Cop16 Prop. 50

Original language: Spanish CoP16 Prop. 50 CONVENTION ON INTERNATIONAL TRADE IN ENDANGERED SPECIES OF WILD FAUNA AND FLORA ____________________ Sixteenth meeting of the Conference of the Parties Bangkok (Thailand), 3-14 March 2013 CONSIDERATION OF PROPOSALS FOR AMENDMENT OF APPENDICES I AND II A. Proposal Inclusion of Yucca queretaroensis in Appendix II in compliance with Article II, paragraph 2(a) of the Convention and in compliance with Resolution Conf. 9.24 (Rev. CoP15), Annex 2 a, criterion B. B. Proponent Mexico*. C. Supporting statement 1. Taxonomy 1.1 Class: Liliopsida 1.2 Order: Asparagales 1.3 Family: Agavaceae 1.4 Genus and species: Yucca queretaroensis Piña (1989). 1.5 Scientific synonyms: None 1.6 Common names: English: Queretaro Yucca, perennial Queretaro swaport and biconvex denticulate leaf yuca French: None Spanish: Estoquillo, lonjas, palma, toquillo, yuca biconvexa, yuca denticulada and yuca biconvexa denticulada 1.7 Code numbers: Not applicable 2. Overview Yucca queretaroensis is a plant endemic to central Mexico, specifically portions of the Sierra Madre Oriental in the states of Guanajuato, Querétaro and Hidalgo. Its wild populations are small (aproximately 60,300 individuals) and fragmented (607.64 km2). In addition, the species has a high habitat specificity (Magallán-Hernández et al., 2011, 2012a, y 2012b); it is therefore considered biologically rare. * The geographical designations employed in this document do not imply the expression of any opinion whatsoever on the part of the CITES Secretariat or the United Nations Environment Programme concerning the legal status of any country, territory, or area, or concerning the delimitation of its frontiers or boundaries. The responsibility for the contents of the document rests exclusively with its author. CoP16 Prop. 50 – p. 1 Currently, national legislation (Official Mexican Standard NOM-059-SEMARNAT-2010) listed the species as ‘Pr’ (subject to special protection). However, the most recent assessment of its state of conservation indicated that it could be listed as “endangered”. Its wild populations have a high vulnerability to intrinsic and extrinsic factors. Notable intrinsic factors include a low sexual reproductive rate, low growth rate, long generation period, specialized habitat and specialized pollination. Extrinsic factors include the harvesting of adult individuals for international trade ends; which diminishes sexual recruitment of wild populations. During the 18th meeting of the Plants Committee (PC18; Buenos Aires, 2009), the Management Authority of Switzerland submitted the document PC18 Doc. 21.1, on Trade in Agavaceae, drawing attention to the growing international demand (mainly in Europe) and trade possibly unsustainable of xerophytes of North America, including wild specimens of Yucca queretaroensis since 2006. In 2011, the CITES Scientific Authority of Mexico (CONABIO) coordinated—together with the Regional Botanical Garden of Cadereyta—a project to assess the conservation status, use and threats of the Yucca queretaroensis Piña (Agavaceae) and the pertinence of including it in CITES Appendices, concluding that the species should be included in CITES Appendix II. The proposal is based on the following points: 1) Yucca queretaroensis is an endemic, rare, endangered species, and therefore meets the biological criteria for inclusion in Appendix I [A and B, of Annex 1 of Resolution Conf. 9.24 (Rev. CoP15)]; 2) Evidence exists of international trade in adult wild specimens of unknown origin, confirmed through an official consultation of Mexico with CITES Authorities of the Regions of North America and Europe; 3) Its international trade needs to be regulated so that this is not the reason it becomes extinct. 3. Species characteristics 3.1 Distribution Yucca queretaroensis, is a species endemic to central Mexico that is distributed in portions of Sierra Madre Oriental in the states of Guanajuato, Querétaro and Hidalgo (20°46´41.8” and 21°20´14.4” N; 99°26´02.3” and 100°01´41.2 W), specifically in the natural region known as Querétaro and Hidalgo’s semi-desert; in an estimated area of 607.64 km2. Its distribution is fragmented, as can be seen in the map of potential distribution drawn up using the MaxEnt algorithm (Ocaña et al 2012); due to geographic barriers such as ravines and steep hillsides (Fig. 1). Below is an aggregated distribution pattern in different scales: small local populations are formed made up of colonies of up to 30 individuals that are separated from each other in different habitat areas (Magallán-Hernández et al., 2011). There are two main populations: one in the municipality of Xichú (Guanajuato); and one with the largest number of sub-populations in the municipalities of Pinal de Amoles, San Joaquín and Cadereyta de Montes (Querétaro), and Pacula and Zimapán (Hidalgo). CoP16 Prop. 50 – p. 2 Figure 1. Potential distribution of Y. queretaroensis according to the Maximum Entropy algorithm (Ocaña et al., 2012). 