Edgar Pérez-Negrón

Evolution of Polaskia chichipe (Cactaceae) under domestication in the Tehuacán Valley, central Mexico: reproductive biology

Polaskia chichipe, a columnar cactus, is cultivated for its edible fruits in central Mexico. This study analyzed whether artificial selection has modified its reproduction patterns and caused barriers to pollen exchange between wild, managed in situ, and cultivated populations. Anthesis was diurnal (∼16 h in winter, ∼10 h in spring) as well as partly nocturnal (∼12 h in winter, ∼3 h in spring), and flowers were pollinated by bees, hummingbirds, and hawk moths. Manual cross-pollination was ∼37-49% effective in all populations. Self-pollination was ∼12% successful in the wild, but twice as successful (∼22-27%) in managed and cultivated populations. Diurnal pollination was ∼35-55% effective in winter and 100% in spring. Nocturnal pollination was successful only in winter (15%). Crosses among individuals were more effective within populations than among populations, including populations under a similar management regimen. The least successful crosses were between wild and cultivated populations. Flowers were produced in all populations from January to March, but flowering peaks differed by 1 mo among wild, managed, and cultivated populations and by 2 mo between wild and cultivated populations. The latter interrupted pollen exchange in May. Seeds from managed and cultivated populations germinated faster than those from wild individuals. Domestication has seemingly favored self-compatible P. chichipe plants with higher fruit yield, a longer period of fruit production, and faster seed germination, attributes that have resulted in partial reproductive barriers between wild and manipulated populations.

Plant Management in the Tehuacán-Cuicatlán Valley, Mexico1

Plant Management in the Tehuacán-Cuicatlán Valley, Mexico. Plant management types currently practiced in the Tehuacán-Cuicatlán Valley, México, were documented and analyzed based on ethnobotanical studies conducted in 13 villages with six indigenous groups and Mestizo people. The information was organized in a data base, and then detailed and guided to a consensus through six workshops carried out by ethnobotanists working in the area. From a total of 1,608 useful plant species, we identified 610 with at least one management type other than simple gathering. Managed species are mainly used as food, fodder, medicinal, and ornamental, and they belong to 101 plant families. The higher species numbers were recorded in Cactaceae, Asteraceae, Fabaceae, Crassulaceae, and Agavaceae. Nearly 60% of the managed species are native to the region and the rest are introduced from other regions of Mexico and the world. In total, 400 species are ex situ managed out of their natural environments through seed sowing and/or planting their vegetative propagules or entire young plants; 373 species are in situ managed in their natural habitats as follows: all these species are deliberately left standing during vegetation clearance, 76 species are also enhanced intentionally favoring their abundance through modifications of their habitat, or directly by planting their propagules, and 51 receive protection through regulations, particular strategies of extraction, and actions against herbivores, competitors, freezing, radiation, and drought. Most management forms involve artificial selection at different intensity levels. The information allows visualizing co-occurrence of incipient and advanced forms of management at different intensity levels within and among species, which helps to postulate testable hypotheses on factors influencing plant management and domestication in an important area for studying the origins of agriculture.Manejo de plantas en el Valle de Tehuacán-Cuicatlán, México. Se documentaron los diferentes tipos de manejo de plantas que practican actualmente los pobladores del Valle de Tehuacán-Cuicatlán, México. El análisis se basa en estudios etnobotánicos llevados a cabo en 13 comunidades campesinas con seis grupos indígenas y poblados mestizos. La información se organizó en una base de datos, la cual posteriormente se detalló y se consensó a través de seis talleres en los que participaron los etnobotánicos trabajando en la región y cuyos trabajos son la base de esta investigación. De un total de 1,608 especies de plantas útiles, identificamos 610 con al menos un tipo de manejo distinto a la recolección simple. Las especies manejadas pertenecen a 101 familias botánicas y se utilizan principalmente como alimento, forraje, medicina y ornamentales. Los mayores números de especies manejadas se registraron entre las Cactaceae, Asteraceae, Fabaceae, Crassulaceae y Agavaceae. Aproximadamente 60% de las especies manejadas son nativas de la región y el resto son introducidas de otras regiones de México y del mundo. En total, 400 especies se manejan ex situ, fuera de sus ambientes naturales, mediante la siembra de sus semillas y la plantación de sus propágulos vegetativos o plantas juveniles; 373 especies se manejan in situ en sus hábitats naturales como sigue: todas estas especies se dejan en pie deliberadamente durante el aclareo de la vegetación; 76 especies son además promovidas intencionalmente, favoreciendo sus abundancias mediante modificaciones a sus hábitats o directamente plantando sus propágulos; y 51 especies reciben protección a través de reglas comunitarias, estrategias particulares de extracción y acciones contra herbívoros, competidores, heladas, radiación solar y sequías. La mayor parte de las formas de manejo involucran selección artificial a diferentes niveles de intensidad. La información permite visualizar la ocurrencia de formas de manejo incipientes y avanzadas a diferentes niveles de intensidad, simultáneamente dentro de una misma especie y entre especies. Esto permite postular hipótesis probables sobre los factores que influyen el manejo de plantas y su domesticación en una región importante para el estudio sobre el origen de la agricultura.

