Effect of the replacement of tropical forests with tree plantations on soil organic carbon levels in the Jomoro district,Ghana

Background and aims

In the Jomoro district in Ghana, tree plantations were the first cause of deforestation in the past, drastically reducing the area occupied by primary forests. The aim of this study was to quantify soil organic carbon (SOC) losses due to a change in land use from primary forest to tree plantations (cocoa, coconut, rubber, oil palm) on the different substrates of the district. Secondary forests and mixed plantations were also included in the study.

Methods

Soils were sampled at different depths up to 100 cm along a series of chronosequences in each of the three substrates (Granite, Lower Birrimian and Tertiary Sands) present in the area.

Results

The highest SOC losses in the 0–30 cm layer were caused by the conversion of primary forests to tree plantations: cocoa ?61 % of the original SOC stock, coconut ?55 %, rubber ?35 % and oil palm 28 %, while mixed plantations and secondary forests showed a loss of 23 % and 21 % of the original SOC stock, respectively. C losses were less apparent from the entire profile (to a depth of 100 cm).

Conclusions

All conversions to tree plantations caused substantial SOC losses, comparable to the conversion of forests to agricultural systems. Secondary forests and mixed plantations were the only sustainable land uses that restricted SOC losses considerably.     

Life cycle greenhouse gas emissions of palm oil production by wet and dry extraction processes in Thailand

Purpose

The crude palm oil (CPO) extraction is normally done by a wet extraction process, and wastewater treatment of the wet process emits high levels of greenhouse gases (GHGs). A dry process extracts mixed palm oil (MPO) from palm fruit without using water and has no GHG emissions from wastewater treatment. This work is aimed at determining the GHG emissions of a dry process and at evaluating GHG savings on changing from wet to dry process, including land use change (LUC) effects.

Methods

Life cycle assessment from cradle to gate was used. The raw material is palm fruits. The dry process includes primary production, oil room, and utilities. MPO is the main product, while palm cake and fine palm residue are co-products sold for animal feed. Case studies were undertaken without and with carbon stocks of firewood and of nitrogen recycling at plantations from fronds. Allocations by mass, economic, and heating values were conducted. The trading of GHG emissions from co-products to GHG emissions from animal feed was assessed. The GHG emissions or savings from direct LUC (dLUC) and from indirect LUC (iLUC) effects and for the change from wet to dry process were determined.

Results and discussion

Palm fruit and firewood were the major GHG emission sources. Nitrogen recycling on plantations from fronds significantly affects the GHG emissions. With the carbon stocks, the GHG emissions allocated by energy value were 550 kg CO₂ eq/t MPO. The GHG emissions were affected by ?3 to 37% for the change from wet to dry process. When the plantation area was increased by 1 ha and the palm oil extraction was changed from wet to dry process, and the change included dLUC and iLUC, the GHG savings ranged from ?0.94 to 5.08 t CO₂ eq/ha year. The iLUC was the main GHG emission source. The GHG saving mostly originated from the change of extraction process and from the dLUC effect. Based on the potential use of biodiesel production from oil palm, during 2015–2036 in Thailand, when the extraction process was changed and dLUC and iLUC effects were included, the saving in GHG emissions was estimated to range from ?35,454 to 274,774 t CO₂ eq/year.

Conclusions

The change of palm oil extraction process and the LUC effects could minimize the GHG emissions from the palm oil industry. This advantage encourages developing policies that support the dry extraction process and contribute to sustainable developments in palm oil production.

     

European renewable energy directive: Critical analysis of important default values and methods for calculating greenhouse gas (GHG) emissions of palm oil biodiesel

Purpose

The aim of this paper is to evaluate assumptions and data used in calculations  related to palm oil produced for biodiesel production relative to the European Renewable Energy Directive (EU-RED). The intent of this paper is not to review all assumptions and data, but rather to evaluate whether the methodology is applied in a consistent way and whether current default values address relevant management practices of palm oil production systems.

Methods

The GHG calculation method provided in Annex V of the EU-RED was used to calculate the GHG-emissions from palm oil production systems. Moreover, the internal nitrogen recycling on the plantation was calculated based on monitoring data in North Sumatra.

