Forest In Mexico Research Articles

Duration of Cattle Ranching Affects Dung Beetle Diversity and Secondary Seed Removal in Tropical Dry Forest Landscapes.

Cattle ranching is an economic activity responsible for the loss of large extensions of tropical dry forest around the world. Several studies have demonstrated that the use of inadequate practices of this activity in tropical forests (e.g., fire, agrochemicals, and lack of rotational grazing systems of cattle in pastures) have negative consequences on dung beetle diversity and their ecological functions. In the present study, the influence of the cattle ranching duration gradient on the diversity of dung beetles and seed removal was evaluated. This study was carried out in pastures with different times of establishment of cattle ranching (between 4 and 40 years) in a tropical dry forest of Mexico. Overall, the species richness of dung beetles was similar along the gradient of grazing ages. However, the diversity of common (q1) and dominant (q2) species decreased and was associated with an increasing abundance of exotic species and a decreasing abundance of native species. Seed removal was mainly carried out by four beetle species, among which the exotic species Digitonthophagus gazella was the most important. The results establish that the duration of cattle ranching primarily influences the composition of dung beetle communities, as reflected in changes in the structure and function of their assemblages in the pastures. Although native dung beetles persist at low abundances along this gradient, the consequences of land use changes are undeniable in other similar ecosystems where these species could definitively disappear.

Land use history and landscape forest cover determine tropical forest recovery

Abstract To conserve biodiversity and combat climate change it is vital to restore forest ecosystems. Natural forest regrowth is a nature‐based solution to restore forests, but it has rarely been evaluated how this is affected by the combination of previous land use intensity and surrounding forest cover, and how this varies between the two main tropical forest types; dry and wet forests. Thirty‐three plots were established on abandoned agricultural fields in a dry (13 plots) and wet (20 plots) tropical forest in Mexico and monitored 3 years for the following tree community attributes: structure, diversity, regeneration mode, potential symbioses with N fixing bacteria and mycorrhizal fungi. Previous land use intensity was described using interviews, and landscape forest cover and fragmentation within a 1000 m radius surrounding the plots were quantified using satellite images. Variable importance analyses indicated that land use intensity was more important than forest cover and fragmentation for the state of the tree community attributes after 3 years. This suggests that previous land use impacts the start of succession and leaves important legacies on the vegetation. Land use intensity, forest cover and fragmentation were equally important in determining the change in tree community attributes over time, indicating that both management practices and dispersal shape subsequently community assembly. A higher land use intensity decreases tree richness recovery, while size of the largest forest patch decreases tree density and connectivity of these patches increases tree density. The dry forest had a faster increase in tree density recovery compared to the wet forest through a high initial resprouting capacity and abiotically dispersed trees. Synthesis and applications: Both a higher land use intensity and fragmented forest landscape decreases the speed of forest recovery, indicating that human actions and landscape transformation shape the course of succession. Restoration in fragmented forest landscapes through natural regeneration is more suitable in areas with low previous land use intensity, higher forest connectivity and abiotically dispersed species. Effective restoration should therefore consider both land use history and landscape forest cover and be tailored to local socio‐ecological conditions.

To stay or not to stay? Temporal shifts in dung beetle occupancy in a cloud forest landscape

Abstract Dynamic occupancy model estimates the probabilities of occupancy, detection, extinction and colonization of individuals throughout seasons and is, thus, a useful tool for identifying whether individuals select a site to improve population phenology and fitness. We used multi‐season dynamics occupancy models to assess how abiotic factors (monthly variation, percentage of forest and edge and temperature) and biotic factors (female abundance) affect the demographic dynamics of coprophagous beetles Deltochilum mexicanum and Dichotomius satanas that differ in their habitat preferences in a human‐modified landscape in a cloud forest in Mexico. For both species, we captured a total of 1069 individuals with a density of 48.2 individuals per trap in forest areas and 14.8 individuals per trap in non‐forest areas. The species differed in their spatiotemporal occupancy dynamics in the landscape. Specifically, we found that monthly variation, percentage of forest cover and percentage of edge affected the models for both species. Each species showed a specific set of explanatory covariates for the model parameters, indicating that phenological and demographic regulatory mechanisms act as drivers of the spatiotemporal occupancy in a year period. We highlight the importance of considering abiotic factors (landscape characteristics) as drivers of occupancy, especially in highly heterogeneous landscapes. Such understanding is relevant to establish the effects of the landscape on the distribution and occurrence of dung beetles by determining how forest and generalist species differ in colonization and extinction patterns with respect to their phenology.

