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Aim of study: To assess the association of deforestation and forest use with tree diversity and dominance of pine species. Area of study: La Malinche National Park, central Mexico. Material and methods: Three forest stands were selected on each of four slopes in La Malinche National Park, in which the percent forest cover was determined using a concave spherical densitometer. Additionally, we estimated logging, firewood, and ocoteo as indirect measures of forest use. In each forest stand, we set five 0.1-ha circular plots and we recorded tree species, diameter at breast height, and height of all individuals ≥1.5 m. We estimated diversity using Hill numbers (qD). We identified dominant species from rank-abundance curves, and explored the dissimilarity between forest stands for the three q orders. Using generalized linear mixed-effects models, we evaluated the relationships of deforestation and forest use with species diversity and pine dominance, and studied the effect of pine dominance on the abundance of other tree species through generalized linear models. Main results: We recorded a total of 16 tree species; a pine (Pinus montezumae) was the dominant species. The diversity of tree species was not associated with forest use or deforestation, but deforestation increased Pinus dominance, with a strong slope effect. Research highlights: Regulation and control of forest use should be prioritized to avoid further deforestation and the transformation of species-diverse forests into monospecific forests, further increasing the dominance of P. montezumae. We also suggest reforesting with native species and those scarcely represented to increase forest cover and maintain tree diversity.

Diet composition and its ecological drivers are rarely investigated in coexisting closely related species. We used a molecular approach to characterize the seasonal variation in diet composition in four spiny lizard species inhabiting a mountainous ecosystem. DNA metabarcoding revealed that the lizards Sceloporus aeneus, S. bicanthalis, S. grammicus, and S. spinosus mostly consumed arthropods of the orders Hemiptera, Araneae, Hymenoptera, and Coleoptera. The terrestrial lizards S. aeneus and S. bicanthalis mostly predated ants and spiders, whereas the arboreal–saxicolous S. grammicus and saxicolous S. spinosus largely consumed grasshoppers and leafhoppers. The taxonomic and phylogenetic diversity of the prey was higher during the dry season than the rainy season, likely because reduced prey availability in the dry season forced lizards to diversify their diets to meet their nutritional demands. Dietary and phylogenetic composition varied seasonally depending on the species, but only dietary composition varied with altitude. Seasonal dietary turnover was greater in S. spinosus than in S. bicanthalis, suggesting site-specific seasonal variability in prey availability; no other differences among species were observed. S. bicanthalis, which lives at the highest altitude in our study site, displayed interseasonal variation in diet breadth. Dietary differences were correlated with the species’ feeding strategies and elevational distribution, which likely contributed to the coexistence of these lizard species in the studied geographic area and beyond.

The results obtained from a second survey for Myxomycetes in the arid areas of Peru are reported. A total of 37 localities from the cactus belt (‘cardonal’), between 1500 and 3000 m a.s.l., were sampled over six years. This survey is based on 601 identifiable collections of myxomycetes, developed in the field under natural conditions or those that were recovered from moist chamber cultures. In total, 84 taxa representing 19 genera were recorded. One new species, Cribraria spinispora Lado & D.Wrigley sp. nov., is described, three species new to South America and 22 additional new species for Peru are reported as well. Endemic plants, expecially cacti, had a particular relevance as myxomycete substrates. The predominance of the order Physarales T.Macbr. in arid areas is reinforced. Comments are included on some collections, as well as SEM micrographs of several species. A statistical evaluation of the diversity of myxomycetes in the cardonal area and a comparison of this area with the dry coastal desert of Peru and other Neotropical xeric environments are also included. Results show that the arid areas are rich in myxomycetes, and that each area has a unique assemblage. The differences appear to be related to the host plants., Se presentan los resultados de un segundo estudio sobre Myxomycetes de zonas áridas de Perú. Un total de 37 localidades del cardonal, situadas entre 1500 y 3000 m s.n.m., fueron muestreadas durante seis años. Este estudio está fundamentado en 601 recolecciones de mixomicetes, obtenidas en el campo o por cultivo en cámara húmeda. En total, se han identificado 84 táxones que corresponden a 19 géneros. Se describe una nueva especie, Cribraria spinispora Lado & D.Wrigley sp. nov., además se registran por primera vez tres especies para Sudamérica y 22 para Perú. Las plantas endémicas, especialmente los cactus, han tenido una especial importancia como substrato para los mixomicetes. Se reafirma el predominio del orden Physarales T.Macbr. en zonas áridas. Se incluyen comentarios sobre algunas recolecciones, así como micrografías al MEB de algunas especies. Se realizó una evaluación estadística de la diversidad de mixomicetes en el cardonal y una comparación entre esta zona, la costa seca de Perú y otros ambientes neotropicales xéricos. Los resultados muestran que las zonas áridas son ricas en mixomicetes y que cada una tiene un conjunto exclusivo de especies. Las diferencias parecen estar relacionadas con las plantas anfitrionas.

Results obtained from the first survey for myxomycetes in the hyperarid areas of Peru are reported. Sampling over three consecutive years was carried out at 96 localities between 0 and 1500 m elevation. A total of 78 species from 23 genera in all 6 myxomycete orders were determined from 723 collections of myxomycetes. One new species, Didymium peruvianum, is described, 2 species new to the Neotropics, 4 new records for South America and 41 additional new species for Peru are reported, increasing the country catalogue by over 50%. Results show that arid areas are rich in myxomycetes, and that each area has a unique species assemblage. Endemic plants had a particular relevance as myxomycete substrates. The predominance of the order Physarales in arid areas is reinforced, and the ecological importance of coastal fogs (garúas) is evident from the results. Comments are included on interesting or rare collections, as are SEM micrographs of several species and statistical evaluation of the results., Se dan a conocer los resultados del primer estudio realizado sobre los Myxomycetes de las regiones hiperáridas de Perú. El muestreo, realizado en tres años consecutivos, se ha llevado a cabo en 96 localidades situadas entre 0 y 1500 m de altitud. En total se obtuvieron 723 colecciones de mixomicetes, pertenecientes a 6 órdenes, 23 géneros y 78 especies. Se describe una nueva especie, Didymium peruvianum, 2 especies se citan por primera vez en el Neotrópico, 4 son nuevos registros para América del Sur y 41 especies más son nuevos registros para Perú, con lo que el catálogo del país se incrementa en un 50%. Los resultados muestran que las zonas áridas son ricas en mixomicetes, y que cada area tiene un conjunto único de especies. Las plantas endémicas, dominantes en estos ambientes, tuvieron una relevancia especial como sustrato para los myxomycetes. Se pone de manifiesto el predominio de los representantes del órden Physarales en las zonas áridas, lo que refuerza resultados previos, así como la importancia ecológica de las nieblas costeras (garúas). Se incluyen comentarios de las especies más interesantes o poco comunes, así como fotografías realizadas con microscopio electrónico de barrido, y una evaluación estadística de los resultados.