Browsing by Subject "BIOMASS"

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  • Gomez Millan, Gerardo; Hellsten, Sanna; King, Alistair W. T.; Pokki, Juha-Pekka; Llorca, Jordi; Sixta, Herbert (2019)
    Furfural (FUR) was produced from xylose using a biphasic batch reaction system. Water-immiscible organic solvents such as isophorone, 2-methyltetrahydrofuran (2-MTHF) and cyclopentyl methyl ether (CPME) were used to promptly extract FUR from the aqueous phase in order to avoid the degradation to humins as largely as possible. The effect of time, temperature, organic solvent and organic-to-aqueous ratio on xylose conversion and FUR yield were investigated in auto-catalyzed conditions. Experiments at three temperatures (170, 190 and 210 degrees C) were carried out in a stirred microwave-assisted batch reactor, which established the optimal conditions for achieving the highest FUR yield. The maximum FUR yields from xylose were 78 mol% when using CPME, 48 mol% using isophorone and 71 mol% in the case of 2-MTHF at an aqueous to organic phase ratio of 1:1 (v/v). Birch hydrolysate was also used to show the high furfural yield that can be obtained in the biphasic system under optimized conditions. The present study suggests that CPME can be used as a green and efficient extraction solvent for the conversion of xylose into furfural without salt addition. (C) 2019 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.
  • Baltrenaite, Edita; Baltrenas, Pranas; Bhatnagar, Amit; Vilppo, Teemu; Selenius, Mikko; Koistinen, Arto; Dahl, Mari; Penttinen, Olli-Pekka (2017)
    The environmental legislation and strict enforcement of environmental regulations are the tools effectively used for developing the market of materials for environmental protection technologies. Sustain ability criteria shift environmental engineering systems to more sustainable-material-based technologies. For carbon-based medium materials in biofiltration, this trend results in attempts to use biochar for biofiltration purposes. The paper presents the analysis of biochar properties based on the main criteria for biofiltration medium integrating the environmental quality properties of biochar, following the European Biochar Certificate guidelines. Three types of biochar produced from feedstock of highly popular and abundant types of waste are analysed. A multi component approach was applied to summarize the results. The lignocellulosic type of biochar was found to be more competitive for use as a biofiltration medium than the types of biochar with high ash or lignin content. (C) 2016 Elsevier Ltd. All rights reserved.
  • Järviö, Natasha; Maljanen, Netta-Leena; Kobayashi, Yumi; Ryynänen, Toni; Tuomisto, Hanna (2021)
    Novel food production technologies are being developed to address the challenges of securing sustainable and healthy nutrition for the growing global population. This study assessed the environmental impacts of microbial protein (MP) produced by autotrophic hydrogen-oxidizing bacteria (HOB). Data was collected from a company currently producing MP using HOB (hereafter simply referred to as MP) on a small-scale. Earlier studies have performed an environmental assessment of MP on a theoretical basis but no study yet has used empirical data. An attributional life cycle assessment (LCA) with a cradle-to-gate approach was used to quantify global warming potential (GWP), land use, freshwater and marine eutrophication potential, water scarcity, human (non-)carcinogenic toxicity, and the cumulative energy demand (CED) of MP production in Finland. A Monte Carlo analysis was performed to assess uncertainties. The impacts of alternative production options and locations were explored. The impacts were compared with animal- and plant-based protein sources for human consumption as well as protein sources for feed. The results showed that electricity consumption had the highest contribution to environmental impacts. Therefore, the source of energy had a substantial impact on the results. MP production using hydropower as an energy source yielded 87.5% lower GWP compared to using the average Finnish electricity mix. In comparison with animal-based protein sources for food production, MP had 53-100% lower environmental impacts depending on the reference product and the source of energy assumed for MP production. When compared with plant-based protein sources for food production, MP had lower land and water use requirements, and eutrophication potential but GWP was reduced only if low-emission energy sources were used. Compared to protein sources for feed production, MP production often resulted in lower environmental impact for GWP (FHE), land use, and eutrophication and acidification potential, but generally caused high water scarcity and required more energy.
