Preference and calorific value of fuelwood species in rural populations in northwestern Patagonia

Traditional knowledge of fuel species was evaluated, associating species preferences with the physical properties of wood and its combustibility. The physical characteristics of 21 popular firewood species were analyzed in three rural communities in the northwest of Patagonia. Semi-structured interviews were carried out in 91 homes, as well as free listing and walks; samples of the woody species were collected in each of the homes visited. We have hypothesized that the experience of gathering and using fuelwood species, as cognitive know-how, over generations will have enabled local people to know species have best fuel attributes, such as hot coals, low spark and low smoke emission. Thus, for each sample, calorific value, density, moisture content and ash content were measured as predictive variables of combustibility. The fuel attributes of the different woods represent physical properties for which were analyzed by means of the classification for Fuel Value Index (FVI) priority species in the area. Results indicate that the species with the highest FVI values are those mostly preferred by local people such as Berberis microphylla, Prosopis denudans, Schinus johnstonii, Lycium spp., Senecio subulatus and Schinus marchandii. This work recommends the cultivation of energy crops of the preferred native species with high combustibility, to be used as bioenergy and multipurpose species.     

Characteristics of some firewood trees and shrubs of the North Eastern Himalayan region, India

An evaluation of the characteristics of 25 indigenous trees and shrubs of the North Eastern Himalayan (NEH) region was carried out to identify trees with potential for firewood production. A fuelwood value index (FVI) was defined as the calorific value×density/ash content. The results showed that Gaultheria fragrantissima, Litsea citrata, Myrica esculenta, Aesculus assamica, Daphniphyllum himalense, Mesua ferrea, and Wendlandia tinctoria had the most promising firewood properties.     

Energy potential of native shrub species in northern Spain

This paper we present an energy review of the waste generated by shrub species in soils of low fertility for use as fuel in a power plant. The residues analysed belong to the species: Rhamus alaternus, Ulex europaeus, Prunus spinosa, Smilax aspera, Erica sp., Rubus ulmifolius, and Pteridium aquilinum. Gross calorific value (GCV), net calorific value (NCV), density, elementary chemical analysis, moisture content, percentage of ash, productivity, energy density and FVI (fuel value index) have been measured. These parameters have been determined for three levels of moisture (maximum, medium and minimum). At medium moisture level, the residues of U. europaeus are those that reach the greatest FVI, 20,000. In the other extreme is the P. aquilinum with an FVI of 403. The average productivity of waste, in t ha⁻¹, of each species has been determined in order to know how much energy is stored per hectare. U. europaeus and P. spinosa are the species which accumulate more energy per hectare, with similar values of around 81 MJ ha⁻¹ yr⁻¹ and installed power of 2.59 W ha⁻¹. The energy recovery of the waste in a thermal power plant would generate an annual revenue of 14.6 M€, taking into account that 40% of the forest land covered by shrub in Cantabria is used for this purpose.     

An evaluation of fuelwood properties of some Aravally mountain tree and shrub species of Western India

The study analyses the fuelwood characteristics of 26 trees including shrub species from the dry deciduous forest in Aravally region, Rajasthan, Western India was carried out to explore trees with potential for fuelwood production. Fuelwood value index (FVI) based on the properties of calorific value, wood density and ash. Calorific value was ranged between 18.54 ± 0.04 and 27.44 ± 0.09 KJ g⁻¹ in Jatropha curcus and Wrightia tinctoria respectively. Wood density varied from 0.538 ± 0.01 to 0.966 ± 0.07 g/cm³ in J. curcus and Acacia nilotica. Same way ash and moisture content was highest in J. curcus (3.38 ± 0.19%) and Sterculia urens (70.28 ± 7.52%) and lowest in Miliusa tomentosa (0.85 ± 0.06%) and Azadirachta indica (30.7 ± 10.02%) respectively. On the basis, of the 26 species analyzed, M. tomentosa has the highest FVI, followed by Lannea coromandelica, Acacia leucophloea, Madhuca indica, A. nilotica, W. tinctoria, Butea monosperma, Zizyphus nummularia, S. urens, Boswellia serrata, A. indica, Grewia tenax, Syzygium cuminii, Tectona grandis and Dalbergia sissoo were shown to have promising fuelwood production.     

