Patricia Dávila-Aranda

The effects of climate change on the long-term conservation of Fagus grandifolia var. mexicana, an important species of the Cloud Forest in Eastern Mexico

We examined the effects of climate change on the future conservation and distribution patterns of the cloud forests in eastern Mexico, by using as a species model to Fagus grandifolia Ehr. var. mexicana (Martinez) Little which is mainly located in this vegetation type, at the Sierra Madre Oriental. This species was selected because it is restricted to the cloud forest, where it is a dominant element and has not been considered for protection in any national or international law. It is probably threatened due to the fact that it plays an important social role as a source of food and furnishing. We used a floristic database and a bioclimatic modeling approach including 19 climatic parameters, in order to obtain the current potential distribution pattern of the species. Currently, its potential distribution pattern shows that it is distributed in six different Mexican Priority Regions for Conservation. In addition, we also selected a future climate scenario, on the basis of some climate changes predictions already proposed. The scenario proposed is characterized by +2 °C and −20% rainfall in the region. Under this predicted climatic condition, we found a drastic distribution contraction of the species, in which most of the remaining populations will inhabit restricted areas located outside the boundaries of the surrounding reserves. Consequently, our results highlight the importance of considering the effects of possible future climate changes on the selection of conservation areas and the urgency to conserve some remaining patches of existing cloud forests. Accordingly, we believe that our bioclimatic modeling approach represents a useful tool to undertake decisions concerning the definition of protected areas, once the current potential distribution pattern of some selected species is known.

Endemic species of grasses in Mexico: a phytogeographic approach

The Poaceae family includes approximately 700 genera and 10 000 species, and Mexico is considered one of its most important centers of diversity and endemism. A total of 256 taxa (including 16 subspecific taxonomic units), belonging to 65 genera, are endemic to Mexico. Some of them are close relatives of important crops, while others are used in different ways all over the country. The aim of this paper is to discuss the distribution patterns at state level of the Mexican endemic species of Poaceae. Using cluster strategies, the states are classified according to their floristic similarities. Later, hotspots of endemism are identified, in order to discuss their role in conservation strategies. To evaluate the importance of each state in the conservation of the Mexican endemic Poaceae, two iterative complementarity methods were also used. Our results show that the largest concentration of endemic taxa occurs in a few states, such as Jalisco, Mexico, Michoacán, Durango, Oaxaca, Veracruz, San Luis Potosi, Chiapas, Chihuahua, Puebla, and Coahuila. The results also show that there are some patterns in the relationship to its endemism that seem to reflect important diversification trends in the family. Accordingly, 31% of the grass genera of Mexico have at least one endemic species, and 16.7% of the genera have only one endemic species. In contrast, six genera contribute 47.2% of the total number of grass endemics in Mexico. The Chloridoideae contributes 42.9% of the total grass endemic species of Mexico, whereas the Panicoideae includes 24.6%, and the Pooideae 19.8%. Thus, these three subfamilies contribute about 87% of the species endemism. On the basis of the habitat and distribution patterns of these subfamilies, two main areas of endemicity can be identified. The first area is located in warm habitats, whereas the second is related to temperate and high regions. The cluster analyses indicate the occurrence of four state groups whose phytogeographical explanation is discussed on the basis of a floristic regionalization of Mexico. The results also indicate the need to establish a relatively high number of sites and states for the conservation of 256 endemic taxa. The elevated number of sites required to conserve the Mexican endemic Poaceae is mainly due to the fact that many taxa have a restricted distribution pattern. On the basis of the patterns obtained, a few proposals are presented for undertaking the establishment of conservation priorities of these taxa.

Nanarepenta juxlahuacensis (Dioscoreaceae), una nueva especie de Oaxaca, México

A new species, Nanarepenta juxtla- huacensis, from the state of Oaxaca, Mexico, is de- scribed. Its habit and diagnostic characters are il- lustrated, and its relationships are discussed. This species is closely related to N. guerrerensis. It is distinguished from that species by having pistillate inflorescences shorter than the leaves, oblong and smooth capsules, as well as by having tectate-per- forate and punctuate pollen grains.

Polianthes multicolor (Agavaceae), especie nueva de Guanajuato, México

RESUMEN. Se describe e ilustra Polianthes mlllticolor, una especie nueva del estado de Guanajuato, Mexico. Esta especie muestra similitudes con Polianth.es geminiff ora (Lexarza) Rose var. gem in iflCora y Polianthes geminif ora var. clivicola McVaugh. Difiere de ambas variedades por la forma del tubo periantico, los lobulos patentes, la presencia de celulas buliformes y la ausencia de taninos en el mesofilo.

Ethnobotany and Ex situ Conservation of Plant Genetic Resources in México

In this chapter, the importance of ex situ conservation is discussed to safeguard plant genetic resources on relationship to its ethnobotanical relevance. It also highlights the importance of preserving the germplasm of species that are closely associated to human being. The diverse forms and intensities of human–plant relationship lead to the accumulation of traditional knowledge and the modification of the characteristics of plant populations as a result of human manipulation. When the germplasm of plant populations that are important to human being is protected, the information associated to this relationship is also protected, so that the conservation of biological diversity of useful plant species favors the protection of cultural diversity associated to its plant use. The urgency to conserve and protect the Mexican germplasm is associated to the fast and dramatic change of habitats that the country is facing.

The deciduous forest in a stream of lava in the center of Veracruz: vascular flora flower list

Resumen es: Se describe e ilustra Tillandsia borealis, conocida de los estados de Durango y Sinaloa, Mexico. Los caracteres que permiten reconocer a la especie aqui...