Traditional Knowledge and Useful Plant Richness in the Tehuacán-Cuicatlán Valley, Mexico

Traditional Knowledge and Useful Plant Richness in the Tehuacán–Cuicatlán Valley, Mexico. This study systematizes ethnobotanical information about the interactions between people and plants, ethnofloristic richness, the relative importance of useful species richness in relation to general species richness, and plant management in the Tehuacán–Cuicatlán Valley of central Mexico. The study recorded a total of 1,605 useful vascular plant species (61.2% of the total species richness of the regional vascular flora), this being the region with the highest absolute richness of useful plant species in Mexico. The null hypothesis that plant families with a higher number of useful species would be those having a higher general species richness was analyzed through residuals method. The plant families richest in useful species were Poaceae, Asteraceae, Cactaceae, Cyperaceae, Mimosaceae, and Solanaceae, most of which also have the highest general floristic richness. However, analyses of use categories did not generally corroborate our hypothesis. About 1,335 of the useful species are wild, more than 500 species are submitted to some type of management (62 species are tolerated, 34 protected, 50 enhanced, and 358 cultivated), but only a few have been studied to document their process of domestication. This information can be useful for developing regional strategies of sustainable management of plant resources.Conocimiento tradicional y riqueza de plantas útiles en el Valle de Tehuacán-Cuicatlán, MéxicoConocimiento tradicional y riqueza de plantas útiles en el Valle de Tehuacán-Cuicatlán, México. Este trabajo sistematiza información etnobotánica sobre las interacciones entre la gente y las plantas, la riqueza etnoflorística, la importancia relativa de las especies útiles con respecto a la riqueza florística general, y sobre el manejo de plantas en el Valle de Tehuacán–Cuicatlán, en el centro de México. Se registró un total de 1,605 especies de plantas vasculares útiles (61.2% de la riqueza total de la flora vascular de la región), lo que identifica a la región como la de mayor riqueza de plantas útiles de México en términos absolutos. Mediante el método de residuales se analizó la hipótesis nula de que las familias con mayor número de especies útiles serían las de mayor riqueza florística. Se encontró que las familias con mayor número de especies útiles fueron Poaceae, Asteraceae, Cactaceae, Cyperaceae, Mimosaceae, y Solanaceae, las cuales en su mayoría son las de mayor riqueza florística en la región. No obstante, al efectuar el análisis por categorías de uso no siempre se confirmó nuestra hipótesis. Casi 1,335 de las plantas útiles son silvestres, pero alrededor de 500 están sometidas a algún tipo de manejo (62 especies son toleradas, 34 protegidas, 50 fomentadas y 358 cultivadas), pero sólo para algunas de ellas se ha estudiado cómo operan los proceso de domesticación. La información generada en el trabajo puede ser útil para el desarrollo de estrategias regionales de manejo sustentable de los recursos vegetales.

Agroforestry systems and biodiversity conservation in arid zones: the case of the Tehuacan Valley, Central Mexico

The role of agroforestry systems in biodiversity conservation was investigated in the semiarid Tehuacán Valley, Central México. Richness and diversity of native plant species were compared between agroforestry systems (6 sampling sites) and the following forests (6 sampling sites) dominated by columnar cacti: (i) “chichipera” dominated by Polaskia chichipe; (ii) “jiotillal” dominated by Escontria chiotilla; and (iii) “garambullal” dominated by Myrtillocactus schenckii. Our information on genetic variation of dominant arboreal species in the study sites was reviewed and included in the analysis. Factors influencing household’s decisions to maintain vegetation cover were compiled through a survey and interviews and analyzed. All the samples of the agroforestry systems studied maintained on average nearly 59% plant species and 94% genetic variation of dominant cacti occurring in the forests, although their ability to preserve endemic rare species is limited. Social factors favoring maintenance of perennial species in agricultural plots include collective rules, households traditions, use of the plants maintained in the systems, and the environmental information gathered from NGOs, the local Biosphere Reserve, and researchers. However, agroforestry systems are losing their capability to maintain vegetation cover, mainly because of (i) decreasing amount of land managed by households, determined by a progressive fragmentation of the land area given to new families, (ii) adoption of technologies to intensify agriculture, and (iii) governmental programs penalizing the presence of vegetation patches within agricultural lands since they are considered “useless” areas. Necessary policies to stop degradation of the agroforestry systems and to improve their conservation capacity are discussed.