A matter of time not of co-occurrence: temporal partitioning facilitates coexistence between coyotes (Canis latrans) and gray foxes (Urocyon cinereoargenteus) in temperate forests of Mexico

A matter of time not of co-occurrence: temporal partitioning facilitates coexistence between coyotes (Canis latrans) and gray foxes (Urocyon cinereoargenteus) in temperate forests of Mexico

Potential for carbon sequestration in severely degraded temperate climate sites: Acrisol and Andosol gullies in Mexico

Aim of study: We assessed potential carbon (C) sequestration in gullies formed in Acrisols and Andosols, on the basis of long-term field restoration trials and GIS analysis. Area of study: Two field trials in Michocán, Mexico, restored with Pinus pseudostrobus, Pinus greggii and Pinus devoniana in 2005 and 2009. Material and methods: Soil C content was analyzed from field samples, and C content of aerial tree biomass of the three Pinus species was estimated by means of allometric equations. The potential restoration area was calculated with a GIS using available layers from the INEGI (Mexican National Institute for Geography and Statistics). Main results: The spatial analysis showed that 1.83% of the Mexican territory are Acrisols and 1.18% are Andosols. From which, 40.87% of Acrisols and 42% of Andosols are eroded. The area with gullies was 2810 km² for both groups of soils within the elevational range of conifer forests in Mexico. C content at the two restored sites was on average of 1.27 t/ha. Soil C content in a 30-cm depth profile was 4.25 t/ha. The potential C sequestration for an average period of 13 years for an area of 2810 km² was 3.947 megatons of C (MtC). A total of four states ‒ Michoacán, Chiapas, Oaxaca, and Puebla ‒ concentrate 89% of the possible capture. Research highlights: Severely degraded sites where gullying is dominant have a high potential for C sequestration once erosion has been controlled and plant cover has been restored.

Assessing ecological traits of a secondary vegetation species in temperate forests of central Mexico: a case study

Background: Plant species used for reforestation purposes are idoneous if native, the use of species that are present in regeneration sources. High germination percentages under different light conditions and a broad phenological pattern enhance adaptability to environmental heterogeneity. Preference for species responsive to mycorrhizal inoculation is recommended. Questions: Is Solanum pubigerum a widespread species in temperate forests of central Mexico?, under which light conditions germination will be the highest?, how abundant is it in natural regeneration sources?, does inoculation with mycorrhizal fungi benefit its germination and growth? Studied species / data description / Mathematical model: Solanum pubigerum/distribution in central Mexico forests, germination and viability percentages, reproductive phenology, growth dependence on AM fungi/ Kruskal-Wallis test, synchrony, Spearman correlations, ANOVA. Study site and dates: Abies religiosa forest, Mexico City. August 2019 – July 2020. Methods: Seeds of S. pubigerum were exposed to different light qualities, their viability was monitored for two years. Its presence in natural regeneration sources was registered. Reproductive phenology was recorded, and seedlings were inoculated with arbuscular mycorrhizal fungi to assess their growth. Results: Highest seed germination occurred under white light conditions, with sustained viability after two years. The species was found in the seed bank across seasons, less abundantly in seed rain during the dry season. It exhibited extensive flowering and fruiting patterns. Mycorrhiza inoculation significantly boosted seed germination and growth. Conclusions: Solanum pubigerum is suitable for reforestation in central Mexico forests due to its high germination percentages and mycorrhizal responsiveness.

Caught in the Act: Incipient Speciation at the Southern Limit of Viburnum in the Central Andes.

