Underestimated endemic species diversity in the dry inter‐Andean valley of the Río Marañón, northern Peru: An example from Mimosa (Leguminosae, Mimosoideae)

Abstract

Molecular phylogenies which include multiple accessions of species and near complete taxon sampling can be an important tool for estimating species diversity when used in combination with traditional morphology‐based taxonomy. Here we use a densely sampled plastid gene tree for a morphologically complex group within the legume genus Mimosa (sect. Batocaulon ser. Andinae) to improve estimates of species limits and diversity in the poorly known dry inter‐Andean valley of the Río Marañón, northern Peru. Based on the plastid gene tree, Mimosa ser. Andinae, which previously comprised four species, is re‐circumscribed to include six Andean dry‐forest species from northern Peru, Ecuador and southern Colombia, including the new species, M. jaenensis, described here. A further three candidate species are identified within the section based on high levels of sequence variation among accessions. With the additional species, the Marañón valley is now known to harbour nine narrowly restricted endemic species of Mimosa, a pattern of multiple congeneric endemics mirrored in many other plant genera as well as several animal groups. Our results, in combination with other published studies, suggest that overall species diversity in the Marañón has been significantly under‐estimated. Further work is needed to identify conservation priority areas in the Marañón in order to protect its unique flora.

Diversity patterns of selected Andean plant groups correspond to topography and habitat dynamics, not orogeny

“…In addition, the AHZ together with the Andes in southern Bolivia/northern Argentina is the region with the highest diversity at the level of Tribus. A study of Andean members of the genus Mimosa paint a similar picture with regard to diversification in the dry valleys of northern Peru and argues for the crucial role of topographic complexity in speciation in this region (Särkinen et al, 2011). Mimosa and Cacti are ecologically the diametrical opposite of the mesic groups studied here and it is thus at first highly surprising that they should also have a center of endemicity in the same region.…”

The role of tropical dry forests for biodiversity, carbon and water conservation in the neotropics: lessons learned and opportunities for its sustainable management

“…In the Americas, each major TDF region has a significant complement of endemic species and a few endemic genera, with TDF endemism levels in most regions tending to be higher than in adjacent moist forests (Linares-Palomino et al 2011;Ceballos 1995;Santos et al 2011; Conservation of neotropical dry forests Sarkinen et al 2011). Linares-Palomino et al (2011 found that 12 of 23 neotropical TDF geographical nuclei have more that 20 % of unique species (a proxy for level of endemism), being the highest nuclei Insular Caribbean (77.5 %) and Mexican Pacific (65.5 %) in the north and Equatorial Pacific (47.1 %) and Peruvian Inter-Andean Valley (46.4 %) in the South.…”

A large and unusually colored new snake species of the genusTantilla(Squamata; Colubridae) from the Peruvian Andes

“…However, SDTFs are considered as being one of the most threatened tropical ecosystems with a strong rate of annual deforestation (Janzen, 1988; Miles et al, 2006; Pennington, Lewis & Ratter, 2006; Linares-Palomino, Oliveira-Filho & Pennington, 2011; DRYFLOR, 2016). The Equatorial dry forest is one representative of this forest type, which expands from southern Ecuador to the northern part of Peru (Brack, 1986; Särkinen et al, 2011; Venegas, 2005), where it extends southward in two small stripes. One stripe continues along the coast west of the Andes, whereas the other penetrates the valley of the Marañón River and its tributaries.…”