| 1. |
- Bargues Tobella, Aida
(författare)
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Determination of land restoration potentials in the semi-arid areas of Chad using systematic monitoring and mapping techniques
- 2023
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Ingår i: Agroforestry Systems. - : Springer Science and Business Media LLC. - 0167-4366 .- 1572-9680. ; 97, s. 1289-1305
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Tidskriftsartikel (refereegranskat)abstract
- The restoration of degraded lands has received increased attention in recent years and many commitments have been made as part of global and regional restoration initiatives. Well-informed policy decisions that support land restoration, require spatially explicit information on restoration potentials to guide the design and implementation of restoration interventions in the context of limited resources. This study assessed ecosystems indicators of land degradation using a systematic approach that combines field surveys and remote sensing data into a set of multi-criteria analyses to map restoration potentials in the semi-arid areas. The indicators considered were soil organic carbon, erosion prevalence, enhanced vegetation index, Normalized differences water index and the Net Primary productivity. Three classes of restoration potential were established: (1) areas not in need of immediate restoration due low degradation status, (2) areas with high potential for restoration with moderate efforts required and (3) areas in critical need of restoration and require high level of efforts. Of the total area of the study site estimated at 88,344 km2, 59,146.12 km2, or 66.94% of the theoretically recoverable area, was considered suitable for restoration, of which 38% required moderate efforts while 28% require less efforts. The recoverable areas suitable for restoration could be restored through tree planting, soil and water conservation practices, farmers managed natural regeneration, and integrated soil fertility management. These results can help to spatially identify suitable multifunctional restoration and regeneration hotspots as an efficient way to prioritize restoration interventions in the context of limited resources.
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| 2. |
- Björklund, Johanna, 1961-, et al.
(författare)
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Exploring the potential of edible forest gardens : experiences from a participatory action research project in Sweden
- 2019
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Ingår i: Agroforestry Systems. - : Springer. - 0167-4366 .- 1572-9680. ; 93:3, s. 1107-1118
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Tidskriftsartikel (refereegranskat)abstract
- To meet the environmental challenges that are presently confronting society, the narrow focus on agricultural production needs to be altered to one that places equal value on the generation of crucial ecosystem services. Current research shows that perennial intercropping systems such as agroforestry may be a feasible alternative. Based on studies during the establishment of edible forest gardens in 12 participating farms in Sweden, this paper explores the potential of utilizing multi-strata designs for food production in temperate, highincome countries. Design and species composition of such gardens, types of food they provide, and how they would best fit into the present landscape are discussed. Factors for success and major problems related to the establishment are shared. Potential benefits were found to be closely related to a thorough analysis of the social and ecological contexts before establishment. Characteristics of the site and goals of the garden need to guide species and design choices. If forest garden approaches to food production should contribute to more than local selfsufficiency, the gardens need to increase in scale. Marginal lands and transitions areas between different land uses may be appropriate. Large knowledge gaps concerning potential production, social and economic benefits, and agronomic issues were identified.
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| 3. |
- Damasco, Gabriel, 1984, et al.
(författare)
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Certification of açaí agroforestry increases the conservation potential of the Amazonian tree flora
- 2022
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Ingår i: Agroforestry Systems. - : Springer Science and Business Media LLC. - 0167-4366 .- 1572-9680. ; 96, s. 407-416
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Tidskriftsartikel (refereegranskat)abstract
- The harvesting of açaí berries (palm fruits from the genus Euterpe) in Amazonia has increased over the last 20 years due to a high local and global market demand and triggered by their widely acclaimed health benefits as a ‘superfood’. Although such increase represents a financial boom for local communities, unregulated extraction in Amazonia risks negative environmental effects including biodiversity loss through açai intensification and deforestation. Alternatively, the introduction of certified sustainable agroforestry production programs of açaí has been strategically applied to reduce the exploitation of Amazonian forests. Local açaí producers are required to follow principles of defined sustainable management practices, environmental guidelines, and social behaviors, paying specific attention to fair trade and human rights. In this study we investigate whether sustainable agroforestry and certification effectively promotes biodiversity conservation in Amazonia. To address this question, we conducted a forestry inventory in two hectares of long-term certified açai harvesting areas to gain further knowledge on the plant diversity and forest structure in açaí managed forests and to understand the contribution of certification towards sustainable forest management. On average, we found that certified managed forests harbor 50% more tree species than non-certified açaí groves. Trees in certified areas also have significantly higher mean basal area, meaning larger and hence older individuals are more likely to be protected. Certified harvesting sites also harbor dense populations of threatened species as classified by the International Union for Conservation of Nature (e.g.Virola surinamensis, classified as ‘endangered’). Besides increasing the knowledge of plant diversity in açaí managed areas, we present baseline information for monitoring the impact of harvesting activities in natural ecosystems in Amazonia.
