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Entre las diversas ideas que se han propuesto para explicar la gran diversidad biológica de México está la que afirma que ésta es el resultado del contacto de las biotas neotropical y neártica; sin embargo, esta explicación relacionada con el gran contacto biótico de las Américas no es completamente satisfactoria y necesita ser revisada a la luz de la biogeografía histórica. En este artículo ofrecemos nuevas perspectivas sobre este asunto por medio de una revisión de la historia de la flora y la heterogeneidad vegetacional del trópico estacionalmente seco de este país. Se han usado varios criterios ambientales para definir las regiones tropicales estacionalmente secas, pero ubicar con precisión sus límites geográficos no es siempre fácil. Esto se debe en gran medida a la gran heterogeneidad de la vegetación presente en esta región, entre la que predomina el bosque tropical caducifolio (BTC). El origen de la flora del BTC se remonta, por lo menos, unos 20 millones de años antes del presente y parece estar asociada con la flora del Terciario de Norteamérica. La evidencia disponible no apoya un origen sudamericano para el BTC. Asimismo, no hay razones que justifiquen de forma convincente la separación de la flora del BTC y la de los desiertos calientes de Norteamérica en dos reinos biogeográficos diferentes. La historia de la flora del trópico estacionalmente seco de México sugiere fuertemente que esta dicotomía biogeográfica debería ser reemplazada por el reconocimiento de la existencia de un Reino Panamericano.

En un ecosistema degradado, que actualmente es objeto de restauración, analizar de manera detallada la estructura de la vegetación y describir su relación con especies de aves es muy relevante para su manejo. El análisis de la arquitectura de las plantas es un método visual para describir la estructura de la vegetación como resultado de su estrategia de crecimiento. Por medio de este método se analizó la oferta de hábitat de las aves insectívoras Myrmeciza longipes (hormiguero ventriblanco), Thamnophilus doliatus (batará rayado) y Synallaxis albescens (pijuí pechiblanco) como parte de un estudio poblacional y de calidad de hábitat en un remanente de bosque seco tropical de 11 079 hectáreas, en Huila, Colombia. Por medio de conteos y también con la información secundaria recopilada, se estableció cómo estas especies usan los diferentes estratos de la vegetación. Teniendo en cuenta que árboles con más perchas incrementan el forrajeo de aves insectívoras, que más perchas significan mayor refugio para las aves, y también que mayor cruce de perchas posibilitan la aparición de horquetas para el anclaje de nidos de estas especies, en 186 parcelas se determinó que la zona está dominada por siete modelos arquitectónicos, divididos en tres grupos según su oferta potencial de recursos del hábitat para las tres especies: 1) modelos arquitectónicos Roux, Petit y Prevost con una calidad alta; 2) modelos arquitectónicos Koriba y Nozerán con una calidad intermedia; y 3) modelos arquitectónicos McClure y Holttum con una calidad muy baja.

For Mexican temperate forests (MTFs), understood as mountain forest ecosystems formed by pine, oak and fir forests, the water-forest-nexus is unknown. Because of their range of climatic, topographic, and overall ecological particularities, estimates for other temperate forests may not be transferred. A systematic literature review has been carried out to compile information on hydrologic variables in MTFs. Existing knowledge specific for MTFs remains scarce, as the limited amount of studies (20) shows, but suggests a water-forest-nexus (higher infiltration offsets evapotranspiration losses, compared to other ecosystems), in central Mexico and some evidence exists for such a nexus in the transition zones to semi-arid environments, for which it is generally assumed that they spend more water in evapotranspiration than they capture. For MTFs, infiltration is statistically significantly larger and faster than in other vegetation types and is associated with the presence of litter in the upper soil layers. The water-forest nexus cannot be expected in tropical dry forests and shrubs, as interception and evapotranspiration are much higher in semi-arid climates and don't leave enough water for deep infiltration. MTFs play a special role compared to other vegetation types because of their structure (especially the presence of litter), composition and function and their geographic setting. MTFs are located in high elevation areas so that they receive larger amounts of precipitation, but at the same time show a decreased potential evapotranspiration because of a decrease in temperature with elevation.

Resumo A definição das zonas de vida de Holdridge é uma ferramenta útil para o planejamento da gestão territorial dos recursos naturais, bem como para subsidiar a elaboração de estratégias e políticas públicas que resultem na definição de áreas prioritárias para conservação e uso sustentável das florestas. Desse modo, o presente estudo teve por objetivo identificar e descrever as zonas de vida que ocorrem no estado do Ceará com base no modelo de Holdridge. Para esse propósito, foram utilizados dados de precipitação anual, biotemperatura e relação de evapotranspiração potencial. Os resultados indicaram que, embora o estado do Ceará esteja majoritariamente sob a influência de um macroclima semiárido, apresenta um espaço geográfico heterogêneo, no qual ocorrem diferentes zonas de vida associadas à diversidade bioclimática. A variável bioclimática mais importante para a classificação das zonas de vida foi a relação de evapotranspiração potencial, que representa a quantidade de água que é transferida para a atmosfera em relação a quantidade de água que é precipitada em determinado local. A classificação climática de Holdridge identificou oito zonas de vida em que todas pertencem à faixa latitudinal tropical e abrangem faixas altitudinais basais (90,04% do território cearense) e premontanas (9,96%), que variam em termos de umidade, desde florestas muito secas até florestas úmidas. A zona de vida mais extensa compreende as áreas de transição entre floresta muito seca e floresta seca tropical basal, ocupando 64.825,69 km2, que recobre 43,54% da área total do estado. Abstract The Holdridge life zone approach is a useful tool for planning the territorial management of natural resources as well as for supporting the development of strategies and public policies that result in the definition of priority areas for conservation and sustainable use of forests. Thus, in the present study, we aimed to identify and describe the life zones that occur in the state of Ceará based on the Holdridge model. For this purpose, we used data on annual precipitation, biotemperature and potential evapotranspiration ratio. The results indicated that, although the state of Ceará is mostly under the influence of a semi-arid macroclimate, it presents a heterogeneous geographic space, in which different life zones associated with bioclimatic diversity occur. The most important bioclimatic variable for the classification of life zones was the potential evapotranspiration ratio, which represents the amount of water that is transferred to the atmosphere in relation to the amount of water that is precipitated in a given location. The Holdridge climatic classification identified eight life zones, all located in the tropical latitudinal zone and basal (90.04% of the Ceará territory) and premontane (9.96%) altitudinal zones, which vary, in terms of humidity, from very dry forests to humid forests. The most extensive life zone comprises the transition areas between very dry forest and basal tropical dry forest, occupying 64,825.69 km2, which covers 43.54% of the Ceará territory.