Results and discussion

A calculation methodology is detailed in Annex V of the EU-RED. Some important aspects necessary to calculate the GHG emission savings correctly are insufficiently considered, e.g.: ? “Nitrogen recycling” within the plantation due to fronds remaining on the plantation is ignored. The associated organic N-input to the plantation and the resulting nitrous oxide emissions is not considered within the calculations, despite crop residues being taken into account for annual crops in the BIOGRACE tool. ? The calculation of GHG-emissions from residue and waste water treatment is inappropriately implemented despite being a hot-spot for GHG emissions within the life cycle of palm oil and palm oil biodiesel. Additionally, no distinction is made between palm oil and palm kernel oil even though palm kernel oil is rarely used for biodiesel production. ? The allocation procedure does not address the most relevant oil mill management practices. Palm oil mills produce crude palm oil (CPO) in addition either nuts or palm kernels and nut shells. In the first case, the nuts would be treated as co-products and upstream emissions would be allocated based on the energy content; in the second case the kernels would be treated as co-products while the shelöls are considered as waste without upstream emissions. This has a significant impact on the resulst or GHG savings, respectively. ? It is not specified whether indirect GHG emissions from nitrogen oxide emission from the heat and power unit of palm oil mills should be taken into account.

Conclusions and recommendations

In conclusion, the existing calculation methodology described in Annex V of the EU-RED and default values are insufficient for calculating the real GHG emission savings from palm oil and palm oil biodiesel. The current default values do not reflect relevant management practices. Additionally, they protect poor management practices, such as the disposal of empty fruit bunches (EFB), and lead to an overestimation of GHG savings from palm oil biodiesel. A default value for EFB disposal must be introduced because resulting GHG emissions are substantial. Organic nitrogen from fronds must be taken into account when calculating real GHG savings from palm oil biodiesel. Further, more conservative data for FFB yield and fugitive emissions from wastewater treatment should be introduced in order to foster environmental friendly management options. Moreover, credits for bioenergy production from crop residues should be allowed in order to foster the mobilization of currently unused biomass.     

Water demand and stress from oil palm-based biodiesel production in Thailand

Purpose

The use and production of biofuels have been strongly promoted in Thailand. In order to achieve a 25 % renewable energy target in 2021, feedstock expansion is needed to satisfy the increased demand for biofuel production putting more pressure on freshwater resources. This is an important implication of biofuel production which has not yet been taken into consideration. Thus, this study intends to address the impact from freshwater use due to the biodiesel target based on life cycle assessment approach as well as to evaluate suitable areas for expansion of oil palm.

Methods

The amount of water for growing oil palm throughout its lifespan is estimated based on theoretical crop water requirement, while water demand for producing biodiesel is referred to from literature. Then, the potential impact on freshwater resources is assessed in terms of water deprivation using the water stress index of Thailand. The Alternative Energy Development Plan for 2012–2021 and areas recommended by the Ministry of Agriculture and Cooperatives are referred in this study. Additionally, two scenarios for increasing new plantation in suitable areas are proposed as expansion in a single region or spread over the three regions.

Results and discussion

The highest water requirement for oil palm-based biodiesel production is found in the central region followed by the eastern and southern (4–9, 5–16, and 4–19 m³ L^?1 biodiesel, respectively). This is because oil palm plantations in the central region are not yet fully mature. As a result, the ratio of crop water requirement associated to crop productivity will be reduced while the water productivity will be increased yearly in yield. Also, more than 99 % of the total water is required during the cultivation period. To achieve the 2021 biodiesel target with a concern towards the impact from freshwater use by means of low water deprivation, cultivating oil palm is recommended entirely in the eastern and the southern parts without expansion to the central region.

Conclusions

The impact on freshwater resources is an important implication of biofuel production as most of the water requirement of palm oil biodiesel was for oil palm cultivation. Accounting the water deprivation as one of the criteria on impact from freshwater use will provide useful support for selecting areas having less potential for inducing water stress in a watershed leads to people in these areas being less vulnerable to water stress.

     

A spatially explicit data-driven approach to assess the effect of agricultural land occupation on species groups

Purpose

Change of vegetation cover and increased land use intensity, particularly for agricultural use, can affect species richness. Within life cycle impact assessment, methods to assess impacts of land use on a global scale are still in need of development. In this work, we present a spatially explicit data-driven approach to characterize the effect of agricultural land occupation on different species groups.

Methods

We derived characterization factors for the direct impact of agricultural land occupation on relative species richness. Our method identifies potential differences in impacts for cultivation of different crop types, on different species groups, and in different world regions. Using empirical species richness data gathered via an extensive literature search, characterization factors were calculated for four crop groups (oil palm, low crops, Pooideae, and Panicoideae), four species groups (arthropods, birds, mammals, and vascular plants), and six biomes.

