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Publikasjoner

NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.

2021

Abstract

In the Bramke valley (western Harz mountains, North Germany), three forested headwater catchments have been monitored since decades. A broad range of observables relevant to forestry, hydrology, hydrochemistry and ecosystem research allows to compare different approaches to environmental monitoring; each of them has its own set of relevant observables. The basic temporal resolution is daily for hydrometeorology and bi-weekly for streamwater chemistry; standing biomass of the Norway spruce stands is measured every couple of years. Tree growth (site index) has changed between and within rotation periods (of up to 129 years); changes in soil nutrient pools are typical variables used to explain this nonstationary forest growth when the spatial-temporal scales match. In hydrology, transport mechanisms of water and solutes through catchment soils are used to model and predict runoff and its chemistry. Given the homogeneity of the area in terms of geology, soils and topography as well as climate, differences between the catchments in the Bramke valley are mostly related to forestry variables. The catchments exhibit long-term changes and spatial gradients related to atmospheric deposition, management and changing climate. After providing a short multivariate summary of the dataset, we present several nonlinear metrics suitable to detect and quantify subtle changes and to describe different behavior, both between different variables from the same catchment, as well as for the same variable across catchments. Soil water potential and solution chemistry are further links between forestry and hydrology. However, at Lange Bramke, similar to other catchment studies, the evaluation of these data sets has not converged to a consistent, realistic model at the catchment scale. We hypothesize that this lack of model integration is due to theoretical rather than technical limits. A possible representation of these limits might be phrased in a category theory approach. How to cite: Hauhs, M., Meesenburg, H., and Lange, H.: Long-term monitoring of vegetation and hydrology in headwater catchments and the difficulties to embrace data-oriented and process-oriented approaches, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-7684, https://doi.org/10.5194/egusphere-egu21-7684, 2021.

To document

Abstract

Plant diseases may survive and be spread by infected seeds. In this study we monitored the longevity of 14 seed-borne pathogens in 9 crop species commonly grown in the Nordic countries, in addition to a sample of sclerotia of Sclerotinia sclerotiorum. The data from the first 30 years of a 100-year seed storage experiment located in a natural −3.5 °C environment (permafrost) in Svalbard, Norway, are presented. To date, the pathogens, tested by traditional seed health testing methods (freezing blotter, agar plates, growing on tests), have survived. Linear regression analyses showed that the seed infection percentages of Drechslera dictyoides in meadow fescue, Drechslera phlei in timothy, and Septoria nodorum in wheat were significantly reduced compared to the percentages at the start of the experiment (from 63% to 34%, from 70% to 65%, and from 15% to 1%, respectively), and that Phoma betae in beet had increased significantly (from 43% to 56%). No trends in the infection percentage were observed over the years in Drechslera spp. in barley (fluctuating between 30% and 64%) or in Alternaria brassicicola in cabbage (fluctuating between 82% and 99%), nor in pathogens with low seed infection percentages at the start of the experiment. A major part of the stored sclerotia was viable after 30 years. To avoid the spread of seed-borne diseases, it is recommended that gene banks implement routines that avoid the use of infected seeds.

To document

Abstract

A better understanding of regional differentiation and local adaptation of rare arable plants is essential for the development of suitable methods for the reintroduction of these species. We set up F1 and F2 greenhouse experiments with 4–12 source populations of five rare arable plant species to test for genetically based differentiation in biomass production and phenology in South Germany. For three species, i.e. Arnoseris minima, Consolida regalis and Teesdalia nudicaulis, reciprocal transplant experiments were performed in arable fields to investigate local adaptation in plant establishment as well as biomass production to the northern or southern regions of three seed transfer zones. We found low regional differentiation, but provenance-specific responses to drought stress in Legousia speculum-veneris biomass and A. minima phenology. Moreover, little evidence was identified for local adaptation, while significant differences were seen in the performance between the transplant sites and study years, indicating a high phenotypic variability. Our results suggest that the current seed zones are suitable for the seed transfer of rare arable plants in the study region. Thus, there is a low risk of maladaptation when using autochthonous seed sources within the seed zones, but a high extinction risk of these species and their respective ecosystem functions if no active restoration is done, including transplant measures.