Least Squares Method and Empirical Modeling: A Case Study in a Mexican Manufacturing Firm

Empirical modeling (EM) has been a useful approach for the analysis of different problems across a number of areas/fields of knowledge. As is known, this type of modeling is particularly helpful when parametric models due to a number of reasons cannot be constructed. Based on different methodologies and approaches (e.g., Least Squares Method, LSM), EM allows the analyst to obtain an initial understanding of the relationships that exists among the different variables that belong to a particular system or a process

Diversidad de helechos y licopodios en el área privada de conservación Talhpan, Papantla, Veracruz, México

ABSTRACT The knowledge of the pteridophyta in flora of the northern zone of Veracruz is scarce, and ever more when it comes to species richness of ferns and lycopods in the elevational low zones. The aim of this research is to analyze the diversity of ferns and lycopods in a semideciduos forest. Were established 15 plots of 20 x 20 m in three habitats (semideciduos forest fragment, riparian vegetation and citrus cultivation) to analyze the richness, abundance and turnover of species of these groups in different habitats. In addition, the species present in areas bordering the reserve were registered. A total of 22 species of ferns and lycopods were recorded, of these, 17 correspond to the sampling plots and the rest were found in adjacent sites. The riparian habitat presented the highest specific richness, followed by the semideciduos forest fragment; these two habitats had a floristic similarity of 22%. Citrus cultivation had the lowest specific richness. The forest in the research area represents a refuge for the diversity of ferns, however the riparian vegetation was the one that presented the greatest diversity. The replacement of species in the different habitats is high, which has a value for conservation plans, since it is necessary to include landscape heterogeneity in the proposals for the preservation of ecosystems.RESUMEN El conocimiento de la pteridoflora de la zona norte de Veracruz es escaso, y más aún cuando se habla de la riqueza de helechos y licopodios en las zonas de baja altitud. El objetivo del estudio fue analizar la diversidad de helechos y licopodios en un fragmento de selva mediana subperennifolia. Se establecieron 15 parcelas de 20 x 20 m, en tres hábitats (fragmento de selva, vegetación ribereña y cultivo de cítricos), para analizar la riqueza, abundancia y recambio de especies de estos grupos en distintos hábitats. Además, se determinaron las especies presentes en zonas aledañas a la reserva. Se registró un total de 22 especies de helechos y licopodios; 17 de ellas estaban presentes en las parcelas de muestreo y el resto se encontraron en sitios aledaños. El hábitat ribereño presentó la mayor riqueza específica, seguido del fragmento de selva; estos dos hábitats tuvieron una similitud florística de 22%. La zona de cultivo presentó la menor riqueza específica. La selva representa un refugio importante para la diversidad de helechos, sin embargo, la vegetación ribereña fue la que mayor diversidad presentó. El recambio de especies fue alto entre ambientes, lo cual tiene un valor para los planes de conservación, ya que es necesario incluir la heterogeneidad paisajística en las propuestas de preservación de los ecosistemas

NEOTROPICAL ALIEN MAMMALS: a data set of occurrence and abundance of alien mammals in the Neotropics

Biological invasion is one of the main threats to native biodiversity. For a species to become invasive, it must be voluntarily or involuntarily introduced by humans into a nonnative habitat. Mammals were among first taxa to be introduced worldwide for game, meat, and labor, yet the number of species introduced in the Neotropics remains unknown. In this data set, we make available occurrence and abundance data on mammal species that (1) transposed a geographical barrier and (2) were voluntarily or involuntarily introduced by humans into the Neotropics. Our data set is composed of 73,738 historical and current georeferenced records on alien mammal species of which around 96% correspond to occurrence data on 77 species belonging to eight orders and 26 families. Data cover 26 continental countries in the Neotropics, ranging from Mexico and its frontier regions (southern Florida and coastal-central Florida in the southeast United States) to Argentina, Paraguay, Chile, and Uruguay, and the 13 countries of Caribbean islands. Our data set also includes neotropical species (e.g., Callithrix sp., Myocastor coypus, Nasua nasua) considered alien in particular areas of Neotropics. The most numerous species in terms of records are from Bos sp. (n = 37,782), Sus scrofa (n = 6,730), and Canis familiaris (n = 10,084); 17 species were represented by only one record (e.g., Syncerus caffer, Cervus timorensis, Cervus unicolor, Canis latrans). Primates have the highest number of species in the data set (n = 20 species), partly because of uncertainties regarding taxonomic identification of the genera Callithrix, which includes the species Callithrix aurita, Callithrix flaviceps, Callithrix geoffroyi, Callithrix jacchus, Callithrix kuhlii, Callithrix penicillata, and their hybrids. This unique data set will be a valuable source of information on invasion risk assessments, biodiversity redistribution and conservation-related research. There are no copyright restrictions. Please cite this data paper when using the data in publications. We also request that researchers and teachers inform us on how they are using the data