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| 4. |
- Elmqvist, Bodil, et al.
(författare)
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A traditional agroforestry system under threat: an analysis of the gum arabic market and cultivation in the Sudan
- 2005
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Ingår i: Agroforestry Systems. - : Springer Science and Business Media LLC. - 1572-9680 .- 0167-4366. ; 64:3, s. 211-218
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Tidskriftsartikel (refereegranskat)abstract
- The main aim of this study is to review the environmental and socioeconomic sustainability of the gum arabic farming system in central Sudan. A further aim is to analyse some of the main factors influencing production in recent decades in order to understand the future trade potential and consequently the smallholder livelihood. The study shows that end-user imports of gum arabic have increased during recent decades. Gum arabic is mainly for uses such as soft drinks, confectionary, and pharmaceuticals. However, even with this increased demand the production in Sudan, the main country of production, is declining. The producers, mainly smallholders, suger from fluctuating prices. If the gum arabic farming system should be able to provide the environmental benefits of improved soil fertility and the socioeconomic benefits of risk spreading and dry season income opportunities, the prices paid to smallholders must be stabilized at a fair level, otherwise a shift to other crops or practices might take place.
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| 5. |
- Getachew, Merkebu, et al.
(författare)
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Within and among farm variability of coffee quality of smallholders in southwest Ethiopia
- 2023
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Ingår i: Agroforestry Systems. - : Springer Science and Business Media LLC. - 0167-4366 .- 1572-9680. ; 97:5, s. 883-905
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Tidskriftsartikel (refereegranskat)abstract
- The biophysical drivers that affect coffee quality vary within and among farms. Quantifying their relative importance is crucial for making informed decisions concerning farm management, marketability and profit for coffee farmers. The present study was designed to quantify the relative importance of biophysical variables affecting coffee bean quality within and among coffee farms and to evaluate a near infrared spectroscopy-based model to predict coffee quality. Twelve coffee plants growing under low, intermediate and dense shade were studied in twelve coffee farms across an elevational gradient (1470–2325 m asl) in Ethiopia. We found large within farm variability, demonstrating that conditions varying at the coffee plant-level are of large importance for physical attributes and cupping scores of green coffee beans. Overall, elevation appeared to be the key biophysical variable influencing all the measured coffee bean quality attributes at the farm level while canopy cover appeared to be the most important biophysical variable driving the above-mentioned coffee bean quality attributes at the coffee plant level. The biophysical variables driving coffee quality (total preliminary and specialty quality) were the same as those driving variations in the near-infrared spectroscopy data, which supports future use of this technology to assess green bean coffee quality. Most importantly, our findings show that random forest is computationally fast and robust to noise, besides having comparable prediction accuracy. Hence, it is a useful machine learning tool for regression studies and has potential for modeling linear and nonlinear multivariate calibrations. The study also confirmed that near-infrared spectroscopic-based predictions can be applied as a supplementary approach for coffee cup quality evaluations.
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| 6. |
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| 7. |
- Kaartinen, Riikka, et al.
(författare)
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Shade trees decrease pest abundances on brassica crops in Kenya
- 2019
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Ingår i: Agroforestry Systems. - : Springer Science and Business Media LLC. - 0167-4366 .- 1572-9680. ; 93, s. 641-652
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Tidskriftsartikel (refereegranskat)abstract
- Agroforestry practices may mitigate the current loss of biodiversity and ecosystem services due to deforestation and agricultural intensification. To examine the effects of agroforestry on the ecosystem service of pest regulation, we assessed pest abundances and biological control potential in shaded and open kale (Brassica oleracea L. acephala) fields in Western Kenya. Specifically, we compared the abundance of pest aphids and caterpillars, ground-dwelling ants, spiders and predatory beetles, and examined aphid parasitism rates, predation rates on diamondback moth eggs, attack rates on surrogate caterpillars and bird predation on aphids. Shade trees effectively reduced abundances of aphids, caterpillars and increased abundances of spiders and predatory beetles, but neither affected ant abundances, or predation and parasitism rates. Our results suggest that presence of shade trees can decrease pest abundances, but that this is not only due to improved biological control by natural enemies but also due to microclimatic conditions affecting pest performance and bottom-up processes such as changes in plant quality and soil conditions. We encourage studies exploring simultaneously how top-down and bottom-up processes affect pest regulation in agroforestry settings.
