Keynote Lecture MEXICAN BAMBOOS IN THE XXI CENTURY: DIVERSITY, USEFUL SPECIES AND CONSERVATION Eduardo Ruiz-Sanchez / [email protected] Departamento de Botánica y Zoología, Centro Universitario de Ciencias Biológicas y Agropecuarias, Universidad de Guadalajara. Camino Ing. Ramón Padilla Sánchez 2100, Nextipac, Zapopán, Jalisco 45110, México. [email protected] Abstract Bamboos are giant grasses belonging to the subfamily Bambusoideae, one of the 12 recognized subfamilies in Poaceae. Bambusoideae has more than 1650 described species of bamboos worldwide both of herbaceous bamboos and woody bamboos. Mexico has 56 native bamboos, 52 of them are woody bamboos and four are herbaceous bamboos. Of these 50 species, 35 are endemic to Mexico, that is, they do not live wild in any other part of the world. Two species in Mexico are the most used since pre-Columbian times; Guadua inermis and Otatea acuminata. Both species have been used for the construction of houses with the technique of "bajereque." Besides these two species, other species have also been used for the same purpose as Guadua paniculata and Otatea fimbriata. Regionally, other species are used for basketry such as Chusquea circinata and Rhipidocladum racemiflorum. Finally, the use of the native species of Mexico as ornamental plants has not been exploited and remains an open field. For conservation purposes, only two endemic species of Mexico (Olmeca recta and Ol. reflexa) are listed in Norma Oficial Mexicana (NOM-059-SEMARNAT-2010) as endangered species. New analyzes and results indicate that eight endemic species should be included as critically endangered category and 27 species in the endangered category. Key words: critically endangered, endangered, Guadua inermis, endemic, Otatea acuminata Introduction Bamboo species worldwide account more than 1650 (Vorontsova et al., 2016), which are divided informally into two large groups; woody bamboos that are usually bamboos with lignified culms, have complex rhizomes, well-differentiated culm leaves, develop branching, have bisexual flowers and generally flowering gregariously and are monocarpic. The second group is the herbaceous bamboos do not present complex rhizomes, the culms are not strongly lignified, they do not present culm leaves, they generally do not develop branching, they have unisexual flowers, continuous flowering and they are not monocarpic (Clark et al., 2015). Bamboos belong to the subfamily Bambusoideae, one of the 12 recognized subfamilies of Poaceae (grass family) (Soreng et al., 2015, 2017). With the exception of Antarctica and Europe, in the rest of the continents we find bamboo growing wild (Clark et al., 2015). Taxonomically bamboos, both herbaceous and woody, are divided into three tribes. The Arundinarieae tribe or temperate woody bamboos have their greatest diversity of species in Asia, and there are only three species in America, particularly in the United States (Clark et al., 2015). The tribe Bambuseae or tropical woody bamboos, is divided into two large clades or monophyletic groups; the Neotropical bamboos exclusive of America and the Paleotropical bamboo of Africa, Asia and Oceania. Finally, the Olyreae tribe or herbaceous bamboos has practically its entire species in America, and only one Buergersiochloa bambusoides is endemic to New Guinea in Asia (Judziewicz et al. 1999; Judziewicz y Clark, 2007; Clark et al. 2015; Wysocki et al. 2015; Soreng et al. 2015, 2017). America has 535 bamboos species, 125 of them are herbaceous bamboos and 410 are woody bamboos (Clark et al., 2015). All countries in the Americas have at least one species of native bamboo, either herbaceous or woody, with the exception of Canada. United States of America has three endemic species of the genus Arundinaria (Tripplett et al., 2010), however in the United States there are no tropical bamboos registered in the wild. The rest of the American species belong to the Bambuseae tribe, which in turn is divided into three subtribes that are exclusive to the Americas; Arthrostylidiinae, Chusqueinae, and Guaduinae (Judziewicz et al., 1999, Clark et al., 2015). The country with the largest number of species is Brazil with more than 256, between herbaceous and woody bamboos (Greco et al. 2015). For Mexico, Ruiz-Sanchez et al. (2015) recorded 54 woody and herbaceous bamboos species. Of those 54 species, 50 are woody bamboos. Seven species of woody bamboos from Mexico belong to the subtribe Arthrostylidiinae. The Chusqueinae subtribe is represented by 21 species and finally, the Guaduinae subtribe has 22 species. The herbaceous bamboos of the Olyreae tribe in Mexico are represented by only four species (Ruiz-Sanchez et al., 2015). 