Biomass productivity and wood energy of Salix species after 2 years growth in SRIC fertilized with wastewater sludge

The energy equivalent of willows in short-rotation intensive culture (SRIC) varies in terms of yield and woody biomass characteristics. Three willow species (Salix discolor Mühl., Salix petiolaris Smith and Salix viminalis L.) were planted on two sites, well-drained and poorly drained, in two different densities (20 000 and 30 000 plants per ha). Four doses of dried and granulated sludge were applied: the equivalents of 0, 100, 200 and 300 kg “available” N per ha. At the end of the second season, above-ground biomass was similar for S. discolor and S. viminalis, and greater than that of S. petiolaris on both sites and for all sludge treatments. On the well-drained site, each increment in the sludge dose significantly increased the performance of the species, regardless of plant density. Fertilized with a sludge dose equivalent to 300 kg N per ha, S. viminalis and S. discolor yielded 30.17 and 24.97 t/ha of dry matter respectively. On the poorly drained site, differences in performance were also observed between fertilized and unfertilized plots, but not among the various treatments. The calorific value of the wood of the three species being similar (19.21–19.59 kJ/g), the energy equivalent of a hectare of willows is proportional to the yield of each species. Thus the energy equivalent of S. viminalis and S. discolor is two to three times that of S. petiolaris. S. viminalis had the highest woody biomass quality, with an FVI (fuelwood value index) of 1030.58 (100%), followed by S. petiolaris with 954.25 (92.6%) and S. discolor with 849.08 (82.4%).     

Patterns and drivers of fuelwood collection and tree planting in a Middle Hill watershed of Nepal

The majority of residents in the rural Middle Hills of Nepal use fuelwood from public and private sources as their primary energy source. This study investigated fuelwood availability in accessed forests, amount of fuelwood collected, preferred tree species for fuelwood, contribution of public and private sources to total fuelwood consumption, and investment in tree planting on agricultural land. Fuelwood availability declined in the decades prior to 1990, but stabilized by 1990. Fuelwood from fifty-three species was collected from forests. Median annual per capita collection was 683 kg and predicted only by family size. Occupational castes (‘low castes’) did not show different harvesting rates than non-occupational castes and non-caste ethnic groups. Wealth was not associated with total fuelwood collection, probably because there was no fuelwood market. Most households collected fuelwood from a private source, namely trees planted on sloping, rain-fed agricultural land (bari), but this accounted for only a small portion of most households’ requirement. Bari landholding area and livestock holdings-typical measures of wealth-drove the decision to plant trees on bari land, and the number of trees that were planted. Bari-poor and landless households were consequently the most vulnerable to forest degradation, so the promotion of private fuelwood planting by large bari landholders could reduce pressure on forests and promote greater fuelwood availability for landless households. Support of community forestry emphasizing access for bari-poor and landless families could further decrease fuelwood vulnerability of poorer households.     

Fuelwood consumption pattern at different altitudes in rural areas of Garhwal Himalaya

