| 1. |
- Roger, Fabian, et al.
(författare)
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Airborne environmental DNA metabarcoding for the monitoring of terrestrial insects—A proof of concept from the field
- 2022
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Ingår i: Environmental DNA. - : Wiley. - 2637-4943. ; 4:4, s. 790-807
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Tidskriftsartikel (refereegranskat)abstract
- Biodiversity is in decline due to human-induced pressures on ecosystems around the world. To be able to counteract this alarming trend, it is paramount to closely monitor biodiversity at global scales. Because this is practically impossible with traditional methods, the last decade has seen a strong push for new solutions. In aquatic ecosystems, the monitoring of species from environmental DNA (eDNA) has emerged as one of the most powerful tools at our disposal, but in terrestrial ecosystems, the power of eDNA for monitoring has so far been hampered by the local scale of the samples. In this study, we report the successful detection of insects from airborne eDNA from samples taken in the field. We compare our results to two traditional insect monitoring methods (1) light traps for moth monitoring and (2) transect walks for the monitoring of butterflies and wild bees. Airborne eDNA metabarcoding revealed DNA from six classes of arthropods, and twelve order of insects—including representatives from the four largest orders: Diptera (flies), Lepidoptera (butterflies and moths), Coleoptera (beetles), and Hymenoptera (bees, wasps, and ants). We did not detect all species observed using traditional methods and suggest further directions for the development of airborne eDNA metabarcoding. We also recovered DNA from nine species of vertebrates, including frogs, birds, and mammals as well as from 12 other phyla. Airborne eDNA has the potential to become a powerful tool for terrestrial biodiversity monitoring, with many impactful applications including the monitoring of pests, invasive, or endangered species and disease vectors.
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| 2. |
- Abdi, Abdulhakim, et al.
(författare)
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Evaluating Water Controls on Vegetation Growth in the Semi-Arid Sahel Using Field and Earth Observation Data
- 2017
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Ingår i: Remote Sensing. - : MDPI AG. - 2072-4292. ; 9:3
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Tidskriftsartikel (refereegranskat)abstract
- Water loss is a crucial factor for vegetation in the semi-arid Sahel region of Africa. Global satellite-driven estimates of plant CO2 uptake (gross primary productivity, GPP) have been found to not accurately account for Sahelian conditions, particularly the impact of canopy water stress. Here, we identify the main biophysical limitations that induce canopy water stress in Sahelian vegetation and evaluate the relationships between field data and Earth observation-derived spectral products for up-scaling GPP. We find that plant-available water and vapor pressure deficit together control the GPP of Sahelian vegetation through their impact on the greening and browning phases. Our results show that a multiple linear regression (MLR) GPP model that combines the enhanced vegetation index, land surface temperature, and the short-wave infrared reflectance (Band 7, 2105–2155 nm) of the moderate-resolution imaging spectroradiometer satellite sensor was able to explain between 88% and 96% of the variability of eddy covariance flux tower GPP at three Sahelian sites (overall = 89%). The MLR GPP model presented here is potentially scalable at a relatively high spatial and temporal resolution. Given the scarcity of field data on CO2 fluxes in the Sahel, this scalability is important due to the low number of flux towers in the region.
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| 3. |
- Abdi, Abdulhakim M., et al.