To document sequestrate fungal diversity in American tropical regions, we performed a series of field surveys in southeastern Mexico and discovered two new species in the phalloid genus Restingomyces (Trappeaceae, Phallales). Here, we describe them based on morphological and phylogenetic analyses of mitochondrial adenosine triphosphatase (ATPase) subunit 6 and nuc 28S rDNA. Restingomyces guzmanianus is characterized by the brownish peridium, yellowish brown gleba, and ellipsoid basidiospores, whereas R. yaaxtax is characterized by the white peridium, pale green gleba, and small ellipsoid basidiospores. Both species occur in medium-statured tropical dry forest. The original diagnosis of the genus Restingomyces is emended to include these novel species. Illustrations are provided.

Objective: The objective of this study was to estimate the heritability (h2 ), repeatability (r), and correlations (r yi yi ) in some traits of zootechnical interest in a population of New Zealand white rabbits of a tropical dry forest area. Materials and Methods: Three mating groups were formed, each one of 1 male and 70 females. The traits evaluated were littersize at birth (LB), born alive (BA), born dead (BD), litter weight born alive (LW), litter weight at weaning (LWW), weaning weight (WW), slaughter weight (SW), and carcass weight (CW). Weaning took place at 42 days, and the fattening phase lasted 60 ± 3 days. A descriptive statistical study was carried out on the study variables. Paternal heritability was esti mated (h2 f ) and maternal (h2 m), repeatability, rabbit index IC, and Pearsons correlations (r yi yi ) between traits. The descriptive statistics showed high variation for the BD traits. Results: The values of the productivity found were similar to those presented in studies around the world. h2 presented magnitudes between low and medium. h2 f ranged between 0.09 and 0.42 and between 0.11 and 0.45 for h2 m. In general, the values of h2 m were higher than the values of h2 f . The r valuesforthe traits LB, BA, LW, LWW, and SW presented low magnitude, while it was medium for WW and CW. From the values of r, IC was calculated for each of the rabbits, allowing their categorization, which will be used in future selection plans. r yi yi among the variables ranged from −0.01 to 0.860. They were generally positive and mostly not significant (p > 0.05); they took a magnitude from low to moderate, except for the correlation between LB and BA. Conclusion: The production of rabbits under tropical conditions is similar to other reports. The genetic parameters evaluated were medium-to-low, indicating a robust non-additive gene and/ or environmental effect. [J Adv Vet Anim Res 2021; 8(3.000): 471-478]

Tropical dry forests are among the most threatened vegetation types in the world, exposed to even higher deforestation rates than rainforests. The largest tropical dry forest is the Caatinga, in the semiarid Northeast region of Brazil. Home to many endemic species and genera, the Caatinga has lost half of its original vegetation cover and become highly fragmented. Furthermore, the Caatinga is little protected by conservation units and subject to multiple human pressures. Brazil committed to the Convention of Biological Diversity’s Strategic Plan for Biodiversity 2011 -2020, including the Aichi Biodiversity Targets, requiring protection of 17 % of terrestrial habitats. Using GIS, we quantified the total area of Caatinga encompassed by fully protected and sustainable use reserves. We found that less than 8 % of the Caatinga is legally protected under Brazil’s national nature reserve legislation (SNUC law), and only 1.3 % is in reserves with full legal protection. We show that the geographical distribution of reserves is biased, leaving some regions of the Caatinga with very little protection. We conclude that Brazil has not met international conservation commitments with respect to the Caatinga and, despite a recent expansion of the protected area network, only small and unrepresentative portions of the Caatinga are effectively safeguarded.

El bosque seco tropical (bs-T) es uno de los ecosistemas más amenazados del planeta, como consecuencia de la presión antrópica. En el enclave subxerofítico del cañón del Chicamocha habita Cavanillesia chicamochae, especie endémica y amenazada que presenta poca supervivencia de sus plántulas, afectando la regeneración de sus poblaciones. El presente estudio evaluó la germinación de C. chicamochae con frutos, semillas y estacas, utilizando tres sustratos diferentes. Se emplearon tres tratamientos, los cuales consistieron en diferentes sustratos: T1: arena de río; T2: tierra negra; T3: mezcla 3/4 tierra -1/4 cascarilla de arroz y se utilizaron frutos, semillas desnudas y estacas. Se implementó un diseño completamente aleatorio con tres sustratos incluyendo frutos y semillas y se realizaron cuatro réplicas. Las variables analizadas se sometieron a un ANOVA; cuando las diferencias fueron significativas (p < 0,05), además se desarrolló un análisis de medias utilizando la prueba de rangos múltiples de Duncan. El porcentaje de germinación por semilla y fruto presentó diferencias significativas; el tratamiento de mayor eficiencia fue T1 (71%-semillas y 54%-frutos). Las semillas almacenadas en condiciones ambientales perdieron su viabilidad a partir de los cuatro meses. El mucílago presentó un adecuado valor bromatológico para la alimentación de rumiantes e importantes contenidos en metabolitos secundarios, con usos potenciales en el área farmacéutica, siendo un valor agregado para la especie. El estrés hídrico selecciona características de conservación del agua para garantizar la sobrevivencia de especies en el tiempo, una mejor comprensión de estas estrategias ayudará a predecir respuestas ante futuras sequías.