  • Kowalczyk, Joanna E.; Saha, Shreya; Mäkelä, Miia R. (2021)
    Dichomitus squalens is an emerging reference species that can be used to investigate white-rot fungal plant biomass degradation, as it has flexible physiology to utilize different types of biomass as sources of carbon and energy. Recent comparative (post-) genomic studies on D. squalens resulted in an increasingly detailed knowledge of the genes and enzymes involved in the lignocellulose breakdown in this fungus and showed a complex transcriptional response in the presence of lignocellulose-derived compounds. To fully utilize this increasing amount of data, efficient and reliable genetic manipulation tools are needed, e.g., to characterize the function of certain proteins in vivo and facilitate the construction of strains with enhanced lignocellulolytic capabilities. However, precise genome alterations are often very difficult in wild-type basidiomycetes partially due to extremely low frequencies of homology directed recombination (HDR) and limited availability of selectable markers. To overcome these obstacles, we assessed various Cas9-single guide RNA (sgRNA) ribonucleoprotein (RNP) -based strategies for selectable homology and non-homologous end joining (NHEJ) -based gene editing in D. squalens. We also showed an induction of HDR-based genetic modifications by using single-stranded oligodeoxynucleotides (ssODNs) in a basidiomycete fungus for the first time. This paper provides directions for the application of targeted CRISPR/Cas9-based genome editing in D. squalens and other wild-type (basidiomycete) fungi.
  • Saarinen, Ninni; Kankare, Ville; Yrttimaa, Tuomas; Viljanen, Niko; Honkavaara, Eija; Holopainen, Markus; Hyyppä, Juha; Huuskonen, Saija; Hynynen, Jari; Vastaranta, Mikko (2020)
    Forest management alters the growing conditions and thus further development of trees. However, quantitative assessment of forest management on tree growth has been demanding as methodologies for capturing changes comprehensively in space and time have been lacking. Terrestrial laser scanning (TLS) has shown to be capable of providing three-dimensional (3D) tree stem reconstructions required for revealing differences between stem shapes and sizes. In this study, we used 3D reconstructions of tree stems from TLS and an unmanned aerial vehicle (UAV) to investigate how varying thinning treatments and the following growth effects affected stem shape and size of Scots pine (Pinus sylvestris L.) trees. The results showed that intensive thinning resulted in more stem volume and therefore total biomass allocation and carbon uptake compared to the moderate thinning.Relationship between tree height and diameter at breast height (i.e. slenderness) varied between both thinning intensity and type (i.e. from below and above) indicating differing response to thinning and allocation of stem growth of Scots pine trees. Furthermore, intensive thinning, especially from below, produced less variation in relative stem attributes characterizing stem shape and size. Thus, it can be concluded that thinning intensity,type, and the following growth effects have an impact on post-thinning stem shape and size of Scots pine trees.Our study presented detailed measurements on post-thinning stem growth of Scots pines that have been laborious or impracticable before the emergence of detailed 3D technologies. Moreover, the stem reconstructions from TLS and UAV provided variety of attributes characterizing stem shape and size that have not traditionally been feasible to obtain. The study demonstrated that detailed 3D technologies, such as TLS and UAV, provide information that can be used to generate new knowledge for supporting forest management and silviculture as well as improving ecological understanding of boreal forests.1
  • Belachew, Kiflemariam Y.; Nagel, Kerstin A.; Poorter, Hendrik; Stoddard, Frederick L. (2019)
    Water deficit may occur at any stage of plant growth, with any intensity and duration. Phenotypic acclimation and the mechanism of adaptation vary with the evolutionary background of germplasm accessions and their stage of growth. Faba bean is considered sensitive to various kinds of drought. Hence, we conducted a greenhouse experiment in rhizotrons under contrasting watering regimes to explore shoot and root traits and drought avoidance mechanisms in young faba bean plants. Eight accessions were investigated for shoot and root morphological and physiological responses in two watering conditions with four replications. Pre-germinated seedlings were transplanted into rhizotron boxes filled with either air-dried or moist peat. The water-limited plants received 50-ml water at transplanting and another 50-ml water 4 days later, then no water was given until the end of the experimental period, 24 days after transplanting. The well-watered plants received 100 ml of water every 12 h throughout the experimental period. Root, stem, and leaf dry mass, their mass fractions, their dry matter contents, apparent specific root length and density, stomatal conductance, SPAD value, and Fv/Fm were recorded. Water deficit resulted in 3–4-fold reductions in shoot biomass, root biomass, and stomatal conductance along with 1.2–1.4-fold increases in leaf and stem dry matter content and SPAD values. Total dry mass and apparent root length density showed accession by treatment interactions. Accessions DS70622, DS11320, and ILB938/2 shared relatively high values of total dry mass and low values of stomatal conductance under water deficit but differed in root distribution parameters. In both treatments, DS70622 was characterized by finer roots that were distributed in both depth and width, whereas DS11320 and ILB938/2 produced less densely growing, thicker roots. French accession Mélodie/2 was susceptible to drought in the vegetative phase, in contrast to previous results from the flowering phase, showing the importance of timing of drought stress on the measured response. Syrian accession DS70622 explored the maximum root volume and maintained its dry matter production, with the difference from the other accessions being particularly large in the water-limited treatment, so it is a valuable source of traits for avoiding transient drought.