Influence of traditional markets on plant management in the Tehuacan Valley.

BackgroundThe Tehuacán Valley, Mexico is a region with exceptionally high biocultural richness. Traditional knowledge in this region comprises information on nearly 1,600 plant species used by local peoples to satisfy their subsistence needs. Plant resources with higher cultural value are interchanged in traditional markets. We inventoried the edible plant species interchanged in regional markets documenting economic, cultural and ecological data and about their extraction and management in order to: (1) assess how commercialization and ecological aspects influence plant management, (2) identify which species are more vulnerable, and (3) analyze how local management contributes to decrease their risk. We hypothesized that scarcer plant species with higher economic value would be under higher pressure motivating more management actions than on more abundant plants with lower economic value. However, construction of management techniques is also influenced by the time-span the management responses have taken as well as biological and ecological aspects of the plant species that limit the implementation of management practices. Plant management mitigates risk, but its absence on plant species under high risk may favor local extinction.MethodsSix traditional markets were studied through 332 semi-structured interviews to local vendors about barter, commercialization, and management types of local edible plant species. We retrieved ethnobotanical information on plant management from ten communities in a workshop and sampled regional vegetation in a total of 98 sites to estimate distribution and abundance of plant species commercialized. Through Canonical Correspondence Analysis (CCA) we analyzed the amount of variation of management types that can be explained from socioeconomic and ecological information. A risk index was calculated relating distribution, abundance, economic value and management of plant resources to identify the most vulnerable species.ResultsWe recorded 122 edible plant species interchanged in the main regional markets. CCA explained significantly 24% of management variation, spatial distribution and plant parts used being particularly important in management decisions. The indeterminate 76% of variation suggests that management decisions depend on particular variables that are not explained by the ecological and socioeconomic factors studied and/or their high variation in the context at the regional scale. The risk index indicated that management was the factor that mostly influences decreasing of risk of interchanged plant species. We identified Clinopodium mexicanum, Pachycereus weberi, Dasylirion serratifolium, Disocorea sp., Ceiba aesculifolia, Neobuxbamia tetetzo, Lippia graveolens, Litsea glaucescens, L. neesiana, Jatropha neopauciflora, Agave potatorum and other agave species used for producing mescal among the more endangered plant species due to human pressure, their relative scarcity and limited or inexistent management.ConclusionSpatial distribution and plant parts used are particularly meaningful factors determining risk and influencing management actions on edible plant species interchanged in the region. Limited or inexistent management may favor extinction of local populations under risk. Local management techniques synthesize knowledge and experiences crucial for designing sustainable management programs. Traditional management techniques supported by ecological information and environmental management approaches could make valuable contributions for sustainable use of plant species, particularly those becoming economically important more recently.

Mazahua ethnobotany and subsistence in the monarch butterfly biosphere reserve, Mexico

This is the first report on Mazahua knowledge and classification of plants and mushrooms and the roles of these resources in the local economy in the Monarch Butterfly Biosphere Reserve, Mexico. A total of 213 useful plant species and 31 species of edible mushrooms were recorded. Fruits ofPrunus serotina, Rubus liebmanii, andCrataegus mexicana were the main wild fruit gathered by people (7.47, 4.40, and 1.82 tons of fruits per year, respectively), whereas their availability in the territory of the village was approximately 302.6, 6.0, and 34.188 tons.Brassica campestris, Rorippa nasturtium-aquaticum, Chenopodium berlandieri, and Amaranthus hybridus were the principal non-cultivated greens consumed by people (4.3, 0.5, 0.7, and 0.9 tons per year, while 23.6, 3.78, traces, and 46.0 tons, respectively, were available). Extraction of medicinal plants is low but gathering ofTernstroemia spp. flowers endangers local populations of these plants. All households of the village used fuelwood (1,767.2 tons per year), mainly of pine and oak species. Strategies for sustainable use of these resources are discussed

Ethnobotany for Sustainable Ecosystem Management: A Regional Perspective in the Tehuacán Valley

