Introduction

Faced with the problem of the use of wood in a traditional way, most governments, among other lines of action, opt for the implementation of saving stoves this fuel, in order to reduce the negative impact on the environment and improve the living conditions of the rural population. Various models have been applied to this end, some quite acceptable results, others have failed. Various types of wood-saving stoves arise from knowledge dialogue between external agencies and local actors, which has allowed the appropriation of these projects. In rural areas the cooked food is a primary need. Therefore, the traditional stove has been around for centuries in Santa Ana Tamazola and Santa Maria La Conception, as the most economical option. With the population increase the availability and quality of wood energy resource has decreased, so it is necessary to optimize consumption through a device that concentrates the energy and at the same time maintain features of the customs of these two communities.

The lorena stove was introduced in the context of sustainability as it contributes to the conservation of vegetation and social welfare of rural families. In this sense, the wood is part of the daily life of these communities, it is necessary for cooking food is available locally and is renewable if properly handled. A device that optimizes wood energy and consider the customs of rural families help conserve tropical deciduous forest, for the benefit of future generations. Less green trees and tear down, the resource will recover and be located closer to the people.

The main objective is to understand the changes within peasant families who adopted the lorena stove and compare them with those that are still using the traditional stove. In particular it comes to determining the adoption and maintenance of Lorena stove; estimate the volumes of wood consumed with it; identify species wood energy used by rural families and conservation of vegetation by the introduction of the device. The hypothesis that guided the research, believes that the lorena stove is a new device used properly improves the use of wood resources and preserves the health of rural families, which contributes to the conservation of vegetation by lower requirements extraction firewood.

In a study in the Mixteca Poblana, ^{Sánchez (1988)} found that rural families mostly employs high for cooking their food cooker. Also, in this region it estimated that about 8 m3 of wood/family/year are consumed. In addition, the fuel comes primarily from rajas of pieces of trees about 1 m in length by 4 to 7 cm thick covering an average of 0.0035 m³. ^{Guízar and Sanchez (1991)} observed that in the Mixteca Poblana fuelwood by households covering the whole year and intensified in the dry season, when the population has less work. In addition, throughout the year it is common to see the passage of people herding animals loaded with firewood leading to sell to the population centers with higher demand.

To meet energy needs in the kitchen, the average monthly consumption of rural families is 500 kg of firewood, which implies an annual extraction nearly six tons. Data from the Agency for Rural Development (ADR) of Mixteca Poblana indicate that on average each family of the region uses 10 logs a day, which adds an annual consumption of 8 m³, equivalent to 32 trees (^{FAO-SAGARPA, 2007}). Meanwhile, the ADR Sierra Mixe, Oaxaca, reported a volume of wood consumption from 20 to 25 m³ per family per year; while the ADR Mextlali, Sierra Negra in Puebla, reports that a family can consume up to 4 m³ of wood per month. These indicators explain why the wood is an increasingly scarce resource, and the fact that the inhabitants of these regions have to invest more time and resources to transport it from increasingly distant locations (^{FAO-SAGARPA, 2007}).

In Mexico, 240 municipalities consume large quantities of firewood, where use can become a problem. These represent 10% of the total; however, they account for 21% of the total population using firewood. They are considered "high priority" by the number of users and its growth rate, as well as the negative environmental impact and elasticity of consumption. In general, these municipalities are concentrated in the mountainous region of central and southeastern Mexico, in places where very similar cultural, environmental and social conditions exist. In general the pattern of use of firewood there is very intense, both in the domestic sector and the thousands of micro dedicated to pottery and brick making, bread and tortillas (^{Diaz and Masera, 2003}).

In Mexico, about 28 million people use firewood to cook their food and heat water. This suggests, if promoted intensively wood stoves, a huge potential for improving the quality of life of families and a significant reduction of greenhouse gases (GEI). The current market for this resource generates more than 12 500 million pesos a year economic benefit and create 104 million jobs annually, representing 417 thousand jobs (^{Masera et al., 2011}). In the early eighties various government institutions began construction of rural saving wood stoves on a large scale and obtained few results, which caused the abandonment of the program (^{Vargas, 1990}).