Introduction: Standing leaf litter represent an essential source of organic matter and nutrients to dynamize biogeochemical processes at the ecosystem level. Objectives: To characterize the accumulation and decomposition of organic materials and flow of nutrients from standing litter in an urban dry tropical forest in a successional stage, after 10 years of abandonment of agricultural activities, and to determine the potential use of three species in future active restoration activities. Materials and methods: Standing litter samples were collected from a forest fragment in Santa Marta, Colombia, separating leaves, reproductive material, woody material and other residues. Additionally, leaves of three species of interest for ecological restoration (Albizia niopoides Spruce ex Benth., Cordia alba [Jacq.] Roem. & Schult. and Machaerium milleflorum Dugand G. A.) were separated and Ca, Mg, K, N and P concentrations were determined. Results and discussion: Total standing litter was 8.3 Mg∙ha-1 with a mean residence time of two years. The leaves represented 20% of the standing litter, with a mean residence time of 1.4 years. Based on the decomposition constant (kj = 0.73) and the rate of leaf litterfall, organic matter returns accounted for 3.4 Mg∙ha-1∙year-1. Leaf decomposition rate decreased in the following order C. alba > M. milleflorum > A. niopoides. P represented the greatest limitation with low release rates (0.1 to 1.2 kg∙ha-1∙year-1). Conclusions: The passive restoration strategy allowed reactivation of biogeochemical cycle via fine leaf litter. Cordia alba showed potential for inclusion in restoration activities, with lower values for leaf N/P ratio, and higher rates for leaf litterfall, litter decomposition and nutrient release.

For better categorization of species according to foliar habit, a set of leaf and wood traits must be observed. Tropical forests are influenced by distinct regional rainfall regimes, microclimates, and dynamics of nutrient cycling, which are responsible for creating key biodiversity patterns and differences in leaf deciduousness to drought. Functional traits studies have improved understanding of the functioning and heterogeneity of complex ecosystems. We have reviewed the literature focusing mainly on tropical dry forests and relationships among leaf habits (evergreen and deciduous) and other leaf and wood traits. Thus, we have compiled 121 original papers, 2 reports, and 9 book chapters published since 2000. We also provide a meta-analysis of these traits from Neotropics. Tropical deciduous species often have high photosynthetic rates per mass and specific leaf area and traits that improve water flow throughout the plant, such as wide xylem diameters and high hydraulic conductivity, maximizing resource capture during a limited growing season because of an acquisition strategy. The opposite is observed in evergreen species, namely as conservative species. Regardless of the plant organ, more morphological than physiological traits are available to compare leaf habits. For better categorization of species according to foliar habit, a set of leaf and wood traits must be observed. However, while local comparisons based on one or few traits may group species according to leaf habit, multivariate analyses for large spatial scales can reveal a different pattern. We have identified some open questions that can be further addressed in this research field to contribute to the improvement of theoretical frameworks as well as the consequences of a changing climate for tropical dry forests.

The forests of South Africa and the neighbouring countries, including Lesotho, eSwatini, Namibia, Botswana, Zimbabwe, and Mozambique (south of the Zambezi River), were mapped and classified according to the global system of biomes. The new four-tier hierarchical biome system suggested in this paper includes zonobiome, global biome, continental biome (all recognised earlier), and regional biome – a novel biome category. The existing spatial coverages of the forests were revised and considerably improved, both in terms of forest-patch coverage and mapping precision. Southern Africa is home to three zonal forest types, namely Subtropical Forests (Zonobiome I), Tropical Dry Forest (TDF; Zonobiome II) and Afrotemperate Forests (Zonobiome X). These three biomes are characterised by unique bioclimatic envelopes. Five, two, and eight regional biomes, respectively, have been recognised within these zonal biomes. Recognition of the Zonobiome I and the global biome Tropical Dry Forests in southern Africa is novel and expands our knowledge of the biome structure of African biotic communities. The system of the azonal regional biomes is also new and comprehensively covers the variability of the azonal helobiomes (riparian woodlands and swamp forests), mangroves, and azonal coastal forests. In total, 11 azonal regional biomes have been recognised in the study area. The forest biomes in southern Africa were captured in our electronic map in the form of more than 60 000 polygons, covering 42 416 km2 (1.27% of the study area). No less than 83% of these forests occur in the territory of southern Mozambique.

Background: Despite long-lasting efforts to disentangle the drivers of orchid pollination, pollination success in tropical dry forest orchids remains largely unknown. Questions and hypothesis: How successful are pollination in three tropical dry forest orchids? How is pollination influenced by floral display and floral rewards (as suggested by floral micromorphology)? We hypothesized a positive effect of floral display on pollinia removal and deposition rates. Studied species: Barkeria whartoniana (C. Schweinf.) Soto Arenas, Clowesia dodsoniana E. Aguirre, and Cyrtopodium macrobulbon (La Llave & Lex.) G.A. Romero & Carnevali. Study site and dates: Nizanda (Oaxaca), Mexico; flowering periods of 2013 and 2014. Methods: We calculated pollinia removal and deposition rates, identified floral visitors and analyzed flower microstructure to search for structures potentially producing rewards. Floral display was measured through number of open flowers, and number and length of inflorescences, and its effect on pollination success was assessed through linear modeling. Results: Pollinia removal rates were higher than deposition rates, and floral display was related to pollination success in C. dodsoniana only. Visitation rates were low for the three species and most visitors were not true pollinators. The three species possess potentially secreting structures, but for B. whartoniana and C. macrobulbon these rewards are likely part of the pollinator deception mechanism. Conclusions: The generalized low pollination success implies the need for high population densities of both interacting parts. We emphasize the need for integrated evaluations of different aspects of the plant-pollinator interaction.

