Los Tuxtlas Biosphere Reserve Research Articles

Climatic effects on primary and secondary growth of Pinus oocarpa trees in southern Mexico

We analyzed the influence of the local climate and three large-scale climatic phenomena on primary (crown) and secondary (radial) growth of 35 Pinus oocarpa trees in the Los Tuxtlas Biosphere Reserve in southeastern Mexico. Whereas local satellite data of the Normalized Difference Vegetation Index (NDVI) was employed to analyze primary growth, annual tree-ring widths were measured and averaged across trees to quantify secondary growth for the site. For primary growth, a monthly time series of 26 years (1982-2008) resulted for the site. For secondary growth, the annual time series of tree-ring widths was for 45 years (1965-2008). The NDVI positively correlated with precipitation for March to May (r = 0.56), and tree-ring widths for January to June (r = 0.63). Maximum temperature correlated negatively with the NDVI for June to July (r =−0.55) and tree ring widths for June (r = -0.55). The results from correlation analysis and spatial correlation maps highlight the negative influence of the Pacific Ocean and the positive influence of the Atlantic Ocean on both types of growth, by causing large-scale climatic phenomena that affect the regional climate. The NDVI and radial growth positively correlated from April to July (r = 0.44), when both growth types resume concurrently, suggesting that carbohydrates produced in the crown lead to increased radial growth at the beginning of the growing season. Our study highlights the differential effects of large-scale climate phenomena on primary and secondary tree growth in a widespread tropical pine species in Mexico.

The ecological functions of dung beetles are shaped by multiple dimensions of diversity

Abstract A mechanistic understanding of the relationship between multiple dimensions of species diversity and ecosystem functioning is needed to safeguard ecological processes critical to human well‐being. We evaluated how taxonomic, functional and phylogenetic diversities, as well as the assembly mechanisms of dung beetle communities, percent forest cover and landscape fragmentation, affect dung burial, soil excavation efficiency and dung fly larvae abundance in Los Tuxtlas Biosphere Reserve, a complex tropical landscape. Dung beetle functions were measured in 15 landscapes representing a gradient of forest cover loss (0%–100%). Phylogenetically clustered assemblages of large tunneler dung beetles showed the highest dung burial efficiency across the landscape. Fly larvae abundance was negatively correlated with the taxonomic diversity and functional evenness of dung beetles. Forest cover and landscape fragmentation did not significantly affect dung burial effectiveness, suggesting a high degree of functional redundancy. Dung burial efficacy is mainly driven by selection mechanisms, in which a single or a few phylogenetically close species disproportionately affect a given function. Fly larvae abundance was controlled by a complementary functional effect where each dung beetle species additively affected fly larvae survival. Hence, multiple functions are maintained by contrasting mechanisms and different diversity dimensions. High dung beetle species richness may foster pest fly control in tropical landscapes such as Los Tuxtlas Biosphere Reserve. Our findings highlight the need to assess multiple dimensions of diversity since each can operate concurrently and contrastingly on the different ecological functions of species assemblages.

Influence of phylogenetic, environmental, and behavioral factors on the gut bacterial community structure of dung beetles (Scarabaeidae: Scarabaeinae) in a Neotropical Biosphere Reserve.

Gut bacteria help dung beetles metabolize nutrients contained and synthesize those unavailable in their food, depending on the ecological scenario in which they develop. However, less is known about the influence of environmental and behavioral factors on the taxonomic composition of bacterial gut communities in Scarabaeinae beetles. To address this research topic, we analyzed 13 tropical dung beetle species in the Los Tuxtlas Biosphere Reserve, Mexico, to understand how the beetle tribe, habitat, food preference, food relocation, and parental care influence the composition of gut bacterial communities. We found that the beetle tribe is the primary factor impacting the taxonomic composition of gut bacterial communities. Among them, Deltochilini displayed the highest variability in diversity due to the different combinations of habitat and food preferences among its species. On the other hand, the other tribes studied did not exhibit such variable combinations. Habitat emerged as the second most influential factor, with forest-dwelling beetles displaying higher diversity. This can be attributed to the heterogeneous environments within tropical forests, which offer a greater diversity of food resources. In contrast, grassland beetles, living in more homogeneous environments and relying on cow feces as their main food source, exhibited lower diversity. Our findings suggest a correlation between bacterial diversity and food resource availability in complex habitats, such as tropical forests, which offer a wider array of food sources compared to simpler environments like grasslands.

