The Relationship between Species Diversity and Genetic Structure in the Rare Picea chihuahuana Tree Species Community, Mexico

Abstract

Species diversity and genetic diversity, the most basic elements of biodiversity, have long been treated as separate topics, although populations evolve within a community context. Recent studies on community genetics and ecology have suggested that genetic diversity is not completely independent of species diversity. The Mexican Picea chihuahuana Martínez is an endemic species listed as “Endangered” on the Red List. Forty populations of Chihuahua spruce have been identified. This species is often associated with tree species of eight genera in gallery forests. This rare Picea chihuahuana tree community covers an area no more than 300 ha and has been subject of several studies involving different topics such as ecology, genetic structure and climate change. The overall aim of these studies was to obtain a dataset for developing management tools to help decision makers implement preservation and conservation strategies. However, this unique forest tree community may also represent an excellent subject for helping us to understand the interplay between ecological and evolutionary processes in determining community structure and dynamics. The AFLP technique and species composition data were used together to test the hypothesis that species diversity is related to the adaptive genetic structure of some dominant tree species (Picea chihuahuana, Pinus strobiformis, Pseudotsuga menziesii and Populus tremuloides) of the Picea chihuahuana tree community at fourteen locations. The Hill numbers were used as a diversity measure. The results revealed a significant correlation between tree species diversity and genetic structure in Populus tremuloides. Because the relationship between the two levels of diversity was found to be positive for the putative adaptive AFLP detected, genetic and species structures of the tree community were possibly simultaneously adapted to a combination of ecological or environmental factors. The present findings indicate that interactions between genetic variants and species diversity may be crucial in shaping tree communities.

Peer Review #2 of "Discrimination of Picea chihuahuana Martinez populations on the basis of climatic, edaphic, dendrometric, genetic and population traits (v0.1)"

“…The genetic diversity in P. chihuahuana is mostly moderate compared with other Picea species (Simental-Rodríguez et al, 2014;Wehenkel & Sáenz-Romero, 2012). The genetic diversity across all the AFLPs studied was not an important variable for separating the two clusters of P.…”

TallPinus luzmariaetrees with genes fromP. herrerae

“…The quality and reproducibility of the analysis were verified by inclusion of reference samples in each plate and independent repetition (replicate PCRs) of analysis at least 16 samples (i.e., a minimum of 16 randomly chosen individuals from each plate). In all replicates, the AFLP pattern was the same as in the first analysis (Simental-Rodríguez et al, 2014;Ávila Flores et al, 2016).…”

Untitled

“…The study was conducted in 14 populations of P. chihuahuana located in several municipalities in the states of Durango and Chihuahua, Mexico (Table 1 and Figure 1). These populations were growing with 15 other tree species, mainly Pinus strobiformis, Pseudotsuga menzesii and Populus tremuloides (Simental-Rodríguez et al, 2014). Each location was represented by one 50 x 50 m (0.25 ha) plot established in the center of the population.…”

“…The populations are fragmented and can be classified into three distinct clusters in the SMO of the two States (south, center and north), each group separated by a distance of about 300 km (Mendoza-Maya et al, 2015). The total area covered Chihuahua spruce trees is less than 300 ha (Simental-Rodríguez et al, 2014). Picea chihuahuana is commonly associated with species of the genera Pinus and Quercus, and occasionally with species of the genera Abies, Pseudotsuga, Cupressus, Populus, Juniperus and Prunus (Gordon, 1968;.…”

“…Needles and leaves from 129 individuals of Pinus strobiformis in ten locations (3-17 trees per plot), trees of Pseudotuga menzesii in six locations (10-11 trees per plot) and 74 trees of Populus tremuloides in five locations (8-13 individuals per plot) were sampled for analysis of the genetic diversity of the Picea chihuahuana tree community.The DNA was extracted using the DNeasy 96 Plant Kit (QIAGEN). The amplified fragment length polymorphism (AFLP) analysis was conducted according to a modified version of the protocol ofVos et al (1995), described bySimental-Rodríguez et al (2014). The restriction enzymes used were Eco RI (selective primer: 5'-…”