A better knowledge of how deadwood decomposes is critical for accurately characterizing carbon and nutrient cycling in forests. Fungi dominate this decomposition process, but we still have limited understanding of fungal community structuring that ultimately controls the fate of wood decomposition. This is particularly true in tropical ecosystems. To address this knowledge gap, our study capitalized on an extreme storm event that caused a large and synchronized input of deadwood to the forest floor. Here we report data for the first year of wood decomposition of trees in a Puerto Rican dry forest for nine tree species that were snapped by Hurricane Maria in 2017. We measured wood properties and the associated fungal communities after 12 months of decomposition and compared them with initial wood properties and stem-inhabiting fungal communities to identify the best predictors of wood decomposition rates and chemical changes. Changes in wood chemistry were primarily explained by rapid xylan losses, the main hemicellulose component for the studied tree species. Fungal communities were dominated by saprotrophic and plant pathogenic fungi and showed moderate changes over time. The initial relative abundances and ratios of different fungal functional guilds were significant predictors of both xylan and glucan losses, with plant pathogenic fungi accelerating cellulose and hemicellulose decomposition rates compared to saprotrophs. Our results confirm that fungi present at the time of treefall are strong drivers of wood decomposition and suggest that plant pathogenic fungi might act as efficient early decomposers of hemicellulose in dry tropical forests.

Linear infrastructure intrusions are common around the world to meet the needs of a growing and interconnected human population. The implementation of linear infrastructures involves numerous forms and mechanisms of land‐use transformation that can facilitate and serve as pathways to the spread of invasive non‐native species. However, the type and intensity of land transformations change over time and this can affect the frequency and intensity in which linear infrastructures route the spread of invasive species.Here, we present results collected over 5 years of monitoring surveys (2015–2019) to assess the relationship between the construction of one of the largest canals to date in Brazil and the spread of non‐native species. We studied the Integration Project of the Sao Francisco River (PISF), a canal fully inserted in the Caatinga biome, a tropical dry forest ecosystem for which information on invasion dynamics are little known.Our results confirmed PISF canals served as habitat and dispersal corridors for non‐native plant species. Monitoring surveys recorded 26 non‐native species established along the 83.2 km2 PISF deployment area. Eleven years after the canal deployment area was completely cleared of vegetation, 92.3% of its extension had non‐native plant populations. Of the 10 species assessed for their population status, 8 had invasive populations.The time immediately after construction work finished was the critical stage for the spread of non‐native woody plants, which increased their distributions with reduced levels of construction intervention, whereas most of the herbaceous species reduced their distributions. When human intervention was drastically reduced, many populations of non‐native plants rapidly formed at the deployment area.Policy implications. Man‐made linear infrastructures can remove biogeographical barriers and serve as pathways for the spread of invasive species over long distances and across ecosystems. Thus, the planning, construction and management of such infrastructures should include measures and funding for risk assessment, prevention, monitoring and control of biological invasions. Agencies responsible for environmental licensing should mandate invasive species management as part of the installation and operation licensing conditions. (English) [ABSTRACT FROM AUTHOR] Resumo: Intervencoes provocadas por infraestruturas lineares sao comuns ao redor do mundo para atender as necessidades de uma crescente e interconectada populacao humana. A implantacao de infraestrutura linear envolve inumeras formas e mecanismos de transformacao no uso do solo que podem facilitar e servir como corredores para a disseminacao de especies exoticas invasoras. No entanto, o tipo e intensidade das transformacoes do solo mudam ao longo do tempo e isso pode afetar a frequencia e intensidade com que infraestruturas lineares direcionam a propagacao de especies invasoras.Aqui nos apresentamos resultados coletados ao longo de cinco anos de campanhas de Monitoramento (2015 a 2019) para avaliar a relacao entre a construcao de uma das maiores infraestruturas lineares do Brasil no momento e a dispersao de especies exoticas. Nos estudamos o Projeto de Integracao do rio Sao Francisco (PISF), um canal totalmente inserido no bioma Caatinga.Nossos resultados confirmam que as estruturas do PISF agem como um corredor para a dispersao de especies de plantas exoticas. As campanhas de monitoramento registraram 26 especies exoticas estabelecidas ao longo de 83,2 km² da area de implantacao do PISF. Onze anos apos a area de implantacao ser completamente desmatada, 92,3% de sua extensao tinha populacoes de plantas exoticas. Das dez especies avaliadas quanto ao status populacional oito tinham populacoes invasoras.O periodo logo apos o termino da construcao foi o estagio critico para a disseminacao de arbustos, arvores e uma especie de liana exotica, que aumentaram suas distribuicoes em niveis reduzidos de intervencao no ambiente, enquanto a maioria das especies herbaceas reduziram suas distribuicoes. Quando o nivel de intervencao humana foi drasticamente reduzido muitas especies de plantas exoticas rapidamente formaram populacoes na area de implantacao.Implicacoes para politicas. Projetos de infraestrutura linear podem remover barreiras biogeograficas e atuar como corredores para a disseminacao de especies invasoras por longas distâncias, entre ecossistemas e em um curto periodo de tempo. O planejamento, construcao e manejo dessas estruturas deve incluir medidas e financiamento para avaliacoes de risco, prevencao, monitoramento e controle de especies exoticas invasoras. Agencias responsaveis pelo licenciamento ambiental devem incluir obrigatoriamente o manejo de especies invasoras como condicionantes do licenciamento de instalacao e operacao dos projetos. (Portuguese) [ABSTRACT FROM AUTHOR] Copyright of Journal of Applied Ecology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This is the first study of the composition of leaf beetles attracted to light in Mexico. We analyze the richness, temporal abundance and similarity between four localities of tropical dry forest in Sierra de San Javier, Sonora. A total of 3217 individuals belonging to 45 morphospecies, 31 genera and 10 tribes within five subfamilies of Chrysomelidae were collected in light traps in the tropical dry forest of Sierra de San Javier, Sonora. Galerucinae was the subfamily with the greatest number of genera and species. The genera with the highest number of species were Pachybrachis Chevrolat and Alagoasa Bechyné. Eight genera were represented by two species and 21 genera by only one species. Metrioidea rugipennis (Blake) was the species with the highest number of individuals (80% of the abundance recorded). According to the taxonomic and species similarity analysis, the sites San Javier and La Barranca had the highest similarity, while the lowest values were recorded at Rancho Las Peñitas and Cañón de Lo de Campa. The low similarity between sites cannot be explained by the geographic distance since it was not a determining factor to explain the low similarity in Sierra de San Javier.