Programs saving stoves have been developed at local and regional levels and have been part of initiatives aimed at restoring forests, biodiversity conservation tasks or peasant organizations. They focus on building or self stoves, with little or no monitoring, which are partially or fully subsidized. Some institutions that promote them have attended priorities and needs of the users, which has improved the level of acceptance (^{Masera et al., 2011}). Since 2003 the diffusion of wood stoves intensified by some organizations, particularly the Interdisciplinary Group of Appropriate Rural Technology AC (GIRA), Center for Research in Ecosystems (CIECO), Institute of Engineering, National Institute of Ecology (INE), those of the National Autonomous University of Mexico (UNAM) and managed to involve government agencies and institutions such as the Federal Commission for the Protection against Sanitary Risk (COFEPRIS), National Forestry Commission (CONAFOR), Secretariat of Social Development (SEDESOL), the National Institute of Public Health (INSP) (^{Masera et al., 2011}).

Studies show that efficient technologies such as wood- saving stoves can decrease the degradation of forest resources, mitigate emissions of greenhouse gases and provide other benefits such as reducing toxic pollutants, consumption of biofuels and time and distance to collect them (^{PNUMA, 2006}). The Agency for Rural Development (ADR) "entrenchment of the Mixteca" in Atempa, Puebla, reports savings of 70% in the consumption of wood using the Lorena stove, representing a decrease in logging 32 to 10 trees per year for family. Moreover, ADR, Mextlali Black Sierra de Puebla and indicates that with the use of wood-saving stoves households reduce their consumption of 4 m³ to 2 m³ per month (^{FAO-SAGARPA, 2007}). In the area of influence of the Nuj ADR Mixe Sierra in Oaxaca higher performance with thrifty use of wood stove it was obtained, 60% decreased consumption. In Tlahuitoltepec, a family of six people previously used two to three loads of wood per day and currently employs only a 1.5, about 40 kg (^{FAO- SAGARPA, 2007}).

Materials and methods

The work was done within the scope of the social sciences and integrates qualitative and quantitative methods. It establishes unit of analysis to peasant families, directly involved in the harvesting and extraction of wood energy resource. The research was divided into two components: the phase of cabinet and the field phase. The first began in late 2012 with the revision of the background on the subject and preparing methodological tools. The field consisted of the application of semi-structured surveys which concluded in March the following year. In field first it was the recognition of the study area at different times of the year, allowing greater understanding and analysis of it. The type of vegetation present level determined territory, peasant families as units of study were considered by the pilot and methodological tools necessary adjusted. In addition coordination with the different stakeholders converge in place for gathering information was sought.

The semistructured survey consists of a series of closed and open questions was used as a methodological tool. The stratified random sampling with proportional allocation was used to determine the number of farm families interviewed, in addition to measurements to estimate the volume of loads of firewood used by farm families in these two communities. Expressions of key informant’s territory level exist and have item also resumed. It is important to consider the contribution of ^{Arana (2003)} on stratified random sampling by referring to is one that divides the population of N individuals in E subpopulations or strata with respect to criteria that may be important in the study. The strata containing N1, ..., NE sampling units.

A municipality level there is a total population of 1 536 peasant families in which a partial population of 200 was made to perform the calculation and get the number of samples to be performed in each subpopulation of the strata was necessary to consider subpopulations for the two communities being of as follows: for the subpopulation of stratum January 55 peasant families who use the Lorena stove they were considered; for the subpopulation of layer 2, 45 to which were given the stove but for some reason do not use it; finally, for 3 100 families who use the traditional stove.

Therefore, the following formula was used:

Where: n= represents the total population sample; N= total population; p= proportion of the population is in favor of using or not using the stove; q= 1-p, where p= 0.5 because the same probability that the Lorena stove is accepted or not given.