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| 8. |
- Kardell, Örjan, 1963-
(författare)
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A theoretical study for North Vietnam of alternative agroforestry systems to pure cassava
- 1993
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Ingår i: Agroforestry Systems. - : Kluwer Academic Publishers. - 0167-4366 .- 1572-9680. ; 21:3, s. 251-262
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Cassava is recognized in the region as the second most important crop after paddy rice. In Vinh Phu province of Vietnam, it is usually grown on highly erodible slopes of the small hills surrounding paddy fields. Cassava crop land is generally in annual use until the yield is less than 3-4 t fresh tubers/ha. This constant cropping system rapidly depletes the soil as fertilizers are infrequently used and crop residues are usually removed from the fields. Erosion is a major problem as the soil is exposed through hand cultivation and regular weeding during a cropping season which coincides with the wet season. Sustainable and productive cropping systems are needed. In order to take a first step towards sustainability, this paper presents several possible agroforestry systems in which cassava could be intercropped with a number of nitrogen fixing trees and shrubs. Several theoretical combinations have been examined assuming a critical lower production limit of 3-4 t fresh tubers/ha. Those with sustained high potential yields are recommended for future field experimentation.
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| 9. |
- Ky-Dembele, Catherine, et al.
(författare)
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Inter- and intra-provenances variations in seed size and seedling characteristics of Khaya senegalensis A. Juss in Burkina Faso
- 2014
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Ingår i: Agroforestry Systems. - : Springer Science and Business Media LLC. - 0167-4366 .- 1572-9680. ; 88, s. 311-320
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Tidskriftsartikel (refereegranskat)abstract
- Within- and between-provenance variations in seed and seedling traits of Khaya senegalensis A. Juss were studied at INERA in Burkina Faso. Nursery grown seedlings from four provenances in Burkina Faso were used for the study. The studies revealed significant variability in all traits evaluated. Seed length and weight significantly varied among provenances and families within provenances, where Bopiel and Koyenga had the highest mean values. Height and root collar diameter of 1 year old seedlings significantly varied among families within provenances. Except leaf biomass ratio and carbon isotope ratio which varied significantly among provenances but not among families within provenances, all other seedling biomass traits-total plant biomass, stem biomass ratio, leaf biomass ratio, root biomass ratio, root shoot ratio, specific leaf area, and leaf area ratio were significantly affected by provenances and families within provenances. The magnitude of variation due to family effect ranged from 65 to 93 % for seed size traits, and from 4.5 to 17.8 % for seedling characters. Estimates of family heritability were moderate to high (0.67-0.95) for seed traits, but low to moderate (0.19-0.59) for seedling characters, indicating that much of the total variation in seed traits is due to the genetic effect. The two most prominent provenances, Koyenga and Bopiel, with higher seed size and greater seedling growth could be considered for an eventual K. senegalensis improvement program in Burkina Faso.
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| 10. |
- Lana, Marcos
(författare)
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Analyzing influencing factors to scale up agroforestry systems in Colombia: A comparative ex-ante assessment of cacao farming and cattle ranching in two regions
- 2022
-
Ingår i: Agroforestry Systems. - : Springer Science and Business Media LLC. - 0167-4366 .- 1572-9680. ; 96, s. 435-446
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Tidskriftsartikel (refereegranskat)abstract
- Agroforestry systems (AFS) are proved to enhance sustainable land management. Thus, there is increasing demand for effective ways to scale up AFS so that more people can benefit. Consequently, this study assesses the scaling-up potential of agroforestry systems (AFS) using cacao farming and cattle ranching in Caqueta and Cesar, Colombia, as examples. An ex-ante assessment using the ScalA tool is conducted through interviews with AFS experts from institutions promoting AFS. Using a comparative approach, results reveal that AFS have different scaling-up potential depending on the type of farming system and location characteristics. In our case, it is slightly higher for cacao farming than for cattle ranching in both regions and it is higher in Caqueta than in Cesar for both systems. Factors hindering the scaling-up potential for both regions are economic conditions at the local and regional levels since there is a lack of stable and differentiated markets to absorb AFS products. In contrast, the scaling-up potential in both regions is increased by the factors related to the capacity of the organizations that promote AFS and the attitudes of local communities toward them. The study generates information about factors that may hinder or foster AFS scaling-up, including not just the capacities and mechanisms to promote them but also the enabling conditions. This contributes to prioritizing AFS interventions and better allocating their resources to increase their chances of successful scaling-up.
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| 11. |
- 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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| 12. |
- Mattsson, Eskil, 1981, et al.