  • Minunno, Francesco; Peltoniemi, Mikko; Harkonen, Sanna; Kalliokoski, Tuomo; Makinen, Harri; Makela, Annikki (2019)
    Policy-relevant forest models must be environment and management sensitive and provide unbiased estimates of predicted variables over their intended areas of application. While empirical models derive their structure and parameters from representative data sets, process-based model (PBM) parameters should be evaluated in ranges that have a biological meaning independently of output data. At the same time PBMs should be calibrated against observations in order to obtain unbiased estimates and an understanding of their predictive capability. By means of model data assimilation, we Bayesian calibrated a forest model (PREBAS) using an extensive dataset that covered a wide range of climatic conditions, species composition and management practices. PREBAS was calibrated for three species in Finland: Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies [L.] H. Karst.) and Silver birch (Betula pendula L.). Data assimilation was strongly effective in reducing the uncertainty of PREBAS parameters and predictions. A country-generic calibration showed robust performances in predicting forest variables and the results were consistent with yield tables and national forest statistics. The posterior predictive uncertainty of the model was mainly influenced by the uncertainty of the structural and measurement error.
  • Palviainen, Marjo; Aaltonen, Heidi; Laurén, Ari; Köster, Kajar; Berninger, Frank; Ojala, Anne; Pumpanen, Jukka (2020)
    Biochar is charred material formed by the pyrolysis of organic matter. The addition of biochar to soil may offer a chance to mitigate climate change by increasing soil carbon stocks, improving soil fertility and enhancing plant growth. Vast majority of biochar studies are conducted in agricultural soils, and field experiments studying the effect of biochar on tree growth in boreal forests are lacking. We applied spruce biochar amendments of 5 and 10 Mg ha(-1) to the soil surface in young boreal Scots pine (Pinus sylvestris L.) forests in Southern Finland and studied the responses in tree growth and needle nitrogen (N) and N-15 concentrations during the first three years after treatment. The biochar amendment of 10 Mg ha(-1) increased the diameter growth of dominant trees significantly, on average by 1 mm year(-1), which corresponded to 25% increase compared to control during the three years study period. The positive growth responses were less pronounced in height than in diameter growth. The biochar amendment of 5 Mg ha(-1) increased the height growth of dominant trees by 0.16 m or 12% compared to the control during three years. Biochar amendments did not affect N and N-15 concentrations in needles. The results suggest that wood biochar amendment can be a climate-friendly method to increase tree biomass production in nutrient poor, xeric, young Scots pine forests.