We present the first δ18O chronology of a tropical dry forest tree species in Brazil. Our results showed a strong relationship of δ18O with inter-annual variation of moisture conditions during the growing season. In seasonally dry tropical environments, natural archives of isotopes present in cellulose of tree rings can be used to study changes in the hydrological cycle. We investigated the stable oxygen isotope ratios in tree-ring cellulose (δ18OTRC) of Cedrela odorata L. from Caatinga forest, northeastern Brazil, and tested if δ18OTRC is correlated to climate parameters. We extracted the α-cellulose from the most recent 50 tree rings (1968–2017). The inter-annual variation of δ18OTRC was strongly synchronized (r = 0.65) among all five studied individuals and closely related to changes in humidity during the growing season. The δ18OTRC was significantly correlated (p

The landscape configuration of socio-ecological land systems results from the interaction between the environmental conditions (relatively homogeneous within ecoregions) and country-level management and land-use decisions. However, social, land-use and sustainability research disciplines often study each independently. We used Euclidean distance analyses of five indicators of land systems functioning to explore the geographical patterns of across-border human-induced asymmetries in transnational ecoregions of South America. The most asymmetric transnational ecoregions occurred in the tropical rainforest biome which also showed the widest range of asymmetry values compared to other biomes. In contrast, transnational ecoregions in montane grasslands showed comparatively little asymmetries, and tropical dry forests showed intermediate asymmetry values. This pattern indicates that major asymmetries occur in land systems located in productive biomes with a comparatively recent history of development, whereas mature socio-ecosystems with a long history of human land use are more homogeneous across borders. In some cases, asymmetries may stabilize as a consequence of reinforcing feedbacks that promote contrasting land-use decisions across borders, including, for example, the establishment of protected areas, or the promotion of agro-industrial activities. Transnational socio-ecological land systems can be used to evaluate alternatives for sustainable development because they highlight the influence of institutions under different governance regimes in defining the spatial configuration and ecological properties of regions. We invite land-use and sustainability scientists to consider political border interactions as valuable “natural experiments” to better understand the interrelations between biophysical and political systems in defining planetary geographical-ecology in the Anthropocene. Universidad Nacional de Tucumán http://dx.doi.org/10.13039/501100007482 Geo.X Research Network Freie Universität Berlin (1008)

Tropical dry forests (TDFs) are ecosystems that present stresses for woody species, and these stresses are expected to filter out many lineages that do not adapt to these stressful environments. In most cases, in the Andes, only small fragments of these forests remain with different conservation conditions in a gradient of altitude and stresses. This work aimed to answer whether taxonomic and phylogenetic diversities increase or decrease with increasing altitude in the Andes TDFs. The working hypothesis was that the variation in altitude determines the taxonomic and phylogenetic diversity of the Andes TDFs. The study was carried out through a floristic census in seven different locations in an Andean slope with altitudes ranging from 282 up to 799 m ASL. In each location, 20 plots of 25-m × 4-m were established, totaling 140 plots. Taxonomic and phylogenetic diversity indices were estimated. We also used principal component analysis to describe the influence of climatic variables at the seven study sites. We found the influence of environmental filtering in the studied sites. As climatic seasonality increases and altitude decreases, taxonomic and phylogenetic diversity decrease and phylogenetic clustering increases. The major concern in a global warming scenario is that increasing the effects of high temperatures and droughts could extinct species and phylogenetic lineages as TDF fragmentation prevents species from migrating upwards in the mountains. Therefore, to promote connectivity is a priority besides stop habitat loss of TDFs.

Tropical dry forests are an intricate ecosystem with special adaptations to periods of drought. Arbuscular mycorrhizal fungi (AMF) are essential for plant survival in all terrestrial ecosystems but might be of even greater importance in dry forests as plant growth is limited due to nutrient and water deficiency during the dry season. Tropical dry forests in Ecuador are highly endangered, but studies about AMF communities are scarce. We investigated the AMF community of a premontane semi-deciduous dry forest in South Ecuador during the dry season. We estimated AMF diversity, distribution, and composition of the study site based on operational taxonomic units (OTUs) and compared the results to those from the tropical montane rainforest and páramo in South Ecuador. OTU delimitation was based on part of the small ribosomal subunit obtained by cloning and Sanger sequencing. Nearly all OTUs were Glomeraceae. The four frequent OTUs were Glomus, and comparison with the MaarjAM database revealed these to be globally distributed with a wide range of ecological adaptations. Several OTUs are shared with virtual taxa from dry forests in Africa. Ordination analysis of AMF communities from the tropical dry and montane rainforests in South Ecuador revealed a unique AMF community in the dry forest with only few overlapping OTUs. Most OTUs that were found in both dry and rainforests and on the two continents were globally distributed Glomus.

The increase in anthropogenic activities that lead to fragmentation and habitat loss, could result in a reduction of connectivity among habitat patches of terrestrial species. We used ecological ni...