(författare)
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What is good about Sri Lankan homegardens with regards to food security? A synthesis of the current scientific knowledge of a multifunctional land-use system
- 2018
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Ingår i: Agroforestry Systems. - : Springer Science and Business Media LLC. - 0167-4366 .- 1572-9680. ; 92:6, s. 1469-1484
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Tidskriftsartikel (refereegranskat)abstract
- Recently, there has been growing interest in agroforestry systems due to their great potential to mitigate threats to household food and nutrition security from soaring food prices but also as carbon sinks. In Sri Lanka, smallholder farms such as homegardens constitute a majority of Sri Lanka's total annual crop and timber production. Despite Sri Lankan homegardens being considered desirable and sustainable land-use systems, their role in food and nutrition security is not yet entirely understood. By synthesising scientific articles and grey literature we sought the link between food security and homegardens by quantifying their products or services and ascertaining whether food security characteristics are assessed as direct or indirect impacts. The results show that 27% of 92 identified articles directly quantified aspects that are relevant to food security. Another 51% of the articles quantified indirect aspects that have relevance for food security, including climate, soil, ecosystem services, structural and floristic diversity and economic aspects. Twenty-two percent of the articles were categorised as being qualitative or conceptual and contained no direct assessments or quantification of food security. The presence of significant merits from homegardens includes providing food security throughout the year at low-cost while sustaining numerous ecosystem services. This benefits particularly the poor farmers. However, many studies are descriptive and only provide location-specific information on single research focuses such as plant species, yield and management. There are few comparisons with crop land, forests or other production systems, and there is even less empirical evidence and quantification of the food security and other benefits. Seven areas where more scientific focus would be beneficial are identified. Homegardens are strong in national policies and to reach a greater level of efficiency within these activities our findings suggest more emphasis on a higher degree of inclusiveness of relevant stakeholders and long-term engagements with context specific guidance.
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| 13. |
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| 14. |
- Mukangango, Marguerite, et al.
(författare)
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Biomass production and nutrient content of three agroforestry tree species growing on an acid Anthropic Ferralsol under recurrent harvesting at different cutting heights
- 2020
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Ingår i: Agroforestry Systems. - : Springer Science and Business Media LLC. - 0167-4366 .- 1572-9680. ; 94, s. 857-867
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Tidskriftsartikel (refereegranskat)abstract
- Agroforestry systems may alleviate challenges relating to soil degradation and low livestock production for smallholder farmers. Species-adjusted management regimes will determine how agroforestry fits in farming systems. Long-term productivity of biomass in agroforestry systems managed for fodder production requires tree species that coppice after repeated cutting. This study evaluated the effect of different cutting heights (0.3 and 1.0 m) and repeated harvests (1-5) on biomass production and chemical composition of the leguminous trees Acacia angustissima, Leucaena pallida and Mimosa scabrella in a field study on an Anthropic Ferralsol in Southern Rwanda. Shoot biomass production was highest at 0.3 m cutting height for A. angustissima and L. pallida, but M. scabrella could not survive that cutting height. Shoot biomass was highest for A. angustissima and lowest for M. scabrella, which did not adapt to repeated harvests. Leaf:stem ratio was not affected by cutting height. Cutting height did not affect crude protein (CP), but neutral detergent fibre (NDF), acid detergent fibre (ADF) and total polyphenol (TP) concentrations were higher at 1.0 m cutting height than at 0.3 m. Crude protein was highest in A. angustissima and lowest in M. scabrella, while NDF and ADF were highest in M. scabrella. Although all species provided high feed quality in terms of high CP content at both cutting heights, low cutting height (0.3 m) is recommended for A. angustissima and L. pallida for higher overall quality and biomass production.
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| 15. |
- Opdenbosch, Harold, et al.
(författare)
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Farmers' willingness to adopt silvopastoral systems: investigating cattle producers' compensation claims and attitudes using a contingent valuation approach
- 2022
-
Ingår i: Agroforestry Systems. - : Springer Science and Business Media LLC. - 0167-4366 .- 1572-9680.
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Tidskriftsartikel (refereegranskat)abstract
- Intensive cattle production systems are currently a major contributor to CO2 emissions and biodiversity loss. Silvopastoral systems that combine foraging pastures and trees into an integrated system for raising livestock have been suggested a promising avenue to store carbon and preserve farmland biodiversity. However, investments and maintenance costs for these improvements are paid by producers, who reap few of the environmental benefits. The objective of the present study was to assess farmers' willingness to adopt silvopastoral systems by reforesting treeless pastures, their compensation claims related to adoption, and how both are affected by their attitudes towards silvopastoral systems. This study was based on a contingent valuation approach coupled with exploratory factor analysis to obtain measures of attitudinal constructs derived from the Theory of Planned Behavior. Results indicate that 52% of respondents were willing to adopt silvopastoral systems and the mean compensation claim per year per hectare is estimated at SEK 3107.17 (308(sic)). Adoption decision is positively correlated with attitudes towards silvopastoral systems, suggesting that decision-making is not solely driven by profit maximization through concerns related to pecuniary factors.