Moreover, it is necessary to calculate the value of "D" as the error is to be considered in the investigation, therefore it is calculated with the following formula:

The result of the above formula is 0.0025, the same that will be used when the formula is applied to obtain the sample in each stratum. To apply stratified random sampling with proportional allocation was required 19 semistructured surveys stratum 1, 15 to stratum 2 and 33 to 3. The survey was targeted at users who are an essential part of rural families and also responsible for cooking food. In total 67 semistructured surveys they were conducted in the two communities under study. To understand the processes of conversion parameters technical firewood volume is used, thus the wood contained in a load can be estimated using the methodology proposed by Romahn and Ramírez (2010) referring to methods for cubing. Their volume is expressed in our country generally in rope or in cubic meters. Stacking coefficients are factors that multiply the apparent volume of a stack of firewood for the actual volume and are obtained by the actual volume ratio between the apparent volumes of a stack of known dimensions.

The formula for cubicar fire wood slice and brazuelo proposed by ^{Rivas (2006)} was used, for which the dimensions of width, length and height of the stack are measured to estimate the volume of wood consumed by farm families with Lorena stove, firewood, either slice or brazuelo. The Brazuelo to understand as short dimensions resulting log chopping tree branches and points that are not thick enough for slit.

The formula used was (^{Rivas, 2006}):

Where: V= volume of firings in m3;l= length of the woodpile in m; a= width of the stack of firewood in m. h= height of the stack in m; Ca= coefficient of stacking (0.7 if slice firewood or 0.5 if brazuelo). In this case 0.5 is used.

The selection for measuring the technical parameters for calculating charges volume was random, and the wood that was in the courtyard, after bringing the employment field. Firewood 10 peasant families used, the wood had been collected by themselves and sometimes buying from vendors nearby communities. Five repetitions with loads were taken into account characteristics of wood in slice stacking where a coefficient of 0.5 and five repetitions with loads brazuelo characteristics considered. In each load they were measured with flexometer length, width and length. Direct observation, the relationship with users and generally peasant families, lumberjacks and actors who know the subject is essential to enrich the present investigation. This activity improves the interpretation and understanding of the subject on the dynamics of rural families, flows of firewood and the current situation that keeps the tropical deciduous forest.

With the information from the questionnaires it developed a database where all information obtained firsthand concentrated. This base was integrated into fields such as name of the respondent, age, level of education, location, number of members in the family and number of loads that consume a week; in later form other estimates were made of the volume used for cooking food and generated economic output. With the information gathered were drawn graphs in Excel for analysis and representation.

The study area. The study area is located in the community of Santa Ana Tamazola and Santa Maria La Conception, belonging to the municipality of Jolalpan, Puebla. It is located southwest of the state, within the Balsas macro- region, the natural region Mezcalapa and planning Mixteca region (^{Cuervo et al., 2003}). Its geographical coordinates are 18° 30 ' latitude north and 99° 05' longitude west (Figure 1).

Figure. 1 Geographical location of the study area. 

In the study area is the presence of massive mountains with steep slopes that extend hilly slope with medium and low, worn by erosion and slightly wavy (^{Diakite, 1978}). According to the classification of Köppen, modified by ^{García (1973)}, subtype predominates climate Aw (w) (I') g which gives rise to the tropical deciduous forest vegetation. It is the driest of tropical climates in wood energy and abundant species, non-timber resources.

Results and discussion

Current use of lorena stove

The current use of cooking devices in the communities studied first is the traditional bonfire, followed by the Lorena stove and finally have a gas stove. Peasant families who adopted the Lorena stove consider that actually saves firewood, which brings benefits to health and the environment favorable impact (Figure 2).

Figure 2 Using the lorena stove. 

Families use a device exclusively, but also some of them use two in combination. Despite considering gas stove device technological advancement and social prestige, it has not displaced the traditional fireplace or lorena stove.

In Figure 3 the result of the analysis of the interviews, each of the studied shows, shows that 53% of farm households only use the Lorena stove tasks cooked in schedules ranging from 8: 00 at 9:00 am to prepare breakfast and 2:00 to 3:00 pm for lunch.