Tropical dry forest is one of the most threatened and least studied tropical ecosystems despite high species diversity and endemism. In Colombia, the knowledge of spider diversity in this ecosystem...

Biocultural conservation approaches recognise the relationships between nature and humans, and are built on local cultural perspectives. Hawai‘i has been described as a model for biocultural conservation, and a biocultural approach can be applied in endangered ecosystems such as tropical dry forests that are often found in human settlement areas. The extent of native tropical dry forest cover remaining in Hawai‘i is as low as 1% on some islands, with 45% of the tropical dry forest plant species at risk of extinction. Despite the long-running relationship of tropical dry forests with ‘Indigenous people and local communities’, there has been little assessment of the potential social–ecological outcomes of a biocultural approach to tropical dry forest restoration. Two Hawai‘i forest restoration projects, located within Ka‘ūpūlehu and Auwahi, have been excluding ungulates and removing alien plant species for >20 years, and have applied biocultural approaches. Drawing on these two sites as case-studies, we explore the motivations for, and components of, a biocultural approach, and highlight four categories (ecological, social, cultural, and spiritual) of biocultural measures of success. We show that a biocultural approach to restoration can provide purpose and meaning to a person’s relationship to place, and can transform conservation biology through Indigenous perspectives. We also address challenges and provide recommendations to those interested in engaging in a biocultural approach.

En el recinto Quimis del Cantón Jipijapa, en la zona Sur de Manabí, Ecuador, se realizó una investigación relacionada con la caracterización de la producción apícola en la Asociación Aroma y Miel, cuyo sustento para las abejas en la producción de miel son las especies del bosque seco tropical. Dicha miel es aprovechada por los residentes locales involucrados para, entre otros usos, comercializarla. El objetivo de este estudio se basó en caracterizar la producción apícola en un sistema cooperativo asociado al bosque seco tropical. Se seleccionaron siete apiarios activos distribuidos dentro del recinto, dónde se realizaron entrevistas semiestructuradas a 38 familias miembros de dicha Asociación. Los resultados muestran que, los meses de mayor floración se enmarcan entre marzo hasta inicios de octubre. El tipo de miel en su mayoría la obtienen de varias flores (28 citaciones) y solo 10 entrevistados citaron optar por una sola flor, siendo esta la flor de la especie Ceiba trichistandra. Los apicultores hacen capturas de la abeja reina y dividen la colmena en lo que llaman su nuevo proyecto reina. Más del 50 % de los entrevistados afirmaron que no alimentan sus abejas, en tanto que clasifican las mieles, basados en el sabor, el color y su contextura, de acuerdo con la flor de la que proceden. El 50 % realizan la trasportación fuera del recinto. Los apicultores desconocen la totalidad de las especies melíferas que florecen durante todo el año, evidenciado en los datos presentados en el calendario floral resultante de esta investigación.

Songbird vocalizations serve diverse functions including territory defence against neighbouring conspecific animals. In tropical and south-temperate regions, it is commonplace for both female and male songbirds to sing solo songs and coordinated vocal duets to defend their territories. The Area de Conservacion Guanacaste in Costa Rica is the site of an ambitious conservation effort to protect and regrow tropical dry forests; it consists of a mosaic of regenerating and mature forest patches, presenting a special opportunity to study the effect of different numbers of neighbours on male and female wrens living in these fragmented forests. We analyzed recordings of Rufous-and-white Wrens (Thryophilus rufalbus) over a 17-year period, focusing on vocal behaviour and variation in the number of territorial neighbours within the fragmented landscape in the conservation area, and on diel and seasonal variation in female and male song. We hypothesized that the number of conspecific neighbours would influence vocal behaviours, including female and male solo song rate, duet responsiveness rate, repertoire use, and song-switching rate. For females, we found that wrens change song-types more often in areas with more neighbours, whereas the other aspects of female vocal behaviour did not vary with the number of neighbours. For males, we found no aspect of vocal behaviour that varied with the number of neighbours. For both sexes, we found variation in vocal behaviours with time of day and time of year, in keeping with previous research. Our results underscore the idea that we must explore female and male birds independently, because the sexes may respond differently to external factors. We did not find strong links between wren vocal behaviour and variation in the number of neighbours, yet we encourage further behavioural studies on vocal behaviour of birds with varying numbers of neighbours in fragmented landscapes.

In tropical dry forests, wildfires are likely to become a major disturbance as a result of anthropogenic pressures and dryer conditions due to climate warming. Based on remote sensing techniques, t...

The impacts of changes in rainfall regimes and atmospheric nitrogen (N) deposition on the biogeochemical cycles of tropical dry forests (TDF) remain unclear. To analyze whether amounts of mean annual rainfall (1240 mm year−1 in subhumid vs. 642 mm year−1 in semiarid forests) and rates of atmospheric N deposition affect the N cycle in TDF, we examined N concentrations in (i) green leaves, (ii) forest floor and mineral soil layers, and (iii) soil microbial biomass, as well as (iv) δ15N natural abundance in green leaves and (v) rates of soil enzyme activity and (vi) N losses in two sites (one subhumid and another semiarid) of Yucatan. The semiarid site had higher N concentrations in leaves and both soil layers than its subhumid counterpart. Natural abundance δ15N in the vegetation suggests a more open N cycle with lower rates of rainfall, which was corroborated by N losses as nitrous oxide (N2O) being twice as high in the semiarid compared to subhumid site. A more open N cycle subject to greater losses in response to N addition in the semiarid site, but not in the subhumid site, reinforce that rainfall amounts strongly affect N cycling in TDF.

