DNA sequencing and taxonomy of unusual serrate Juniperus from Mexico: Chloroplast capture and incomplete lineage sorting in J. coahuilensis and allied taxa

Analysis of nrDNA, petN-psbM, trnS-trnG, trmD-trnT, and trnF-trnL of Juniperus coahuilensis and allied taxa of Mexico found typical J. coahuilensis, as well as individuals with: coahuilensis cp and hybrid ITS; coahuilensis cp and novel ITS sequence (La Parrilla type); novel Blue Fruited cp (blue fruited taxon) and coahuilensis ITS; plus Blue Fruited cp and La Parrila ITS. nrDNA data was examined and found to detect hybridization, chloroplast capture and incomplete lineage sorting. In addition, a new taxon was found with Blue Fruited (Blue Fruited) cp and J. martinezii ITS, suggestive of chloroplast capture. New records of J. saltillensis were confirmed from Zacatecas. A new record of J. martinezii from Durango was also confirmed. Several plants affiliated with either J. martinezii, or J. flaccida were in distinct clades showing the need for additional research on their volatile leaf oils, morphology and ecology to address their taxonomic status. And lastly, a very unusual population of junipers large, single stemmed trees with aff. J. poblana was found in Nayarit, with long and pendulous foliage. Analysis of the leaf volatile oils, ecology and morphology of this taxon is necessary (in progress) to ascertain its taxonomic rank

DNA sequencing and taxonomy of unusual serrate Juniperus from Mexico: Chloroplast capture and incomplete lineage sorting in J. coahuilensis and allied taxa

Analysis of nrDNA, petN-psbM, trnS-trnG, trmD-trnT, and trnF-trnL of Juniperus coahuilensis and allied taxa of Mexico found typical J. coahuilensis, as well as individuals with: coahuilensis cp and hybrid ITS; coahuilensis cp and novel ITS sequence (La Parrilla type); novel Blue Fruited cp (blue fruited taxon) and coahuilensis ITS; plus Blue Fruited cp and La Parrila ITS. nrDNA data was examined and found to detect hybridization, chloroplast capture and incomplete lineage sorting. In addition, a new taxon was found with Blue Fruited (Blue Fruited) cp and J. martinezii ITS, suggestive of chloroplast capture. New records of J. saltillensis were confirmed from Zacatecas. A new record of J. martinezii from Durango was also confirmed. Several plants affiliated with either J. martinezii, or J. flaccida were in distinct clades showing the need for additional research on their volatile leaf oils, morphology and ecology to address their taxonomic status. And lastly, a very unusual population of junipers large, single stemmed trees with aff. J. poblana was found in Nayarit, with long and pendulous foliage. Analysis of the leaf volatile oils, ecology and morphology of this taxon is necessary (in progress) to ascertain its taxonomic rank

Comparative analyses of the nutritional and antinutritional composition of pod flours from Neltuma spp. (Fabaceae, Caesalpinioideae) species from drylands of Mexico, Kenya and Tanzania

Identifying novel risk-resilient diets is urgent to address food insecurity and tackle global hunger and malnutrition. This study evaluated the suitability of mesquite (Neltuma spp.) pod flours as food staples for human nourishment and compared nutritional properties of mesquites growing natively or as introduced species in the drylands of Mexico, Kenya and Tanzania. Using gas chromatography and mass spectrometry, we analysed chemical composition, dietary fibre, antinutrients, amino acids and fatty acids of pod flours from Neltuma laevigata, N. laevigata N. odorata and N. velutina (abundant native species of Northern Mexico). We also studied the introduced N. juliflora from Kenya, and N. pallida from Tanzania which have become invasive. This research demonstrates that mesquite flour contains all the essential amino acids, with the highest being valine, leucine and lysine. The most abundant non-essential amino acids are aspartate, glutamate and proline. Mesquite flours are rich in palmitic, oleic and linolenic acids. Besides this, mesquite flour is abundant in phenols and contains less gallic and phytic acids than wheat. We show that nutritionally, mesquite flours are comparable to wheat flour. These findings demonstrate that Neltuma pod flours are excellent candidates to reduce malnutrition and hunger for the poorest people of the world