Figure. 3 Percentage of use of the devices in the kitchens. 

Moreover, only 63% use traditional stove, which corresponds to families with fewer resources. The gas stove does not deal exclusively, it serves rather for emergencies (heat food or make coffee at night, make tea when someone is sick, etc.). It is noted that the mixed use of devices is important to save energy. Thus, the combination of the traditional stove and stove Lorena recorded 37%, while the traditional stove and gas stove reached 47%.

The adoption of the lorena stove is shown in Figure 4, of the 100 established Lorena stoves are still used only 55%, and some of them are still used with some modifications to the original design.

Figure. 4 Degree of adoption of the lorena stove. 

Which were not used there are different reasons for the lack of adoption, ranging from outright rejection to special circumstances as the fact some families built under a roof thinking that in the future there would your kitchen, which for various reasons it never happened and for that reason was in abandoning the device, so even comment that is stoves that work well if properly handled and save significant amounts of firewood, but there are also opinions against.

The scarcity of resources and better taste perception obtained with wood processed foods, especially tortillas, favoring the adoption of the lorena stove. To this we must add the ability for users and the various activities carried out with the appliance to shore up the family economy. The high costs of other energy sources such as liquid petroleum gas (LP) require the use of firewood, for their availability and direct access to, and certainly by the characteristic of being renewable if exploited and handled appropriately.

In the Figure 5 is an example of the various uses of Lorena stove cooking chores.

Figure 5 Women user roasting tomatoes for making sauces. 

Making tortillas is the activity that consumes more fuel, followed by the preparation of soups, moles, roasts and traditional tamales (corn leaf and fish) for consumption and sale. At the end of cooking the product users collect coal combustion of wood and use it later in a brazier for cooking foods like boiled corn and beans mainly.

Firewood is considered an indispensable natural resource because it satisfies its energy needs and although new technologies arrive, it will remain the main input. Collecting firewood is the social living space where family members and families interact with each other, rebuilds and strengthens the social fabric and also serves to plan different activities for community development.

A gas stove LP used only for emergencies, communities, owning this device requires financial resources and is part of the social prestige of the owners. To optimize energy complementing the traditional stove with LP gas stove and currently lorena stove with LP gas.

Species wood energy used by rural families. Increasing population puts increasing pressure on land, firewood and other resources of tropical deciduous forest. It has increased the need to clear land for agricultural production. The high cost of LP increases the demand for firewood. Peasant families recognize that wood is becoming scarcer day even to get some good quality should be moved to more remote locations. Despite changes in other aspects, preferences for the wood energy resource is preserved.

In Figure 6 the frequency of use of wood energy species used for cooking food for farm families is presented.

Figure 6 Frequency of preference of the species used as fuel wood energy for rural families. 

The preferred species is white cubata (Acacia pennatula) with 97%, followed brazilwood (Haematoxylum brasiletto) with 60%, the tlahuitole (Lysiloma divaricata) with 45%, the matarrata (Gliricidia sepium) with 40%, the leg goat (Lysiloma tergemina Benth) with 20% and others are used less frequently. The white cubata has economic importance and greater availability locally, extends from the lands of common use to agricultural plots and pastures. It is a pioneer in the recovery of degraded areas and open by human activity. It is located in the nearest places in the village and can be classified as second quality wood.

The load of wood white cubata in the local market reaches a value of 90 pesos. Lumberjacks prefer the ease to cut it and crack it, which means less effort for collection. This coincides with that mentioned by ^{Yescas (2012)} in a study conducted in the state of Morelos, within the Sierra de Huautla, about the exploitation of this species that keeps endangered species on land that entity bordering Jolalpan. The Brazilwood, meanwhile, is in open areas of shallow, rocky soil and deep soil glens. It is the species that ranks second in terms of use by rural families. Its wood is hard and is considered top quality wood, burn well, produces little smoke and makes excellent grilled which is attractive for domestic consumption. Locally it has up to 10% premium for load.

