| 1. |
- Lindström, Sara, et al.
(författare)
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Forest cover change in Sri Lanka: The role of small scale farmers
- 2012
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Ingår i: Applied Geography. - : Elsevier BV. - 0143-6228. ; 34, s. 680-692
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Tidskriftsartikel (refereegranskat)abstract
- Forest cover in Sri Lanka has decreased rapidly during the last century and only fragments of the once widespread natural forest cover remain. This paper analyzes forest cover change and small scale farmers' relation to natural forests around two protected forest areas in Sri Lanka; Kanneliya Forest Reserve and Knuckles Conservation Forest. Methods used are spatial analysis to observe changes in forest cover from the 1980s until 2010, interviews with small scale farmers and key informants as well as field observations. In Kanneliya Forest Reserve, a decrease in forest cover is observed, particularly due to population increase and expanding tea plantations. In Knuckles Conservation Forest on the other hand, we find an overall increase in forest cover due to expansion of tree plantations, a ban on shifting cultivation and emigration from the area followed by natural forest regeneration. Agriculture is the most common source of income in both study areas and there is a clear link between conversions of forests to agricultural expansion. The profits from agricultural activities are in general insufficient to sustain small scale farmers' needs and the most common alternative source of income is achieved through resources extracted from the forest. Since 2001, demarcation of forest boundaries around the two forest reserves has reduced encroachment and illegal felling of timber. However, this policy has simultaneously threatened the livelihoods of peripheral communities in the forest buffer zones, especially in the investigated villages around Knuckles Conservation Forest. Despite successful attempts to reduce deforestation rates through governmental interventions, further incorporation of local people into the management of forests as stipulated in the current forest policy should be continued. (C) 2012 Elsevier Ltd. All rights reserved.
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| 2. |
- Mattsson, Eskil, 1981, et al.
(författare)
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Carbon stock and tree diversity of dry-zone homegardens in southern Sri Lanka
- 2014
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Ingår i: Book of Abstracts - World Congress on Agroforestry.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Tropical homegardens hold a large potential for climate change mitigation and adaptation due to their multi-functional role in providing income and ecosystem services while decreasing pressure on natural forests. However, there is still lack of quantitative data on homegardens and their landscape potential for carbon sequestration services. In this study, tree diversity and above-ground biomass carbon of woody species was estimated on dry-zone homegardens in the dry south-eastern part of Sri Lanka. A total of 45 homegardens were sampled on size, floristic composition of trees, diameter at breast height (GBH) and height of trees. In total, 4278 trees were sampled and 82 different tree species were recorded. The Shannon Wiener index used to evaluate biodiversity ranged from 0.76–3.01 with a mean value of 2.05. Using allometric models, we find a mean above-ground biomass stock of 13 Mg carbon (C) ha-1 with a large range among homegardens (1–56 Mg C ha-1, n=45) due to a variation of tree diversity, species and composition between individual homegardens. Per unit area basis, mean above ground carbon stock was higher in small homegardens (<0.2 ha, 26 Mg C ha-1, n=11) than medium (0.4–0.8 ha, 9 Mg C ha-1 n=27) and large (>1 ha, 8 Mg C ha-1, n=7) homegardens due to a higher tree density. The results show a vast heterogeneity in terms of carbon and biological diversity within the dry zone homegardens; results that will contribute to closing the knowledge gap of the less studied dry-zone homegarden systems and their functions in storing carbon and providing multi-functional benefits to its users. The results are also useful for whether homegardens should directly or indirectly be considered to be included as an activity within Sri Lanka’s newly commenced UN-REDD National Programme.
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| 3. |
- Mattsson, Eskil, 1981, et al.