The use of fuelwood as a primary source of energy for domestic use is causing severe deforestation in Garhwal Himalaya. In the present study fuelwood consumption patterns have been studied in six villages; two each in tropical (Ganga Bhogpur and Kunow), sub-tropical (Bhainswara and Ghargoan) and temperate (Dhaulana and Chunnikhal) regions under various ecological and socio-economic conditions. The total average fuelwood consumption in the present study was observed to be highest for Ganga Bhogpur (2.52 kg per capita per day) in the tropical region, whereas, lowest for Ghargoan (1.63 kg per capita per day) in the sub-tropical region. The labour energy expenditure for fuelwood collection was greatest for Dhaulana (146.62 MJ per capita per day) in the temperate region, and lowest for Ganga Bhogpur (88.80 MJ per capita per day) in the tropical region. The fuelwood consumption rate oscillated considerably across the different seasons. The tree and shrub species preferred by the inhabitants for fuelwood were Holoptelea integrifolia, Anogeissus latifolia and Lantana camara in the tropical region; A. latifolia, Acacia catechu and Carissa spinarum in the sub-tropical region; and Quercus leucotrichophora, Myrica esculenta and Pyracantha crenulata in the temperate region, respectively.     

Assessment of the fuel wood of India: A case study based on fuel characteristics of some indigenous species of Arunachal Pradesh

Biomass in the form of fuelwood has been a source of energy for many centuries all over the world. In rural India, fuelwood remains the first choice of energy source. Arunachal Pradesh is home to many different tree species; so far most of the fuelwoods of Arunachal Pradesh have never been studied for their fuel characteristics. This study is carried out with the following objectives: (i) Identification and selection of indigenous fuelwood species, which are widely distributed throughout Arunachal Pradesh, North East India; (ii) quantitative and qualitative analysis of these fuelwoods; and (iii) to rank these fuelwoods according to their fuel value index.     

Fuelwood characteristics of some tropical trees of India

Twenty-two species growing in their natural habitat in Indian forests were collected and fuelwood properties viz. calorific value, ash, density, silica, moisture, carbon, nitrogen and volatile matter were determined and the Fuel Value Index (FVI) calculated to screen desirable species for potential production of fuelwood on marginal lands. The present study revealed that Osmanthus fragrans, Quercus incana, Machilus odoratissma, Lagertroemia indica and Punica granatum have the best fuelwood qualities among the species examined. The other species have calorific value within the acceptable limit except for Zanthoxylum alatum and Grewia tiliaefolia.     

Energy value as a factor of agroforestry wood species selectivity in Akinyele and Ido local government areas of Oyo State, Nigeria

Wood usage for cooking and heating is still very relevant in most developing countries especially those of sub-Saharan Africa and many parts of Asia. Therefore, sustainable means of generating it for this and other purposes are necessary bearing in mind the influence of indigenous knowledge/users' perspective on any production method regarding success and sustenance. In conformity with this view, questionnaires were administered on 240 respondents in 8 rural communities of Akinyele and Ido Local Government Areas (LGAs) of Oyo State, Nigeria, to elicit information on species that can be used as fuelwood, preferred by the respondents for incorporation into and/or retention in agroforestry plots, out of which 179 (i.e. 75% of the total number of questionnaires administered) were successfully retrieved for statistical analyses. Twelve woody species namely: Annona senegalensis, Anogeissus leiocarpus, Bridelia ferruginea, Daniellia oliveri, Detarium microcarpum, Gardenia ternifolia, Hymenocardia acida, Lophira lanceolata, Parkia biglobosa, Terminalia avicennioides, Triplochiton scleroxylon and Vitellaria paradoxa were prioritized on the basis of respondents' preference using a ranking pattern. Friedman chi-square analysis showed that there was no significant difference (p < 0.05) in the ranking pattern of the respondents from the two LGAs. The mean net calorific values (NCV) of the 12 species were found to be 17.71, 18.63, 18.04, 16.03, 17.67, 18.46, 19.00, 21.68, 19.63, 18.25, 14.65, and 19.47 MJ kg⁻¹ respectively. The result of a two-way analysis of variance indicated a significant variation (p < 0.05) in NCV data for all the species pooled together but not for each species except for D. oliveri with a follow-up test using Fisher's Least Significant Difference. The Pearson's moment correlation analysis gave positive coefficient values (r = 0.868 and 0.874, p < 0.05) between NCV and the cumulative ranking values in Akinyele and Ido LGAs respectively. There was also a coefficient value of 0.873 (p < 0.05) between the cumulative ranking values in the two LGAs. In line with the outcome of this study, it was therefore recommended that native intelligence/indigenous knowledge and/or users' perspective should be part of the criteria for selecting potential fuelwood species for incorporation into and/or retention in agroforestry systems in this and other areas with similar characteristics.     