Co-limitation towards lower latitudes shapes global forest diversity gradients

The latitudinal diversity gradient (LDG) is one of the most recognized global patterns of species richness exhibited across a wide range of taxa. Numerous hypotheses have been proposed in the past two centuries to explain LDG, but rigorous tests of the drivers of LDGs have been limited by a lack of high-quality global species richness data. Here we produce a high-resolution (0.025° × 0.025°) map of local tree species richness using a global forest inventory database with individual tree information and local biophysical characteristics from ~1.3 million sample plots. We then quantify drivers of local tree species richness patterns across latitudes. Generally, annual mean temperature was a dominant predictor of tree species richness, which is most consistent with the metabolic theory of biodiversity (MTB). However, MTB underestimated LDG in the tropics, where high species richness was also moderated by topographic, soil and anthropogenic factors operating at local scales. Given that local landscape variables operate synergistically with bioclimatic factors in shaping the global LDG pattern, we suggest that MTB be extended to account for co-limitation by subordinate drivers

Effect of forest management on tree diversity in temperate ecosystem forests in northern Mexico.

An important challenge for silvicultural practices is the conservation of tree diversity while fulfilling the traditional objectives of forest management, most notably timber harvesting. The purpose of this study was to compare the tree diversity before and after the application of silvicultural treatments in a temperate forest in northern Mexico. Fifteen experimental plots, each measuring 2500 m2, were established to evaluate the immediate effect of four silvicultural treatments. These treatments were identified by their levels of management: intensive (clearcut, removal 100%), semi-intensive (removal of 59-61% of basal area), conservative (removal of 29-31% of basal area), and a control group. New forest guidelines, in contrast to conventional approaches, were applied to the semi-intensive and conservative treatments based on health and diversity conditions. Basal area, canopy cover, tree and total volume were measured in each plot. The Importance Value Index, alpha diversity, and evenness were estimated before and after treatments. Eighteen species belonging to five genera and five families were found in the study area. The species with the highest ecological values were Pinus durangensis, P. teocote, Quercus sideroxyla, and Quercus convallata with IVI numbers between 13.6 and 24.5%. Alpha diversity was intermediate (Margalef: 2.9 to 3.8), while dominance and evenness were above average compared to other studies (Simpson: 0.69 to 0.77; Shannon-Wiener: 1.44 to 1.6; Pielou: 0.76 to 0.85). The species evenness index in the conservative treatment was high (Sorensen, Jaccard, quantitative Sorensen and Morisita-Horn; 88 to 99%), although abundance decreased. Overall, there were no significant differences in IVI values and diversity indicators before and after treatments, with the exception of the clearcut treatment. When associating the diversity indices with stand variables, only the Pielou's evenness index showed a significant relationship between them. We concluded that both the conservative and semi-intensive treatments did not generate significant changes in tree diversity, but the former had slightly higher alpha diversity indices. These results can provide a better insight on silvicultural practices and their effects on species composition

Genotype file

This file contains genotype information for all 51633 SNPs coded as 0,1,2 (based on the number of minor alleles)

Data from: The role of hybridization during ecological divergence of southwestern white pine (Pinus strobiformis) and limber pine (P. flexilis)

Interactions between extrinsic factors, such as disruptive selection, and intrinsic factors, such as genetic incompatibilities among loci, often contribute towards the maintenance of species boundaries. The relative roles of these factors in the establishment of reproductive isolation can be examined using species pairs characterized by gene flow throughout their divergence history. We investigated the process of speciation and the maintenance of species boundaries between Pinus strobiformis and P. flexilis. Utilizing ecological niche modeling, demographic modeling, and genomic cline analyses, we illustrated a divergence history with continuous gene flow. Our results supported an abundance of advanced generation hybrids and a lack of loci exhibiting steep transition in allele frequency across the hybrid zone. Additionally, we found evidence for climate-associated variation in the hybrid index and niche divergence between parental species and the hybrid zone. These results are consistent with extrinsic factors, such as climate, being an important isolating mechanism. A buildup of intrinsic incompatibilities and of co-adapted gene complexes is also apparent, although these appear to be in the earliest stages of development. This supports previous work in coniferous species demonstrating the importance of extrinsic factors in facilitating speciation. Overall, our findings lend support to the hypothesis that varying strengths and directions of selection pressures across the long lifespans of conifers, in combination with their life history strategies, delay the evolution of strong intrinsic incompatibilities

Demographic_Models

Python scripts used to run 11 demographic models for SWWP (core and periphery) & L

SDM_locations

Filtered occurrence records for Core, Periphery & P. flexilis used in ENM