Terrestrial herbs are important elements of tropical forests; however, there is a lack of research on their diversity patterns and how they respond to different intensities of forest-use. The aim of this study was to analyze the diversity of herbaceous angiosperms along gradients of elevation (50 m to 3500 m) and forest-use intensity on the eastern slopes of the Cofre de Perote, Veracruz, Mexico. We recorded the occurrence of all herbaceous angiosperm species within 120 plots of 20 m x 20 m each. The plots were located at eight study locations separated by ~500 m in elevation and within three different habitats that differ in forest-use intensity: old-growth, degraded, and secondary forest. We analyzed species richness and floristic composition of herb communities among different elevations and habitats. Of the 264 plant species recorded, 31 are endemic to Mexico. Both α- and γ-diversity display a hump-shaped relation to elevation peaking at 2500 m and 3000 m, respectively. The relative contribution of between-habitat β-diversity to γ-diversity also showed a unimodal hump whereas within-habitat β-diversity declined with elevation. Forest-use intensity did not affect α-diversity, but β-diversity was high between old-growth and secondary forests. Overall, γ-diversity peaked at 2500 m (72 species), driven mainly by high within- and among-habitat β-diversity. We infer that this belt is highly sensitive to anthropogenic disturbance and forest-use intensification. At 3100 m, high γ-diversity (50 species) was driven by high α- and within-habitat β-diversity. There, losing a specific forest area might be compensated if similar assemblages occur in nearby areas. The high β-diversity and endemism suggest that mixes of different habitats are needed to sustain high γ-richness of terrestrial herbs along this elevational gradient.

Se presenta el listado de las especies de helechos y licófitos registrados a lo largo del gradiente altitudinal (20-3,500 m s.n.m.) del Cofre de Perote, Veracruz, abarcando ambientes contrastantes y bosques con diferentes grados de perturbación, así como vegetación azonal. Se establecieron 15 a 25 parcelas de 20 × 20 m en ocho pisos altitudinales, separados por 500 m de altitud. En cada parcela, se registraron las especies terrestres y epífitas del sotobosque (hasta una altura aproximada de 8 m). En 135 parcelas, se registraron 140 especies y cuatro variedades de helechos (22 familias, 59 géneros), así como 11 especies de licófitos (dos familias, tres géneros), representando el 27,5 % de la pteridoflora de Veracruz. Dos especies del género Elaphoglossum ( E. pallidum , E. squarrosum ) y Polystichum muricatum , registradas a 2,500 m, son nuevos registros para el estado. El número de especies es contrastante en diferentes pisos altitudinales del gradiente y en las elevaciones medias con bosque mesófilo de montaña entre 1,500 y 2,500 m se presentan los valores máximos de riqueza. En los extremos superior e inferior del gradiente, caracterizado por bosque de coníferas y selva mediana subcaducifolia respectivamente, el número de especies disminuye. Se destaca la riqueza del bosque mesófilo y la pérdida de especies del mismo cuando existe una perturbación de origen antrópico. Además, la vegetación azonal en cañadas y al lado de ríos representa un reservorio importante de la pteridoflora, lo que resalta su valor para la conservación.

Se describe y compara la riqueza y composición florística de pteridobiontes del bosque mesófilo demontaña y ambientes asociados con diferentes grados de afectación humana en la loma de Santa Rita, ubicada enla sierra de Chiconquiaco del centro de Veracruz, México. Se realizó una comparación con la pteridoflora de otrosbosques mesófilos del centro de Veracruz, con base en estudios disponibles en la literatura. Se establecieron 72parcelas de muestreo de 10 × 10 m cada uno en 6 ambientes diferentes; bosque natural, bosque secundario maduroy joven, café de sombra, plantación de Pinus patula y pastizales con árboles remanentes. Se registraron un total de81 especies distribuidas en 18 familias y 36 géneros. Los resultados indican que el bosque natural contiene la mayorriqueza, misma que disminuye conforme aumenta el grado de perturbación del ambiente hasta en un 70%. Se destacala importancia de los acahuales y el cafetal bajo sombra por retener y permitir el establecimiento de muchas especiescompartidas con en el bosque.

Aim: To assess the range size patterns of ferns and lycophytes along elevational gradients at different latitudes in an ecographical transition zone and search for predictors of range size from a set of environmental factors.Location: Mexico, from 15° to 23° N.Taxon: Ferns and lycophytes.Methods: All terrestrial and epiphytic species were recorded in 658 plots of 400 m² along eight elevational gradients. To test whether the range size within assemblages increases with elevation and latitude, we calculated the latitudinal range using the northern and southern limits of each species and averaged the latitudinal range of all species within assemblages weighted by their abundances. We related climatic factors and the changes with latitude and elevation with range size using linear mixed‐effects models.Results: Species richness per plot increased with elevation up to about 1,500–2,000 m, with strong differences in overall species richness between transects and a reduction with increasing latitude. The mean weighted range size of species within assemblages declined with elevation, and increased with latitude, as predicted by theory. However, we also found marked differences between the Atlantic and Pacific slopes of Mexico, as well as low range size in humid regions. The best models described about 76%–80% of the variability in range size and included the seasonality in both temperature and precipitation, and annual cloud cover.Main conclusion: Latitudinal and elevational patterns of range size in fern assemblages are driven by an interplay of factors favouring wide‐ranging species (higher latitudes with increasing temperature seasonality; dryer habitat conditions) and those favouring species with restricted ranges (higher elevations; humid habitat conditions), with additional variation introduced by the specific conditions of individual mountain ranges. Climatically stable, humid habitats apparently provide favourable conditions for small‐ranged fern species, and should accordingly be given high priority in regional conservation planning.