(författare)
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Biodiversity decline with increasing crop productivity in agricultural fields revealed by satellite remote sensing
- 2021
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Ingår i: Ecological Indicators. - : Elsevier BV. - 1470-160X. ; 130
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Tidskriftsartikel (refereegranskat)abstract
- Increasing land-use intensity is a main driver of biodiversity loss in farmland, but measuring proxies for land-use intensity across entire landscapes is challenging. Here, we develop a novel method for the assessment of the impact of land-use intensity on biodiversity in agricultural landscapes using remote sensing parameters derived from the Sentinel-2 satellites. We link crop phenology and productivity parameters derived from time-series of a two-band enhanced vegetation index with biodiversity indicators (insect pollinators and insect-pollinated vascular plants) in agricultural fields in southern Sweden, with contrasting land management (i.e. conventional and organic farming). Our results show that arable land-use intensity in cereal systems dominated by spring-sown cereals can be approximated using Sentinel-2 productivity parameters. This was shown by the significant positive correlations between the amplitude and maximum value of the enhanced vegetation index on one side and farmer reported yields on the other. We also found that conventional cereal fields had 17% higher maximum and 13% higher amplitude of their enhanced vegetation index than organic fields. Sentinel-2 derived parameters were more strongly correlated with the abundance and species richness of bumblebees and the richness of vascular plants than the abundance and species richness of butterflies. The relationships we found between biodiversity and crop production proxies are consistent with predictions that increasing agricultural land-use intensity decreases field biodiversity. The newly developed method based on crop phenology and productivity parameters derived from Sentinel-2 data serves as a proof of concept for the assessment of the impact of land-use intensity on biodiversity over cereal fields across larger areas. It enables the estimation of arable productivity in cereal systems, which can then be used by ecologists and develop tools for land managers as a proxy for land-use intensity. Coupled with spatially explicit databases on agricultural land-use, this method will enable crop-specific cereal productivity estimation across large geographical regions.
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| 4. |
- Andersson, Georg K.S., et al.
(författare)
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Landscape-scale diversity of plants, bumblebees and butterflies in mixed farm-forest landscapes of Northern Europe : Clear-cuts do not compensate for the negative effects of plantation forest cover
- 2022
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Ingår i: Biological Conservation. - : Elsevier BV. - 0006-3207. ; 274
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Tidskriftsartikel (refereegranskat)abstract
- To assess the biodiversity consequences of contemporary land-use trends in Northern Europe, where agriculture is being replaced by forestry, we need a better knowledge of the contributions of constituting habitats to biodiversity. Here, we use purposefully collected data from 87 sites to model how agricultural habitats, including semi-natural pastures, sown temporary grassland (leys), cereal crops, and forest habitats comprising both mature production forests and clear-cuts, contribute to landscape-scale diversity of plants, bumblebees and butterflies in boreonemoral Sweden. At the local scale, species richness was highest in semi-natural pastures, intermediate in cereal crops and leys and lowest in forest. In clear-cuts, species richness was similarly high to that in semi-natural pastures. Countryside species-area models show that at a landscape scale, the high local richness in clear-cuts was more than offset by the low species richness encountered in forest. At landscape scale, semi-natural pastures, and in the case of plants also cereal crops, were major contributors of unique species. Leys and semi-natural pastures were both important contributors to bumblebee diversity. The effect of the surrounding landscape composition on local diversity was weak, suggesting that area-based approximations of landscape-scale species richness were reasonable. We conclude that clear-cuts constitute habitats for open-land species but cannot maintain landscape-scale diversity in the face of agricultural abandonment when open land is replaced by even-aged production forests. Maintaining farmland, in particular semi-natural pastures but also cereals and leys, is therefore critical to maintaining the landscape-scale species richness of plants and insects in forestry-dominated areas.
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| 5. |
- Andersson, Magnus, et al.
(författare)
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Does Large-Scale Gold Mining Reduce Agricultural Growth? Case studies from Burkina Faso, Ghana, Mali and Tanzania
- 2015
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Ingår i: Annual World Bank Conference on Land and Poverty 2015 : Linking Land Tenure and Use for Shared Prosperity - Linking Land Tenure and Use for Shared Prosperity. - : The World Bank. ; , s. 1-27
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Konferensbidrag (refereegranskat)abstract
- We apply a novel analytical framework based on medium resolution satellite data for the period 2001 – 2012 to estimate the effects of gold mining on agricultural production in Ghana, Mali, Tanzania and Burkina Faso. Our analysis finds a strong correlation between official statistics of agricultural production and vegetation index from satellite data at district level in these countries. Agricultural productivity as proxied by greenness index (NDVI) does not decrease in the proximity of large scale gold mines. Our empirical estimations show that economic activity as proxied by night lights, increase in the proximity of mining but the estimates remains statistically insignificant.