Temporal changes of taxonomic and functional diversity in dung beetles inhabiting forest fragments and pastures in Los Tuxtlas Biosphere Reserve, Mexico

We evaluated short- (among months within-years) and long-term (between 1999-2000 and 2016-2017) temporal patterns of taxonomic and functional β- diversity (and its components of substitution and gain/loss) of dung beetle assemblages in forest fragments and pastures in the Los Tuxtlas Biosphere Reserve (LTBR). Habitat type affected the taxonomic dissimilarity and the richness difference component, with average values being respectively 1.42 and 1.56 times higher in pastures than in forest fragments. Only habitat type was important for functional richness, being 1.93 and 1.69 higher in forest fragments than pastures in 1999-2000 and 2016-2017, respectively. Pastures were taxonomically and functionally poorer but were also more temporally dynamic than forest fragments both within-year and between-years. Habitat type is a determining factor for temporal dynamics, with forest fragments presenting more stable dung beetle assemblages than cattle pastures.

One step forward, two steps backward: The frailty of howler monkey conservation in Los Tuxtlas, Mexico.

Most primate taxa are threatened by extinction and their populations are decreasing. The persistence of primates is thus conditional on conservation actions aimed at protecting them and their habitat. Here, we focus on the conservation of mantled howler monkeys (Alouatta palliata) in the Los Tuxtlas Biosphere Reserve, Mexico. Following the creation of the reserve in 1998, habitat availability and howler monkey abundance increased, suggesting that progress was being made in terms of the conservation of this species. Recent events, however, suggest otherwise, as mantled howler monkey habitat within the biosphere reserve is being disturbed by mining operations endorsed by the Mexican government. We report this case to raise awareness about the challenges for primate and habitat conservation in protected areas.

Dung beetles maintain phylogenetic divergence but functional convergence across a highly fragmented tropical landscape

Abstract Understanding how human‐modified landscapes affect the phylogenetic composition and assembly mechanisms of biological communities is critical for effectively managing and restoring tropical ecosystems. We evaluated how forest coverage loss, fragmentation and landscape heterogeneity affect the phylogenetic diversity of dung beetles and their assembly mechanisms in Los Tuxtlas Biosphere Reserve, a protected but highly fragmented tropical landscape. We calculated Faith's phylogenetic diversity, mean pairwise phylogenetic distance and mean nearest taxon distance for 5,388 individuals in 36 species. The standardised effect sizes of these metrics were estimated to control their correlation with species richness. Phylogenetic diversity was also assessed separately for each dung beetle functional group. Finally, we compared the mean functional and phylogenetic pairwise distance and mean nearest taxon distance and measured the phylogenetic signal among dung beetle functional traits to determine the influence of niche conservatism on the phylogenetic structure of species assemblages. Faith's phylogenetic diversity of dung beetles was positively correlated with forest coverage, while their mean phylogenetic and nearest taxon distance values decreased with increasing landscape fragmentation. Necrophagous beetles and forest specialists responded most negatively to forest coverage loss and fragmentation. Alpha and beta diversity values showed phylogenetic overdispersion but functional convergence and weak phylogenetic signals in their functional traits, suggesting low niche conservatism. Landscapes with moderate forest coverage (≥40%) favoured higher phylogenetic beta diversity, whereas phylogenetic and functional beta diversity decreased significantly in landscapes with low forest coverage (<30%). Synthesis and applications. Forest habitats in fragmented landscapes are essential for safeguarding the evolutionary history of dung beetles, reducing biotic homogenisation processes by favouring phylogenetic overdispersion and complementarity between sites. Therefore, to secure the phylogenetic diversity of dung beetles within fragmented tropical reserves, we recommend protecting the existing forests, preventing further fragmentation of continuous forest areas and increasing matrix quality by implementing biodiversity‐friendly production systems. Finally, managers should consider assessing different functional groups in other species, as their response to landscape disturbance may not be phylogenetically similar. The above will allow more effective management practices to protect the species most susceptible to disturbances.