Firewood use in Bulamogi County, Uganda: species selection, harvesting and consumption patterns

This study was carried out in Bulamogi, Uganda, with the main objective of determining preferred firewood species, their harvesting and consumption patterns. Data collected through household and key-informants interviews, using open- and close-ended questionnaires and semi-structured interviews, showed that 48 plant species in 36 genera and 20 families are used as firewood. These plants have other uses as herbal medicines and in traditional cultural rites. There is almost total dependence on firewood for domestic cooking and small-scale industries. Firewood is used to fire bricks (55%), distil spirits (26%), cure fish (10%), cook food in restaurants (6%) and to produce charcoal (3%). Firewood for domestic use is collected mainly by women, and largely comprises of dead wood. The distances travelled to firewood collection areas are short and little time is spent. The harvesting of firewood for domestic use may have a lower direct impact on the native flora, than the harvesting of fuelwood for commercial use by small-scale industries and to make charcoal, which requires large amounts of wood that is often green. According to the community response, firewood is abundant but declining. This decline may be related to increasing demands generated by the growing human population of Bulamogi, and growing national need for charcoal. Cultural taboos that have hitherto played an important role in plant conservation appear to be weakening. There is limited trading of firewood in the community.     

Fuelwood characteristics of some indigenous woody species of north-east India

Wood energy is identified as the major source of energy in rural India and this has necessitated the identification of suitable tree species that can be included in energy plantation programme. As a preliminary to a more detailed future study of wood energy plantation, four indigenous perennial tree species, viz. Albizzia lucida, Syzygium fruticosum, Pterospermum lanceaefolium and Premna bengalensis growing in their natural habitat of north-east India were collected for fuelwood characterization studies. Various physico-chemical properties, viz. moisture and ash content, density, solubility in cold water, hot water and alkali, cellulose, holocellulose, lignin and extractive contents of different parts of these species were determined on ash-free dry weight and extractive-free dry weight basis to find out relationship, if any, between ash and extractive content with the calorific value. In all the species, leaf component contained the highest calorific value presumably because of the presence of extractives in higher amount, followed by heartwood. Elimination of ash from the plant parts increased calorific value while extractive-free materials declined in net caloric content in all plant parts, indicating a possible relationship of these two parameters with the heat of combustion. This study concludes that A. lucida, S. fruticosum and P. lanceaefolium have better fuelwood properties and can be considered for inclusion in the energy plantation programme of north-east India.     

Fuelwood characteristics of indigenous tree species of north-east India

Fuelwood characteristics viz. moisture content, ash, silica, carbon, nitrogen, volatile matter, density and calorific value of 35 indigenous tree species of the age group of 10–15 years growing in their natural habitat in north-eastern region of India were determined and Fuel Value Index (FVI) of each of them was calculated. From the experimental data and the FVIs, it is found that Acacia nilotica, Acacia auriculiformis, Albizzia lebbeck, Albizzia procera, Pinus kesiya and Elaeognus umbellata possess better fuelwood characteristics and they may be considered for inclusion in energy plantation programme in the region.     

Biomass fuel use by the rural households in Chittagong region,Bangladesh

An exploratory survey was carried out to assess biomass fuel use by the rural households in the Chittagong region, Bangladesh. A multistage random sampling technique was adopted to perform the study. Based on the monthly income, respondents were categorized into rich, medium and poor and a total of 45 homesteads, 15 from each category were selected randomly for the study. The study revealed that stems, branches, leaves of trees and agricultural residues were the biomass fuel used by the respondents. Market, homestead, agricultural field, secondary forests/plantation were the sources of biomass fuel identified. Male and female were identified as the major collectors of fuelwood from the nearby forests/plantations and homesteads, respectively. Six fuelwood species were identified as the most preferred in the study area. The study identified the rainy season as the woodfuel shortage period spanning between May and August.     

