimated.
Sammendrag
During recent decades, forests have expanded into new areas throughout the whole of Norway. The processes explained as causing the forest expansion have focused mainly on climate or land use changes. To enable a spatially explicit separation of the effects following these two main drivers behind forest expansion, the authors set out to model the potential for natural forest regeneration following land use abandonment, given the present climatic conditions. The present forest distribution, a number of high-resolution land cover maps, and GIS methods were used to model the potential for natural forest regeneration. Furthermore, the results were tested with independent local models, explanatory variables and predictive modelling. The modelling results show that land use abandonment, in a long-term perspective, has the climatic and edaphic potential to cause natural forest regeneration of 48,800 km2, or 15.9% of mainland Norway. The future natural forest regeneration following land use change or abandonment can now be spatially separated from the effects of climate changes. The different independent model tests support the main findings, but small fractions of the modelled potential natural forest regeneration will probably be caused by other processes than land use abandonment.
Sammendrag
Rapporten beskriver mulig metode for kartlegging av reinbeiter, her definert av fire årstidsbeiter. Utgangspunktet er kartlegging av vegetasjon-/naturtyper som kobles til reinens foretrukne diett gjennom året. Kartleggingen kan utføres ved feltkartlegging, fjernmåling, modellering eller statistiske utvalgsundersøkelser. Modellen som ligger til grunn for å klassifisere et areal som viktig beiteareal er kun basert på vegetasjon-/naturtypenes forventede egnethet som fôrgrunnlag for rein. I praksis vil reinens faktiske arealbruk ha mye å si, og den kan ikke kartlegges gjennom beitekartlegging. Beitekartlegginga sin viktigste funksjon som verktøy ved vurdering av reinbeiteareal, for eksempel i konsekvensutredninger, er å gi en systematisk oversikt over arealene. Beitekartlegging kan ikke erstatte reindriftsutøvernes kunnskap om reinens arealbruk, men være et supplement når en skal vurdere hvilke konsekvenser et tiltak kan få for reindriftsnæringa. Metoden er beheftet med mange usikkerhetsmomenter og må prøves ut og vurderes gjennom uttestinger.
Forfattere
Anders Bryn Rune Halvorsen Peter Horvath Lasse Torben Keetz Ida Marielle Mienna Trond Simensen Olav Skarpaas Ingrid Vesterdal Tjessem Joachim Paul Töpper Vigdis Vandvik Liv Guri Velle Catharina Caspara VloonSammendrag
Det er ikke registrert sammendrag
Forfattere
Lawrence Richard Kirkendall Kyrre Linné Kausrud Martin Malmstrøm Paul Ragnar Berg Anders Bryn Kjetil Hindar Johanna Järnegren Anders Nielsen Erlend Birkeland Nilsen Brett Kevin Sandercock Eva Bonsak Thorstad Gaute VelleSammendrag
The Norwegian Environment Agency has asked VKM to evaluate the risks to biodiversity associated with the import of two species of leeches to Norway, Hirudo medicinalis and H. verbana (so-called medicinal leeches). In addition, they ask that the project group suggest mitigating measures that could reduce any potential risks, should import of the two species be granted. Background Bloodsucking leeches have been employed by humans for millennia. The two species Hirudo medicinalis and H. verbana have dominated the trade in medicinal leeches in Europe. Overcollection combined with loss or degradation of freshwater habitats led to a precipitous decline in European populations by the 1800s and led to a corresponding increase in imports from Turkey, North Africa, Russia and the Middle East. By the turn of the 19th century, the demand for live leeches in Europe had tapered off as contemporary medicine developed, only to have a small resurgence over the last decades as live leeches became recognized as useful for a variety of medical and cosmetic procedures, and to be the source of bioactive molecules of interest to medical researchers. As traditional medicine in Asia also uses a variety of leech products, there is a robust global market for live leeches and leech derivatives that is being met mostly by leech aquaculture, where the live leech trade seems dominated by H. verbana. There is increasing interest in commercializing production and sale of three similar leech species, H. orientalis from Central Asia, H. sulukii from a small region in Turkey, and H. troctina from North Africa. Hirudo medicinalis has been used medicinally in Norway since at least the Middle Ages when they were used by barber-surgeons for bloodletting. Leeches have been dispensed by apothecaries up until the end of the 1950s. Phylogeographic studies have treated the species as native to southern Norway and the Norwegian Biodiversity Information Centre has numerous records of H. medicinalis, with recent records primarily from the eastern coast of southern Norway. The Norwegian Red List for Species categorizes H. medicinalis as being of Least Concern in Norway. Hirudo verbana naturally occurs in southern Europe and has not been observed in Scandinavia so far (see map in Figure 2). Methods for the risk assessment VKM established a small working group with expertise in invertebrates and risk assessment. Our group combed the scientific literature and relevant websites for information on the taxonomy, natural history, ecology, and medical uses of medicinal leeches broadly and H. medicinalis and H. verbana specifically. The project group contacted major leech providers in Europe and North America to learn more about leech production and sale. Using the EICAT (Environmental Impact Classification for Alien Taxa) system developed by the IUCN, The project group identified those mechanisms (“hazards”) through which these two species could affect native biodiversity in Norway should imported specimens become established in Norwegian nature, and characterized the risk related to each of these hazards. The project group then conducted a semi-quantitative risk assessment for the species according to four categories: Low, Medium, Possibly high, and High risk. Hazards: how likely, how impactful, and overall risks In our report, VKM regard H. medicinalis as a native species, since it is so treated by Hirudo experts and is widespread in Norway. The project group regards H. verbana as non-native to Norway. The potential hazards from the EICAT system that could be associated with introducing one or both species include predation and parasitism, competition, disease transmission, and hybridization. ................................ .................................... Conclusions VKM concludes that the overall risk to biodiversity in Norway from importing live H. medicinalis and H. verbana is low.