Sabal

Abstract: Sabal palm has been used for thatching the traditional Maya house for over 3000 yr. The great importance of this resource has promoted its management within home gardens. Although traditionally managed populations in home gardens are capable of ecological long-term persistence, the impact of cultural change on sustainable resource management is poorly understood. By means of interviews in 108 households, we obtained information about Sabal management practices, leaf demand, and sociocultural data. Density and size structure of the palm populations in the respective home gardens were also measured. By means of principal components analysis, the sociocultural data were summarized into a cultural change index, which was then statistically related to palm density, size structure, leaf demand, and management practices. Leaf demand along the cultural change gradient was estimated. Sabal populations were affected by the cultural change index. Palm density and the proportion of harvestable individuals were higher in the more traditional households. The number of management practices decreased, and the probability of felling adult palms increased with cultural change. As a result, the percentage of the total leaf demand satisfied by home garden production diminished from 118.2-69.4% as cultural change increased. Traditional practices seem oriented to increasing the palm availability. Seed sowing and the protection of seedlings and adults affect the life stages with the largest impact on the population growth rate, as measured through sensitivity analysis. This means that abandoning traditional practices and felling adults more frequently should reduce rapidly, which is consistent with the low palm density observed in less traditional households. The application of demographic models to Sabal tells us that traditional management warrants the persistence of the resource as long as the current conditions remain unchanged. In contrast, our data show that Sabal management may not be sustainable from a cultural perspective, since the cultural attitudes that affect palm management and demand change over time. Both approaches assess the same problem from different viewpoints reaching different but complementary conclusions. In this study, we propose new methods that integrate the ecological and cultural processes, which affect the sustainable management of the natural resources.

Abstract: Sabal palmetto and Thrinax morrisii, Arecaceae, are important ornamental palms of socioeconomic importance. Experiments using physical, mechanical and chemical pre-sowing treatments were conducted to determine the germination response of these two palm species. Among various treatments, soaking of Sabal seeds in 500 ppm gibberellic acid (GA3) for 24 h resulted in a highest final germination percentage (FGP) of 95% in day 14 of culture and number of days lapsed to reach 50% of FGP (GT50) of 6.8 days. Nontreated Sabal seeds exhibited FGP of 75% in day 16and GT50 of 7.39 days. Soaking of Thrinax seeds in H2SO4 for 30 min resulted in a highest FGP of 90% in day 14 of culture and GT50 of 5.19 days. Non-treated Thrinax seeds exhibited FGP of 70% in day 16 and GT50 of 8.07 days. The results indicate that Thrinax seeds exhibit exogenous dormancy which is entirely imposed by the hard seed coat, whereas the Sabal seeds exhibit both exogenous and physiological dormancy.

Abstract: Two species occurring in southeastern Texas, USA, of the predominately tropical genus Agra Fabricius, 1801 are described as new: oblongopunctata group - Agra rileyi Erwin, new species (type locality: Cameron County, Paloma Blanca Road, near Sabal Palm Sanctuary); and truquii group - Agra wickhami Erwin, new species (type locality: Cameron County, Brownsville). Both species are presently known from extreme southeast Texas in Cameron County, and A. rileyi was also found in Hidalgo and Starr Counties. Agra rileyi adults are associated with sabal palms (Sabal mexicana Mart., Arecaceae) and sugar hackberry trees (Celtis laevigata Willd., Ulmaceae). Agra wickhami is also known from the Yucatan peninsula. Adults of both species have been incorrectly identified in the past in collections and in the literature as Agra oblongopunctata Chevrolat, which occurs only in southern Mexico and Guatemala. A new group, truquii species-group, is established. Many specimen labels studied indicate that “beating vegetat...

Abstract: Seeds of two palm species conforming to the extant genus Sabal have been recovered from the Campanian (Upper Cretaceous) Aguja Formation of Big Bend National Park, Texas: Sabal bigbendense sp. nov. and Sabal bracknellense (Chandler) Mai. These remains, found together with anatomically preserved palm stems, augment previous reports of Sabalites ungeri (Lesq.) Dorf leaves from the same formation. The co‐occurrence of palm seeds with numerous juvenile hadrosaur and ceratopsian bones indicates that palms closely related to modern cabbage palms may have provided fodder and shelter for young herbivorous dinosaurs. The distribution of these and other Late Cretaceous palm fossils is reviewed.