| 1. |
- Hansson, Karna, et al.
(författare)
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Carbon and nitrogen pools and fluxes above and below ground in spruce, pine and birch stands in southern Sweden
- 2013
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Ingår i: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 309, s. 28-35
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Tidskriftsartikel (refereegranskat)abstract
- We synthesised results on soil carbon (C) and nitrogen (N) fluxes and the accumulation of soil organic C and N under adjacent 50-year-old Norway spruce, Scots pine and silver birch stands growing on similar soils and evaluated the different processes involved. C and N budgets were calculated. Spruce stands had larger stocks of C and N in biomass and soil than birch stands, with pine intermediate. The differences in soil stocks were mainly found in the organic layer, whereas differences in the mineral soil were small. The study showed that there is no simple answer to what is causing the differences in soil C and N stocks, because several processes are interacting. Spruce and pine trees had higher biomass and litter production than birch trees, but total litter inputs showed no significant difference between stands, because the rich ground vegetation under pine and birch contributed with substantial litter inputs, in contrast to the poor ground vegetation under spruce. Decomposition rate (per g of C) was markedly higher under birch than under spruce and pine resulting in lower C and N stocks in the organic layer. This effect was amplified by higher abundance and biomass of earthworms, favoured by higher pH and palatable litter under birch. Earthworm bioturbation probably both increased decomposition rate and damaged the ectomycorrhizal network with negative consequences for the formation of mycorrhizal litter and C storage. In conclusion, the direct effects of spruce, pine and birch litter on C and N pools and fluxes were modified by indirect effects of understorey structure, pH and earthworm responses. (C) 2013 Elsevier B.V. All rights reserved.
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| 2. |
- Hudson, Lawrence N., et al.
(författare)
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The PREDICTS database : a global database of how local terrestrial biodiversity responds to human impacts
- 2014
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Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 4:24, s. 4701-4735
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Tidskriftsartikel (refereegranskat)abstract
- Biodiversity continues to decline in the face of increasing anthropogenic pressures such as habitat destruction, exploitation, pollution and introduction of alien species. Existing global databases of species' threat status or population time series are dominated by charismatic species. The collation of datasets with broad taxonomic and biogeographic extents, and that support computation of a range of biodiversity indicators, is necessary to enable better understanding of historical declines and to project - and avert - future declines. We describe and assess a new database of more than 1.6 million samples from 78 countries representing over 28,000 species, collated from existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world. The database contains measurements taken in 208 (of 814) ecoregions, 13 (of 14) biomes, 25 (of 35) biodiversity hotspots and 16 (of 17) megadiverse countries. The database contains more than 1% of the total number of all species described, and more than 1% of the described species within many taxonomic groups - including flowering plants, gymnosperms, birds, mammals, reptiles, amphibians, beetles, lepidopterans and hymenopterans. The dataset, which is still being added to, is therefore already considerably larger and more representative than those used by previous quantitative models of biodiversity trends and responses. The database is being assembled as part of the PREDICTS project (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems - ). We make site-level summary data available alongside this article. The full database will be publicly available in 2015.
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| 3. |
- Adler, Karl, et al.
(författare)
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Digital Soil Mapping of Cadmium: Identifying Arable Land for Producing Winter Wheat with Low Concentrations of Cadmium
- 2023
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Ingår i: Agronomy. - : MDPI AG. - 2073-4395. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- Intake of cadmium (Cd) via vegetable food poses a possible health risk. Cereals are one of the major sources of Cd, and the Cd concentration in the soil has a great effect on the levels in the grain. The aim of the study was to produce decision support for identification of areas suitable for low-Cd winter wheat production in the form of a detailed digital soil map covering an important agricultural region in southern Sweden. A two-step approach was used: (1) we increased the number of soil Cd observations by combining two sets of soil samples, one with laboratory Cd analyses (304 samples) and one with predicted Cd from a portable x-ray fluorescent (PXRF) sensor (2097 samples); and (2) a digital soil mapping (DSM) model (gradient boosting regression) was calibrated on all 2401 soil samples to create a soil Cd concentration map using a number of covariates, of which airborne gamma ray data was identified as the most important. In the first step, cross-validation of the PXRF model obtained a model efficiency (E) of 0.82 and mean absolute error (MAE) of 0.08 mg kg(-1). The DSM model had an E of 0.69 and MAE of 0.11 mg kg(-1). The map of predicted soil Cd concentrations were compared against 307 winter wheat (Triticum aestivum L.) grain samples with laboratory-analyzed Cd concentrations. Areas in the map with low soil Cd concentrations had a high frequency of lower grain Cd concentrations. The map thus seemed to have potential for finding areas suitable for production of low-Cd winter wheat; e.g., for baby food.