The influence of anthropogenic noise on the behavior of male mantled howler monkeys.

Anthropogenic noise is increasingly disturbing natural soundscapes and affecting the physiology, behavior, and fitness of wildlife. However, our knowledge about the impact of anthropogenic noise on wild primates is scant. Here, we assess the effects of anthropogenic noise on the behavior of male mantled howler monkeys (Alouatta palliata). Specifically, we describe the types, rates, and sound pressure level (SPL) of anthropogenic noise that occurs in areas inhabited by mantled howler monkeys and determine if the behavioral responses of males to anthropogenic noise are influenced by noise attributes. For 1 year (1753 h), we characterized anthropogenic noise in the Los Tuxtlas Biosphere Reserve (Veracruz, Mexico) and studied the behavior of males belonging to five groups. Anthropogenic noise was common, diverse, and varied among areas in terms of rate, type, and SPL. Males did not display behavioral responses toward most (60%) anthropogenic noises, but were more likely to respond to certain noise types (e.g., aerial traffic) and toward noise with high SPL. Group identity influenced the likelihood of displaying behavioral responses to noise. The most common behavioral responses were vocalizations and vigilance. Males vocalized in response to noise with high SPL, although this relationship depended on group identity. The effect of the number of noises on vocalizations also varied among groups. Males were more likely to display vigilance toward high SPL and infrequent noise, but, again, these relationships varied among groups. In sum, anthropogenic noise is pervasive in areas inhabited by mantled howler monkeys and influences male behavior. Experience and frequency of exposure may modulate the behavioral responses of male mantled howler monkeys to noise and explain the group differences.

Arboreal elements of the agricultural matrix as structural connecting devices in fragmented landscapes – A case study in the Los Tuxtlas Biosphere Reserve

Agriculture is one of the main drivers of deforestation worldwide, generating highly fragmented landscapes that severely limit the mobility of forest species. Knowledge of the state of previously forested landscapes, taking into account all of its arboreal elements (including isolated trees, living fences, riparian corridors, and others) is a necessary first step to gaining a better understanding of the ecological dynamics of anthropic landscapes, and for designing conservation and management plans that enhance functional connectivity within these landscapes. We used high-resolution images (2.5 m/pixel) to identify all of the arboreal elements—from single tree crowns up to large forest fragments—for 40,000 ha of the Los Tuxtlas Biosphere Reserve. We included isolated trees, usually ignored in most inventories of fragmented landscapes, but which together with the other arboreal elements play an important role as landscape connectors and extra habitat for many species. Using a graph theory approach, we assessed landscape connectivity at six inter-patch distances across open areas (from 50 to 500 m), and propose two strategies for improving landscape connectivity: the creation of woodland islets and the widening of forested riparian corridors in the agricultural matrix. The main arboreal elements that influenced connectivity were old-growth forest fragments and widespread treed living fences, each increasing connectivity by up to 57% (depending on the threshold distance), while riparian corridors and isolated trees contributed 38% and 6%, respectively. Isolated trees in pastures substantially increased the number of effective connections at all distances (>85%). The GIS-simulated restoration proposals to establish circular woodland islets (10 m radius) in the middle of open agricultural areas increased connectivity by 26%, while widening riparian corridors by up to 10 m per riverside increased it by 11%. Increasing the number of arboreal elements within the agricultural matrix at key sites would enhance landscape connectivity considerably, benefiting the organisms that live in forest remnants in the study area without the need to stop agricultural activities.

Long-term assessment of the translocation of an endangered primate into an agroforestry system