Results and discussion

Analysis of the collected data showed that vascular plant richness is more sensitive than the species richness of arthropods to agricultural land occupation. Regarding the differences between world regions, the impact of agricultural land use was lower in boreal forests/taiga than in temperate and tropical regions. The impact of oil palm plantations was found to be larger than that of Pooideae croplands, although we cannot rule out that this difference is influenced by the spatial difference between the oil palm- and Pooideae-growing regions as well. Analysis of a subset of data showed that the impact of conventional farming was larger than the impact of low-input farming.

Conclusions

The impact of land occupation on relative species richness depends on the taxonomic groups considered, the climatic region, and farm management. The influence of crop type, however, was found to be of less importance.     

Effects of oil palm plantations on habitat structure and fish assemblages in Amazon streams

The aim of this research is to assess the effects of oil palm plantations on stream habitat and their fish assemblage diversity. We hypothesize that streams which drain through oil palm plantations tend to be less heterogeneous, limiting the occurrence of many species, than streams that drain through forest fragments, which support higher fish diversity. A total of 17 streams were sampled; eight in forest fragments and nine in oil palm plantations. Environmental and biological variables were sampled along 150 m stretch in each stream. Of the 242 environmental variables measured, ten were considered important to assess the condition of structural habitat, and out of these variables, four were considered relevant in the distinction between streams in oil palm plantations and forest fragments. A total of 7245 fishes were collected, belonging to 63 species. Unlike our original hypothesis, the species richness did not differ between forest fragment and oil palm plantations streams, showing that it is not a good divert measure in streams disturbance assessment. However, fish assemblages differed in species composition, and 56 species were recorded in oil palm plantation streams, while 44 species were recorded in forest fragments streams. Some species were identified as indicators of either altered (Aequidens tetramerus and Apistogramma agassizii) or undisturbed areas (Helogenes marmoratus). Overall, oil palm plantations were proven to change stream habitat structure and fish species distribution, corroborating other studies that have evidenced changes in patterns of biological community structure due to impacts by different land uses.     

Social life cycle assessment of palm oil biodiesel: a case study in Jambi Province of Indonesia

Purpose

This study aims to investigate the social implications of palm oil biodiesel via a case study using a life cycle assessment framework.

Methods

The case study was conducted in Jambi Province of Indonesia and involved several stakeholders, such as value chain actors, employees, local community members, government, and nongovernmental organization representatives related in palm oil industry. The assessment was carried out using social criteria developed by adopting the Society of Environmental Toxicology and Chemistry/United Nations Environment Programme Code of Practice, supplemented by an expert survey, and supported by literature review. Stakeholders’ perspectives were evaluated by determining the gaps between expected and perceived quality of each social criterion, which are gauged using seven-point Likert scale.

Results and discussion

Twenty-four social criteria were developed and aggregated into five social impact categories: human rights, working condition, cultural heritage, social–economic repercussion, and governance. These criteria have been weighted, useful for further application in multicriteria decision analysis. The results of the stakeholders’ survey reveal the critical social hotspots, which are the issues within the impact categories of working conditions and cultural heritage.

Conclusions

In order to achieve the social equitability of palm oil biodiesel, which is an important pillar to sustainability, efforts must be put to address these social hotspots through actions in various policy level.     

Environmental life cycle assessment of biodiesel produced with palm oil from Colombia

Purpose

Palm biodiesel life cycle studies have been mainly performed for Asia and focused on greenhouse gas (GHG) intensity. The purpose of this article is to present an environmental life cycle assessment (LCA) of biodiesel produced in Portugal from palm oil (PO) imported from Colombia, addressing the direct effects of land-use change (LUC), different fertilization schemes, and biogas management options at the extraction mill.

Methods

An LC inventory and model of PO biodiesel was implemented based on data collected in five Portuguese biodiesel plants and in a palm plantation and extraction mill in the Orinoquía Region of Colombia. The emissions due to carbon stock changes associated with LUC were calculated based on the Colombian oil palm area expansion from 1990 to 2010 and on historical data of vegetation cleared for planting new palm trees. Five impact categories were assessed based on ReCiPe and CML-IA methods: GHG intensity, freshwater and marine eutrophication, photochemical oxidant formation, terrestrial acidification. A sensitivity analysis of alternative allocation approaches was performed.

