Climate change adaptation,mitigation and livelihood benefits in coffee production: where are the synergies?

There are worldwide approximately 4.3 million coffee (Coffea arabica) producing smallholders generating a large share of tropical developing countries’ gross domestic product, notably in Central America. Their livelihoods and coffee production are facing major challenges due to projected climate change, requiring adaptation decisions that may range from changes in management practices to changes in crops or migration. Since management practices such as shade use and reforestation influence both climate vulnerability and carbon stocks in coffee, there may be synergies between climate change adaptation and mitigation that could make it advantageous to jointly pursue both objectives. In some cases, carbon accounting for mitigation actions might even be used to incentivize and subsidize adaptation actions. To assess potential synergies between climate change mitigation and adaptation in smallholder coffee production systems, we quantified (i) the potential of changes in coffee production and processing practices as well as other livelihood activities to reduce net greenhouse gas emissions, (ii) coffee farmers’ climate change vulnerability and need for adaptation, including the possibility of carbon markets subsidizing adaptation. We worked with smallholder organic coffee farmers in Northern Nicaragua, using workshops, interviews, farm visits and the Cool Farm Tool software to calculate greenhouse gas balances of coffee farms. From the 12 activities found to be relevant for adaptation, two showed strong and five showed modest synergies with mitigation. Afforestation of degraded areas with coffee agroforestry systems and boundary tree plantings resulted in the highest synergies between adaptation and mitigation. Financing possibilities for joint adaptation-mitigation activities could arise through carbon offsetting, carbon insetting, and carbon footprint reductions. Non-monetary benefits such as technical assistance and capacity building could be effective in promoting such synergies at low transaction costs.     

Modelling the costs of fox predation and preventive measures on sheep farms in Britain

Economic analysis is a useful tool to aid decisions on what to do about wildlife impacts, such as those of vertebrate predators on livestock farmers. The case-study of lamb predation by foxes in Britain is used to develop a theoretical economic model, with the aim of determining a financially optimal solution to minimise the total costs of livestock predation at the farm-level. Total costs include output losses and expenditure on preventive and control measures, in this case indoor housing and lethal fox control. The model is tested empirically with data from a questionnaire survey of sheep farmers and field data on fox population densities in Britain. Regression analyses are used to determine the relationships between lamb losses and expenditure on indoor housing, fox population density and other non-management characteristics. The effect of fox abundance on the cost of fox control is also assessed. Marginal analysis is used to determine the total cost-minimising solution from the farmer's point-of-view, in terms of how many ewes should be housed indoors and for how long, as well as how many foxes should be killed in addition to any lethal control already carried out. Optimal solutions vary according to farm characteristics, including flock size and the regional location of farms. In all cases, to minimise the costs of predation, as many ewes as possible should be housed. However, it is not worthwhile housing them for more than a day after lambing. Efficient fox predation management does not necessarily mean that lamb losses should be reduced to zero, and additional fox control is not worthwhile on the majority of farms. The analysis provides a framework for future evaluations of wildlife impacts and cost-effective management of these problems.     

Large particles are responsible for elevated bacterial marker levels in school air upon occupation

Muramic acid (Mur) is found in bacterial peptidoglycan (PG) whereas 3-hydroxy fatty acids (3-OH FAs) are found in Gram-negative bacterial lipopolysaccharide (LPS). Thus Mur and 3-OH FAs serve as markers to assess bacterial levels in indoor air. An initial survey, in a school, demonstrated that the levels of dust, PG and LPS (pmol m(-3)) were each much higher in occupied rooms than in the same rooms when unoccupied. In each instance, the Mur content of dust was increased and the hydroxy fatty acid distribution changed similarly suggesting an alteration in the bacterial population. Here, findings are compared with results from two additional schools. Follow-up aerosol monitoring by particle size was also performed for the first time for all 3 schools. The particle size distribution was shown to be quite different in occupied versus unoccupied schoolrooms. Within individual classrooms, concentrations of airborne particles [greater-than-or-equal]0.8 [micro sign]m in diameter, and CO(2) were correlated. This suggests that the increased levels of larger particles are responsible for elevation of bacterial markers during occupation. Release of culturable and non-culturable bacteria or bacterial aggregates from children (e.g. from flaking skin) might explain this phenomenon.     

The Arctic sea butterfly<Emphasis Type="Italic"> Limacina helicina</Emphasis>: lipids and life strategy