  • Palviainen, Marjo; Aaltonen, Heidi; Laurén, Ari; Köster, Kajar; Berninger, Frank; Ojala, Anne; Pumpanen, Jukka (2020)
    Biochar is charred material formed by the pyrolysis of organic matter. The addition of biochar to soil may offer a chance to mitigate climate change by increasing soil carbon stocks, improving soil fertility and enhancing plant growth. Vast majority of biochar studies are conducted in agricultural soils, and field experiments studying the effect of biochar on tree growth in boreal forests are lacking. We applied spruce biochar amendments of 5 and 10 Mg ha(-1) to the soil surface in young boreal Scots pine (Pinus sylvestris L.) forests in Southern Finland and studied the responses in tree growth and needle nitrogen (N) and N-15 concentrations during the first three years after treatment. The biochar amendment of 10 Mg ha(-1) increased the diameter growth of dominant trees significantly, on average by 1 mm year(-1), which corresponded to 25% increase compared to control during the three years study period. The positive growth responses were less pronounced in height than in diameter growth. The biochar amendment of 5 Mg ha(-1) increased the height growth of dominant trees by 0.16 m or 12% compared to the control during three years. Biochar amendments did not affect N and N-15 concentrations in needles. The results suggest that wood biochar amendment can be a climate-friendly method to increase tree biomass production in nutrient poor, xeric, young Scots pine forests.
  • Palviainen, Marjo; Aaltonen, Heidi; Laurén, Ari; Köster, Kajar; Berninger, Frank; Ojala, Anne; Pumpanen, Jukka (2020)
    Biochar is charred material formed by the pyrolysis of organic matter. The addition of biochar to soil may offer a chance to mitigate climate change by increasing soil carbon stocks, improving soil fertility and enhancing plant growth. Vast majority of biochar studies are conducted in agricultural soils, and field experiments studying the effect of biochar on tree growth in boreal forests are lacking. We applied spruce biochar amendments of 5 and 10 Mg ha(-1) to the soil surface in young boreal Scots pine (Pinus sylvestris L.) forests in Southern Finland and studied the responses in tree growth and needle nitrogen (N) and N-15 concentrations during the first three years after treatment. The biochar amendment of 10 Mg ha(-1) increased the diameter growth of dominant trees significantly, on average by 1 mm year(-1), which corresponded to 25% increase compared to control during the three years study period. The positive growth responses were less pronounced in height than in diameter growth. The biochar amendment of 5 Mg ha(-1) increased the height growth of dominant trees by 0.16 m or 12% compared to the control during three years. Biochar amendments did not affect N and N-15 concentrations in needles. The results suggest that wood biochar amendment can be a climate-friendly method to increase tree biomass production in nutrient poor, xeric, young Scots pine forests.
  • Li, Quan; Song, Xinzhang; Yrjälä, Kim; Lv, Jianhua; Li, Yongfu; Wu, Jiasheng; Qin, Hua (2020)
    Increased reactive N deposition has widespread effects on terrestrial ecosystems, such as biodiversity loss, soil acidification, as well as stimulated plant growth. Empirical studies show that biochar often affects soil quality, crop productivity, soil microbial community composition and enzyme activities. However, the effect of biochar addition on forest soil bacterial community along with enzyme activities under nitrogen (N) deposition and its related mechanisms have not been well studied yet. Therefore, a 2-year field study was conducted to investigate the effects of biochar amendment (0, 20, 40 kg biochar ha−1 yr−1) on soil nutrients, enzyme activities, and bacterial community in a Torreya grandis orchard under different levels of N deposition (0, 30, 60 kg N ha−1 yr−1). N deposition significantly increased soil nutrients availability, such as N, phosphorus (P) and potassium (K), while biochar amendment led to significant increase in soil pH, organic carbon (SOC), total N (TN), total P (TP), available P (AP) and available K (AK). Both N deposition and biochar amendment significantly decreased the soil microbial biomass carbon (MBC), altered soil microbial community and enzyme activities significantly. Biochar addition increased the relative abundance of phylum Proteobacteria under different levels of N deposition, but had variable effect on Acidobacteria groups. Non-metric multidimensional scaling (NMDS) indicated that biochar amendment can mitigate the effect of N deposition on soil bacterial community composition and enzyme activities. Soil pH and SOC played an important role in shaping soil bacterial community composition, while available AP and AK contents significantly related to the variation of soil enzyme activities. Structure equation modeling (SEM) revealed that N deposition had negative effect on soil enzyme activities while biochar amendment can mitigate this negative effect through increasing AP content. Our result suggests that biochar amendment can mitigate the alteration of soil bacterial community and enzyme activities induced by N deposition, and this mitigation effect was linked to the alteration of soil physicochemical properties, especially the increased AP content. Thus, biochar amendment could be a promising way to develop sustainable forest management under increasing N deposition.