Translocation is increasingly being used as a conservation tool in wildlife management, but long-term assessments of the animals’ establishment in the new habitat are rarely done. In addition, finding protected areas for translocations can often be a limitation, but habitat patches managed for productive purposes could potentially be used for translocations. Here, we present a translocation case study of the Endangered Mexican howler monkey Alouatta palliata mexicana into a forest fragment managed as an agroforest in the Los Tuxtlas Biosphere Reserve (Mexico). We compared the behavior of the translocated focal group 6 yr after translocation with that observed 1 yr after translocation (Year 1 vs. Year 6), and with reference parameters for conserved forest. We also examined the 14 yr trajectory of the translocated population through published data. We found that in Year 6, monkeys spent less time on locomotion and more time consuming fruit than in Year 1. The focal group in Year 6 had doubled its activity area compared to Year 1. All behavioral parameters during Year 6 were similar to those reported for the species in conserved forest. During the first 14 yr, the translocated population increased at a rate of 1.29 ind. yr-1. We conclude that this translocation succeeded in establishing a thriving population and that certain agroforestry systems may be adequate habitat for primate translocations. We also discuss how the translocation of howler monkeys into defaunated habitats might help restore ecological functions associated with these primates, such as the dispersal of large-seeded plants. Long-term information on successful primate translocations has high practical value for designing adequate conservation strategies in anthropogenic landscapes.

Vulnerabilities and Threats to Natural Forest Regrowth: Land Tenure Reform, Land Markets, Pasturelands, Plantations, and Urbanization in Indigenous Communities in Mexico

Despite the economic and social costs of national and international efforts to restore millions of hectares of deforested and degraded landscapes, results have not met expectations due to land tenure conflicts, land-use transformation, and top-down decision-making policies. Privatization of land, expansion of cattle raising, plantations, and urbanization have created an increasingly competitive land market, dispossessing local communities and threatening forest conservation and regeneration. In contrast to significant investments in reforestation, natural regrowth, which could contribute to landscape regeneration, has not been sufficiently promoted by national governments. This study analyzes socio-ecological and economic vulnerabilities of indigenous and other peasant communities in the Mexican states of Veracruz, Chiapas, and Morelos related to the inclusion of natural regeneration in their forest cycles. While these communities are located within protected areas (Los Tuxtlas Biosphere Reserve, Montes Azules Biosphere Reserve, El Tepozteco National Park, and Chichinautzin Biological Corridor), various threats and vulnerabilities impede natural regeneration. Although landscape restoration involves complex political, economic, and social relationships and decisions by a variety of stakeholders, we focus on communities’ vulnerable land rights and the impacts of privatization on changes in land use and forest conservation. We conclude that the social, economic, political, and environmental vulnerabilities of the study communities threaten natural regeneration, and we explore necessary changes for incorporating this process in landscape restoration.

The Primate Cultural Significance Index: applications with Popoluca Indigenous people at Los Tuxtlas Biosphere Reserve

BackgroundThe study of the cultural significance (CS) of biodiversity provides key information to develop conservation strategies consistent with traditions and perceptions of human communities. In Los Tuxtlas Biosphere Reserve (TBR) in Mexico, the mantled howler monkeys (Alouatta palliata mexicana) and the black-handed spider monkeys (Ateles geoffroyi vellerosus) have historically coexisted with Popoluca Indigenous Peoples. This study sought to determine how the presence of a natural protected area (TBR location) and a range of sociodemographic factors (gender, age, origin, language proficiency, education level, religion) relate to the CS held by the Popoluca Indigenous People in relation to these two endangered primate species.MethodsThe first Primate Cultural Significance Index (PCSI) was designed as a composed index of 11 cultural variables (sub-indices) and was applied randomly to a representative size sample of people over 15 years old in two Popolucas communities, one within the TBR (Piedra Labrada = 81 people) and another outside (Los Mangos = 91). U Mann–Whitney tests were used to compare the PCSI between communities and Generalized Linear Models (GLM) to evaluate the sociodemographic factors of participants that influenced the sub-indices in the PCSI.ResultsThe cultural significance of spider monkeys held by the Popolucas was higher for the community within the TBR than for the community outside, while for howler monkeys it was higher outside. For both primate species across the two communities, the most relevant sub-indices were (1) interest in conservation and (2) touristic significance of primates. Sociodemographic factors of participants influenced nine sub-indices of cultural significance out of the possible 10 sub-indices applied for each primate species. The demographic factors that most influenced each sub-index for both species were location and gender.ConclusionsThe main differences found between communities may be linked to the conservation and sustainable development programs promoted by the reserve, as well as the greater persistence of Popolucan ancestral traditions within the boundaries of the reserve. We recommend that conservation efforts should focus on people less interested about primate conservation (women, non-natives and residents outside the reserve), and turn to the leadership of people more interested (native men who reside inside the reserve).