A fundamental objective of evolutionary biology is to understand the origin of independently evolving species. Phylogenetic studies of species radiations rarely are able to document ongoing speciation; instead, modes of speciation, entailing geographic separation and/or ecological differentiation, are posited retrospectively. The Oreinotinus clade of Viburnum has radiated recently from north to south through the cloud forests of Mexico and Central America to the Central Andes. Our analyses support a hypothesis of incipient speciation in Oreinotinus at the southern edge of its geographic range, from central Peru to northern Argentina. Although several species and infraspecific taxa have been recognized in this area, multiple lines of evidence and analytical approaches (including analyses of phylogenetic relationships, genetic structure, leaf morphology, and climatic envelopes) favor the recognition of just a single species, V. seemenii. We show that what has previously been recognized as V. seemenii f. minor has recently occupied the drier Tucuman-Bolivian forest region from Samaipata in Bolivia to Salta in northern Argentina. Plants in these populations form a well-supported clade with a distinctive genetic signature and they have evolved smaller, narrower leaves. We interpret this as the beginning of a within-species divergence process that has elsewhere in the neotropics resulted repeatedly in Viburnum species with a particular set of leaf ecomorphs. Specifically, the southern populations are in the process of evolving the small, glabrous, and entire leaf ecomorph that has evolved in four other montane areas of endemism. As predicted based on our studies of leaf ecomorphs in Chiapas, Mexico, these southern populations experience generally drier conditions, with large diurnal temperature fluctuations. In a central portion of the range of V. seemenii, characterized by wetter climatic conditions, we also document what may be the initial differentiation of the leaf ecomorph with larger, pubescent, and toothy leaves. The emergence of these ecomorphs thus appears to be driven by adaptation to subtly different climatic conditions in separate geographic regions, as opposed to parapatric differentiation along elevational gradients as suggested by Viburnum species distributions in other parts of the neotropics.

Two new species of Platynothrus and Heminothrus (Oribatida: Crotoniidae) from Mexico

The oribatid mite genera Platynothrus and Heminothrus currently comprise 20 and 10 species, respectively, and collectively have a cosmopolitan distribution. They have been classified into three to five subgenera, depending on the classification. For Platynothrus, a couple of new species have been described in the last two years, while for Heminothrus, the last formal description of a new species was 26 years ago. In this study, we describe two new species of these crotoniid mites, discovered in the soil and litter of a tropical montane cloud forest in Mexico. One of these new species belongs to the genus Platynothrus, which can be distinguished from other species of this genus by the short clavate sensillus, curved smooth interlamellar seta, and the length of the notogastral setae. The second new species belongs to the genus Heminothrus, being characterized by a short rhomboidal sensillus and a very long interlamellar seta. Intraspecific genetic distances of the COX-1 mitochondrial marker were 2.15%, and 0.81% for the new Platynothrus and Heminothrus species, respectively.

Crown cover of a dominant pioneer legume affects tree species regeneration in a secondary tropical dry forest

Background: Individual pioneer tree species often dominate early tropical dry forest succession and thereby affect possible successional pathways. Mimosa acantholoba var. eurycarpa is a highly dominant species in the tropical dry forest in Mexico.
 Hypothesis: Mimosa acantholoba var. eurycarpa exerts an inhibitory effect on the germination, establishment, survival, and early growth of light-demanding pioneers, while facilitating these processes for shade-tolerant old-growth forests species.
 Studied species: Lonchocarpus torresiorum, Lysiloma divaricatum, Mimosa acantholoba var. eurycarpa and Vachellia farnesiana.
 Study site and dates: Nizanda, Oaxaca, Mexico, 2020-2021.
 Methods: In 12 early successional plots, we applied three levels of crown cover removal (100, 50, and 0 %) of established trees of the dominant pioneer legume (M. acantholoba var. eurycarpa). We sowed seeds of the four study species in each experimental plot and recorded their germination, establishment, survival, and early growth over a 2-mo period.
 Results: The removal of crown cover of established M. acantholoba var. eurycarpa trees did not significantly affect germination. Lysiloma divaricatum had the highest germination probability, the fastest germination, and the highest establishment probability regardless of treatment. Lonchocarpus torresiorum had the highest establishment probability in plots where the crown cover of established M. acantholoba var. eurycarpa trees was removed The survival probability of both shade-tolerant species was highest in the 100 % removal treatment.
 Conclusions: Despite successful germination of shade-tolerant species, their survival is inhibited under the dense canopy of the dominant legume. Therefore, interventions to reduce the crown cover area of this dominant legume may stimulate forest recovery.