  • Masiero, Mauro; Secco, Laura; Pettenella, Davide; Da Re, Riccardo; Bernö, Hanna; Carreira, Ariane; Dobrovolsky, Alexander; Giertlieova, Blanka; Giurca, Alexandru; Holmgren, Sara; Mark-Herbert, Cecilia; Navrátilová, Lenka; Pülzl, Helga; Ranacher, Lea; Salvalaggio, Alessandra; Sergent, Arnaud; Sopanen, Juuso; Stelzer, Cristoph; Stetter, Theresa; Valsta, Lauri; Výbošťok, Jozef; Wallin, Ida (2020)
    This article provides useful information for universities offering forestry programs and facing the growing demand for bioeconomy education. An explorative survey on bioeconomy perception among 1400 students enrolled in 29 universities across nine European countries offering forestry programs was performed. The data have been elaborated via descriptive statistics and cluster analysis. Around 70% of respondents have heard about the bioeconomy, mainly through university courses. Students perceive forestry as the most important sector for bioeconomy; however, the extent of perceived importance of forestry varies between countries, most significantly across groups of countries along a North–South European axis. Although differences across bachelor and master programs are less pronounced, they shed light on how bioeconomy is addressed by university programs and the level of student satisfaction with this. These differences and particularities are relevant for potential development routes towards comprehensive bioeconomy curricula at European forestry universities with a forestry focus.
  • Mäki, Mari; Aaltonen, Hermanni; Heinonsalo, Jussi; Hellén, Heidi; Pumpanen, Jukka; Bäck, Jaana (2019)
    Vegetation emissions of volatile organic compounds (VOCs) are intensively studied world-wide, because oxidation products of VOCs contribute to atmospheric processes. The overall aim of this study was to identify and quantify the VOCs that originate from boreal podzolized forest soil at different depths, in addition to studying the association of VOC concentrations with VOC and CO2 fluxes from the boreal forest floor.
  • Walde, Manuel; Allan, Eric; Cappelli, Seraina L.; Didion-Gency, Margaux; Gessler, Arthur; Lehmann, Marco M.; Pichon, Noemie A.; Grossiord, Charlotte (2021)
    Many experiments have shown that biodiversity promotes ecosystem functioning and stability and that this relationship varies with resource availability. However, we still have a poor understanding of the underlying physiological and ecological mechanisms driving diversity effects and how they may interact with soil nutrient availability. We collected data in a grassland experiment factorially manipulating fertilization, species richness (SR), functional composition (slow-growing vs. fast-growing species) and functional diversity in resource economic traits. We measured above-ground productivity (AP), nitrogen (N) uptake, photosynthesis and water use efficiency by combining a N-15 labelling approach with productivity, gas exchange and stable isotope measurements in 3 years differing in rainfall. We found that sown SR increased AP, N uptake and photosynthesis, suggesting that SR is the most important driver of ecosystem productivity and nutrient cycling. Similarly, photosynthesis was affected by functional composition but not by functional diversity. Water use efficiency was reduced by sown SR for communities dominated by slow-growing species but not for communities dominated by fast-growing species. Fertilization increased productivity, N uptake and water use efficiency. The positive effects of high SR on ecosystem functions were independent of fertility levels. Synthesis. Our results provide evidence that high species richness in temperate grasslands could enhance productivity and reduce the negative impacts of drought events. Multiple factors and community characteristics are important in driving enhanced ecosystem functioning in biodiverse grasslands and seem to affect functioning and stability through different mechanisms.