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| 16. |
- Parsons, David
(författare)
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Potential of the APSIM model to simulate impacts of shading on maize productivity
- 2018
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Ingår i: Agroforestry Systems. - : Springer Science and Business Media LLC. - 0167-4366 .- 1572-9680. ; 92, s. 1699-1709
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Tidskriftsartikel (refereegranskat)abstract
- A number of agroforestry models have been developed to simulate growth outcomes based on the interactions between components of agroforestry systems. A major component of this interaction is the impact of shade from trees on crop growth and yield. Capability in the agricultural production systems simulator (APSIM) model to simulate the impacts of shading on crop performance could be particularly useful, as the model is already widely used to simulate agricultural crop production. To quantify and simulate the impacts of shading on maize performance without trees, a field experiment was conducted at Melkassa Agricultural Research Centre, Ethiopia. The treatments contained three levels of shading intensity that reduced incident radiation by 0 (control), 50 and 75% using shade cloth. Data from a similar field experiment at Machakos Research Station, Kenya, with 0, 25 and 50% shading were also used for simulation. APSIM adequately simulated maize grain yield (r(2)=0.97) and total above-ground biomass (r(2)=0.95) in the control and in the 50% treatments at Melkassa, and likewise in the control (r(2)=0.99), 25% (r(2)=0.90) and 50% (r(2)=0.98) treatments at Machakos. Similarly, APSIM effectively predicted Leaf Area Index attained at the flowering (r(2)=0.90) and maturity (r(2)=0.94) stages. However, APSIM under-estimated maize biomass and yield at 75% shading. In conclusion, the model can be reliably employed to simulate maize productivity in agroforestry systems with up to 50% shading, but caution is required at higher levels of shading.
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| 17. |
- Parsons, David
(författare)
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Tree pruning, zone and fertiliser interactions determine maize productivity in the Faidherbia albida (Delile) A. Chev parkland agroforestry system of Ethiopia
- 2019
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Ingår i: Agroforestry Systems. - : Springer Science and Business Media LLC. - 0167-4366 .- 1572-9680. ; 93, s. 1897-1907
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Tidskriftsartikel (refereegranskat)abstract
- Faidherbia albida is an important tree species in the parkland agroforestry system of the Rift Valley region, central and south-eastern Ethiopia. Positive effects of F. albida on crop production are widely recognised. However, the effects of tree pruning, zone and fertiliser interactions on crop growth have not been addressed in earlier studies. A field experiment containing three levels of tree pruning (100% pruned, 50% pruned, and unpruned) as main plots, and application of recommended rates of N and P fertilisers as sub-plots, was conducted during the 2015 and 2016 growing seasons. Maize grain yield and biomass, light intensity, and soil nutrients and moisture were measured at different positions from each F. albida tree trunk (0-2, 2-4 and 4-6 m) and in crop-only plots. Biomass and yield of maize were significantly greater under tree canopies compared to crop-only plots in both the 2015 and 2016 growing seasons, regardless of pruning levels. Fertilisation significantly increased yields under tree canopies compared to crop-only plots in both years. Light intensity increased with distance from trees and with greater pruning levels. Soil carbon and nutrient concentrations and moisture content decreased with increasing distance from tree and with soil depth. These results suggest that maize production and profitability could be maintained or improved through only partial pruning of F. albida rather than pollarding, and by preferentially applying fertilisers in normal and wet years. Recommendations need to be evaluated in a total system context including other rotational crops, fuel, livestock and socio-economic factors.
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| 18. |
- Romeo Bazie, Hugues, et al.
(författare)
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Temporal variations in transpiration of Vitellaria paradoxa in West African agroforestry parklands
- 2018
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Ingår i: Agroforestry Systems. - : Springer Science and Business Media LLC. - 0167-4366 .- 1572-9680. ; 92, s. 1673-1686
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Tidskriftsartikel (refereegranskat)abstract
- Lack of data on water use of key species of drylands constitutes an obstacle to understanding their role in hydrological processes in this environment. To elucidate seasonal variation in water consumption by Vitellaria paradoxa, the dominant species of parklands of the semi-arid areas of West Africa, we've measured its transpiration using heat ratio method (HRM) and seven potential explanatory variables. Sap flux was found to be significantly different among years with 0.64, 0.59 and 0.67Lh(-1)dm(-2) in 2008, 2009 and 2010, respectively. Sap flux was significantly higher in the dry (0.73Lh(-1)dm(-2)) than in the wet season (0.53Lh(-1)dm(-2)). Nighttime sap flux during dry season (0.48Lh(-1)dm(-2)) was significantly higher than that of the wet season (0.20Lh(-1)dm(-2)) and it contributes on average to 26% of daily sap flow with a maximum reaching 49%. The mean transpiration rate per tree was 151Lday(-1) and all measured variables except rainfall and soil water content were significantly correlated with sap flux. These correlations were stronger (higher R value) during the rainy than in the dry season. Vapor Pressure Deficit (VPD) explained the highest proportion of sap flux variation and their curve was of parabolic type (R-2=0.54) indicating that V. paradoxa can probably down-regulate its canopy conductance beyond a certain threshold of VPD, which is about 3kPa in the present study. Future studies should investigate such hypothesis as well as the impacts of the variation of V. paradoxa transpiration due to climatic variables on hydrological cycles.
