Patrícia Muniz de Medeiros

The ecological apparency hypothesis and the importance of useful plants in rural communities from northeastern Brazil: an assessment based on use value.

The ecological apparency hypothesis in ethnobotanical studies predicts that the apparent plants (i.e., the most easily found in the vegetation) would be the most commonly collected and used by people. To test this hypothesis, it has been used the concept of use value (VU), which measures the relative importance of useful plants for a group of people. However, the use value has got some limitations, including the fact that it does not distinguish current use (plants which are effectively used) from potential use (well known plants, however not used). Therefore, this study has tested whether the obtained results through three different use value calculations could be useful in testing the ecological apparency hypothesis. These calculations have included the current use value, the potential use value, and the general use value. It has been carried out a vegetation survey and an interview for residents from the rural communities from Barrocas and Cachoeira (Soledade, Paraíba, Brazil). It has been used Spearmans coefficient to correlate phytosociological and ethnobotanical data. It has been observed that phytosociological parameters in Cachoeira were not correlated with any of the use values calculations, except the relationship between the current use value and the relative dominance (r(s)xa0=xa00.57; pxa0<xa00.05). In Barrocas, every use value calculation was correlated with the basal area and the relative dominance. When each category of use is analyzed separately, it has been observed that there was no correlation between the use value and the phytosociological parameters, except for the construction category, in which the current use value in Cachoeira was correlated with the relative dominance (r(s)xa0=xa00.63; pxa0<xa00.05), importance value (r(s)xa0=xa00.67; pxa0<xa00.01), relative frequency (r(s)xa0=xa00.71; pxa0<xa00.05), and relative density (r(s)xa0=xa00.72; pxa0<xa00.01). In Barrocas, the UVc for the construction category was correlated with relative frequency (r(s)xa0=xa00.69; pxa0<xa00.05) and relative density (r(s)xa0=xa00.66; pxa0<xa00.01). These results have suggested that, the use value calculation, which takes into consideration just the current use of the species, is the one that best fits in the ecological apparency hypothesis.

The Use of Medicinal Plants by Migrant People: Adaptation, Maintenance, and Replacement

Given the importance of studying the knowledge, beliefs, and practices of migrant communities to understand the dynamics of plant resource use, we reviewed the scientific literature concerning the use of medicinal plants by migrant populations engaged in international or long-distance migrations. We considered the importance of two processes: (1) adaptation to the new flora of the host country (i.e., substitution and incorporation of plants in the pharmacopoeia) and (2) continued use and acquisition of the original flora from migrants home countries (i.e., importation, cultivation, and/or continued use of plants that grow in both host and home environments). We suggest that, depending on the specific context and conditions of migration, different processes that determine the use and/or selection of plants as herbal medicines may become predominant.

Patterns of medicinal plant use by inhabitants of Brazilian urban and rural areas: a macroscale investigation based on available literature.

ETHNOPHARMACOLOGICAL RELEVANCEnAlthough the relationship between local people and plants may be idiosyncratic, some human behaviors are common to different communities and can be influenced by cultural and environmental factors. Thus, this study drew upon a systematic review and meta-analysis to evaluate if there are patterns of medicinal plant use in different Brazilian ethnobotanical studies and if these patterns are influenced by the urbanization or ecosystems where the studies were conducted.nnnMATERIALS AND METHODSnThe factors evaluated concerned the origin of the species used (native vs. exotic), plant habit (woody vs. non-woody) and plant parts (permanent and non-permanent). Two kinds of analysis were performed: the integrative and the meta-analytical.nnnRESULTSnThe factors varied depending on the ecosystems in which the studies were conducted. In the Amazon, Cerrado and Caatinga, native and woody medicinal species dominated; conversely, this pattern was not the case for the Atlantic Forest and Pampas ecosystems. Permanent plant parts were predominant in the Cerrado, and considering only native plants, permanent parts dominated in the Amazon, Cerrado and Caatinga. Urbanization did not significantly affect these patterns. Additionally, the species relative importance (RI) did not change as a function of the ecosystem or the degree of urbanization.nnnCONCLUSIONSnThe phenomena observed in this study can be explained in light of the chemical ecology and historical and cultural aspects of the species, and the findings have important implications for bioprospecting and conservation.