30 woody bamboo species are endemic to Mexico, that is, they do not live anywhere else in the world. The states of the Mexican Republic with the greatest diversity of species are Chiapas with 32 species, Veracruz with 25 species and Oaxaca with 23 species. On the other hand, the states that do not register any native species are Baja California, Baja California Sur, Coahuila and Tlaxcala (Ruiz-Sanchez et al., 2015) (Figure 1). This study gathers a new list of woody and herbaceous bamboos for Mexico that includes the newly described species. Also, it identifies the species with the greatest potential commercially speaking and compiles a list of species that deserve to be protected to some degree of conservation. Material and Methods Data source A database of Mexican woody and herbaceous bamboo species of georeferenced was gathered (Table 1). The information was obtained from field work, scientific collections of herbarium records from the following herbaria; IBUG, IEB, MEXU and XAL (Thiers 2010) and from the public database GBIF (Global Biodiversity Information Facility) (GBIF 2012). Doubtful records, particularly those that did not have specimens and duplicate records (same species collected multiple times in the same locality) or that did not have enough information to be able to be georeferenced (ambiguous localities) were not taken into account in the final database. Conservation analysis To determine the conservation status of each species of woody bamboos present in Mexico, only the geographical distribution was taken into account and the conservation criteria proposed by the IUCN Red List of Endangered Species (IUCN 2012) were considered. For this, the occupation area (AOO) was evaluated, where a cell of 2 x 2 km was calculated for each point of presence of each species (IUCN 2016, Willis et al., 2003). The AOO index was estimated using the GeoCat software (Bachman et al., 2011). Results and Discussion The herbaceous bamboos of Mexico are represented by three genera (Cryptochloa, Lithachne, and Olyra) and four species that grow below 1300 m in tropical rainforest, subdeciduos forest and cloud forest (Ruiz-Sanchez et al. 2015). Cryptochloa strictiflora is the smallest herbaceous bamboo of Mexico, since it only measures about 20 cm in height and is found exclusively tropical rainforest at an altitude no higher than 900 m (Ruiz-Sanchez and Clark 2018). The woody bamboos of Mexico are represented by eight genera and 52 species. The genera that are only represented by a single species are Arthrostylidium, Aulonemia and Merostachys. Rhipidoclaum is represented by four species, Olmeca by five species, Guadua by seven species, Otatea by 11 species, and Chusquea by 22 species (Table 1) (Ruiz-Sanchez et al 2015, 2017, 2018a, Ruiz-Sanchez and Castro-Castro 2016). Ruiz-Sanchez et al. (2015), reported 54 species of native bamboos for Mexico. However, the number increased to 56 species by the description of Otatea nayeeri (Ruiz-Sanchez and Castro-Castro 2016) and Chusquea septentrionalis (Ruiz-Sanchez et al., 2017). Additionally, Merostachys mexicana was described (Ruiz-Sanchez et al., 2018a), however, this new species does not increase the list of species of Mexico, because it had already been considered in the study by Ruiz-Sanchez et al. (2015) as Merostachys sp. From the 1650 bamboo species described to date, only 45 of them are considered economically important (Benton 2015). Of those 45 species, only three are native species of America (Guadua angustifolia, G. amplexifolia and G. chacoensis). Ruiz-Sanchez et al. (2018b) suggest the inclusion of Guadua inermis and Otatea acuminata to that the list. Guadua inermis has a geographical distribution on the slope of the Gulf of Mexico, is a medium to large bamboo of 4 to 15 m in height, 4 to 10 cm in diameter, the culms are generally solid or with very thick walls (Cortés-Rodríguez 2000, Londoño and Ruiz 2014). The culms of this species are used mainly for the construction of rural houses, fences, palapas, and furniture (Cortés-Rodríguez 2000). Trabanino and Nuñez (2014) found archaeological evidence of the use of Guadua in Mayan graves, possibly it could have been Guadua inermis. There is also a record of the use of Guadua inermis in Oaxaca in the construction of "bajereque" walls. Otatea acuminata is the most used species in Mexico, is distributed mainly by the Pacific slope and the central part of Mexico, from Jalisco to Veracruz. It is a small to medium-sized bamboo 2 to 8 m high, 1 to 5 cm in diameter with hollow or solid culms (Ruiz-Sanchez and Sosa 2010, Ruiz-Sanchez et al., 2011, Ruiz-Sanchez 2015). The culms of this species are used to build roofs and walls of rural houses, doors, fences, basketry, "burritas" walking sticks, tutors for agriculture among other uses (Gúzman et al., 1984, Vázquez-López 1995, Judziewicz et al. 1999, Cortés-Rodríguez 2000, Vázquez-López 2004). There is archaeological evidence that this species was already used by Mesoamerican cultures (800-890 BC) to build houses with the technique of "bajereque" (Júarez and Márquez 1992). Other species that have been registered uses in the construction of houses is Guadua aculeata in the states of Veracruz and Puebla. Guadua paniculata and Otatea fimbriata were also used in the construction of bajereque walls in Chiapas. It should be noted that Guadua aculeata is the largest bamboo species in Mexico, reaching up to 20 meters and 18 cm in diameter.