Results and discussion

Palm plantation was the LC phase which contributed the most to eutrophication and acidification impacts, whereas transportation and oil extraction contributed the most to photochemical oxidation. An increase in carbon stock due to LUC associated with the expansion of Colombian oil palm was calculated (palm is a perennial crop with higher carbon stock than most previous land-uses). The choice of the fertilization scheme that leads to the lowest environmental impacts is contradictory among various categories. The use of calcium ammonium nitrate (followed by ammonium sulfate) leads to the lowest acidification and eutrophication impacts. The highest GHG intensity was calculated for calcium ammonium nitrate, while the lowest was for ammonium sulfate and poultry manure. Biogas captured and flared at the oil extraction mill instead of being released into the atmosphere had the lowest impacts in all categories (GHG intensity reduced by more than 60 % when biogas is flared instead of released).

Conclusions

Recommendation on the selection of the fertilization scheme depends on the environmental priority. ReCiPe and CML showed contradictory results for eutrophication and photochemical oxidation; however, uncertainty may impair strong recommendations. GHG intensity and photochemical oxidation impacts can be significantly reduced if biogas is flared instead of being released. However, more efficient biogas management should be implemented in order to reduce the impacts further.

     

Diversity and occupancy of small carnivores within oil palm plantations in central Sumatra,Indonesia

In Southeast Asia, the conversion of native forests to oil palm plantations threatens tropical biodiversity, but very little is known about the impacts of oil palm cultivation on small carnivore species. To determine the diversity and occupancy of small carnivores within oil palm plantations and to investigate possible factors that might affect their presence within oil palm, we used camera-traps within two oil palm plantations in central Sumatra, analysed the data using occupancy modelling and tested whether two covariates (distance to the edge of the oil palm habitat and distance from extensive areas of lowland forest) affected the model parameters for each small carnivore species. From 3164 camera-trap days, we detected only three small carnivores: leopard cat (Prionailurus bengalensis), common palm civet (Paradoxurus hermaphroditus) and Malay civet (Viverra tangalunga), which indicates that there was a low diversity of small carnivores within the oil palm plantations. Both the leopard cat and common palm civet were found deep within the oil palm, whereas the Malay civet was only detected near the edge in one of the plantations. The leopard cat and common palm civet had very high occupancy values, whereas the Malay civet had low values for both occupancy and detection probability. Neither covariate affected occupancy of the leopard cat and common palm civet, but distance from the edge of the oil palm habitat did influence their detection probabilities. Malay civet occupancy decreased with distance from the oil palm edge, and detection probability was affected by distance from extensive areas of lowland forest. Forests and rest/den site availability are suggested to be important features for small carnivores with oil palm-dominated landscapes.     

Exploring variability in methods and data sensitivity in carbon footprints of feed ingredients

Purpose

Production of feed is an important contributor to life cycle greenhouse gas emissions, or carbon footprints (CFPs), of livestock products. Consequences of methodological choices and data sensitivity on CFPs of feed ingredients were explored to improve comparison and interpretation of CFP studies. Methods and data for emissions from cultivation and processing, land use (LU), and land use change (LUC) were analyzed.

Method

For six ingredients (maize, wheat, palm kernel expeller, rapeseed meal, soybean meal, and beet pulp), CFPs resulting from a single change in methods and data were compared with a reference CFP, i.e., based on IPCC Tier 1 methods, and data from literature.

Results and discussion

Results show that using more detailed methods to compute N₂O emissions from cultivation hardly affected reference CFPs, except for methods to determine $ \mathrm{NO}_3^{-} $ leaching (contributing to indirect N₂O emissions) in which the influence is about ?7 to +12 %. Overall, CFPs appeared most sensitive to changes in crop yield and applied synthetic fertilizer N. The inclusion of LULUC emissions can change CFPs considerably, i.e., up to 877 %. The level of LUC emissions per feed ingredient highly depends on the method chosen, as well as on assumptions on area of LUC, C stock levels (mainly aboveground C and soil C), and amortization period.

Conclusions

We concluded that variability in methods and data can significantly affect CFPs of feed ingredients and hence CFPs of livestock products. Transparency in methods and data is therefore required. For harmonization, focus should be on methods to calculate $ \mathrm{NO}_3^{-} $ leaching and emissions from LULUC. It is important to consider LUC in CFP studies of food, feed, and bioenergy products.     