3.2 Habitat Yucca queretaroensis is found in folded chains and with faults, mountainous hillsides with reclined limestone folds, mountainside valleys and intermountain valleys (GEQ, 2009), associated with temporary and permanent water runoffs, preferably in terrains facing NW and sloped 40-70° that are terraced and with a uniform slope. It altitude interval is 986-1800 metres above sea level, but is concentrated between 1,000 and 1,340 metres above sea level. It grows in shallow sandy lithosols and regosols, on medium-sized rocks such as Mesozoic limestone and shale. It occurs in “warm sub- humid climates with summer rains” and “semi-dry warm climates with summer rains” (according to the Köppen climate classification system, modified by Enriqueta García; in GEQ, 2002), with an annual average temperature of 16-17° C and precipitation of 600-1,050 mm, concentrated at 950-1,000 mm. It is associated exclusively with sub-mountain thicket (Zamudio et al., 1992), with open canopy and low density, with 30-40 % cover. No need for a nurse has been observed for its development; but rather, the species acts as a nurse for other species (Magallán-Hernández et al., 2012a). 3.3 Biological characteristics Yucca queretaroensis is a species with a low growth rate and long generation period. It is hermaphrodite and reproduces mostly asexually, via the production of ramets (rosettes) at the base of mother plants (Magallán-Hernández et al., 2011 and 2012a), which makes the species a clonal organism (Golubov et al., 2007; Mandujano, 2007). After two years of monitoring, it was observed that sexual reproduction, unlike other Yucca species, is not annual, only five individuals bearing fruit were observed in years and populations that were different, which suggests that the species behaves sporadically in its sexual reproduction. Mature fruit was observed between June and July, however few plants bearing fruit in the wild were observed. The fruit production in the wild is low compared to flower production. The fertility rate is lower than 10 % of potential reproductive capacity per individual (Magallán-Hernández et al., 2012a); which CoP16 Prop. 50 – p. 3 could be due to the specificity of the pollinator and a high reproductive cost of the species, whose low fruit production is probably a factor in adjusting to its environment (Calvo y Horvitz, 1999). Although the pollinator is not known, the co-evolutionary relationship of the Yucca species with Tegeticula or Parategeticula moths has been documented (Pellmyr, 2003) and larvae have been observed inside the fruit of the Yucca queretaroensis. Owing to the characteristics of the fruit and seeds, it is likely that they are spread by mammals and/or birds, however there is no specific information on its dispersal and germination. In greenhouse conditions, germination of over 80 % has been observed. 3.4 Morphological characteristics It is an arborescent species that reaches a maximum height of 6 m (Annex 1, Fig. 1). Its stem is generally found covered in dry straight leaves, light grey, arranged in levels (Annex 1, Fig. 2). Very dense rosettes grow in an almost spherical shape, each one with up to 1,300 leaves (Annex 1, Fig. 3). Fresh leaves have a linear shape and are 45-74 cm long and 2-5 mm wide, light green and smooth, with a serrate hyaline margin (Annex 1, Fig. 4). The terminal spine of the leaf is very small (3-8 mm), conical and reddish coffee coloured (Annex 1, Fig. 5). The leaves are flexible, which can be demonstrated with a knot test, in which a simple knot is made with the leaf, as if it were a rope, and it does not break (Annex 1, Fig. 6). Also, in a cross-section of the leaf, it is bio-convex along its length, both surfaces with central papillae keels that run lengthwise along the leaf converging around the terminal spine. Picked leaves, upon loosing their turgidity, have a rhomboid cross-section (Annex 1, Fig. 7) (Magallán-Hernández et al., 2012). The inflorescence is a panicle of approximately 1,000 creamy-white flowers (Annex 1, Fig. 8). The panicle is 60 to 100 cm wide, oval and elliptical, upright, projecting from the rosette; the flowering part covers 90 % of the inflorescence, with 120-140 branches; each branch has 4-10 flowers. The flowers are 2.2-3.6 cm long, campanulate, round and pendulous. Fruit is fleshy and indehiscent (they do not open spontaneously when ripe) (Annex 1, Fig. 9), it is 7.5- 11.5 cm long and 3-4.5 cm wide, cylindrical, pendulous, green coloured. The seeds have different shapes depending on the location in the fruit and are flat, oval, spherical or lacriform (Annex 1, Fig. 10) 6.3-9.1 mm long, and 2-3(-6) mm thick, black and with a ruminate head (Annex 1, Fig. 11). 3.5 Role of the species in its ecosystem Yucca queretaroensis contributes to soil formation and retention, thanks to its shallow and fibrous root system (Magallán-Hernández et al., 2012a).

Load more