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.
2022
Authors
Melissa MagerøyAbstract
No abstract has been registered
Abstract
There is debate on which tree species can sustain forest ecosystem services in a drier and warmer future. In Europe, the use of non-native timber species, such as Douglas fir (Pseudotsuga menziesii [Mirb.] Franco), is suggested as a solution to mitigate climate change impacts because of their high growth resilience to drought. However, the biogeographical, climatic and ecological limits for widely planted timber species still need to be defined. Here, we study the growth response to climate variables and drought of four Douglas fir plantations in northern Spain subjected to contrasting climate conditions. Further, we measure wood density in one of the sites to obtain a better understanding of growth responses to climate. Correlative analyses and simulations based on the Vaganov–Shaskin process-based model confirm that growth of Douglas fir is constrained by warm and dry conditions during summer and early autumn, particularly in the driest study site. Minimum wood density increased in response to dry spring conditions. Therefore, planting Douglas fir in sites with a marked summer drought will result in reduced growth but a dense earlywood. Stands inhabiting dry sites are vulnerable to late-summer drought stress and can act as “sentinel plantations”, delineating the tolerance climate limits of timber species.
Authors
Anna Birgitte MilfordAbstract
No abstract has been registered
Abstract
1. Spatial resources accessible for the derivation of biodiversity indicators of the class ecosystem structure are sparse and disparate, and their integration into computer algorithms for biodiversity monitoring remains problematic. We describe ecochange as an R-package that integrates spatial analyses with a monitoring workflow for computing routines necessary for biodiversity monitoring. 2. The ecochange comprises three modules for data integration, statistical analysis and graphics. The first module currently downloads and integrates diverse remote sensing products belonging to the essential biodiversity class of structure. The module for statistical analysis calculates RasterStack ecosystem-change representations across areas of interest; this module also allows focusing on species habitats while deriving changes in a variety of indicators, including ecosystem areas, conditional entropy and fractal dimension indices. The graphics module produces level and bar plots that ease the development of indicator reports. 3. Its functionality is described with an example workflow to calculate ecosystem-class areas and conditional entropy across an area of interest contained in the package documentation. 4. We conclude that ecochange features procedures necessary to derive ecosystem structure indicators integrating the retrieval of spatially explicit data with the use of workflows to calculate/visualize biodiversity indicators at the national/regional scales.
Abstract
The species composition of benthic algae changes as water phosphorus concentrations increase, and these changes can be used for ecological status assessment according to the Water Framework Directive. Natural background phosphorus concentrations in rivers and streams that are unaffected by anthropogenic impacts are usually low. Running waters draining catchments with deposits of marine clay, however, may have enhanced phosphorus concentrations, because the clay is naturally rich in apatite. Almost all clay rich areas have been cultivated for centuries, however, and fertilization has increased the soil phosphorus levels. It has, therefore, been difficult to disentangle natural from anthropogenically enhanced phosphorus in streams draining clay rich areas. We compared water phosphorus concentrations, and the Periphyton Index of Trophic Status PIT, between clay and non-clay, impacted and unimpacted rivers in Norway. We found that water phosphorus concentrations and the PIT index were higher in unimpacted clay rivers than in unimpacted non-clay rivers, indicating that natural phosphorus concentrations in clay rivers are indeed enhanced compared to rivers without deposits of marine clay. In addition, phosphate-P contributed 18–23% to total phosphorus in unimpacted clay rivers, but 33–37% in unimpacted and impacted non-clay rivers and clay rivers affected by agriculture. This indicates that the total phosphorus in unimpacted clay rivers is less bioavailable than in non-clay rivers and in impacted clay rivers. Water total phosphorus concentrations in unimpacted clay rivers significantly increased with catchment clay cover. Based on these findings, we derived new status class boundaries for the PIT index in clay rivers. Clay rivers are suggested to be assessed in only two status classes, i.e., “good or better” or “moderate or worse”, respectively. The good/moderate status class boundary for the PIT index was shown to increase with increasing catchment clay cover.
Authors
Christian PedersenAbstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Michel Bechtold Bjørn Kløve Annalea Lohila Massimo Lupascu Line Rochefort Hanna Marika SilvennoinenAbstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
No abstract has been registered