(författare)
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Carbon stock and tree diversity of dry-zone homegardens in Southern Sri Lanka
- 2014
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Ingår i: Proceedings of the Global Land Project 2nd Open Science Meeting, Berlin, March 19-21, 2014.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Traditional land-use systems such as tropical homegardens hold a large potential for climate change mitigation and adaptation due to their multi-functional role in providing income and ecosystem services while decreasing pressure on natural forests. Although, the importance and recognition of homegardens has been highlighted for their large potential in carbon sequestration, tree diversity and functioning there is still lack of quantitative data on homegardens and their contribution to climate change mitigation. In this study, tree diversity and above-ground biomass carbon of woody species was estimated on a local level around the village of Beralihela in the dry south-eastern part of Sri Lanka. A total of 45 homegardens were sampled on size, floristic composition of trees, girth at breast height (GBH) and height of trees. In total, 4278 trees were sampled and 82 different tree species were recorded. The Shannon Wiener index used to evaluate biodiversity ranged from 0.76–3.01 with a mean value of 2.05. Using allometric models, we find a mean above ground biomass carbon stock of 13 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, species and composition between individual homegardens. Per unit area basis, above ground carbon stock was higher in small homegardens (26 Mg C ha-1) than medium (9 Mg C ha-1) and large (7 Mg C ha-1) homegardens due to a higher tree density. The results of this study contribute to closing the knowledge gap of the less studied dry-zone homegarden agroforestry systems and their function in storing carbon and provide multi-functional benefits to its users. The results are also useful for the national process of whether homegardens should directly or indirectly be considered to be included as an activity within Sri Lanka’s newly commenced UN-REDD National Programme. This study shows the potential of using tropical homegardens for future land-use planning and multiple benefits including carbon sequestration potential, particularly in terms of land scarcity and climate mitigation options. The concept of homegardens in Sri Lanka also provides interesting aspects to the debate and future research in terms of forest definitions and general sustainability.
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| 4. |
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| 5. |
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| 6. |
- 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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| 7. |
- Mattsson, Eskil, 1981, et al.
(författare)
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Recovery and protection of coastal ecosystems after tsunami event and potential for participatory forestry CDM - examples from Sri Lanka
- 2008
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Ingår i: Ocean & Coastal Management. - : Elsevier BV. - 0964-5691 .- 1873-524X. ; 52:1, s. 1-9
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Tidskriftsartikel (refereegranskat)abstract
- By using an integrated approach, tsunami affected land, vegetation and inhabitants were assessed to evaluate the potential to restore and protect coastal land in the context of Kyoto Protocol's Clean Development Mechanism in Hambantota district in the south-eastern part of Sri Lanka. Firstly, assessments of the status of the tsunami affected area were carried out by collecting soil and well water samplings for carbon and salinity analysis. Secondly, identification of potential tree species for carbon sequestration and sustainable development was conducted to determine carbon stock and suitability to grow under the prevailing conditions. In addition, interviews to understand the local people's perception of forest plantations and land use were conducted. The results showed that the resilience process of salt intruded lands from the 2004 Asian tsunami has progressed rapidly with low salinity level in the soils 14 months after the event, while the well water showed evidence of salinity contamination. The carbon stock was highest in natural forests followed by coconut plantations. Land users could envision expanding their present plantations or establish new ones. The barriers were defined as lack of financial investment capital and limited land for extended plantations. If a Clean Development Mechanism project is to be established, the coconut tree was found to be the most appropriate tree species since it has high carbon content, had co-benefits and possesses a salt-tolerant characteristic. Finally, the tsunami event has triggered land users to perceive environmental benefits of protection from mangrove or other adequate vegetation such as coconut plantations as welcome and desired to decrease their vulnerability. The assessment of multi-functionality of forest plantations, such as small-scale community based Clean Development Mechanism, its generated income from carbon credits as well as the wish for environmental protection should be considered to increase the attractiveness of plantation projects in the coastal areas.
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| 8. |
- Mattsson, Eskil, 1981, et al.