  • Koster, Egle; Koster, Kajar; Berninger, Frank; Aaltonen, Heidi; Zhou, Xuan; Pumpanen, Jukka (2017)
    Forest fires are one of the most important natural disturbances in boreal forests, and their occurrence and severity are expected to increase as a result of climate warming. A combination of factors induced by fire leads to a thawing of the near-surface permafrost layer in subarctic boreal forest. Earlier studies reported that an increase in the active layer thickness results in higher carbon dioxide (CO2) and methane (CH4) emissions. We studied changes in CO2, CH4 and nitrous oxide (N2O) fluxes in this study, and the significance of several environmental factors that influence the greenhouse gas (GHG) fluxes at three forest sites that last had fires in 2012, 1990 and 1969, and we compared these to a control area that had no fire for at least 100 years. The soils in our study acted as sources of CO2 and N2O and sinks for CH4. The elapsed time since the last forest fire was the only factor that significantly influenced all studied GHG fluxes. Soil temperature affected the uptake of CH4, and the N2O fluxes were significantly influenced by nitrogen and carbon content of the soil, and by the active layer depth. Results of our study confirm that the impacts of a forest fire on GHGs last for a rather long period of time in boreal forests, and are influenced by the fire induced changes in the ecosystem. (C) 2017 Elsevier B.V. All rights reserved.
  • Waldén, Pirjetta; Ollikainen, Markku; Kahiluoto, Helena (2020)
    The impact of carbon revenue on the profitability of agroforestry systems in comparison to monocultures is unexplored in regard to Sub-Saharan Africa. This study creates a multivariate model to evaluate the impact of carbon revenue on the profitability of agroforestry relative to the dominant monocultures in Ethiopia by using stylized plots. Yields and carbon stock changes of eight agroforestry systems were modeled based on data from agroforestry plots in the Ethiopian Central Rift Valley. According to our model, agroforestry was, on average, four times more profitable than the main monoculture systems (wheat, barley, maize, teff, sorghum, sugarcane and lentil) even when carbon revenues were excluded, primarily due to the higher prices of fruit produce. Carbon revenues were estimated using a plausible carbon price ranging from US$8/tCO2e to $40/tCO2e and carbon sequestration rates of 0.59 to 17.2 Mg C ha−1 year−1. The possibility of receiving carbon revenue increased the profitability of agroforestry by 0.5% when using the lowest utilized carbon price and carbon sequestration rate, by 20% when using the carbon price of $20 and the average carbon sequestration rate, and by 70% when using the highest price and highest sequestration rate of carbon. On average, carbon revenue increased the profitability of agroforestry by 150% in comparison to monoculture farming. We conclude that carbon income may have significant potential to motivate smallholders to convert to agroforestry when there is a proper management system, a sufficiently high carbon price and effective institutional support to mitigate the transition and transaction costs.
  • Larjavaara, Markku; Kanninen, Markku Tapani; Alam, Syed Ashraful; Mäkinen, Antti; Poeplau, Christopher (2017)
    Land use directly impacts ecosystem carbon and indirectly influences atmospheric carbon. Computing ecosystem carbon for an area experiencing changes in land use is not trivial, as carbon densities change slowly after land-use changes. We developed a tool, CarboScen, to estimate ecosystem carbon in landscapes. It is a simple tool typically used with an annual time step, and is based on carbon pools and densities. It assumes that carbon density asymptotically approaches a value, which is set for the land-use type in question. We recommend CarboScen for landscapes with spatially relatively homogenous soils and climate, multiple land uses, and changes between these leading to slow changes in carbon densities because either soil organic carbon is included in the analysis or afforestation occurs. Thanks to its simplicity, it is particularly suitable for participatory planning, rapid assessment of REDD+ project potential, and educational use.
  • Sugano, Junko; Linnakoski, Riikka; Huhtinen, Seppo; Pappinen, Ari; Niemela, Pekka; Asiegbu, Fred O. (2019)
    The initial stage of cellulose degradation has been studied via in vitro assays of fungi isolated from rotten wood in a boreal forest. Among the 37 isolates, Antrodia sinuosa appeared to be an effective cellulose degrader and was selected for studying the initial degradation process. In the liquid cultivation with carboxymethylcellulose (CMC), the increase of the mycelial dry weight coincided with the pH decrease of the culture medium from pH 5.7 to 3.9, between the 3rd and 6th cultivation day. At the same time, the cellulolytic activity increased; the CMCase activity increased sharply and the reducing sugars reached their maximum concentration in the culture medium. It seems that the decreasing pH enables the cellulose degradation by A. sinuosa at an early stage of the process. The results of this study may be useful for a more efficient industrial application of biomass by means of brown-rot fungi.