Habitat Use and Selection by the Collared Forest-Falcon (Micrastur semitorquatus) in the Tropical Rainforest of Los Tuxtlas Biosphere Reserve, Mexico

The availability of habitat determines patterns of habitat use and selection by raptors, and habitat loss in human-modified landscapes may influence habitat use by individual raptors. This is important for tropical forest-dependent species, which face an accelerated rate of habitat loss worldwide. I evaluated habitat use and selection by Collared Forest-Falcons (Micrastur semitorquatus) in the fragmented rainforest of the Los Tuxtlas Biosphere Reserve, state of Veracruz, Mexico. I conducted vantage point and transect observations combined with playbacks to survey Collared Forest-Falcons in March–June 2012 and 2013. I estimated habitat use and selection by forest falcons that inhabit low forest-cover and high forest-cover landscapes. In general, Collared Forest-Falcons selected primary forest and included higher proportions of this habitat within their territories and core areas. Even though the falcons avoided cattle pastures, individuals inhabiting low forest-cover landscapes included a higher proportion of this land cover within their territories, probably as a response to low forest availability in the landscape. Results from this study demonstrate that Collared Forest-Falcons preferentially selected primary rain forests but also used secondary forests in Los Tuxtlas Biosphere Reserve. Low forest-cover in the landscape may be influencing habitat use patterns of falcons, forcing them to use a higher amount of the suboptimal habitat, and increasing their risk of mortality with potential consequences for population dynamics.

Landscape effects on taxonomic and functional diversity of dung beetle assemblages in a highly fragmented tropical forest

We evaluated how the taxonomic and functional diversity of dung beetles responds to landscape fragmentation in Los Tuxtlas Biosphere Reserve (LTBR). We sampled dung beetle assemblages in 15 landscapes (spatial windows) representing a gradient of forest cover loss and evaluated the degree of forest fragmentation in each landscape. The percentage of forest coverage of each landscape had a significant positive effect on species richness (0D), Shannon diversity (1D), and functional divergence of dung beetles. Forest fragmentation was negatively related to Simpson diversity (2D), biomass, and functional evenness of dung beetles, whereas their functional richness expanded as forest fragmentation increased. Taxonomic and functional beta diversity were positively correlated; the former was driven mainly by species replacement and the latter by nestedness. Functional alpha and beta diversities varied mostly at random, as did the probability of co-occurrence between species. However, the few non-random positive associations between species involved small-bodied forest dung beetles. Species and their ecological traits are lost randomly in the landscape, suggesting a surprising resilience of dung beetle assemblages to forest cover loss. Nevertheless, loss and fragmentation of forest coverage had an unbalancing effect on dung beetle abundance and trait distribution, reducing their functional evenness, and divergence while favoring the establishment of small-sized species. In conclusion, although the LTBR has buffered further loss of dung beetle species and functional richness, it cannot effectively safeguard all aspects of their functional diversity. Our results suggest that the recovery of the original forest cover and large mammals is crucial for maintaining the taxonomic and functional diversity of dung beetles in tropical rainforests.

Diversity and activity patterns of medium- and large-sized terrestrial mammals at the Los Tuxtlas Biosphere Reserve, México

Studies on diversity of animal communities allow determination of their species richness and composition. This information is particularly relevant to establish sound conservation programs in biosphere reserves, where human activities should be focused on the sustainable use of natural resources and ensure biodiversity protection. This study estimated the diversity and species richness and determined the species composition and activity patterns of medium- and large-sized terrestrial mammals in the Los Tuxtlas Biosphere Reserve (LTBR) located in Veracruz, Mexico. We set 18 camera traps to record medium and large-sized terrestrial mammals from August 2016 to January 2017. We calculated the trapping rate, guilds, and activity patterns of species. Diversity was estimated with Hill numbers. We compared our estimates with other studies in tropical forest in Mexico. We obtained 308 independent captures of 13 species; Cuniculus paca and Dasyprocta mexicana were the species with the highest trapping rate. Order-0, order-1, and order-2 diversity values were 13.99, 6.50, and 4.75 effective species, respectively, which ranks LTBR the fourth-most diverse reserve of medium- and large-sized terrestrial mammals compared to six other tropical rainforest sites in southern Mexico. We recorded mammals representing five trophic guilds, of which frugivore-folivores (five species) and omnivores (three species) ranked highest. All recorded species were primarily nocturnal (six species) or diurnal (six species). Tamandua mexicana, Leopardus pardalis, L. wiedii, and Eira barbara are listed as endangered in the Mexican Official Standard Norm NOM-059-2019, and L. wiedii is listed as near threatened in the IUCN Red List of Threatened Species. We were able to record 40.6 % of the terrestrial mammal species known to inhabit the LTBR. The absence of large-sized species such as large predators and herbivores was notable. Comparison of medium and large-sized mammal diversity of camera trapping studies in Mexico show that landscape degradation is impoverishing terrestrial mammal communities.