(författare)
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REDD plus readiness implications for Sri Lanka in terms of reducing deforestation
- 2012
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Ingår i: Journal of Environmental Management. - : Elsevier. - 0301-4797 .- 1095-8630. ; 100, s. 29-40
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Tidskriftsartikel (refereegranskat)abstract
- Any system to compensate countries for reduced emissions from deforestation and forest degradation (REDD+) requires a historical reference level against which future performance can be measured. Here we examine the possibilities Sri Lanka, a small forest country with limited data on forest carbon stocks, has to get ready for REDD+. We construct a historical reference level using available forest inventory data combined with updated 2008 and 2009 in situ carbon density data for Sri Lankan forests. Furthermore, we use a combination of qualitative and quantitative data to attribute the clearing of Sri Lankan forests in the latest years for which national forest inventory data are available, 1992-1996, to various proximate drivers and to estimate the opportunity cost of forest conservation. We estimate that baseline deforestation emissions in Sri Lanka amounted to 17 MtCO(2) yr(-1) in the 1992-1996 period, but conclude that it is challenging for Sri Lanka to produce a robust and accurate reference level due to the lack of nationally based inventories. We find that the majority of forest clearing (87%) is due to small-scale, rainfed farming, with the two other major drivers being rice and tea cultivation. Further, Sri Lankan revenues from REDD+ participation could be substantial, but they are sensitive to REDD+ policy transaction cost, highly uncertain timber revenues, and particularly the carbon price paid for emission reductions. The latter needs to be higher than $5-10/tCO(2) if there are to be substantial incentives for Sri Lanka to participate in REDD+. There is, however, a large gap in the knowledge of deforestation drivers that needs to be filled if Sri Lanka is to formulate an effective policy response to forest degradation in REDD+. For successful REDD+ implementation in Sri Lanka to happen, technological assistance, readiness assistance, and continued political momentum are crucial.
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| 9. |
- Mattsson, Eskil, et al.
(författare)
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Topmost trees and foremost species underlie tropical forest structure, diversity and biomass through opposing mechanisms
- 2020
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Ingår i: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 473
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Tidskriftsartikel (refereegranskat)abstract
- Tropical forests play a main role in the global carbon cycle due to their higher exchange capacity of carbon dioxide with the atmosphere than any other forest type on the Earth. In this study, we aimed to explore the relative importance of foremost species and topmost trees in shaping forest structure, diversity and biomass in natural tropical forests. We hypothesized that topmost trees promote but foremost species decline tropical forest structure, diversity and biomass in a changing environment (i.e. the ‘tree overtopping hypothesis’). We formulated three questions to address the proposed hypothesis: (1) Are forest structure, diversity and biomass affected by both foremost species and topmost trees, and what is the magnitude and direction of each relative effect? (2) Are foremost species and topmost trees influenced similarly by multiple environmental factors? (3) How do foremost species and topmost trees mediate the feedbacks of forest structure, diversity and biomass to environmental factors? Using 189 plots data from Sri Lanka, we quantified 16 environmental (9 climate and 7 soil) factors, two indices of the topmost trees (i.e. top 1% large-diameter, and tall-stature) and their combination, four indices of foremost species (i.e. top 1% species' importance value index or each of its three components including either relative basal area, relative frequency or relative density), rarefied species richness, and stand density. We used structural equation modeling to test the proposed hypothesis. Strong positive effects of topmost trees whereas negative to negligible positive effects of foremost species shaped tropical forest structure, diversity and biomass through opposing mechanisms, i.e., the promoting part of big trees and suppressing part of dominant species, respectively. Moreover, forest structure promoted biomass directly and indirectly via forest diversity. Environmental factors (i.e. high climatic water and low soil fertility) increased forest structure, diversity and biomass indirectly via topmost trees but decreased via foremost species. The main novelty or contribution of this study determines that the adverse effects of few foremost (i.e. dominant or abundant) species shaped forest structure, diversity and biomass in tropical forests when simultaneously considered the positive effects of topmost trees. Hence, encouraging topmost trees while managing foremost species might necessarily increase complementarity resource-use within a forest community, leading to positive forest diversity – structure – biomass relationships. We argue that both topmost trees and foremost species might have important influences on forest carbon stock in the context of global climate change.
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| 10. |
- 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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