Tropical dry forests (TDFs) usually occur as mosaics at different stages of natural regeneration, along which variations in soil attributes (fertility and texture) can affect plant growth and leaf traits and, consequently, leaf herbivory. In the present study, we used a chronosequence approach to determine the variations in plant growth, leaf defense, and insect herbivory in different successional species groups, following the predictions of the resource availability hypothesis: plants at early successional stages would grow faster, have lower specific leaf mass (SLM), and suffer higher herbivore damage than late successional plants. For this purpose, we measured plant diameter and collected leaves at the end of the rainy season (April) during three consecutive years in three different successional stages (early, intermediate, and late). In total, we sampled 38 plant species, from which 31 species were exclusive to a single successional stage (10 early, 13 intermediate, and eight late species). Our results did not conform to the resource availability hypothesis, as plants growing in early successional stages had higher growth rates and SLM, and lower leaf damage by herbivores. Soil fertility and texture did not affect plant growth or SLM, but leaf damage was negatively affected by SLM. Apart from being a defensive trait, SLM is also involved in the conservation of water and nutrients and photoprotection, and its variation along successional gradients in TDFs conforms to a continuum from conservative traits in hot and dry, early successional stages, to acquisitive traits in more humid late stages. Although other plant defenses must be considered, our three-year study indicates that the resource availability hypothesis, which was formulated for wet forests, should be adapted to deciduous TDFs where water availability is the main environmental filter along succession.

Tropical trees are particularly vulnerable to forest fragmentation because of their low densities, self-incompatibilty system, and high rates of outbreeding. Forest fragmentation is likely to decrease gene flow, increase endogamy, and eventually produce a high differentiation among remnant populations. Our objectives were to evaluate the effect of forest fragmentation on the reproductive success, progeny vigor, and genetic variation of the tropical dry-forest tree Samanea saman. We conducted our study in the dry forest of Costa Rica and compared two tree conditions to evaluate forest fragmentation: (1) isolated, individual trees more than 500 m from the nearest conspecific and surrounded by agricultural fields, pastures, or small remnant forest patches and (2) trees in continuous populations of 10 or more individuals per hectare and surrounded by undisturbed forest. We compared the probability of natural pollination, seed production, genetic variation, and progeny vigor of trees in isolation and in continuous populations. The probability of flowers receiving more than 23 pollen tubes at the base of styles (the flowers more likely to produce a mature fruit) was significantly greater for trees in continuous populations (2.1%) than for trees in isolation (0.4%). However, flowers from the two tree conditions received similar pollen loads on their stigmas. Fruits of trees from continuous populations produced similar numbers of seeds as isolated trees did and had a similar probability of seed abortion. The probability of seed predation by bruchid beetles was significantly greater in continuous populations (30%) than in isolated trees (20%). The number of undamaged seeds ( potentially viable) was similar for both tree conditions. A genetic analysis of progeny showed that levels of genetic diversity in trees in isolation and in continuous populations were comparable. The effective self-fertilization rate and inbreeding coefficient of the progeny were slightly higher for isolated trees than for trees in continuous populations. In addition, there was more genetic similarity in the progeny of isolated trees, within and between fruits. Seeds produced by different fruits within a tree were more likely to be related in an isolated tree than in a tree from continuous populations. Seeds produced by trees from continuous populations were more likely to germinate and to produce greater leaf area and biomass as seedlings than progeny from isolated trees. We concluded that the fragmentation of tropical dry forests affects the genetic variation and vigor of S. saman progeny. Isolated trees showed high reproductive capacity, however, in spite of their habitat condition. Resumen: Los arboles tropicales son particularmente vulnerables a la fragmentacion de bosques debido a su baja densidad, su sistema de auto-incompatibilidad y altas tasas de exogamia. La fragmentacion del bosque posiblemente decrece el flujo de genes, incrementa la endogamia y eventualmente produce una alta diferenciacion entre las poblaciones remanentes. Nuestros objetivos fueron evaluar el efecto de la fragmentacion del bosque sobre el exito reproductivo, el vigor de la progenie y la variacion genetica del arbol de bosque tropical seco Samanea saman. Realizamos nuestro estudio en el bosque tropical seco de Costa Rica y comparamos dos condiciones de los arboles para evaluar la fragmentacion del bosque: (1) individuos aislados mas de 500 m del individuo conespecifico mas cercano y rodeados por campos agricolas, ganaderos o pequenos fragmentos de bosque y (2) arboles en poblaciones continuas de 10 o mas individuos por hectarea y rodeados de bosque no perturbado. Comparamos la probabilidad de la polinizacion natural, produccion de semillas, variacion genetica y vigor de la progenie en arboles aislados y en poblaciones continuas. La probabilidad de que las flores reciban mas de 23 tubos de polen en la base de los pistilos ( las flores con mayor probabilidad de producir un fruto maduro) fue significativamente mayor para arboles en poblaciones continuas (2.1%) que en arboles aislados (0.4%). Sin embargo, flores en arboles en las dos condiciones recibieron similares cargas de polen en sus estigmas. Los frutos de arboles de poblaciones continuas produjeron similares numeros de semillas y tuvieron similar probabilidad de abortar que los de arboles aislados. La probabilidad de depredacion de semillas por escarabajos bruquidos fue significativamente mayor en las poblaciones continuas (30%) que en arboles aislados (20%). El numero de semillas sin dano ( potencialmente viables) fue similar en arboles en las dos condiciones. El analisis genetico de la progenie mostro que los niveles de diversidad genetica de arboles aislados y en poblaciones continuas fueron comparables. La tasa de autofecundacion efectiva y el coeficiente de endogamia de la progenie fue ligeramente mayor en arboles aislados que en los de poblaciones continuas. Adicionalmente, hubo mayor similitud genetica en la progenie de arboles aislados, dentro y entre frutos. Semillas producidas por distintos frutos del mismo arbol tuvieron mas probabilidad de relacion que los de poblaciones continuas. Semillas producidas por arboles en poblaciones continuas tuvieron mayor posibilidad de germinar y producir mayor area foliar y biomasa que las plantulas de la progenie de arboles aislados. Concluimos que la fragmentacion de bosques tropicales secos afecta la variacion genetica y el vigor de la progenie de S. saman. Sin embargo, los arboles aislados tuvieron una alta capacidad reproductiva a pesar de la condicion de su habitat.