Assessing the impact of land use change on different components of plant diversity in a tropical montane cloud forest of Mexico

Assessing the impact of land use change on different components of plant diversity in a tropical montane cloud forest of Mexico

Genetic and morphological differentiation among populations of the narrowly endemic and karst forest-adapted Pilea pteridophylla (Urticaceae)

In this study, the influence of geographic isolation on the levels of morphological and genetic differentiation among populations of the karst forest-adapted Pilea pteridophylla (Urticaceae) was evaluated. Based on our results, there is a strong morphological differentiation among the only two know populations of Pilea pteridophylla. Both populations can be clearly differentiated based on vegetative and reproductive characters, and the observed variation is geographically structured. Moreover, our genetic data from the chloroplast genome show strong levels of population differentiation and no shared haplotypes were observed between populations. Also, our estimation of divergence times supports a long-term isolation hypothesis between populations. Based on our results, dispersal seed limitation, long-term forest isolation and topographic heterogeneity (local adaptation) are related to high levels of endemism and species turnover in the mountain karst forests of Mexico.

Fire effect on the diversity of forest species in a medium superennifolia forest of Mexico

Objective: Evaluate the effect of fire on natural regeneration and forest species diversity in a medium superennifolia forest in southeastern Mexico.
 Design/methodology/approach: Natural regeneration was classified into three height categories (0 to 30 cm, 31 cm to 1 m and 1 to 3 m) and trees in three forest sites burned and unburnt by fire.
 Results: A total of 1193 individuals belonging to 69 species in 29 taxonomic families were recorded. Regeneration from 0 to 30 cm presented significant differences in species diversity in unburnt forest sites, while in regeneration from 1 to 3 m in burned forest sites.
 Limitations on study/implications: These types of studies are a first approximation to natural regeneration after a fire in tropical forests, so it is important to maintain permanent sites to monitor the recovery of ecosystems and thus be able to establish management strategies for the restoration of these ecosystems.
 Findings/conclusions: Regeneration after the fire was established with a low but constant number of species, indicating a tendency towards vegetation resilience. This information allows government institutions to make better decisions on the management and prevention of these ecosystems in Mexico.

Thelephora pacifica (Basidiomycota: Thelephorales), a new species of the tropical forests in the Mexican Pacific coast

Thelephora is a genus of ectomycorrhizal fungi distributed in angiosperm and gymnosperm forests around the world. In this study, we describe Thelephora pacifica, a new species associated with tropical oak forests in Mexico. Phylogenetically, it is the sister group of T. pseudoganbajun from China. Morphologically, it corresponds to T. vialis previously reported in Mexico. Thelephora pacifica has a flabelliform basidiocarp with a hymenophore of grayish-brown color with pinkish tinges contrasting with the yellowish-olive margin. It is distributed in the Pacific forests of Mexico, an area with a high potential for endemism.

Current status of the remaining Mexican cloud forests: landscape findings and conservation initiatives.