Carbon sequestration and soil fertility of tropical tree plantations and secondary forest established on degraded land

Purpose

Much tropical land requires rehabilitation but the capacity of reforestation with plantations or naturally regenerating secondary forests for overcoming soil degradation remains unclear. We hypothesised that desirable effects, including improved soil fertility and carbon sequestration, are achieved to a greater extent in Acacia mangium plantations and secondary forests than in Eucalyptus urophylla plantations.

Methods

We tested our hypothesis across soil and climate gradients in Vietnam with linear mixed-effect models and other, comparing A. mangium and E. urophylla plantations, secondary forests and pasture.

Results

A. mangium plantations and secondary forests showed a positive correlation between biomass production and desirable soils properties including increased soil carbon, nitrogen and phosphorus, and reduced bulk density. All plantations, but not secondary forests, caused increases in soil acidity. Eight-year old A. mangium plantations contained most carbon in biomass+soil, and secondary forests and pastures had similar or higher soil carbon. E. urophylla plantations had the lowest soil carbon status, raising doubt about their sequestration capacity in current 6–8 year rotations.

Conclusions

The study demonstrates that appropriate reforestation enhances soil fertility and promotes carbon sequestration on degraded tropical lands and that unmanaged secondary forests are effective at improving soil fertility and sequestering carbon at low cost.     

Impact of Logging and Forest Conversion to Oil Palm Plantations on Soil Bacterial Communities in Borneo

Tropical forests are being rapidly altered by logging and cleared for agriculture. Understanding the effects of these land use changes on soil bacteria, which constitute a large proportion of total biodiversity and perform important ecosystem functions, is a major conservation frontier. Here we studied the effects of logging history and forest conversion to oil palm plantations in Sabah, Borneo, on the soil bacterial community. We used paired-end Illumina sequencing of the 16S rRNA gene, V3 region, to compare the bacterial communities in primary, once-logged, and twice-logged forest and land converted to oil palm plantations. Bacteria were grouped into operational taxonomic units (OTUs) at the 97% similarity level, and OTU richness and local-scale α-diversity showed no difference between the various forest types and oil palm plantations. Focusing on the turnover of bacteria across space, true β-diversity was higher in oil palm plantation soil than in forest soil, whereas community dissimilarity-based metrics of β-diversity were only marginally different between habitats, suggesting that at large scales, oil palm plantation soil could have higher overall γ-diversity than forest soil, driven by a slightly more heterogeneous community across space. Clearance of primary and logged forest for oil palm plantations did, however, significantly impact the composition of soil bacterial communities, reflecting in part the loss of some forest bacteria, whereas primary and logged forests did not differ in composition. Overall, our results suggest that the soil bacteria of tropical forest are to some extent resilient or resistant to logging but that the impacts of forest conversion to oil palm plantations are more severe.     

Potential for optimized production and use of rapeseed biodiesel. Based on a comprehensive real-time LCA case study in Denmark with multiple pathways

Purpose

Several factors contribute to the current increased focus on alternative fuels such as biodiesel, including an increasing awareness of the environmental impact of petrochemical (PC) oil products such as PC diesel, the continuously increasing price of PC oil, and the depletion of PC oil. For these reasons, the European Union has enacted a directive requiring each member state to ensure that the share of energy from renewable sources in transport be at least 10 % of the final consumption of energy by 2020 (The European Parliament and the Council 2009). This LCA study assesses the specific environmental impacts from the production and use of biodiesel as it is today (real-time), based on rapeseed oil and different types of alcohols, and using technologies that are currently available or will be available shortly. Different options are evaluated for the environmental improvement of production methods. The modeling of the LCA is based on a specific Danish biodiesel production facility.

Methods

The functional unit is “1,000 km transportation for a standard passenger car.” All relevant process stages are included, such as rapeseed production including carbon sequestration and N₂O balances, and transportation of products used in the life cycle of biodiesel. System expansion has been used to handle allocation issues.

Results and discussion

The climate change potential from the production and use of biodiesel today is 57 kg CO₂-eq/1,000 km, while PC diesel is 214 kg CO₂-eq/1,000 km. Options for improvement include the increased use of residual straw from rapeseed fields for combustion in a power plant where carbon sequestration is considered, and a change in transesterification from a conventional process to an enzymatic process when using bioethanol instead of PC methanol. This research also evaluates results for land use, respiratory inorganics potential, human toxicity (carc) potential, ecotoxicity (freshwater) potential, and aquatic eutrophication (N) potential. Different sources for uncertainty are evaluated, and the largest drivers for uncertainty are the assumptions embedded into the substitution effects. The results presented should not be interpreted as a blueprint for the increased production of biodiesel but rather as a benchmarking point for the present, actual impact in a well-to-wheels perspective of biodiesel, with options for improving production and use.

