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| 2. |
- Mattsson, Eskil, 1981, et al.
(författare)
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Quantification of carbon stock and tree diversity of homegardens in a dry zone area of Moneragala District, Sri Lanka
- 2015
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Ingår i: Agroforestry Systems. - : Springer Science and Business Media LLC. - 1572-9680 .- 0167-4366. ; 89:3, s. 435-445
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Tidskriftsartikel (refereegranskat)abstract
- Homegarden agroforestry systems are suggested to hold a large potential for climate change mitigation and adaptation. This is due to their multifunctional role in providing income, food and ecosystem services while decreasing pressure on natural forests and hence saving and storing carbon. In this paper, above-ground biomass carbon and tree species diversity of trees was quantified in homegardens around two villages in the dry south-eastern part of Moneragala district of Sri Lanka. A total of 45 dry zone homegardens were sampled on size, diameter at breast height, tree height and species diversity. Using allometric equations, we find a mean above-ground biomass stock of 13 mega grams of carbon per hectare (Mg C ha−1) with a large range among homegardens (1–56 Mg C ha−1, n = 45) due to a variation of tree diversity and composition between individual homegardens. Mean above-ground carbon stock per unit area was higher in small homegardens (0.2 ha, 26 Mg C ha−1, n = 11) and statistically different compared to medium (0.4–0.8 ha, 9 Mg C ha−1, n = 27) and large (1.0–1.2 ha, 8 Mg C ha−1, n = 7) homegardens. In total, 4,278 trees were sampled and 70 tree species identified and recorded. The Shannon Wiener index were used to evaluate diversity per homegarden and ranged from 0.76 to 3.01 with a mean value of 2.05 ± 0.07 indicating a medium evenly distributed diversity of sampled tree species. The results show a vast heterogeneity in terms of carbon stock and tree diversity within the less studied dry zone homegardens; results that contribute to more knowledge of their expansion potential as well as climate mitigation and adaptation potential. The results are also useful for whether homegardens should be considered to be included as an activity to enhance natural forest cover within Sri Lanka’s newly commenced UN-REDD National Programme.
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| 3. |
- Ritter, Camila, et al.
(författare)
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Biodiversity assessments in the 21st century: The potential of insect traps to complement environmental samples for estimating eukaryotic and prokaryotic diversity using high-throughput DNA metabarcoding.
- 2019
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Ingår i: Genome. - : Canadian Science Publishing. - 1480-3321 .- 0831-2796. ; 62:3, s. 147-159
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Tidskriftsartikel (refereegranskat)abstract
- The rapid loss of biodiversity, coupled with difficulties in species identification, call for innovative approaches to assess biodiversity. Insects make up a substantial proportion of extant diversity and play fundamental roles in any given ecosystem. To complement morphological species identification, new techniques such as metabarcoding make it possible to quantify insect diversity and insect-ecosystem interactions through DNA sequencing. Here we examine the potential of bulk insect samples (i.e., containing many non-sorted specimens) to assess prokaryote and eukaryote biodiversity and to complement the taxonomic coverage of soil samples. We sampled 25 sites on three continents and in various ecosystems, collecting insects with Slam-traps (Brazil) and Malaise-traps (South Africa and Sweden). We then compared our diversity estimates with the results obtained with biodiversity data from soil samples from the same localities. We found a largely different taxonomic composition between the soil and insect samples, testifying to the potential of bulk insect samples to complement soil samples. Finally, we found that non-destructive DNA extraction protocols, which preserve insect specimens for morphological studies, constitute a promising choice for cost-effective biodiversity assessments. We propose that the sampling and sequencing of insect samples should become a standard complement for biodiversity studies based on environmental DNA.
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| 5. |
- Messing, Ingmar, et al.
(författare)
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Rovdrift på åkermark i Uppsala
- 2012
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Ingår i: Upsala nya tidning. - 1104-0173. ; , s. 5-
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Annan publikation (populärvet., debatt m.m.)
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| 6. |
- Liljenström, Hans, et al.