Tropical montane cloud forests are known for their unique biodiversity and their critical role in sustaining ecosystem services; however, approximately 50% of their original cover in Mexico was estimated to have been lost by 1998. The Mexican ecoregion that supports these ecosystems experienced one of the highest rates of deforestation between 2001 and 2021. Thus, a more recent evaluation of Mexico's cloud forests is required. There is limited data on the landscape structure of cloud forests in Mexico, despite the possible application of landscape factors in conservation planning. Here, we estimated the average total area, number of patches, effective mesh size, total edge, and the shape of mixed forests that was present in 2020 within polygons of cloud forests defined in 1999 by Mexico's National Commission for the Use and Knowledge of Biodiversity (CONABIO for its acronym in Spanish). We estimated land cover using data from the North American Land Change Monitoring System, which classifies cloud forests as mixed forests. We found that eight out of the 109 polygons have no mixed forests and that an average of 49% of the 1,768,914 ha of cloud forests polygons are now covered by mixed forests distributed across 13 states. Additionally, within the remaining 101 polygons that do contain this type of vegetation, mixed forest is distributed on average across 140 patches (range = 1-1,473); 80% of these forests have very low effective mesh size values; 90% of them have low total edge values (<2,000 km); and their shapes tend to be uniformly distributed. Furthermore, most of cloud forest polygons are located outside of federal protected areas. Overall, our results suggest that the remaining Mexican cloud forests are extremely vulnerable and fragmented and that their extent has steadily declined since 1999. To ensure the survival of Mexican cloud forests, it will be crucial to prioritize high-diversity areas, strengthen protection in critical zones, establish ecological corridors, encourage sustainable practices, and actively engage local communities. This study highlights the complex issues and inherent heterogeneity that characterize cloud forest ecosystems in Mexico and provides crucial insights for conservation.

How does urbanization affect the fauna of the largest urban forest in Mexico?

Animals in urban forests provide ecological and cultural services, but the quality of these services often depends on floral diversity and animal diversity. In turn, animal diversity in urban forests is influenced by various aspects of habitat quality, in spatial scale- and taxon-dependent ways. Understanding the effect of individual habitat factors on different animal groups can provide valuable information for urban forest management. We estimated the relationships of 25 environmental, vegetation, land cover and anthropogenic perturbation variables to the fauna of Chapultepec Forest within Mexico City, Mexico. We included flower-visiting flies (Diptera: Bombyliidae, Syrphidae), bees (Hymenoptera: Apoidea), butterflies (Lepidoptera: Papilionoidea), birds, and reptiles (Squamata and Testudines). Insect populations were more strongly affected by herb and flower variables, while variables related to trees and shrubs were more important to vertebrate taxa. In general, human density, buildings cover and pavement cover were the most relevant anthropogenic perturbation factors. Birds and butterflies were more tolerant of urbanization than the other groups. Effects for each taxon are discussed. Our results suggest that urban park management plans should focus on enhancing habitat heterogeneity and vegetation structure complexity. Specifically, maintaining herb and tree diversity would likely promote animal diversity and ecosystem services in the Chapultepec Forest.

New Suctobelbidae (Acari, Oribatida) from Mexico

ABSTRACT Two new suctobelbid mite species (Oribatida, Suctobelbidae), Suctobelbella (Flagrosuctobelba) crassisetosa sp. nov. and Suctobelbila tetrasetosa sp. nov. are described based on adults collected from leaf litter in secondary semi-evergreen tropical forest in Mexico. Suctobelbella (F.) crassisetosa sp. nov. is similar to S. (F.) muronokiensis and S. (F.) plumosa in having thick notogastral setae and numerous lateral teeth on the rostrum, but differs from both by the number of genital setae, and the morphology and length of some notogastral setae. Suctobelbila tetrasetosa sp. nov. is similar to S-bila dentata in having one pair of notogastral tubercles, three pairs of simple lateral teeth on the rostrum and short notogastral setae, but differs from the later by the number of genital setae and the presence of long notogastral cristae.

New faunistic and taxonomic data on oribatid mites (Acari: Oribatida) of Mexico

This study is based on oribatid mite materials collected from leaf litter in secondary semi-evergreen tropical forests in Mexico; 85 species from 64 genera and 37 families are found; of these, 15 species are recorded for the first time in Mexico, and three species are recorded for the first time in the Neotropical region. A new species of the genus Mucrobates (Scheloribatidae) – Mucrobates solidarensis sp. n. – is described. An identification key to the known representatives of Mucrobates is presented.