Comparative study of fuelwood consumption by villagers and seasonal “Dhaba owners” in the tourist affected regions of Garhwal Himalaya,India

The rural inhabitants of the Himalayan region have been exploiting forest resources for their livelihood for generations. The excessive and uncontrolled use of firewood for domestic purposes has ended up with severe deforestation. Therefore, quantification, assessment and restoration of such valuable but exhaustible resources and is imperative their scientific management. The estimates reflect that a total of 88 species are consumed as fuelwood (54 trees and 34 shrubs) by the local people. Fuelwood consumption by ‘dhaba’ (roadside refreshment establishments) owners (90–120 kg/household/day) was much higher over the common villagers (20–22 kg/household/day). The fuelwood is mainly burnt for cooking, water heating, space heating and lighting, etc. Among these, cooking consumes the fuelwood most. In addition, fuelwood demand increases due to influx of tourists. In the near future, this may also affect the status of the undisturbed forests at the middle elevation. The information in this communication could be utilized for developing various conservation and sustainable strategies in the region to mitigate the impact of forest resource for fodder and fuelwood.     

Generalized Fisher index or Siegel–Shapley decomposition?

It is generally believed that index decomposition analysis (IDA) and input–output structural decomposition analysis (SDA) [Rose, A., Casler, S., Input–output structural decomposition analysis: a critical appraisal, Economic Systems Research 1996; 8; 33–62; Dietzenbacher, E., Los, B., Structural decomposition techniques: sense and sensitivity. Economic Systems Research 1998;10; 307–323] are different approaches in energy studies; see for instance Ang et al. [Ang, B.W., Liu, F.L., Chung, H.S., A generalized Fisher index approach to energy decomposition analysis. Energy Economics 2004; 26; 757–763]. In this paper it is shown that the generalized Fisher approach, introduced in IDA by Ang et al. [Ang, B.W., Liu, F.L., Chung, H.S., A generalized Fisher index approach to energy decomposition analysis. Energy Economics 2004; 26; 757–763] for the decomposition of an aggregate change in a variable in r = 2, 3 or 4 factors is equivalent to SDA. They base their formulae on the very complicated generic formula that Shapley [Shapley, L., A value for n-person games. In: Kuhn H.W., Tucker A.W. (Eds), Contributions to the theory of games, vol. 2. Princeton University: Princeton; 1953. p. 307–317] derived for his value of n-person games, and mention that Siegel [Siegel, I.H., The generalized “ideal” index–number formula. Journal of the American Statistical Association 1945; 40; 520–523] gave their formulae using a different route. In this paper tables are given from which the formulae of the generalized Fisher approach can easily be derived for the cases of r = 2, 3 or 4 factors. It is shown that these tables can easily be extended to cover the cases of r = 5 and r = 6 factors.     

Fuelwood characteristics and its relation with extractives and chemical properties of ten fast-growth species in Costa Rica

The aim of this study was to investigate the fuel characteristics (calorific value and fuel value index) of 10 fast-growing species in plantations in Costa Rica. The effect of the chemical properties, extractives and moisture content were evaluated. The results revealed that the gross calorific value varied from 16.5 to 20.6 MJ kg⁻¹ for sapwood, and from 16.3 to 20.1 MJ kg⁻¹ for heartwood. No consistency was observed with regard to which type of wood (sapwood or heartwood) had the highest gross calorific value. Large variations among the species were observed in the case of the fuel value index. For heartwood, the slope gradient of linear correlation was affected by lignin and extractives in sodium hydroxide and dichloromethane solution, whereas in the case of sapwood, only ashes content affected significantly to calorific value. For chemical parameters or the amount of extractives, carbon, nitrogen and lignin contents, ashes and extracts in dichloromethane influenced significantly the calorific value of heartwood. The calorific value in sapwood was affected by the amount of extractives in ethanol–toluene and the amount of ashes. Finally, the fuel value index was affected by the quantity of carbon, the extractives in sodium hydroxide and dichloromethane.     