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| 19. |
- Schaffer, Christina, 1965-, et al.
(författare)
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Motivation and perception of farmers on the benefits and challenges of agroforestry in Sweden (Northern Europe)
- 2024
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Ingår i: Agroforestry Systems. - : Springer. - 0167-4366 .- 1572-9680.
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Tidskriftsartikel (refereegranskat)abstract
- Agroforestry systems provide multiple benefits for human wellbeing and biodiversity; however, their diversity and spatial distribution has sharply declined across Europe. This study focuses on agroforestry farms in Sweden. The aim of the study was to explore farmers' motivations to start agroforestry, what benefits farmers attributed to their agroforestry farms and perceived challenges to practising agroforestry in Sweden. In total, 13 farms that practise various agroforestry forms were selected as case studies. A focus group, semi-structured interviews and field observations were used for data collection. We identified four types of agroforestry systems such as silvopasture, silvoarable, forest farming and forest gardens established on different land such as forested or agricultural land. All studied agroforestry farms were small but had complex spatial and temporal arrangements of crops, trees and animals, which were crucial to generating multiple benefits. Our results show that the multifunctionality of agroforestry systems resulted from farmers' desire to design such systems. Farmers' intentions to get foods and materials from their farms were always intentionally unified with multiple ecosystem services. We argue that agroforestry farmers are designers of multifunctional landscapes, as they deliberately organised their farming activities to get a bundle of ecosystem services belonging to all four categories-provisioning, regulating, supporting and cultural. However, the complexity of agroforestry management, lack of technologies suitable for small-scale agroforestry farms, limited plant materials (including seedlings) and limited knowledge about how to do agroforestry challenged the scaling up of agroforestry practices.
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| 20. |
- Skovsgaard, Jens Peter
(författare)
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Models for supporting forest management in a changing environment
- 2010
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Ingår i: Agroforestry Systems. - 0167-4366 .- 1572-9680. ; 19, s. 8-29
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Tidskriftsartikel (refereegranskat)abstract
- Forests are experiencing an environment that changes much faster than during the past several hundred years. In addition, the abiotic factors determining forest dynamics vary depending on its location. Forest modeling thus faces the new challenge of supporting forest management in the context of environmental change. This review focuses on three types of models that are used in forest management: empirical (EM), process-based (PBM) and hybrid models. Recent approaches may lead to the applicability of empirical models under changing environmental conditions, such as (i) the dynamic state-space approach, or (ii) the development of productivity-environment relationships. Twenty-five process-based models in use in Europe were analyzed in terms of their structure, inputs and outputs having in mind a forest management perspective. Two paths for hybrid modeling were distinguished: (i) coupling of EMs and PBMs by developing signal-transfer environment-productivity functions; (ii) hybrid models with causal structure including both empirical and mechanistic components. Several gaps of knowledge were identified for the three types of models reviewed.The strengths and weaknesses of the three model types differ and all are likely to remain in use. There is a trade-off between how little data the models need for calibration and simulation purposes, and the variety of input-output relationships that they can quantify. PBMs are the most versatile, with a wide range of environmental conditions and output variables they can account for. However, PBMs require more data making them less applicable whenever data for calibration are scarce. EMs, on the other hand, are easier to run as they require much less prior information, but the aggregated representation of environmental effects makes them less reliable in the context of environmental changes. The different disadvantages of PBMs and EMs suggest that hybrid models may be a good compromise, but a more extensive testing of these models in practice is required.
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| 21. |
- Ståhl, Lena, et al.
(författare)
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Measuring nitrogen fixation by Sesbania sesban planted fallows using 15N tracer technique in Kenya
- 2005
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Ingår i: Agroforestry Systems. - : Springer Science and Business Media LLC. - 0167-4366 .- 1572-9680. ; 65, s. 67-79
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Tidskriftsartikel (refereegranskat)abstract
- A field experiment was performed in eastern Kenya to estimate N2 fixation by Sesbania sesban over an 18-month period using the 15N dilution method. The influence of three reference species, Senna spectabilis, Eucalyptus saligna and Grevillea robusta, on the estimates of N2 fixation was also assessed. Percentage Ndfa (nitrogen derived from the atmosphere) was calculated based on foliar atom excess (FAE), above-ground atom excess (AAE) or whole tree atom excess (WAE) data. The differences in atom% 15N excess values between species and plant parts are presented and discussed. We recommend the use of several reference species for estimating %Ndfa and that the different results obtained should be carefully considered in relation to the issues being addressed. In this study, Senna was the most suitable of the three reference species because its N uptake pattern and phenology were very similar to those of Sesbania. When well established, the amount of N fixed by Sesbania accounts for more than 80% of its total N content, according to FAE-based estimates. We estimated the Ndfa by Sesbania after 18 months to between 500 and 600 kg ha−1 , depending on whether FAE, AAE or WAE data were used and on the choice of reference species. The substantial accumulation of N in planted Sesbania highlighted its potential to increase the sustainability of crop production on N-limited soils. We consider the 15N dilution method to be appropriate for quantifying N2 fixation in improved fallows in studies, similar to this one, of young trees with high N2-fixing ability.