(författare)
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Scoping Report on Socio-Economic and Land Use Dynamics in the Stockholm-Mälar Region
- 2014
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This scoping report for the COMPLEX work package 4 (WP4) on Socio-Economic and Land Use Dynamics in the Stockholm-Mälar Region has several objectives. The first is to present and outline the state-of-the-art, including a literature review, with regard to complex pathways to a low carbon society, with special relevance to the Stockholm-Mälar region. It will do so in a larger context of complex socio-natural systems, with an emphasis on a green economy, bioen-ergy and land use, as well as on societal transformation and behavioural change. Another objec-tive is to inform primarily our partners in COMPLEX, but also others who might be interested, including stakeholders in our study region. Perhaps the most important objective with this re-port is to provide a basis for the collaborative work within our work package, and with our col-leagues elsewhere. In this second revised version of the report, we have extended some parts, and shortened others, depending on suggestions and interesting new information. A part of this new information has come from a stakeholder workshop held in Sigtuna in early 2014, which to a great extent could contribute to a more elaborate analysis of stakeholder and policy maker positions. In addition, there is now a more extensive description of relevant land use modelling. The illustrations included in this report are extracted from scientific articles and other material that we are referring to. Their origin is explicitly cited but no copyright authorization has been requested, while this report is intended primarily for internal spread and use within the COM-PLEX consortium and its networks.
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| 8. |
- Weslien, Per, 1963, et al.
(författare)
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Carrot cropping on organic soil is a hotspot for nitrous oxide emissions
- 2012
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Ingår i: Nutrient Cycling in Agroecosystems. - : Springer Science and Business Media LLC. - 1385-1314 .- 1573-0867. ; 94:2-3, s. 249-253
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Tidskriftsartikel (refereegranskat)abstract
- The emissions of the greenhouse gas nitrous oxide (N2O) were measured from a non nitrogen fertilized carrot (Daucus carota ssp. sativa) field on an organic soil in Sweden during one cropping and post-harvest season. The cumulative emission during the measuring period of 149 days was 41 (±2.8) kg N2O ha−1. Dividing the measuring period into a cropping and a post-harvest period revealed that the presence of carrots strongly stimulated N2O emissions, as the emission during the cropping period was one order of magnitude higher compared to the post-harvest period. The N2O emission from the carrot field were higher than fluxes reported from cereal crop and grass production, but in the same order as reported fluxes from vegetable cropping on organic soils. In conclusion, our results indicate that the cultivation of root vegetable, such as carrots, on organic soil can be a high point source for N2O emissions.
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| 9. |
- Montelius, Malin
(författare)
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Chlorine Cycling in Terrestrial Environments
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Chlorinated organic compounds (Clorg) are produced naturally in soil. Formation and degradation of Clorg affect the chlorine (Cl) cycling in terrestrial environments and chlorine can be retained or released from soil. Cl is known to have the same behaviour as radioactive chlorine-36 (36Cl), a long-lived radioisotope with a half-life of 300,000 years. 36Cl attracts interest because of its presence in radioactive waste, making 36Cl a potential risk for humans and animals due to possible biological uptake. This thesis studies the distribution and cycling of chloride (Cl–) and Clorg in terrestrial environments by using laboratory controlled soil incubation studies and a forest field study. The results show higher amounts of Cl– and Clorg and higher chlorination rates in coniferous forest soils than in pasture and agricultural soils. Tree species is the most important factor regulating Cl– and Clorg levels, whereas geographical location, atmospheric deposition, and soil type are less important. The root zone was the most active site of the chlorination process. Moreover, this thesis confirms that bulk Clorg dechlorination rates are similar to, or higher than, chlorination rates and that there are at least two major Clorg pools, one being dechlorinated quickly and one remarkably slower. While chlorination rates were negatively influenced by nitrogen additions, dechlorination rates, seem unaffected by nitrogen. The results implicate that Cl cycling is highly active in soils and Cl– and Clorg levels result from a dynamic equilibrium between chlorination and dechlorination. Influence of tree species and the rapid and slow cycling of some Cl pools, are critical to consider in studies of Cl in terrestrial environments. This information can be used to better understand Cl in risk-assessment modelling including inorganic and organic 36Cl.
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