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| 4. |
- Persson, Tryggve, et al.
(författare)
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Forest soil carbon sink in the Nordic region
- 2014
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- A Nordic/Baltic network was established to connect research groups working on soil carbon storage and dynamics. The region stores vast amounts of carbon in soil organic matter that may be sensitive to increasing temperatures and intensified biomass harvest. The experimental research of the network focussed on the effects of tree species, harvesting regimes, nitrogen deposition, soil warming and land use change on soil organic carbon stocks and their sensitivity to change. Process studies particularly on belowground allocation of plant carbon and the role of mycorrhiza were also performed. Regional differences in the soil carbon stocks were explored in monitoring data and forest models were used for long term predictions.
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| 5. |
- Persson, Tryggve, et al.
(författare)
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High species richness in spruce stumps
- 2017
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Ingår i: Stump harvesting: impact on climate and environment. ; :Task 43: 2017:02, s. 54-66
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 6. |
- Persson, Tryggve, et al.
(författare)
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Hög artmångfald i granstubbar
- 2017
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Ingår i: Stubbskörd – hur påverkas klimat och miljö?. - 9789157694546 ; , s. 56-65
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Bokkapitel (populärvet., debatt m.m.)
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| 7. |
- Vestergren, Johan, et al.
(författare)
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High resolution characterization of organic phosphorus in soil extracts using 2D 1H-31P NMR correlation spectroscopy
- 2012
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 46:7, s. 3950-3956
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Tidskriftsartikel (refereegranskat)abstract
- Organic phosphorus (P) compounds represent a major component of soil P in many soils and are key sources of P for microbes and plants. Solution NMR (nuclear magnetic resonance spectroscopy) is a powerful technique for characterizing organic P species. However, 31P NMR spectra are often complicated by overlapping peaks, which hampers identification and quantification of the numerous P species present in soils. Overlap is often exacerbated by the presence of paramagnetic metal ions, even if they are in complexes with EDTA following NaOH/EDTA extraction. By removing paramagnetic impurities using a new precipitation protocol, we achieved a dramatic improvement in spectral resolution. Furthermore, the obtained reduction in line widths enabled the use of multi-dimensional NMR methods to resolve overlapping 31P signals. Using the new protocol on samples from two boreal humus soils with different Fe contents, two-dimensional 1H-31P correlation spectra allowed unambiguous identification of a large number of P species based on their 31P and 1H chemical shifts and their characteristic coupling patterns, which would not have been possible using previous protocols. This approach can be used to identify organic P species in samples from both terrestrial and aquatic environments, increasing our understanding of organic P biogeochemistry.
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| 8. |
- Edström, Mats, et al.
