Species richness, endemism, and conservation of American tree ferns (Cyatheales)

Abstract

Analyses of richness and endemism of Cyatheales (tree ferns) in tropical America were performed and evidence of a diversity gradient is presented. For this, the occurrence ranges of 239 species were plotted into a 5°9 5°grid-cell map and then analyzed using species richness and endemism indices. Here we show that species richness and endemism are not distributed randomly over the landscape, but do aggregate into defined regions of high diversity in tropical America: the northern Andes, lower Central America, upper Central America and Mexico, the Guyana Highlands, southeastern Brazil, and the Antilles. These distributional patterns are congruent with the geographical distribution of cloud forest, which in turn is determined by topography, high humidity, and persistent cloud immersion. The mountain regions of tropical America, especially the cloud forests, harbour most of the species of American Cyatheales and have high levels of habitat loss and climatic fragility. Conservation policies for Cyatheales are centred on the local use and trade of many tree fern species, but none such policies focus on cloud forest habitat loss. This makes tree ferns a critically endangered group of plants. In the face of the current environmental crisis and global climate change, the presence of Cyatheales in these regions sounds the alarm on their conservation priorities.Electronic supplementary material The online version of this article (

Rates of molecular evolution in tree ferns are associated with body size, environmental temperature, and biological productivity

“…The distribution data have been previously used in biogeographic studies (Ramírez‐Barahona et al. , ; Ramírez‐Barahona and Luna‐Vega ; Sosa et al. ).…”

“…Core tree ferns, particularly the species‐rich Cyatheaceae ( ca . 643 species), are highly diverse in the Neotropics and Malaysia (Holttum ; Ramírez‐Barahona et al., , ), particularly in cool, wet environments with low seasonality (Bystriakova et al. ; Noben and Lehnert ).…”

“…Core tree ferns, particularly the species-rich Cyatheaceae (ca. 643 species), are highly diverse in the Neotropics and Malaysia (Holttum 1963;Ramírez-Barahona et al, 2011, particularly in cool, wet environments with low seasonality (Bystriakova et al 2011;Noben and Lehnert 2013). This group represents a good biological system to study the drivers of heterotachy for several reasons.…”

Historical reconstruction of climatic and elevation preferences and the evolution of cloud forest-adapted tree ferns in Mesoamerica

“…Cloud forests of tropical America harbor most of the species of American Cyatheales, mainly in Mesoamerica, the northern Andes, southeastern Brazil and the Antilles (Arens & Sánchez-Baracaldo, 1998; Arens, 2001; Kluge & Kessler, 2001; Ramírez-Barahona, Luna-Vega & Tejero-Díez, 2011). In Mexico, the distribution of most scaly tree ferns is limited almost entirely to the cloud forest, locally shaped by light sensitivity (Riaño & Briones, 2013).…”

Estructura poblacional y características del hábitat de dos especies de Cyatheaceae del estado de Hidalgo

“…En la República Mexicana, siguen un patrón de distribución montano, principalmente en la vertiente de sotavento de la Sierra Madre del Sur y Sierra Madre Oriental, y en los extremos oceánicos de la Faja Volcánica Transmexicana. Se encuentran en ambientes de atmósfera saturada de humedad, como es el bosque húmedo de montaña (BHM), donde tienen una distribución más o menos homogénea y llegan a constituirse como parte importante del estrato arbóreo inferior (Ramírez-Barahona et al, 2011).…”