  • Tammeorg, Priit; Soronen, Päivi Anneli; Riikonen, Anu; Salo, Esko; Tikka, Suvi Maria; Koivunen, Minja; Salonen, Anna-Reetta; Kopakkala, Topi Pietari; Jalas, Mikko (2021)
    In order to achieve the goals of carbon (C) neutrality within next 20 year, municipalities worldwide need to increasingly apply negative emission technologies. We focus on the main principles of urban demonstration areas using biochars for C sequestration and explore the lessons learned from a co-creation process of one such park, Hyvantoivonpuisto in Helsinki, Finland. Demonstration sites of urban C sinks in public parks must be safe, visible and scientifically sound for reliable and cost-effective verification of carbon sequestration. We find that different interests can be arbitrated and that synergy that emerges from co-creation of urban C sink parks between stakeholders (scientists, city officials, companies, and citizens) can result in demo areas with maximized potential for impact, dissemination and consideration of principles of scientific experimentation.
  • Yu, Xiaowei; Hyyppä, Juha; Karjalainen, Mika; Nurminen, Kimmo; Karila, Kirsi; Vastaranta, Mikko; Kankare, Ville; Kaartinen, Harri; Holopainen, Markus; Honkavaara, Eija; Kukko, Antero; Jaakkola, Anttoni; Liang, Xinlian; Wang, Yunsheng; Hyyppä, Hannu; Katoh, Masato (2015)
    It is anticipated that many of the future forest mapping applications will be based on three-dimensional (3D) point clouds. A comparison study was conducted to verify the explanatory power and information contents of several 3D remote sensing data sources on the retrieval of above ground biomass (AGB), stem volume (VOL), basal area (G), basal-area weighted mean diameter (D-g) and Lorey's mean height (H-g) at the plot level, utilizing the following data: synthetic aperture radar (SAR) Interferometry, SAR radargrammetry, satellite-imagery having stereo viewing capability, airborne laser scanning (ALS) with various densities (0.8-6 pulses/m(2)) and aerial stereo imagery. Laser scanning is generally known as the primary source providing a 3D point cloud. However, photogrammetric, radargrammetric and interferometric techniques can be used to produce 3D point clouds from space- and air-borne stereo images. Such an image-based point cloud could be utilized in a similar manner as ALS providing that accurate digital terrain model is available. In this study, the performance of these data sources for providing point cloud data was evaluated with 91 sample plots that were established in Evo, southern Finland within a boreal forest zone and surveyed in 2014 for this comparison. The prediction models were built using random forests technique with features derived from each data sources as independent variables and field measurements of forest attributes as response variable. The relative root mean square errors (RMSEs) varied in the ranges of 4.6% (0.97 m)-13.4% (2.83 m) for H-g, 11.7% (3.0 cm)-20.6% (5.3 cm) for D-g, 14.8% (4.0 m(2)/ha)-25.8% (6.9 m(2)/ha) for G, 15.9% (43.0 m(3)/ha)-31.2% (84.2 m(3)/ha) for VOL and 14.3% (19.2 Mg/ha)-27.5% (37.0 Mg/ha) for AGB, respectively, depending on the data used. Results indicate that ALS data achieved the most accurate estimates for all forest inventory attributes. For image-based 3D data, high-altitude aerial images and WorldView-2 satellite optical image gave similar results for H-g and D-g, which were only slightly worse than those of ALS data. As expected, spaceborne SAR data produced the worst estimates. WorldView-2 satellite data performed well, achieving accuracy comparable to the one with ALS data for G, VOL and AGB estimation. SAR interferometry data seems to contain more information for forest inventory than SAR radargrammetry and reach a better accuracy (relative RMSE decreased from 13.4% to 9.5% for H-g, 20.6% to 19.2% for D-g, 25.8% to 20.9% for G, 31.2% to 22.0% for VOL and 27.5% to 20.7% for AGB, respectively). However, the availability of interferometry data is limited. The results confirmed the high potential of all 3D remote sensing data sources for forest inventory purposes. However, the assumption of using other than ALS data is that there exist a high quality digital terrain model, in our case it was derived from ALS.