Conclusions

Based on this analysis, we recommend investigating additional options and incentives regarding the increased use of rape straw, particularly considering the carbon sequestration issues (from the perspective of potential climate change) of using bioalcohol instead of PC alcohol for the transesterification process.     

Quantifying above‐ and belowground biomass carbon loss with forest conversion in tropical lowlands of Sumatra (Indonesia)

Natural forests in South‐East Asia have been extensively converted into other land‐use systems in the past decades and still show high deforestation rates. Historically, lowland forests have been converted into rubber forests, but more recently, the dominant conversion is into oil palm plantations. While it is expected that the large‐scale conversion has strong effects on the carbon cycle, detailed studies quantifying carbon pools and total net primary production (NPP_total) in above‐ and belowground tree biomass in land‐use systems replacing rainforest (incl. oil palm plantations) are rare so far. We measured above‐ and belowground carbon pools in tree biomass together with NPP_total in natural old‐growth forests, ‘jungle rubber’ agroforests under natural tree cover, and rubber and oil palm monocultures in Sumatra. In total, 32 stands (eight plot replicates per land‐use system) were studied in two different regions. Total tree biomass in the natural forest (mean: 384 Mg ha^?1) was more than two times higher than in jungle rubber stands (147 Mg ha^?1) and >four times higher than in monoculture rubber and oil palm plantations (78 and 50 Mg ha^?1). NPP_total was higher in the natural forest (24 Mg ha^?1 yr^?1) than in the rubber systems (20 and 15 Mg ha^?1 yr^?1), but was highest in the oil palm system (33 Mg ha^?1 yr^?1) due to very high fruit production (15–20 Mg ha^?1 yr^?1). NPP_total was dominated in all systems by aboveground production, but belowground productivity was significantly higher in the natural forest and jungle rubber than in plantations. We conclude that conversion of natural lowland forest into different agricultural systems leads to a strong reduction not only in the biomass carbon pool (up to 166 Mg C ha^?1) but also in carbon sequestration as carbon residence time (i.e. biomass‐C:NPP‐C) was 3–10 times higher in the natural forest than in rubber and oil palm plantations.     

Life cycle assessment of soybean-based biodiesel in Argentina for export

Background, aim and scope

Regional specificities are a key factor when analyzing the environmental impact of a biofuel pathway through a life cycle assessment (LCA). Due to different energy mixes, transport distances, agricultural practices and land use changes, results can significantly vary from one country to another. The Republic of Argentina is the first exporter of soybean oil and meal and the third largest soybean producer in the world, and therefore, soybean-based biodiesel production is expected to significantly increase in the near future, mostly for exportation. Moreover, Argentinean biodiesel producers will need to evaluate the environmental performances of their product in order to comply with sustainability criteria being developed. However, because of regional specificities, the environmental performances of this biofuel pathway can be expected to be different from those obtained for other countries and feedstocks previously studied. This work aims at analyzing the environmental impact of soybean-based biodiesel production in Argentina for export. The relevant impact categories account for the primary non-renewable energy consumption (CED), the global warming potential (GWP), the eutrophication potential (EP), the acidification potential (AP), the terrestrial ecotoxicity (TE), the aquatic ecotoxicity (AE), the human toxicity (HT) and land use competition (LU). The paper tackles the feedstock and country specificities in biodiesel production by comparing the results of soybean-based biodiesel in Argentina with other reference cases. Emphasis is put on explaining the factors that contribute most to the final results and the regional specificities that lead to different results for each biodiesel pathway.