Forest resource use pattern in Kedarnath wildlife sanctuary and its fringe areas (a case study from Western Himalaya,India)

The rural population of Himalaya has been strongly dependent on the forest resources for their livelihood for generations. The present study, carried out at three different altitudes of Kedarnath Wildlife Sanctuary (KWLS), explored forest resource-use patterns to understand rural peoples' dependency on the adjacent forests. A total of six forests were selected and the seven dependent villages were surveyed for the study of forest resource use patterns in relation to their socioeconomic status. Average fuelwood and fodder consumption were found to be 2.42 kg/capita/day and 43.96 kg/household/day respectively which was higher than the earlier reported values. Average fuelwood consumption by temporary dhaba (roadside refreshment establishments) owners (52.5 kg/dhaba/day) is much higher than the permanent villagers. Average cultivated land per family was less than 1 ha (0.56 ha). Inaccessibility of the area and deprived socio-economic status of the locals are largely responsible for the total dependency of the local inhabitants on nearby forests for fuelwood, fodder and other life supporting demands. Extensive farming of fuelwood trees on less used, barren land and establishment of fodder banks could be the alternative to bridge the gap between the demand and supply. Active participation of local people is mandatory for the conservation of these forests.     

Solar radiation climate in Malawi

Recently, Diabaté et al. [Diabaté, L., Blanc, Ph., Wald, L., 2004. Solar climate in Africa. Solar Energy 76, 733–744] created a map of solar radiation climate in Africa using clearness index for 62 sites. They established a solar climate class II located in Malawi and Madagascar. However, their analysis did not include any irradiation data from a site in Malawi. In this study, the solar radiation climate of Malawi has been studied using long-term global radiation data from a local site. The mean monthly (K_tm) and seasonal (K_ts) daily clearness indices for the site were computed. It is observed that K_tm has two maxima in a year (K_tm = 0.58 in May and K_tm = 0.64 in September), in close conformity with findings of Diabaté et al. (2004). Other results are presented and discussed.     

NOx emissions and thermal efficiencies of small scale biomass-fuelled combustion plant with reference to process industries in a developing country

Solid biomass materials are an important industrial fuel in many developing countries and also show good potential for usage in Europe within a future mix of renewable energy resources. The sustainable use of wood fuels for combustion relies on operation of plant with acceptable thermal efficiency. There is a clear link between plant efficiency and environmental impacts due to air pollution and deforestation. To supplement a somewhat sparse literature on thermal efficiencies and nitrogen oxide emissions from biomass-fuelled plants in developing countries, this paper presents results for tests carried out on 14 combustion units obtained during field trials in Sri Lanka. The plants tested comprised steam boilers and process air heaters. Biomass fuels included: rubber-wood, fuelwood from natural forests; coconut shells; rice husks; and sugar cane bagasse. Average NO_x (NO and NO₂) emissions for the plants were found to be 47 gNO₂ GJ⁻¹ with 18% conversion of fuel nitrogen. The former value is the range of NO_x emission values quoted for combustion of coal in grate-fired systems; some oil-fired systems and systems operating on natural gas, but is less than the emission levels for the combustion of pulverized fuel and heavy fuel oil. This value is significantly within current European standards for NO_x emission from large combustion plants. Average thermal efficiency of the plants was found to be 50%. Observations made on operational practices demonstrated that there is considerable scope for the improvement of this thermal efficiency value by plant supervisor training, drying of fuelwood and the use of simple instruments for monitoring plant performance.