Lucas Reijnders

Biofuel plantations on forested lands: double jeopardy for biodiversity and climate

The growing demand for biofuels is promoting the expansion of a number of agricultural commodities, including oil palm (Elaeis guineensis). Oil-palm plantations cover over 13 million ha, primarily in Southeast Asia, where they have directly or indirectly replaced tropical rainforest. We explored the impact of the spread of oil-palm plantations on greenhouse gas emission and biodiversity. We assessed changes in carbon stocks with changing land use and compared this with the amount of fossil-fuel carbon emission avoided through its replacement by biofuel carbon. We estimated it would take between 75 and 93 years for the carbon emissions saved through use of biofuel to compensate for the carbon lost through forest conversion, depending on how the forest was cleared. If the original habitat was peatland, carbon balance would take more than 600 years. Conversely, planting oil palms on degraded grassland would lead to a net removal of carbon within 10 years. These estimates have associated uncertainty, but their magnitude and relative proportions seem credible. We carried out a meta-analysis of published faunal studies that compared forest with oil palm. We found that plantations supported species-poor communities containing few forest species. Because no published data on flora were available, we present results from our sampling of plants in oil palm and forest plots in Indonesia. Although the species richness of pteridophytes was higher in plantations, they held few forest species. Trees, lianas, epiphytic orchids, and indigenous palms were wholly absent from oil-palm plantations. The majority of individual plants and animals in oil-palm plantations belonged to a small number of generalist species of low conservation concern. As countries strive to meet obligations to reduce carbon emissions under one international agreement (Kyoto Protocol), they may not only fail to meet their obligations under another (Convention on Biological Diversity) but may actually hasten global climate change. Reducing deforestation is likely to represent a more effective climate-change mitigation strategy than converting forest for biofuel production, and it may help nations meet their international commitments to reduce biodiversity loss.

Priority assessment of toxic substances in life cycle assessment. Part I: Calculation of toxicity potentials for 181 substances with the nested multi-media fate, exposure and effects model USES-LCA

Toxicity potentials are standard values used in life cycle assessment (LCA) to enable a comparison of toxic impacts between substances. In most cases, toxicity potentials are calculated with multi-media fate models. Until now, unrealistic system settings were used for these calculations. The present paper outlines an improved model to calculate toxicity potentials: the global nested multi-media fate, exposure and effects model USES-LCA. It is based on the Uniform System for the Evaluation of Substances 2.0 (USES 2.0). USES-LCA was used to calculate for 181 substances toxicity potentials for the six impact categories freshwater aquatic ecotoxicity, marine aquatic ecotoxicity, freshwater sediment ecotoxicity, marine sediment ecotoxicity, terrestrial ecotoxicity and human toxicity, after initial emission to the compartments air, freshwater, seawater, industrial soil and agricultural soil, respectively. Differences of several orders of magnitude were found between the new toxicity potentials and those calculated previously.

Gel electrophoresis of RNA under denaturing conditions

Abstract 1. We have studied the electrophoretic mobility of RNAs in acrylamide gels under denaturing conditions, using 8 M urea and low salt buffer at 60 °C. In these “urea gels” the mobilities of a number of RNAs in the molecular weight range of 0.5 · 106–1.5 · 106 are inversely related to their log molecular weights. 2. We have determined molecular weights in “urea gels” of a number of RNAs for which controversial estimates were available, including phage Qβ RNA (1.4 · 106), cell-sap rRNAs of Tetrahymena pyriformis ( 0.59+0.59 · 10 6 and 0.52 · 106) and Crithidia luciliae ( 0.83+0.56 · 10 6 and 0.74 · 106) and some mitochondrial rRNAs. 3. We have redetermined the molecular weights of the large subunit rRNAs from Escherichia coli (1.13 · 106) and rat-liver cell sap (1.57 · 106), phage MS2 RNA (1.23 · 106) and the small subunit rRNA from yeast cell sap (0.72 · 106) by sedimentation equilibrium. Only the latter value is significantly different from that reported by others (0.62 · 106). 4. For a number of viral and rRNAs relative gel electrophoretic mobilities were determined at a range of temperatures, in a standard neutral salt buffer. No simple relationship was found between the variations in mobility and the gross characteristics of the RNAs. Differences in relative gel electrophoretic mobilities of RNAs in the Tris-phosphate-EDTA buffer introduced by Loening, and the Tris-borate-EDTA buffer introduced by Peacock and Dingman, can be attributed to differences in ionic concentrations.

Spatially Explicit Characterization of Acidifying and Eutrophying Air Pollution in Life‐Cycle Assessment

Simple models are often used to assess the potential impact of acidifying and eutrophying substances released during the life cycle of products. As fate, background depositions, and ecosystem sensitivity are not included in these models, environmental life-cycle assessment of products (LCA) may produce incorrect results for these impact categories. This paper outlines the spatially explicit regional air pollution information and simulation model (RAINSLCA), which was developed for the calculation of acidification and terrestrial eutrophication potentials of ammonia (NH3) and nitrogen oxide (NOx) air emissions and acidification potentials for sulfur dioxide (SO2) air emissions for Europe and a number of European regions, taking fate, background depositions and effects into account. Two impact definitions are explored in the calculations: (1) the marginal change in the hazard index of all ecosystems in Europe and (2) the marginal change in the hazard index of ecosystems in Europe where the critical load is actually exceeded. The inclusion of fate, background depositions, and ecosystem sensitivity results in a different ranking of substances compared to simpler model outcomes.