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| 22. |
- Valinger, Erik, et al.
(författare)
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Reindeer husbandry in a mountain Sami village in boreal Sweden: the social and economic effect of introducing GPS collars and adaptive forest management
- 2018
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Ingår i: Agroforestry Systems. - : Springer Science and Business Media LLC. - 0167-4366 .- 1572-9680. ; 92, s. 933-943
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Tidskriftsartikel (refereegranskat)abstract
- Reindeer husbandry in northern Sweden, Norway, and Finland is an extensive agroforestry system, and the management of reindeer occurs alongside other land uses such as forestry, hunting, and tourism. The economic, social, and environmental impact of using GPS collars to track the reindeer was evaluated in the Sami village of Njaarke in boreal Sweden. A second objective was to evaluate how adapted forest management influenced reindeer husbandry. The results show that the use of GPS tracking enables the improved monitoring of the reindeer but the financial costs were greater than the financial benefits. The increased income did not cover the costs of depreciation and maintenance. Whilst the labour inputs associated with reindeer husbandry were high, 30-40% of the gross value added by village activities were related to hunting, tourism, and the renting of fishing rights. The use of adaptive forest management was assumed to increase the number of reindeer that could be reared through to slaughter and it was calculated to increase the gross value added by reindeer husbandry by more than 30%.
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| 23. |
- Westholm, Lisa, et al.
(författare)
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Food production and gender relations in multifunctional landscapes: a literature review
- 2020
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Ingår i: Agroforestry Systems. - : Springer Science and Business Media LLC. - 1572-9680 .- 0167-4366. ; 94:2, s. 359-374
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Forskningsöversikt (refereegranskat)abstract
- High expectations are put to multifunctional land use systems that they can provide solutions to the increasing global demand for land and food. In this literature review, we ask whether multifunctional landscapes hold specific opportunities for women in enhancing food production and security in a context of gender inequality guided by a framework of access to productive resources and commercialisation. We review 104 scientific articles dealing with food production and security in a range of multifunctional land use systems across Africa, Asia and Latin America, including agroforestry, homegardens, livestock systems and urban agriculture. We find that the specific role of a landscape’s multifunctionality for women’s opportunities to enhance food security, is rarely explicitly examined in scientific literature. Our review shows that in a multifunctional setting, the products controlled by women are often secondary and far from markets, and therefore they risk being ignored in decision-making or by policy makers. Further, efforts to increase the value of traditionally “female products” risk having adverse effects on women’s empowerment, in cases where powerful actors take over all or parts of the value chain, or appropriate the benefits. To remove these barriers traditional gender roles have to change. However, the instability of gender relations can also work in women’s favour in a multifunctional landscape where several products and production systems exist, providing opportunities to claim new roles or resources, especially in the context of changing external circumstances, such as urbanization, a shift from pastoralism to sedentary livelihoods, or an expansion of the monetary economy.
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| 24. |
- Öborn, Ingrid
(författare)
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Enhancing maize productivity in agroforestry systems through managing competition: lessons from smallholders' farms, Rift valley, Kenya
- 2019
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Ingår i: Agroforestry Systems. - : Springer Science and Business Media LLC. - 0167-4366 .- 1572-9680. ; 93, s. 715-730
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Tidskriftsartikel (refereegranskat)abstract
- Understanding crop performance and productivity in relation to intercropped tree species, tree management and prevailing environmental conditions may assist farmers in managing agroforestry systems appropriately. Our study evaluated the management and spatial effect of six dominant tree species (Eucalyptus spp., Sesbania sesban, Grevillea robusta, Calliandra calothyrsus, Markhamia lutea and Croton macrostachyus) on water availability and crop performance in smallholders' maize fields in Rift valley, Kenya. Maize performance under C. macrostachyus and M. lutea was also evaluated at on-station experiment in the same area. The smallholder farmers in the study area remain important maize producers in Kenya with an average maize yield of 6.5tonsha(-1) recorded. Maize yield under the dominant tree species in studied smallholder farms showed significant differences (P<0.001) with leguminous species (C. calothyrsus and S. sesban) recording the highest amount of grain weight. Farmers selectively prune tree they perceive as competitive but still want to maintain them in the farms such as Eucalyptus spp. and G. robusta but miss to equally prune M. lutea and C. macrostachyus which would greatly improve performance of associated crops. In addition to presence of great tree management diversity, the study clearly showed that tree in smallholder farms either have competitive, complementary or balanced-off interaction with crops. Lastly, despite the adequate rainfall throughout the cropping season, dominant tree species in smallholder farms were shown to significantly (P<0.0001) influence the spatial distribution of soil water.