The matarrata abounds in these places due to the disruption suffered by the tropical deciduous forest, hence prefer it for their abundance and fast ignition. It is in disturbed and open the tropical deciduous forest land. Burn well, but does good coal. Besides being a wood energy species can feed livestock for its high bromatological value. The root is used to fight rodents. In the local market the burden of firewood matarrata has an average price of 85 pesos.

Another species used is the tlahuitol, much appreciated by peasant families in the communities studied. It is distributed mainly in the open hillsides, where man has done some activity or is in constant interaction. It is also located on the edge of the cliffs. Its wood is valued as good quality wood, burn well and produces good coal. Timber loading tlahuitol reaches a value of one hundred pesos, similar to brazilwood.

The attributes most important to some of the wood energy species used for cooking food is presented in Figure 7 shows that the form as burning is a major consideration, 32% of rural families prefer species with this feature, wealth is valued by 30% of them, 24% consider it important that embers, which then becomes coal and 14% is considered to produce little smoke obtained.

Figure 7 Attributes established for the species wood energy users. 

A mong the findings it high lighted the traditional measure that farmers in these two communities called "load of firewood", composed of 40 logs of about one meter in length, different diameter and weighing about 80 kg.According to the formula ^{Rivas (2006)}, a load has a volume of 0.17 m3. Based on the above, it is established that a cubic meter of firewood, equivalent to 5.9 loads corresponding approximately; four trees. In the Figure 8 shows the measurements made to loads of firewood in the communities are observed.

Figure 8 Measuring loads of firewood. 

The firewood saving is important for the development of peasant families in the community of Santa Ana Tamazola and Santa Maria La Conception. According to the data of Table 1, saving wood Lorena stove with ranges between 11.06 and 11.39 loads of wood a year.

Table 1 Savings loads of f irewood per year with lorena stove. 

This saving represents between 25.56 and 26.12% compared with the traditional stove. Some researchers reported 50% savings with this type of stove. The information should reflect important differences in relation to the technical data, however, have to consider the culture of use, resistance to other technologies implemented in the territory, lack of technical assistance and the lack of a previous diagnosis. Despite which, some families consider the Lorena stove is a viable option as it used properly requires less firewood.

The perception of the Lorena stove is that it is a device that saves fire wood because only three thin logs are needed to keep it on, not smoked pots, not much smoke is breathed product of combustion, the less time is required for resource harvesting and less money for purchase. The appropriation of the device is related to socioeconomic status and the ability of each user. On the issue of conservation of vegetation, since 2009 and to date has ceased to cut 40 trees per farm family that owns a Lorena stove. The farmers claim that on average there are 80 trees per hectare white cubata. This data is similar to that obtained by the Study of Forest Management Program of Santa Ana Tamazola-timber which was approved by the Secretariat of Environment and Natural Resources, Delegation Puebla (^{Matías, 2013}). This means that it has stopped cutting about 0.5 hectare of white cubata by peasant family, resulting in lower area of deforestation of tropical deciduous forest.

Conclusions

The lorena stove is a new device that was implanted in the communities of Santa Ana and Santa Maria Tamazola Conception as an alternative for cooking food and currently is being used, with grade over 50% acceptance. The input using this device is the wood from the tropical deciduous forest and is considered by peasant families as a necessary and indispensable resource. With the use of lorena stove benefits for communities that adopt achieved, since fuel consumption are reduced by about 25% of the volumes, which results in decreased work or fuel costs, plus benefits decreased smoke in the habitat of the family and reduced impact on the vegetation.

Users of wood has its own criteria to set your preferences on fuel species and accordingly are affected species with the preferred attributes, therefore, some tree species with high wood energy potential have been declining in surrounding communities, and are located in more remote locations. Given this, the lorena stoves help reduce pressure on species and vegetation preferred because their use means up to 25% reduction in consumption per year per family trees using this fuel saving device.