Isolation of yeast mitochondrial ribosomes highly active in protein synthesis

Abstract 1. We have obtained active ribosomes in 60 % yield from puromycin-pretreated mitochondria by purification through 1 M sucrose containing 500 mM NH 4 Cl. Neither the spectral properties nor the density in CsCl of these ribosomes suggest that they contain membranous material. 2. When combined with supernatant factors from Escherichia coli these ribosomes catalyze poly(U)-directed polyphenylalanine synthesis at rates up to 3.7 nmoles/mg RNA per 30 min, a value approaching that obtained with ribosomes from E. coli . Poly (U,G) stimulated incorporation of phenylalanine, leucine and glycine into acid-insoluble material, and leucine incorporation in this system was as sensitive to inhibition by chloramphenicol as with ribosomes from E. coli . 3. The ribosome is a 74-S particle and it contains 22- and 15-S RNA. Under ionic conditions similar to those used for the dissociation of bacterial ribosomes it readily dissociates into two subunits, 50 S and 37 S. Both subunits are required for poly (U)-directed polyphenylalanine synthesis. 4. An unusual feature of these ribosomes is their sensitivity to NH 4 Cl; 125 mM inhibits poly (U)-directed polyphenylalanine synthesis over 90 %.

Do biofuels from microalgae beat biofuels from terrestrial plants

The best way to displace fossil fuels is much debated. Chisti [1] has argued that in displacing fossil fuels, microalgal biodiesel outperforms biodiesel and bioethanol from terrestrial plants because microalgal biofuel yields ha−1 can be larger. However, Chisti did not consider fossil fuel inputs during the biofuel life cycle. Fossil fuels are currently used for building the facilities (bioreactor, pond) and for operational activities such as supplying nutrients, maintenance, mixing, the collection of microalgae and biomass processing.

Hazard reduction for the application of titania nanoparticles in environmental technology.

Photocatalytically active titania (TiO2) nanoparticles are applied, and considered for application, in the degradation of hazardous substances. However, these nanoparticles are also hazardous by themselves. High efficiency immobilization of TiO2 nanoparticles on large inorganic supports that are not vulnerable to photocatalytic degradation is conducive to hazard reduction. Immobilization should also aim at minimizing the release of TiO2 nanoparticles from such supports due to attrition. In doing so there may be a trade off between hazard and photocatalytic activity.

Hybridization studies with yeast mitochondrial RNAs.

Abstract 1. 1. RNA from highly purified mitochondrial ribosomes of Saccharomyces carlsbergensis was hybridized with homologous mtDNA, purified by a procedure that avoids equilibrium centrifugation in CsCl. Maximally 2.4 % of the DNA could be converted into hybrid, showing that not more than one gene is present for each of the rRNAs. 2. 2. Separate plateaus were observed for the rRNAs from purified ribosomal subunits, showing that substantial base sequence homologies between these RNAs are absent. 3. 3. Co-sedimentation of mitochondrial rRNA with Escherichia coli rRNA through gradients containing 99 % dimethyl sulphoxide, shows that both mitochondrial rRNAs are slightly larger than the corresponding E. coli rRNAs. 4. 4. The base composition of mitochondrial rRNA in mole percent is 39 % A, 39 % U, 14 % G and 9 % C. 5. 5. Total mtRNA hybridized to a large extent with nuclear DNA of S. carlsbergensis, but the hybridization was suppressed to near background (0.07 % of DNA in hybrid) by excess cold cell-sap rRNA. This indicates that yeast mitochondria do not contain substantial amounts of imported nuclear transcripts.

A normative strategy for sustainable resource choice and recycling

A normative strategy is proposed for resource choice and recycling to meet the criterion of sustainability, defined as near constancy of natural resources. In this strategy resource choice should be fitted to the fate of products and product wastes, with geochemically scarce virtually non-renewable resources being reserved for uses that allow for nearly 100% recycling and negligible loss of irretrievable material and material deterioration. Sustainable recycling is argued to be strongly dependent on product design that slows loss of quality by products and materials. Recycling processes should aim at quality conservation by cascading. Non-product and recycling outputs should match with required inputs into the economy. Finally technologies should be employed that prevent the build-up of contaminants in products. Examples are given of the ways in which elements of this normative strategy may be implemented. Internalisation of currently external costs will strongly favour the proposed strategy.

Policies influencing cleaner production: the role of prices and regulation

Abstract Low prices of inputs, low costs associated with non-product outputs and poor regulatory forcing have often not been conducive to diffusion of cleaner production. However developments may be noted in the field of taxation, subsidies, liability and permits that tend to be more favourable to cleaner production. Extension thereof may favour cleaner production more in the future. Cleaner production stands to gain much by slashing subsidies and substantial ecotaxation of inputs and non-product outputs. Similarly the regulatory enforcement of best available technologies, liability for waste and tradable permits may help the diffusion of cleaner production.