The sea butterfly Limacina helicina was collected from May to September 2001 in Kongsfjorden, Spitsbergen, to investigate population structure and body and lipid composition with regard to life cycle and reproductive strategy. Veligers and juveniles were only found in late autumn and spring, whereas females occurred from July to September. The size of the females increased until mid-August and decreased in September. Dry and lipid mass were closely related to size; dry mass increased exponentially and lipids linearly with size. The lipid content was highest in veligers (31.5% of dry mass) and juveniles (23.6%) but low in females (<10%). Phospholipids were the dominating lipid class followed by triacylglycerols. Females, veligers, and egg ribbons, all from September, were richest in phospholipids. Juveniles contained the highest amounts of triacylglycerols, whereas females had low levels in July and the beginning of August. In mid-August, levels of triacylglycerols were variable and higher. This suggests that females were in their main spawning period and the high variability in triacylglycerols points to different stages within the spawning cycle. Enhanced amounts of free fatty acids in females from July may be related to gonad development. The 16:1(n-7) fatty acid was more dominant in spring whereas 18:4(n-3) increased in summer and autumn, which reflects a change in diet from diatom-dominated food items in spring to dinoflagellates in summer/autumn. Small amounts of long-chain monounsaturated fatty acids suggest ingestion of copepods, and the fatty acid composition of veligers feeding on particulate matter. L. helicina has a one-year life cycle with peak spawning in August and over-winters as veligers that may grow to juveniles during the winter period. They metamorphose into juveniles during spring, develop to males in early summer, and mature into females in July and August.Communicated by M. Kühl, Helsingør     

Attenuation of methane and volatile organic compounds in landfill soil covers

The potential for natural attenuation of volatile organic compounds (VOCs) in landfill covers was investigated in soil microcosms incubated with methane and air, simulating the gas composition in landfill soil covers. Soil was sampled at Skellingsted Landfill at a location emitting methane. In total, 26 VOCs were investigated, including chlorinated methanes, ethanes, ethenes, fluorinated hydrocarbons, and aromatic hydrocarbons. The soil showed a high capacity for methane oxidation resulting in very high oxidation rates of between 24 and 112 microg CH4 g(-1) h(-1). All lower chlorinated compounds were shown degradable, and the degradation occurred in parallel with the oxidation of methane. In general, the degradation rates of the chlorinated aliphatics were inversely related to the chlorine to carbon ratios. For example, in batch experiments with chlorinated ethylenes, the highest rates were observed for vinyl chloride (VC) and lowest rates for trichloroethylene (TCE), while tetrachloroethylene (PCE) was not degraded. Maximal oxidation rates for the halogenated aliphatic compounds varied between 0.03 and 1.7 microg g(-1) h(-1). Fully halogenated hydrocarbons (PCE, tetrachloromethane [TeCM], chlorofluorocarbon [CFC]-11, CFC-12, and CFC-113) were not degraded in the presence of methane and oxygen. Aromatic hydrocarbons were rapidly degraded giving high maximal oxidation rates (0.17-1.4 microg g(-1) h(-1)). The capacity for methane oxidation was related to the depth of oxygen penetration. The methane oxidizers were very active in oxidizing methane and the selected trace components down to a depth of 50 cm below the surface. Maximal oxidation activity occurred in a zone between 15 and 20 cm below the surface, as this depth allowed sufficient supply of both methane and oxygen. Mass balance calculations using the maximal oxidation rates obtained demonstrated that landfill soil covers have a significant potential for not only methane oxidation but also cometabolic degradation of selected volatile organics, thereby reducing emissions to the atmosphere.     

Longevity can buffer plant and animal populations against changing climatic variability

Both means and year-to-year variances of climate variables such as temperature and precipitation are predicted to change. However, the potential impact of changing climatic variability on the fate of populations has been largely unexamined. We analyzed multiyear demographic data for 36 plant and animal species with a broad range of life histories and types of environment to ask how sensitive their long-term stochastic population growth rates are likely to be to changes in the means and standard deviations of vital rates (survival, reproduction, growth) in response to changing climate. We quantified responsiveness using elasticities of the long-term population growth rate predicted by stochastic projection matrix models. Short-lived species (insects and annual plants and algae) are predicted to be more strongly (and negatively) affected by increasing vital rate variability relative to longer-lived species (perennial plants, birds, ungulates). Taxonomic affiliation has little power to explain sensitivity to increasing variability once longevity has been taken into account. Our results highlight the potential vulnerability of short-lived species to an increasingly variable climate, but also suggest that problems associated with short-lived undesirable species (agricultural pests, disease vectors, invasive weedy plants) may be exacerbated in regions where climate variability decreases.     

Mitigation of methane emission from an old unlined landfill in Klintholm,Denmark using a passive biocover system

Methane generated at landfills contributes to global warming and can be mitigated by biocover systems relying on microbial methane oxidation. As part of a closure plan for an old unlined landfill without any gas management measures, an innovative biocover system was established. The system was designed based on a conceptual model of the gas emission patterns established through an initial baseline study. The study included construction of gas collection trenches along the slopes of the landfill where the majority of the methane emissions occurred. Local compost materials were tested as to their usefulness as bioactive methane oxidizing material and a suitable compost mixture was selected. Whole site methane emission quantifications based on combined tracer release and downwind measurements in combination with several local experimental activities (gas composition within biocover layers, flux chamber based emission measurements and logging of compost temperatures) proved that the biocover system had an average mitigation efficiency of approximately 80%. The study showed that the system also had a high efficiency during winter periods with temperatures below freezing. An economic analysis indicated that the mitigation costs of the biocover system were competitive to other existing greenhouse gas mitigation options.