(författare)
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Rötning av fjäderfägödsel med gödselförädling i tillämpad skala
- 2018
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Ett tjugotal lantbrukare i Mönsterås kommun planerar för att bygga en stor biogasanläggning som kommer att ha fastgödsel från höns som huvudsubstrat. Den gemensamma biogasanläggning kan bli den största i sitt slag i Sverige, med en biogasproduktion på ca 70 GWh biogas/år för produktion av drivmedel. Den genererade rötresten kan kväveförsörja ca 12 000 ha/år växtodling och fosforförsörja ca 20 000 ha/år. Den rötade gödseln bidrar i princip till all växtnäring i rötresten, där fjäderfägödseln kommer att bidra med ca 80 % av rötrestens innehåll av kväve och fosfor. Ett hinder för att realisera denna anläggning är att det idag saknas erfarenhet från praktisk drift av rötningsanläggningar med betydande inblandning av fjäderfägödsel. Fjäderfägödsel är både ett fosfor- och kväverikt substrat, och innehåller dessutom både tunga och lätta partiklar som riskerar att bilda sediment och svämtäcken i rötkammaren. Idag betraktas fjäderfägödsel framför allt som ett fosforgödselmedel eftersom huvuddelen av kvävet inte är direkt upptagbart av växter, men rötning av fjäderfägödsel ökar andelen direktverkanande kväve. För att optimera hantering, spridning och utnyttjande av kväve och fosfor i fjäderfägödsel är det önskvärt att processa denna gödsel för att generera fyra stycken gödselmedel med olika kväve- och fosforkvot. För att kunna studera dessa frågeställningar och bredda gödselbasen för rötning har Vinnova, under 2016-2018, finansierat denna tillämpade studie.Under ett tillämpat försök genomfördes rötning i pilotskala av kväverik hönsgödsel som huvudsubstrat. Rötningsprocessen gick att driva stabilt vid en ammoniumkvävehalt på närmare 6 g/l inom det mesofila temperaturområdet i en totalomblandad rötkammare med volymetrisk metanproduktion som uppgick till 1,1 m3 CH4/m3 slamvolym & dag. Järnklorid tillfördes rötkammaren för att hålla biogasens innehåll av svavelväte vid ca 100 ppm. För att hålla ammoniumhalten vid angiven nivå tillfördes vatten motsvarande halva inflödet in i rötkammaren, för att späda ner kvävet till denna nivå. Efter rötningen av substratblandningen ökade dess ammoniuminnehåll med 3,7 gånger.Under pilotförsöket producerades ca 13 m3 rötrest som sparades och lagrades 4–8 månader innan den förädlades i två steg till två olika gödselmedel. I första steget genomfördes fasseparation med en dekantercentrifug följt av indunstning av surgjord tunnfas. Baserat på dessa försök beräknas fassepareringen kunna generera ett fast gödselmedel vars vikt motsvarar 23 % av i rötningsprocessen producerad rötrest. Det fasta gödselmedlets innehåll av fosfor utgör dryga 70 % av rötrestens fosforinnehåll. Vidare beräknas indunstningen kunna generera ett uppkoncentrerat flytande gödselmedel vars vikt motsvarar 2o % av i rötningsprocessen producerad rötrest. Det flytande gödselmedlets innehåll av ammoniumkvävet utgör dryga 70 % av rötrestens ammoniuminnehåll. Det producerade koncentratgödselmedlet liksom tunnfasgödselmedlet hade en hög andel lättillgängligt kväve, vilket är en viktig delförutsättning för att uppnå höga skördar vid växtodling. Gödselmedel från Mönsterås Biogas planerade biogasanläggning kan i framtiden bidra till att jordbruket i Kalmar län med omnejd kan gå mot en hållbar intensifiering av livsmedelsproduktionen.
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| 9. |
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| 10. |
- Alshihabi, Omran, et al.
(författare)
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Post-processing yield maps of winter wheat using data from satellites and combines
- 2023
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Konferensbidrag (refereegranskat)abstract
- Yield mapping is important for evaluation of crop management and for delineation of management zones. In this study, a simple approach was developed to map winter wheat (Triticum aestivum L.) yield in fields missing combine yield data, based on yield data from other fields in the neighbourhood combined with Sentinel-2 data (ESA, EU). The study focused on which vegetation index (VI), which growth stage and which spatial resolution was optimal for yield mapping. The results showed that the VI map resolution did not significantly affect the mapping model, a combination of bands in the short-wave infrared and near infrared region was the most efficient in yield mapping and that satellite data from later growth stages (in the milk development stage) were better in mapping the final yield if compared with earlier stages.
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