Rivers shape population genetic structure in Mauritia flexuosa (Arecaceae).

The Mauritia flexuosa L.f. palm is known as the "tree of life" given its importance as fundamental food and construction resources for humans. The species is broadly distributed in wet habitats of Amazonia and dry habitats of the Amazon and Orinoco river basins and in the Cerrado savanna. We collected 179 individuals from eight different localities throughout these habitats and used microsatellites to characterize their population structure and patterns of gene flow. Overall, we found high genetic variation, except in one savanna locality. Gene flow between populations is largely congruent with river basins and the direction of water flow within and among them, suggesting their importance for seed dispersal. Further, rivers have had a higher frequency of human settlements than forested sites, contributing to population diversity and structure through increased human use and consumption of M. flexuosa along rivers. Gene flow patterns revealed that migrants are sourced primarily from within the same river basin, such as those from Madeira and Tapajós basins. Our work suggests that rivers and their inhabitants are a critical element of the landscape in Amazonia and have impacted the dispersal and subsequent distribution of tropical palm species, as shown by the patterns of genetic variation in M. flexuosa.

Ethnoecology of the palm Brahea dulcis (Kunth) Mart. in central Mexico.

BACKGROUND: There have been few studies on the sustainable use of non-timber forest products in arid and semi-arid zones. The palm Brahea dulcis has been one of the most important resources in semi-arid Mesoamerica, since pre-Hispanic times. Currently, some populations grow within protected natural areas, representing both a challenge and an opportunity for local development. This ethnoecological study of B. dulcis in central Mexico aimed to evaluate their uses, harvesting context, and potential for exploitation, in order to give practical advice on their best use and management. METHODS: Ethnographic and ecological information was obtained in Barranca de Metztitlán Biosphere Reserve and Valle del Mezquital, Mexico. We studied the population structure and density; additionally, we evaluated the rate of leaf production, leaf renewal rate, percent survival of new leaves, the development of reproductive structures and performed a one-year defoliation experiment (involving a control and four treatments including a mix of semiannual and annual frequency of harvest and removal of two new leaves and/or two mature leaves). RESULTS: Twenty uses of the palm were recorded in the study area. Religious/symbolic and handicraft uses are highlighted. The population density of this species was the highest reported for the genus (1244 ± 231.7 ind/ha). The leaf production rate was the highest reported for arborescent palms of the Americas (11.83 ± 0.036 leaves/individual/year). The sexual reproductive cycle was 2.3 years long. A one-year defoliation experiment did not show statistically significant differences. Recommendations include: 1) implement management focused on increasing the abundance and quality of this useful resource in Metztitlán; 2) employ a strategy of focusing on ethnicity and gender in promoting their exploitation; 3) learn from theoretical frameworks of other non timber forest product studies. CONCLUSIONS: We propose that Brahea dulcis is the palm with the highest potential for sustainable use in the arid and semi-arid zones of Mexico. The challenge to improving management includes simplifying the legal protection framework, promoting uses and developing a market strategy. Collaborations to share experiences with peasant farmers from Guerrero is recommended. We further recommend the development of a governmental strategy to enhance and reassess this important resource.

[State strategy for Cycad (Zamiaceae) conservation: a proposal for the State of Hidalgo, Mexico]. / Estrategia estatal de conservación de las cícadas (Zamiaceae): una propuesta para el estado de Hidalgo, México.

Mexico has the second largest cycad diversity in the world, and the Sierra Madre Oriental (SMO) is one of the richest biogeographic regions for these plants. Despite there is a general Cycad National Program in the country, there are no state-level cycad conservation strategies or programs. Thus the aim of this study was to propose a cycad conservation strategy for the state of Hidalgo, which is located in the Southern part of the SMO. For this, a cycad species inventory was made in the state, for which three methods were used: review of published literature; consultation in the main Mexican herbaria to verify botanical specimens; and exhaustive field research to compare findings with previously reported species and to recognize new records at the county and state level. The proposed research work strategy combined the following elements: prioritize the county and local areas with greatest cycad species richness; prioritize the species least resistant to environmental change and/or having restricted geographic distribution; and to consider the main uses of these plants by local residents. The results showed that Hidalgo has three genera and eight species ofcycads: Ceratozamia fuscoviridis, C. latifolia, C. mexicana, C. sabatoi, Dioon edule, Zamia fischeri, Z. loddigesii and Z. vazquezii, all of which are considered by the International Union for Conservation of Nature (IUCN). This study added two new species records for Hidalgo and 21 at the county level. The species are distributed in 26 counties, of which Chapulhuacán and Pisaflores are notable for their high species richness. Hidalgo has the fourth-greatest cycad species richness among Mexican states, although its area accounts for only 1.07% of the country. The state's diversity is greater than in other states with larger area, and even than in some other entire countries in Mesoamerica. The presented state cycad conservation strategy proposes that a total of some 11,325 ha to be conserved in nine zones, including different vegetation types, distributed in seven counties. The strategy involves a mixed scheme that incorporates conservation in Protected Natural Areas (ANP), Small Farmer Reserves (Reservas Campesinas) and Environmental Management Units (UMA in Spanish). This proposal will be useful for government agencies to take into account in the process of designating land use for the Cloud Forest Biological Corridor (CBBMM in Spanish), a ANP in creation. The state of Hidalgo urgently needs a detailed analysis of trends in changes in vegetation cover and land use, and demographic studies of the cycads. It is recommended that the implementation phase of this state strategy be carried out jointly with local communities, academia, and state and federal agencies responsible for biodiversity conservation.