Different indicators of global change identify that industrial processes are principal causes of the severe human impact on ecosystems of Earth. However, although industrial processes predominate in the world, numerous rural societies with a different rationality and organization coexist with the hegemonic mode of production. In indigenous communities the traditional botanical, zoological and ecological knowledge as well as traditional technologies of local resources and ecosystem management are particularly rich, as product of hundreds or thousands of years of experience. Indigenous communities have historically built diverse forms of managing the socioecological systems and the biocultural diversity adapted to local conditions, which are generally much more environmental friendly than other intensive forms of management. In this study we document the management of plant resources by peoples of the Tehuacan Valley, Mexico. We have inventoried more than 1600 plant species used for satisfying a broad spectrum of needs. People gather nearly 90 % of those species from wild populations, but practice different forms of incipient management (tolerance, enhancing, transplantation and seed sowing) in order to increase availability of nearly 400 important plant resources. The indigenous communities may adopt some modern techniques of managing resources and ecosystems, and select those according with their conditions and views. Based on these processes people construct hybrid techniques that may be adapted to the local environments. Agroecologists and ethnobotanists have visualized the high value of traditional management systems for generating technological viable alternatives for designing forms of sustainable management adapted to satisfy local needs and conserving biodiversity and ecosystems, and the continuous innovation tested by local people. It has been recognized that, in general, the traditional management systems have higher capacity for conserving biodiversity and ensuring the resilience of socioecological systems than industrial systems and that both traditional and modern techniques may contribute to better forms of management, but the form that the process adopts is crucial. Understanding traditional management systems are therefore the opportunity to reproduce valuable experiences, models and lessons for sustainable management and participatory adoption of new techniques may help to solve problems not traditionally solved. This chapter shows a general panorama of ethnobotanical information about resources and local traditional management strategies among Nahua, Mixtec, Mazatec, Cuicatec, Popoloca, Ixcatec and Mestizo peoples of the Tehuacan Valley, in order to analyse their role in designing a future for the region based on sustainability, an experience that may be useful for this and other regions of Mexico.

Ethnobotany in Mexico: History, Development, and Perspectives

Ethnobotany is defined as the study of the traditional botanical knowledge of different cultures, the techniques utilized in the use and management of plant resources, and the place they have in their cultural Cosmo vision. This study aimed to review the development and perspectives of ethnobotany in Mexico, based on an extensive review of all ethnobotanical studies showed at the Mexican Botanical Congress (MBC), the main forum of ethnobotanical studies in Mexico, between 1963 and 2010. We systematized a total of 897 works, identifying their progressive increase in the generation of investigative papers up until 1990, then a decrease until 1995 and a new increase from 1995 to the present. The main Mexican institutions studying ethnobotany are the Universidad Nacional Autonoma de Mexico, Universidad Autonoma Chapingo, Instituto Politecnico Nacional, Universidad Autonoma Metropolitana, and the Universidad Autonoma de Nuevo Leon, which produced nearly half of all the studies recorded. The best represented cultural groups studied were the Maya, Nahua, Otomi, Totonac, and Mixtec, studied under the predominant approach of descriptive ethnobotany. Ethnobotany in Mexico is in a stage of growth and therefore in the phase of consolidating its approaches, particularly in the areas of ecological, economic, quantitative, and evolutionary ethnobotany. In order to achieve the development of sustainable management strategies of plant resources, it is of the highest priority to consolidate ethnobotanical research and direct it towards the analysis of environmental degradation and solutions.

Use of columnar cacti in the Tehuacán Valley, Mexico: perspectives for sustainable management of non-timber forest products

BackgroundTEK, ecological and economic aspects of columnar cacti were studied in the Tehuacán Valley, Mexico to design sustainable regimes of fruit harvest. We analysed the amounts of edible fruit, seeds and flowers produced per hectare of cardonal, jiotillal and tetechera forests, their economic value and actual extraction rates, hypothesizing that the economic benefits of these NTFP would potentially be comparable to maize agriculture, which involves forest removal.MethodsOur study comprised the whole territory of the community of Quiotepec, Oaxaca. Sustainable gathering rates were analysed through population dynamics models and simulations of harvesting regimes (10%, 25%, and 50% of fruit gathered) per hectare of forest type. We used estimations on economic benefit and ecological impact of these scenarios to evaluate their relative sustainability, compared with maize agroforestry systems harbouring 2-47% of vegetation cover.ResultsFor the whole territory, the total annual fruit production is 509.3 ton of Pachycereus weberi, 267.4 ton of Neobuxbaumia tetetzo, 99.5 ton of Escontria chiotilla, and 8.1 ton of Myrtillocactus geometrizans. The total economic value of fruits per hectare was

In situ Management and Domestication of Plants in Mesoamerica

315.00 U.S. dollars for cardonal,