Physiological and Phenotypic Plasticity of Ferns in a Tropical Dry Forest in Mexico

The study of the causes and expressions of physiological and phenotypic plasticity in plants is crucial to understanding the responses of plants to environmental heterogeneity, which may reflect central aspects of plant strategies.

Tree species differ in plant economic spectrum traits in the tropical dry forest of Mexico.

In tropical dry forests, studies on wood anatomical traits have concentrated mainly on variations in vessel diameter and frequency. Recent research suggests that parenchyma and fibers also play an important role in water conduction and in xylem hydraulic safety. However, these relationships are not fully understood, and wood trait variation among different functional profiles as well as their variation under different water availability scenarios have been little studied. In this work, we aim to (1) characterize a set of wood anatomical traits among six selected tree species that represent the economic spectrum of tropical dry forests, (2) assess the variation in these traits under three different rainfall regimes, and (3) determine the relationships between wood anatomical traits and possible functional trade-offs. Differences among species and sites in wood traits were explored. Linear mixed models were fitted, and model comparison was performed. Most variation occurred among species along the economic spectrum. Obligate deciduous, low wood density species were characterized by wood with wide vessels and low frequency, suggesting high water transport capacity but sensitivity to drought. Moreover, high cell fractions of carbon and water storage were also found in these tree species related to the occurrence of abundant parenchyma or septate fibers. Contrary to what most studies show, Cochlospermum vitifolium, a succulent tree species, presented the greatest variation in wood traits. Facultative deciduous, high wood density species were characterized by a sturdy vascular system that may favor resistance to cavitation and low reserve storage. Contrary to our expectations, variation among the rainfall regimes was generally low in all species and was mostly related to vessel traits, while fiber and parenchyma traits presented little variation among species. Strong functional associations between wood anatomical traits and functional trade-offs were found for the six tree species studied along the economic spectrum of tropical dry forests.

DIVERSIDAD MORFOLÓGICA DE Ardisia compressa Kunth, DEL NORESTE DE CHIAPAS, MÉXICO

&lt;p&gt;&lt;strong&gt;Background&lt;/strong&gt;. &lt;em&gt;Ardisia compressa &lt;/em&gt;Kunth, is a wild species native from tropical evergreen forests of Mexico, it produces fruits with phytochemical, ecological and dietary potencial. Its fruits are appreciated by people from local communities. However, in Mexico there are no studies that allow knowing the state of its phenotypic diversity. &lt;strong&gt;Objective.&lt;/strong&gt; Characterize the morphological diversity of &lt;em&gt;A. compressa&lt;/em&gt; populations from Chiapas state, Mexico. &lt;strong&gt;Methodology&lt;/strong&gt;. Ninety individuals of nine wild populations of &lt;em&gt;A. compressa &lt;/em&gt;were evaluated using 45 morphological traits (16 qualitative and 29 quantitative). The qualitative data were subjected to descriptive analysis and quantitative data were used in an analysis of variance (ANOVA) and finally the qualitative and quantitative data were analyzed simultaneously by means of a multivariate analysis with the Ward-MLM Method. &lt;strong&gt;Results. &lt;/strong&gt;The qualitative traits showed phenotypic variability in the characteristics of leaf and fruit color. The quantitative data showed significant differences (&lt;em&gt;P&lt;/em&gt;≤ 0.05) in all traits evaluated. The results of the principal component analysis (PCA) and cluster analysis (UPGMA) grouped the populations into three morphological groups differentiated by the similarity of the morphological traits of the populations and not by their geographical origin. &lt;strong&gt;Implications.&lt;/strong&gt; The results in this study should be considered to implementing strategies of plant production and conservation of &lt;em&gt;A. compressa&lt;/em&gt;. &lt;strong&gt;Conclusion. &lt;/strong&gt;A wide phenotypic variability was found organized into three morphological groups defined base on characteristics of tree height, number of fruits, number of flowers and ratio of length to thickness leaf. The quantitative traits allowed us to observe the greatest morphological variability in the populations of &lt;em&gt;A. compressa&lt;/em&gt;. &lt;/p&gt;