Estrategia estatal de conservación de las cícadas (Zamiaceae): una propuesta para el estado de Hidalgo, México / State strategy for Cycad (Zamiaceae) conservation: A proposal for the State of Hidalgo, Mexico

Mexico has the second largest cycad diversity in the world, and the Sierra Madre Oriental (SMO) is one of the richest biogeographic regions for these plants. Despite there is a general Cycad National Program in the country, there are no state-level cycad conservation strategies or programs. Thus the aim of this study was to propose a cycad conservation strategy for the state of Hidalgo, which is located in the Southern part of the SMO. For this, a cycad species inventory was made in the state, for which three methods were used: review of published literature; consultation in the main Mexican herbaria to verify botanical specimens; and exhaustive field research to compare findings with previously reported species and to recognize new records at the county and state level. The proposed research work strategy combined the following elements: prioritize the county and local areas with greatest cycad species richness; prioritize the species least resistant to environmental change and/or having restricted geographic distribution; and to consider the main uses of these plants by local residents. The results showed that Hidalgo has three genera and eight species of cycads: Ceratozamia fuscoviridis, C. latifolia, C. mexicana, C. sabatoi, Dioon edule, Zamia fischeri, Z. loddigesii and Z. vazquezii, all of which are considered by the International Union for Conservation of Nature (IUCN). This study added two new species records for Hidalgo and 21 at the county level. The species are distributed in 26 counties, of which Chapulhuacán and Pisaflores are notable for their high species richness. Hidalgo has the fourth-greatest cycad species richness among Mexican states, although its area accounts for only 1.07% of the country. The state’s diversity is greater than in other states with larger area, and even than in some other entire countries in Mesoamerica. The presented state cycad conservation strategy proposes that a total of some 11 325ha to be conserved in nine zones, including different vegetation types, distributed in seven counties. The strategy involves a mixed scheme that incorporates conservation in Protected Natural Areas (ANP), Small Farmer Reserves (Reservas Campesinas) and Environmental Management Units (UMA in Spanish). This proposal will be useful for government agencies to take into account in the process of designating land use for the Cloud Forest Biological Corridor (CBBMM in Spanish), a ANP in creation. The state of Hidalgo urgently needs a detailed analysis of trends in changes in vegetation cover and land use, and demographic studies of the cycads. It is recommended that the implementation phase of this state strategy be carried out jointly with local communities, academia, and state and federal agencies responsible for biodiversity conservation.

México es el segundo país con mayor diversidad de cícadas en el mundo. En él, la Sierra Madre Oriental (SMO) es una de las regiones biogeográficas con mayor riqueza de estas plantas. El objetivo de este estudio fue plantear la estrategia de conservación de cícadas para el estado de Hidalgo, ubicado en la parte sur de la SMO; para esto se revisó la literatura científica, se consultaron los principales herbarios de México y se hicieron recorridos de campo. Los resultados muestran que Hidalgo alberga tres géneros y ocho especies: Ceratozamia fuscoviridis, C. latifolia, C. mexicana, C. sabatoi, Dioon edule, Zamia fischeri, Z. loddigesii, Z. vazquezii, posicionándose en el cuarto lugar nacional en riqueza de cícadas. Las especies se distribuyen en 26 municipios. Se encontró que la diversidad de cícadas es mayor a la de otras entidades con mayor superficie e incluso a la de algunos países de Centroamérica. La estrategia estatal de conservación de cícadas aquí desarrollada propone conservar cerca de 11 325ha, distribuidas en siete municipios, bajo un esquema mixto de conservación. Esta propuesta será útil para que las instancias gubernamentales establezcan nuevas ANP’s en la región biogeográfica de la SMO.

Balancing shifting cultivation and forest conservation: lessons from a "sustainable landscape" in southeastern Mexico.

Shifting cultivation is often perceived to be a threat to forests, but it is also central to the culture and livelihoods of millions of people worldwide. Balancing agriculture and forest conservation requires knowledge of how agricultural land uses evolve in landscapes with forest conservation initiatives. Based on a case study from Quintana Roo, Mexico, and remote sensing data, we investigated land use and land cover change (LUCC) in relation to accessibility (from main settlement and road) in search of evidence for agricultural expansion and/or intensification after the initiation of a community forestry program in 1986. Intensification was through a shortening of the fallow period. Defining the sampling space as a function of human needs and accessibility to agricultural resources was critical to ensure a user-centered perspective of the landscape. The composition of the accessible landscape changed substantially between 1976 and 1997. Over the 21-year period studied, the local population saw the accessible landscape transformed from a heterogeneous array of different successional stages including mature forests to a landscape dominated by young fallows. We detected a dynamic characterized by intensification of shifting cultivation in the most accessible areas with milpas being felled more and more from young fallows in spite of a preference for felling secondary forests. We argue that the resulting landscape provides a poorer resource base for sustaining agricultural livelihoods and discuss ways in which agricultural change could be better addressed through participatory land use planning. Balancing agricultural production and forest conservation will become even more important in a context of intense negotiations for carbon credits, an emerging market that is likely to drive future land changes worldwide.