Materials and methods

The Argentinean (AR) biodiesel pathway was modelled through an LCA and was compared with reference cases available in the ecoinvent® 2.01 database, namely, soybean-based biodiesel production in Brazil (BR) and the United States (US), rapeseed-based biodiesel production in the European Union (EU) and Switzerland (CH) and palm-oil-based biodiesel production in Malaysia (MY). In all cases, the systems were modelled from feedstock production to biodiesel use as B100 in a 28 t truck in CH. Furthermore, biodiesel pathways were compared with fossil low-sulphur diesel produced and used in CH. The LCA was performed according to the ISO standards. The life cycle inventory and the life cycle impact assessment (LCIA) were performed in Excel spreadsheets using the ecoinvent® 2.01 database. The cumulative energy demand (CED) and the GWP were estimated through the CED for fossil and nuclear energy and the IPCC 2001 (climate change) LCIA methods, respectively. Other impact categories were assessed according to CML 2001, as implemented in ecoinvent. As the product is a fuel for transportation (service), the system was defined for one vehicle kilometre (functional unit) and was divided into seven unit processes, namely, agricultural phase, soybean oil extraction and refining, transesterification, transport to port, transport to the destination country border, distribution and utilisation.

Results

The Argentinean pathway results in the highest GWP, CED, AE and HT compared with the reference biofuel pathways. Compared with the fossil reference, all impact categories are higher for the AR case, except for the CED. The most significant factor that contributes to the environmental impact in the Argentinean case varies depending on the evaluated category. Land provision through deforestation for soybean cultivation is the most impacting factor of the AR biodiesel pathway for the GWP, the CED and the HT categories. Whilst nitrogen oxide emissions during the fuel use are the main cause of acidification, nitrate leaching during soybean cultivation is the main factor of eutrophication. LU is almost totally affected by arable land occupation for soybean cultivation. Cypermethrin used as pesticide in feedstock production accounts for almost the total impact on TE and AE.

Discussion

The sensitivity analysis shows that an increase of 10% in the soybean yield, whilst keeping the same inputs, will reduce the total impact of the system. Avoiding deforestation is the main challenge to improve the environmental performances of soybean-based biodiesel production in AR. If the soybean expansion can be done on marginal and set-aside agricultural land, the negative impact of the system will be significantly reduced. Further implementation of crops’ successions, soybean inoculation, reduced tillage and less toxic pesticides will also improve the environmental performances. Using ethanol as alcohol in the transesterification process could significantly improve the energy balance of the Argentinean pathway.

Conclusions

The main explaining factors depend on regional specificities of the system that lead to different results from those obtained in the reference cases. Significantly different results can be obtained depending on the level of detail of the input data, the use of punctual or average data and the assumptions made to build up the LCA inventory. Further improvement of the AR biodiesel pathways should be done in order to comply with international sustainability criteria on biofuel production.

Recommendations and perspectives

Due to the influence of land use changes in the final results, more efforts should be made to account for land use changes others than deforestation. More data are needed to determine the part of deforestation attributable to soybean cultivation. More efforts should be done to improve modelling of interaction between variables and previous crops in the agricultural phase, future transesterification technologies and market prices evolution. In order to assess more accurately the environmental impact of soybean-based biodiesel production in Argentina, further considerations should be made to account for indirect land use changes, domestic biodiesel consumption and exportation to other regions, production scale and regional georeferenced differentiation of production systems.     

Dynamic of reserve compounds of mesocarp and seeds of macaw palm (<Emphasis Type="Italic">Acrocomia aculeata)</Emphasis> submitted to different storage conditions

Key message

Storage changed carbohydrate and protein levels, which can be related to embryo viability. The fatty acid profile was constant, and the embryo composition was similar to the mesocarp, not the endosperm.

Abstract

Macaw palm fruits have a diverse biochemical constitution, and there is significant commercial interest in this species among food, pharmaceutical, cosmetics, and bioenergy industries. We evaluated changes in the reserve compounds of macaw palm mesocarp and seeds from fruits stored for 1 year under three different conditions. Protein and carbohydrate levels were highest in the embryo than in the endosperm. Fatty acid profiles were very similar over time under all storage conditions and in each structure evaluated, with the embryo composition being very similar to the mesocarp. Macaw palm oil remained well preserved under all storage conditions tested, but seed reserves and seed viability are best maintained at room temperatures. The endosperm contained higher levels of saturated fatty acids than either the embryo or mesocarp, making seeds more resistant to oxidative deterioration than the mesocarp. The results showed that the composition of the mesocarp oil promises the production of high-quality biodiesel from this structure, and changes in carbohydrate and protein levels show that laboratory conditions are the most efficient for maintaining seed quality during storage.