Pressure Indicators of Wood Resource Use in an Atlantic Forest Area, Northeastern Brazil

Wood resources are often used to support the needs of the local population. In order to protect biodiversity and resources, conservation strategies need to consider what types of wood use have the strongest impacts on forested areas. This study aimed to identify the use categories that put higher pressure on an Atlantic forest region located in the municipality of Igarassu in Pernambuco, northeastern Brazil. To conduct the study, we measured the volume of all wood products in 62 surveyed residences and registered the average replacement time for such products. The fuelwood category was most important locally and accounted for 92% of annual wood consumption. However, the construction category harvests more destructively and concentrates on the consumption of a few wood species. Therefore we recommend the fuelwood category to be the main focus of conservation effforts. In addition, the most important species for construction purposes (e.g., Eschweilera ovata (Cambess.) Miers, Apuleia leiocarpa (Vogel) J.F. Macbr. and Pogonophora schomburgkiana Miers ex Benth) should also be considered as a priority for conservation.

The most commonly available woody plant species are the most useful for human populations: a meta‐analysis

An increasing number of studies have aimed to clarify the factors leading human groups to prioritize the use of some woody plant species compared to others. Some of these studies have tested the apparency hypothesis in aiming to understand this phenomenon. According to the apparency hypothesis, the most commonly available local plant species on a forest path are the most useful to that local human population. However, the sparse and diverse nature of the results from studies investigating the factors that influence human exploitation of plant resources motivated us to perform a meta-analysis on the apparency hypothesis. We searched in the main databases (Scopus, ScienceDirect, Google Scholar, and Scielo) for studies that correlated the environmental availability of woody species (estimated through vegetation parameters) with the degree of importance of such species to the local human population (estimated by means of the use value index). Overall, this meta-analysis supported the apparency hypothesis, although we also found high levels of heterogeneity in these studies. When the distinct uses of woody flora were considered separately, we found that local species availability is important for fuelwood (firewood and charcoal) and construction (houses, fences, etc.) purposes but does not explain medicinal and technological (object manufacture) plant use. We found no important differences in correlationxa0values between the degree of species importance for people and the different vegetation parameters, although correlations are slightly higher for the dominance and importance value index. Our findings suggest that the exploitation of woody flora is influenced by local availability.

Does the selection of medicinal plants by Brazilian local populations suffer taxonomic influence

ETHNOPHARMACOLOGICAL RELEVANCEnThe analysis of the influence of taxonomic affiliation on the selection of medicinal plants by Brazilian local populations can help elucidate theoretical aspects of medicinal plant selection.nnnMATERIALS AND METHODSnEthnobotanical medicinal plant studies were compiled and the resulting medicinal flora was compared to the total angiosperm flora with a Bayesian approach and the IDM model.nnnRESULTSnA total of 35 families were considered to be overused and six were classified as underused for the Bayesian approach. On the other hand, the IDM model considered 13 families as overused and five as underused (all of them were also highlighted by the Bayesian approach). A high overuse level of Bixaceae, Amaranthaceae, Anacardiaceae and Smilacaceae was recorded for both Bayesian and IDM model, while Orchidaceae, Melastomataceae, Eriocaulaceae, Poaceae and Bromeliaceae were considered as underused for both analyses. The most dissimilar body system in terms of family composition was mental and behavioral disorders. It was also found that the body systems are different from one another in the proportion of taxonomic groups, which could indicate chemical specificity in the treatment of diseases.nnnCONCLUSIONSnResults indicate that the chemical specificity of taxonomic groups directly influences medicinal plant selection. Moreover, when data presented here are compared to other studies, there is clearly an overuse pattern for families like Lamiaceae, Rosaceae and Euphorbiaceae and an underuse pattern for Poaceae and Orchidaceae.

Can organoleptic properties explain the differential use of medicinal plants? Evidence from Northeastern Brazil

ETHNOPHARMACOLOGICAL RELEVANCEnThis study examined how people classify plants in terms of their taste and smell, and how those organoleptic properties influence the differential use of medicinal plants for treating different diseases.nnnMETHODSnWe conducted an ethnobotanical survey of household heads in the community of Sucruiu, located in Barreiras, Bahia, Brazil. The head of each family was questioned concerning their knowledge and use of medicinal plants, as well as the therapeutic indications (TIs), taste, and smell of each plant. We then tested for associations between the therapeutic indications and taste attributes of various plants using the Chi-squared test on a contingency table with Monte Carlo simulations. The same analysis was performed for associations between TIs and smell.nnnRESULTSnThe study participants provided more details when classifying tastes than when classifying smells. We considered only the most cited TIs and attributes, and found significant associations between both taste and therapeutic indications (p<0.001) and smell and therapeutic indications (p<0.0001).nnnCONCLUSIONSnOur results showed that the taste and smell of a plant can influence its differential medicinal use, since plants with certain tastes and smells prevailed in the treatment of distinct diseases. However, our results are valid only for the most popular TIs and organoleptic attributes.