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| 25. |
- Öztas, Ahmet M., et al.
(författare)
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Spacetime curvature is important for cosmology constrained with supernova emissions
- 2008
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Ingår i: International journal of theoretical physics. - : Springer Science and Business Media LLC. - 0020-7748 .- 1572-9575. ; 47:9, s. 2464-2478
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Tidskriftsartikel (refereegranskat)abstract
- We investigate universe expansion models as functions of emission frequency ratio decline rather than redshift z, using the latest on-line, self-consistent data from 192 supernovae. We present results for simpler and some current models of cosmology, including those with dark energy (standard model) and a recent model correcting for the effect of a small time-dependent, emission frequency increase with lookback. This new model, with a gentle lookback decline of the Planck constant, and the standard model fit the data with similar confidence according to Bayesian Information Criteria. The standard model tends towards solutions high in matter density while remaining flat, but models without dark energy tend towards dilute universes with significant spacetime and curvature and a smaller Hubble constant. We conclude the normalized spacetime parameter, Ω k , should not be ignored and it includes the combined contributions of huge spacetime magnitude and curvature.
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| 26. |
- Christiansen, Peter, et al.
(författare)
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The influence of detector effects on TPC performance
- 2009
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0167-5087 .- 0168-9002. ; 609:2-3, s. 149-155
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Tidskriftsartikel (refereegranskat)abstract
- TPC stand alone simulations based on different energy loss models are compared to previously reported measurements with an ALICE TPC prototype. The performance obtained from simulations is shown to depend significantly on all the included detector effects stressing that energy loss model calculations alone are inadequate for describing the performance. When all effects are included, a good quantitative description of both the specific energy loss and the space point resolution can be obtained from all models. This shows that the TPC description in the official ALICE TPC simulation is in agreement with the measured test beam data. (C) 2009 Elsevier B.V. All rights reserved.
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| 27. |
- Ellberg, Carolina, et al.
(författare)
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Breast cancer and spider telangiectasias at diagnosis and its relation to histopathology and prognosis: a population-based study.
- 2012
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Ingår i: Breast Cancer Research and Treatment. - : Springer Science and Business Media LLC. - 1573-7217 .- 0167-6806. ; 131:1, s. 177-186
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Tidskriftsartikel (refereegranskat)abstract
- Angiogenesis is one of the hallmarks of breast cancer. The status of angiogenesis is important in therapy choice. Spider telangiectasias (telangiectasias) may reflect an increased ability to form vessels. Our first aim was to identify patient and tumor characteristics associated with the occurrence of telangiectasias at the time of breast cancer diagnosis. The second aim was to study the overall survival in relation to the occurrence of telangiectasias at the time of breast cancer diagnosis. A standardized questionnaire was used to interview 1682 consecutive breast cancer patients about risk factors between 1980 and 2009. Occurrence of telangiectasias at the time of breast cancer diagnosis on the upper thorax, head, and/or neck was recorded by one physician. In the cohort, 93 women (5.5%) had telangiectasias. Occurrence of telangiectasias was positively associated with weight, odds ratio (OR) 1.02 (95% confidence interval (CI) 1.00-1.05) per kg, ever-use of oral contraceptives OR 2.67(CI 1.55-4.63) and hormone replacement therapy OR 2.68(CI 1.63-4.39), and negatively associated with parity OR 0.45(CI 0.25-0.79). Telangiectasias were not present in patients with comedo breast cancer. Patients with occurrences of telangiectasias diagnosed before the age of 50 had a statistically non-significant worse overall survival, whereas the patients with occurrences of telangiectasias diagnosed at age 50 or after had a statistically significant better overall survival (P interaction = 0.016). The relationship between the occurrence of telangiectasias and the overall survival in the older patient-group was independent of ever-use of HRT. Hormonal risk factors for breast cancer were associated with the occurrence of spider telangiectasias. The occurrence of telangiectasias may reflect the angiogenic status of the tumor. We hypothesize that telangiectasias could be used as selection criteria for anti-angiogenic therapy in younger breast cancer patients. Therefore, patients with comedo breast cancers maybe a group that may benefit less from anti-angiogenic therapy.
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