     

Survival strategies of a frugivore,the sun bear,in a forest-oil palm landscape

As large areas of forest are lost throughout the tropics, prime habitat of many species decline and become fragmented. The island of Borneo is a prime example, with accelerated clearing of forests primarily for oil palm expansion. Borneo is recognized as an important stronghold for the conservation of the sun bear (Helarctos malayanus), but it is unclear how habitat reduction and fragmentation is affecting this frugivore. We used camera traps and sign surveys to understand patterns of sun bear habitat use in a matrix of fragmented forests and extensive oil palm development, which has existed as such for?>?15 years: the Lower Kinabatangan floodplain in Sabah, Malaysian Borneo. Within these small forest fragments, squeezed between a major river and oil palm plantations, bears exhibited selection for areas farther from human activity (plantations, river boat traffic, and buildings), and were rarely active during the day, demonstrating both spatial and temporal avoidance of potential human-related threats. They selected large trees to feed and rest, and also exploited adjacent plantations to feed on oil palm fruits. We conclude that even relatively small forest fragments (~?2000 ha) within large agricultural landscapes can be important for sun bears. Our research highlights the remarkable adaptations this species has employed to persist in a drastically modified landscape.     

The impacts of habitat disturbance on adult and larval dragonflies (Odonata) in rainforest streams in Sabah,Malaysian Borneo

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Updated and harmonised greenhouse gas emissions for crop inventories

Purpose

The emission of greenhouse gases (GHG) is a key criterion in the environmental assessment of biofuels. Life cycle inventories taking into account the latest methodological developments are an essential prerequisite for this assessment. In the last years, substantial progresses in the modelling of nitrogen emissions relevant for the climate as well as in modelling the emissions from land use change (LUC) have been achieved. Therefore, the biomass production inventories in the ecoinvent database were revised to take into account these developments.

Methods

The IPCC method tier 1 has been used for the assessment of N₂O emissions. Induced emissions from NH₃ and NO₃ were included as well. Due to the importance of the latter emissions for N₂O formation, these emissions have also been updated and harmonised. The Agrammon model was used for the NH₃ emissions. The SALCA-NO₃ model has been applied in the European inventories to estimate nitrate leaching, whilst in non-European inventories the SQCB-NO₃ model has been used. The quantification of the land use change areas has been based on annualized, retrospective data of the last 20 years. All carbon pools (from aboveground biomass to soil organic carbon) were considered and differentiated on a regional level for all of the natural vegetation categories affected. Whenever possible, default values and methods from the IPCC 2006 were applied.

Results and discussion

The changes for ammonia emissions were generally very small (?5 % on average). The nitrate emissions increased on average by +13 %, but this slight trend is the result of important downward and upward changes, whilst the average N₂O emissions decreased by ?26 %. For the existing inventories of soybean, palm oil and sugarcane production, significant increases of GHG emissions resulted from LUC modelling. This was mainly due to the consistent inclusion of all carbon stocks according to the IPCC guidelines. The calculation method can also result in important C sequestration effects in certain cases like African Jatropha production.

Conclusions

The changes in greenhouse gas emissions due to the updated methodology were significant. This shows that life cycle assessment studies for biofuels using older methodological bases need to be revised and could lead to different conclusions. The implemented and cultivated superstructure for LUC modelling is modular and flexible and can be easily extended to other important crop activities. The new parameterisation functionality applied for the activities provides powerful means for the simple generation of site-specific activities.

     

Estimating the impact of changing fertilizer application rate, land use, and climate on nitrous oxide emissions in Irish grasslands

Aim

This study examines the impact of changing nitrogen (N) fertilizer application rates, land use and climate on N fertilizer-derived direct nitrous oxide (N₂O) emissions in Irish grasslands.

Methods

A set of N fertilizer application rates, land use and climate change scenarios were developed for the baseline year 2000 and then for the years 2020 and 2050. Direct N₂O emissions under the different scenarios were estimated using three different types of emission factors and a newly developed Irish grassland N₂O emissions empirical model.

Results

There were large differences in the predicted N₂O emissions between the methodologies, however, all methods predicted that the overall N₂O emissions from Irish grasslands would decrease by 2050 (by 40–60 %) relative to the year 2000. Reduced N fertilizer application rate and land-use changes resulted in decreases of 19–34 % and 11–60 % in N₂O emission respectively, while climate change led to an increase of 5–80 % in N₂O emission by 2050.

Conclusions

It was observed in the study that a reduction in N fertilizer and a reduction in the land used for agriculture could mitigate emissions of N₂O, however, future changes in climate may be responsible for increases in emissions causing the positive feedback of climate on emissions of N₂O.