Socio-economic predictors of domestic wood use in an Atlantic forest area (north-east Brazil): a tool for directing conservation efforts

Given the excessive use pressure on forests, characterisation of the major users of forest resources can help guide conservation efforts. This study examines whether socio-economic variables explain domestic wood use in an area of Atlantic forest in the community of Tres Ladeiras (Pernambuco, north-east Brazil). Socio-economic data were collected from 62 households, and geometric measurements of wood products in each household were taken to calculate the wood volume. An informant in each household indicated the average replacement time for each type of wood use. Data were analysed for static volume (wood volume found at the time of the visit) and dynamic volume (rate of wood consumption, calculated as the ratio between volume and replacement time). Multiple regression analyses were performed to determine the relationships between wood volume (static and dynamic) and the number of species used; independent variables including monthly family income, number of residents, average age of heads of the household...Given the excessive use pressure on forests, characterisation of the major users of forest resources can help guide conservation efforts. This study examines whether socio-economic variables explain domestic wood use in an area of Atlantic forest in the community of Três Ladeiras (Pernambuco, north-east Brazil). Socio-economic data were collected from 62 households, and geometric measurements of wood products in each household were taken to calculate the wood volume. An informant in each household indicated the average replacement time for each type of wood use. Data were analysed for static volume (wood volume found at the time of the visit) and dynamic volume (rate of wood consumption, calculated as the ratio between volume and replacement time). Multiple regression analyses were performed to determine the relationships between wood volume (static and dynamic) and the number of species used; independent variables including monthly family income, number of residents, average age of heads of the household, age of oldest household member, average residence time of heads of the household, average education level of heads of the household and education level of the most educated household member. Monthly income was inversely related to the static wood volume (adjusted R 2 = 17.6%, p < 0.001), rate of wood consumption (adjusted R 2 = 23.0%, p < 0.001) and number of species used (adjusted R 2 = 22.3%, p < 0.001) and was the most important predictive variable for these three outcomes. Other factors such as average education level and average age of heads of the household were also explanatory variables of the total rate of wood consumption, as these two variables, together with monthly family income, explain 31.3% of the total dynamic volume. Given the high importance of income in our study, we suggest that future conservation strategies give special attention to the poorest members of the community.

“I eat the manofê so it is not forgotten”: local perceptions and consumption of native wild edible plants from seasonal dry forests in Brazil

BackgroundThere is little information available on the factors influencing people’s selection of wild plants for consumption. Studies suggest a suitable method of understanding the selection of edible plants is to assess people’s perceptions of these resources. The use and knowledge of wild resources is disappearing, as is the opportunity to use them. This study analyzes people’s perceptions of native wild edible plants in a rural Caatinga (seasonal dry forest) community in Northeast Brazil and the relationships between the use of these resources and socioeconomic factors.MethodsSemi-structured interviews with 39 people were conducted to form a convenience sample to gather information regarding people’s perceptions of 12 native wild edible plant species. The relationships between variables were assessed by simple linear regression analysis, Pearson and Spearman correlation analyses, and in the case of nominal variables, contingency tables. The discourse of participants regarding their opinions of the use of wild plants as food was analyzed through the collective subject discourse analysis technique.ResultsPerceptions were classified into 18 categories. The most cited category was organoleptic characteristics of the edible part; more specifically, flavor. Flavor was the main positive perception associated with plant use, whereas the negative perception that most limited the use of these plants was cultural acceptance. Perceptions of the use of wild edible plants were directly correlated with both interviewee age and income.ConclusionWithin the studied community, people’s perceptions of native wild edible plants are related to their consumption. Moreover, the study found that young people have less interest in these resources. These findings suggest that changing perceptions may affect the conservation of plants, traditional practices and the associated knowledge.

Effect of Gender on the Knowledge of Medicinal Plants: Systematic Review and Meta-Analysis

Knowledge of medicinal plants is not only one of the main components in the structure of knowledge in local medical systems but also one of the most studied resources. This study uses a systematic review and meta-analysis of a compilation of ethnobiological studies with a medicinal plant component and the variable of gender to evaluate whether there is a gender-based pattern in medicinal plant knowledge on different scales (national, continental, and global). In this study, three types of meta-analysis are conducted on different scales. We detect no significant differences on the global level; women and men have the same rich knowledge. On the national and continental levels, significant differences are observed in both directions (significant for men and for women), and a lack of significant differences in the knowledge of the genders is also observed. This finding demonstrates that there is no gender-based pattern for knowledge on different scales.