Diversity begets diversity: Phorophyte and microsite relations of foliicolous lichens in the lowland rain forest at Los Tuxtlas Biosphere Reserve (Veracruz, Mexico)

AbstractWe analyzed the structure of foliicolous lichen communities in the northernmost lowland forest of the Neotropics, Los Tuxtlas Tropical Biology Station in Veracruz, Mexico, and its dependence on phorophyte and microclimate. Along a 420‐m long transect with 15 equidistant sampling points, within a 10 m radius of each point, we sampled a total 137 phorophytes and 411 leaves. The phorophytes represented 13 species, with diverse leaf traits regarding size, texture, presence of hairs and/or glands, and longevity, including: Astrocaryum mexicanum (Arecaceae), Chamaedorea ernesti‐augustii (Arecaceae), Costus scaber (Costaceae), Guarea glabra (Meliaceae), Heliconia latispatha (Heliconiaceae), Monstera acuminata (Araceae), Myriocarpa longipes (Urticaceae), Piper hispidum (Piperaceae), Poulsenia armata (Moraceae), Pseudolmedia oxyphyllaria (Moraceae), Salacia megistophylla (Celastraceae), Siparuna thecaphora (Siparunaceae) and Syngonium podophyllum (Araceae). NDMS ordination and cluster analysis grouped the phorophytes into hierarchically structured clusters variously correlated with microsite, phorophyte species and foliicolous lichen species richness. Indicator species analysis revealed statistically significant foliicolous lichen species characteristic for terminal clusters and for phorophyte species. We conclude that the principle of “diversity begets diversity” may apply, in that phorophyte diversity influences the diversity of foliicolous lichen communities through the manifestation of subtle phorophyte preferences, best seen in well‐developed communities on leaves with higher longevity. Thus, well‐preserved forest ecosystems, with a higher diversity of suitable phorophytes, will support a higher diversity of foliicolous lichens, a phenomenon that extents to epiphytes in general.

Aproximación a la percepción social del patrimonio natural y cultural entre sectores clave de turismo en Los Tuxtlas, Veracruz, México

Esta investigación analiza la percepción social del patrimonio natural y cultural (especialmente arqueológico) entre sectores claves de San Andrés Tuxtla y Catemaco, Veracruz, en la Reserva de la Biósfera de Los Tuxtlas. Metodológicamente, aplicamos entrevistas semiestructuradas para diagnosticar necesidades de formación sobre patrimonio natural y cultural a productores de bienes y servicios turísticos y funcionarios públicos, y realizamos talleres con enfoque colaborativo para sensibilizar, revalorizar y reactivar aspectos de cultura material e inmaterial que impulsen productos turísticos orientados a conservar el patrimonio natural y cultural. Los resultados muestran percepciones desiguales sobre el patrimonio natural y cultural, también un reconocimiento del potencial que representa la cultura y los elementos patrimoniales cuyo aprovechamiento puede ser beneficioso para las economías local y regional, siempre que haya una participación transversal de los sectores involucrados. Se concluye que es necesaria la valoración de la cultura para su inclusión en programas de formación sobre turismo cultural sustentable, fortalecer la vinculación entre sectores gubernamentales, sector privado, población local, académicos y turistas, recalcando la importancia de reactivar y reforzar las identidades de una sociedad asentada en un territorio cultural y ecológicamente rico.