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| 6. |
- Andersson, Magnus, et al.
(författare)
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Mining, Economic Activity and Remote Sensing : Case studies from Burkina Faso, Ghana, Mali and Tanzania
- 2015
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Ingår i: CSAE Conference 2015: Economic Development in Africa. ; , s. 1-42
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Konferensbidrag (refereegranskat)abstract
- Mining is a major economic activity in many developing countries particularly in Africa. Mining operations, whether small- or large-scale, have an impact on local communities. Previous research focus on how the gold mining sector in Africa is dependent on policy reforms in order to enable countries to better benefit from the sector, changing environmental conditions or the structure of the economic activities in the areas surrounding mines. Here, we apply a novel analytical framework based on medium resolution satellite data for the period 2001 – 2012 to estimate the economic effects of mining in Ghana, Mali, Burkina Faso and Tanzania. Through the analysis of nighttime lights, agricultural vegetation dynamics and forest change, we find a positive effect on average economic growth for most mining districts in Mali, Burkina Faso and Tanzania. Moreover, our analysis establishes strong relationship between statistics of agricultural production and vegetation index from satellite data on district level in Mali, Ghana and Tanzania.
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| 7. |
- Blanke, Jan, et al.
(författare)
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Implications of accounting for management intensity on carbon and nitrogen balances of European grasslands
- 2018
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 13:8
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Tidskriftsartikel (refereegranskat)abstract
- European managed grasslands are amongst the most productive in the world. Besides temperature and the amount and timing of precipitation, grass production is also highly controlled by applications of nitrogen fertilizers and land management to sustain a high productivity. Since management characteristics of pastures vary greatly across Europe, land-use intensity and their projections are critical input variables in earth system modeling when examining and predicting the effects of increasingly intensified agricultural and livestock systems on the environment. In this study, we aim to improve the representation of pastures in the dynamic global vegetation model LPJ-GUESS. This is done by incorporating daily carbon allocation for grasses as a foundation to further implement daily land management routines and land-use intensity data into the model to discriminate between intensively and extensively used regions. We further compare our new simulations with leaf area index observations, reported regional grassland productivity, and simulations conducted with the vegetation model ORCHIDEE-GM. Additionally, we analyze the implications of including pasture fertilization and daily management compared to the standard version of LPJ-GUESS. Our results demonstrate that grassland productivity cannot be adequately captured without including land-use intensity data in form of nitrogen applications. Using this type of information improved spatial patterns of grassland productivity significantly compared to standard LPJ-GUESS. In general, simulations for net primary productivity, net ecosystem carbon balance and nitrogen leaching were considerably increased in the extended version. Finally, the adapted version of LPJ-GUESS, driven with projections of climate and land-use intensity, simulated an increase in potential grassland productivity until 2050 for several agro-climatic regions, most notably for the Mediterranean North, the Mediterranean South, the Atlantic Central and the Atlantic South.
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| 8. |
- Boke-Olén, Niklas, et al.
(författare)
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Analyzing savannah vegetation phenology with remotely sensed data, lagged time-series models and phenopictures
- 2016
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Konferensbidrag (refereegranskat)abstract
- It is predicted that savannah regions will see changes in precipitation patterns due to current climate change pro-jections. The change will most likely affect leaf phenology which controls net primary production. It is thereforeimportant to; 1) study those changes and its drivers, 2) to be able to correctly model the changes to vegetationphenology due to climate change. To our knowledge there is no existing global savannah phenology model thatcan capture both the phenological events and the vegetation state between the events. We therefore, investigate howday length, mean annual precipitation and soil moisture affects and controls the vegetation phenology of savannahs(using MODIS NDVI as a proxy for phenological state) with a lagged time series model for global application. Wefurthermore use phenological pictures (phenopictures) to investigate savannah tree and grass phenology. Phenopic-tures are pictures taken with a digital time-lapse camera with the purpose of recording and studying phenologicalevents. We used climate data from 15 flux towers sites located in 4 continents together with normalized differencevegetation index from MODIS for the model development. Two of the sites located in Africa were further ana-lyzed using phenopictures. The developed model identified all three considered variables as usable for modellingof savannah leaf phenology but showed some inconsistent result for some of the sites indicating the difficultiesin creating a simple common model that works equally well across sites. We attribute some of these difficultiesto site specific differences (e.g. grazing or tree and grass ratio) that the simplified model did not consider. Butwe expect it to on average give the cross-validated result (r2= 0.6, RMSE = 0.1) when applied to other savannahareas. The preliminary analysis of the phenological pictures with respect to tree and grass to some extent supportthis by showing differences in the start of the leaves development in the beginning of the season. However, thisdiffered between the two studied sites which further highlights the difficulties in creating a common model thatworks equally well for individual sites.
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| 9. |
- Boke-Olén, Niklas, et al.
(författare)
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Data Descriptor : High-resolution African population projections from radiative forcing and socio-economic models, 2000 to 2100
- 2017
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Ingår i: Scientific Data. - : Springer Science and Business Media LLC. - 2052-4463. ; 4
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Tidskriftsartikel (refereegranskat)abstract
- For its fifth assessment report, the Intergovernmental Panel on Climate Change divided future scenario projections (2005-2100) into two groups: Socio-Economic Pathways (SSPs) and Representative Concentration Pathways (RCPs). Each SSP has country-level urban and rural population projections, while the RCPs are based on radiative forcing caused by greenhouse gases, aerosols and associated land-use change. In order for these projections to be applicable in earth system models, SSP and RCP population projections must be at the same spatial scale. Thus, a gridded population dataset that takes into account both RCP-based urban fractions and SSP-based population projection is needed. To support this need, an annual (2000-2100) high resolution (approximately 1km at the equator) gridded population dataset conforming to both RCPs (urban land use) and SSPs (population) country level scenario data were created.
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| 10. |
- Boke Olén, Niklas, et al.
(författare)
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Effects of farm type on food production, landscape openness, grassland biodiversity, and greenhouse gas emissions in mixed agricultural-forestry regions
- 2021
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Ingår i: Agricultural Systems. - : Elsevier BV. - 0308-521X .- 1873-2267. ; 189
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Tidskriftsartikel (refereegranskat)abstract
- Context: The global demand for food is expected to continue increasing for decades, which may drive both agricultural expansion and intensification. The associated environmental impacts are potentially considerable but will depend on how the agricultural sector develops. Currently, there are contrasting regional developments in agriculture; expansion and/or intensification in some regions and abandonment in others, as well as changes in the type of farming. However, the environmental consequences of changes in farm type are not well understood. Objective: We have evaluated the impacts of farm type on food production and three key environmental variables—landscape openness, grassland biodiversity and greenhouse gas (GHG) emissions—in three marginal agricultural regions in Sweden. Methods: We do this by first dividing the population of farms in each region into types, based on their land-use and livestock holdings using an innovative clustering method. Thereafter we analysed changes in production activities for farm types over time and evaluated the environmental and food-production impacts, where landscape openness is quantified using a novel indicator. Results and conclusion: Our results show that there is not one single farm type that would simultaneously maximize food production, grassland biodiversity, and landscape openness, whilst minimizing GHG emissions. However, there exists considerable potential to manage the trade-offs between food production and these environmental variables. For example, by reducing land use for dairying and instead increasing both cropping for food production and extensive livestock grazing to maintain landscape openness and biodiversity-rich semi-natural pastures, it would keep food production at similar levels. Significance: Our farm typology allows us to assess the multifunctionality of farming, by relating contrasting production activities to multiple ecosystem services, grassland biodiversity and GHG emissions for informing policy towards more sustainable agriculture. We have demonstrated this with examples under Swedish conditions, but it should to a large extent also be applicable for other countries.
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