Disentangling the effects of legacies from those of current land use on soil properties in Los Tuxtlas Biosphere Reserve, Mexico

Soil properties are the product of current land use as well as legacies of historic use. Disentangling these effects is particularly challenging in tropical landscapes where plot-level land use history consists of varied sequences of uses punctuated by periods of abandonment. Here, we studied the soils of 63 plots in three sites of the Los Tuxtlas Biosphere Reserve, Mexico, and used detailed landowner accounts of land use history to model the effects of land use and its legacies. Electrical conductivity, N-NO3− and ant species richness were higher in current land uses featuring developed canopies (forests, secondary growth and palm and coffee plantations) compared to intensive land uses (livestock pastures and maize-slash and burn). Land uses aimed at soil restoration (maize-mucuna and tree plantations on degraded soils) improved soil bulk density only with respect to intensive land uses. The most frequent effects of historical land use variables (time since forest felling and cumulative times under each land use type) on soil properties occurred in interaction with each other and independently of the current land use. Beta glucosidase activity, pH and nematode richness were explained exclusively by historical use. In general, the duration of use dictated soil deterioration; however, the accumulation of time under intensive land uses had stronger legacies, in terms of soil physical and chemical properties, compared to that under agroforestry (coffee and palm cultivation). The richness of four taxa was sensitive to the land use history variables. Surprisingly, Nematoda and plant symbionts (nitrogen fixing bacteria and arbuscular mycorrhizal fungi) richness, but not that of Coleoptera, increased with accumulated time (20–40 yr) under maize cultivation. We suggest that the long history of traditional maize cultivation in polycultures has permitted the development of a rich soil biota.

Habitat Use and Selection by the Collared Forest-Falcon (Micrastur semitorquatus) in the Tropical Rainforest of Los Tuxtlas Biosphere Reserve, Mexico

Habitat Use and Selection by the Collared Forest-Falcon (Micrastur semitorquatus) in the Tropical Rainforest of Los Tuxtlas Biosphere Reserve, Mexico

El ecoturismo como estrategia de fortalecimiento en las acciones de conservación ambiental: Un análisis regional en Los Tuxtlas, Veracruz, México

The Los Tuxtlas region in the South of the state of Veracruz is privileged by a diversity of aspects of its ecology and landscape, result of its volcanic geomorphology and its tropical climate, which allows the presence of mesophilic forests and humid forests. These forests provide numerous ecological services to the local populations and hold a great biodiversity, of importance on a national scale. Therefore, in 1998 under federal decree the Los Tuxtlas Biosphere Reserve was created, whose objective was to incorporate the inhabitants of this area in conservation strategies, through different mechanisms, including ecotourism. The present research analyses the contributions and impacts of this activity in terms of environmental conservation, considering ethnographic methods and a cartographic representation, which assist in the understanding of the activity’s territorial composition.

Spatial and temporal changes in the dung beetle diversity of a protected, but fragmented, landscape of the northernmost Neotropical rainforest

Abstract Studies addressing the temporal changes of ecological communities within fragmented forests transformed into natural protected areas are urgently needed. The creation of the Los Tuxtlas Biosphere Reserve (LTBR) in 1998 stopped the deforestation process of the northernmost tropical rainforest of the Neotropical region, allowing the analysis of the long-term effects on native communities after the halting of habitat fragmentation. We compared the diversity of dung beetles in 11 forest fragments and eight pastures in the LTBR between two periods: 1999–2000, the early years after the creation of the LTBR; and 2016–2017, i.e., 17 years later. Species richness and abundance of dung beetles were similar in both periods, being higher in forest fragments than in pastures; however, the dominant species were different in each period in both forest fragments and pastures. The number of habitat indicator species increased in 2016–2017 compared to 1999–2000, with a high species diversity of forest indicators relative to pasture indicators at both periods. Alpha and gamma diversities were lower in 1999–2000 than in 2016–2017. Beta-diversity at the spatial level was strongly driven by species turnover, which was higher in pastures than in forest fragments. All functional groups (dwellers, rollers, and tunnellers) showed higher abundances in forest fragments than in pastures in both 1999–2000 and 2016–2017 periods. Our results suggest that stopping the fragmentation process in the LTBR has allowed the survival of native dung beetle assemblages, which are undergoing a recovery process of their populations and ecological functions over the years.