RESUMEN El estudio de la dieta de los murciélagos es importante para entender cómo se conforma su ensamblaje y cómo aportan a la dinámica de los bosques. Al ser pocos los estudios de dieta de murciélagos frugívoros en el bosque seco tropical, nuestro objetivo fue describir su dieta y analizar cuál es su efecto sobre la germinación de semillas. El trabajo se realizó en el Área Natural Única Los Estoraques, Norte de Santander, Colombia; una zona de vida de bosque seco premontano (bs-PM). Para la captura de murciélagos se utilizaron redes de niebla y se recolectaron sus excretas. Las semillas de Vismia baccifera y Piper sp4, obtenidas de las excretas, fueron seleccionadas para el experimento de germinación cuya respuesta se analizó mediante el índice de capacidad de germinación. Se hizo una curva de acumulación para describir la riqueza de semillas, se calculó el índice de mejor dispersor DII y el índice de Morisita para estudiar solapamiento de dieta. Se registraron diez especies de murciélagos con siete registros nuevos para un total de 18 en la zona, trece de ellas fueron frugívoras. Carollia brevicauda fue la especie más abundante y la mejor dispersora, considerándola clave para la mayoría de las especies vegetales. Se identificaron 18 morfoespecies de semillas, incluyendo Calycolpus moritzianus, nuevo registro en la dieta de los murciélagos. En ninguna de las dos especies de plantas se encontraron diferencias en la germinación de semillas obtenidas de las excretas y aquellas extraídas del fruto directamente. ABSTRACT The study of bat diets is important to understand how their assemblage is shaped and how they can contribute to the dynamics of the forests. Since there are few studies on the diet of fruit bats in the tropical dry forest, our objective was to describe their diet and to understand their effect on seed germination. The work was carried out in the Área Natural Única Los Estoraques, Norte de Santander, Colombia, corresponding to a premontane dry forest life zone (bs-PM). Mist nets were used to capture bats; their excreta were also collected. The seeds of Vismia baccifera and Piper sp4, obtained from the excreta, were selected for the germination experiment whose response was analyzed by means of the germination capacity index. An accumulation curve was made for the seeds richness, the best disperser index DII and the Morisita index were calculated to study diet overlap. Ten species of fruit bats were recorded from which seven are new local records for a total of 18 species in the area, thirteen of these were frugivorous species. Carollia brevicauda was the most abundant and the best disperser species, considering it key for the dispersal of most plant species. A total of 18 seed morphospecies were identified, including Calycolpus moritzianus, being a new record for the diet of bats. We did not find differences in the germination of seeds of the two plant species obtained from either the excreta of from the fruit directly.

This chapter encompasses a literature survey and strategic analysis to understand the elaboration and implementation of Participatory Forest Management (PFM) in Benin, with a focus on the case of the “Forêt des Trois Rivières”. By analyzing the historical background of forest management systems in Benin, we highlighted two major turning points. The first relates to the creation and autocratic management of protected forests, which took place from 1940 to 1990. The second change took place after the Rio conference in 1992, and this emphasized the importance of local communities in natural resources management. Moreover, the results of our strategic analysis of stakeholders involved in the specific case of Participatory Forest Management Plan (PFMP) of the “Forêt des Trois Rivières” showed that it is important to emphasize on active community participation while designing a participatory management plan and for decision making at the implementation stage. We also observed that alliances between foresters and timber loggers are likely to hinder the achievement of the PFM objectives.

Tropical dry forests (TDFs) are characterized by pronounced seasonality in precipitation, with several months of prolonged drought, 80% of annual precipitation occurring during a four- to six-month rainy season, and high interannual rainfall variability. Surprisingly, there are relatively few studies addressing patterns of functional trait in tropical dry forest (TDF) ecosystems. Functional trait analysis across plant species and the environment is a rapidly developing research field with many possible applications for forest restoration practice. Trait-based ecological research within TDFs will advance our understanding of how these ecosystems interact with and differ from other tropical ecosystems.

Forest degradation is attributed to the excessive use of forest resources and extraction, whether for subsistence or commercial purposes. With an increase in human population pressure on forests, forest degradation is becoming a concern for the conservation of biodiversity. The high human dependence on tropical dry forests underscores the need for a complete understanding of the interaction of humans and these forests to ensure their persistence and the wellbeing of the people who depend on these resources. This chapter examines forest resource use and degradation to provide a nuanced understanding of forest degradation and the impact of forest resource use.

Species distribution models have become an essential tool for the selection of conservation areas. Given this perspective, this research aimed to analyze the dynamics of the fundamental niche of Ziziphus joazeiro Mart. facing climate change. The MaxEnt algorithm was used to correlate species points of occurrence with bioclimatic variables of four periods: Middle Holocene, current period, and the optimistic and pessimistic future scenarios of the HadGEM2-ES model of general atmospheric circulation. The accuracy of the predictions and the influence of the variables was evaluated using the area under the curve (AUC index) and the Jackknife test. The predictions showed high precision (AUC > 0.895), and the bioclimatic variables related to precipitation were the ones that most contributed to determining potential areas for the occurrence of the species. A reduction of more than 60% was observed in the area with climatic suitability for the occurrence of Z. joazeiro, over time. The range that comprises the central region of the distribution of the species stands out as the region with the greatest suitability, as projected for the current and future period, this being the area that should receive the most attention for the conservation programs of the species.

Habitat conversion is one of the major threats for biodiversity conservation and viability of natural populations. Thus, habitat disturbance alters distinct ecological processes, such as plant reproductive success and diaspore fate. In this study, we determined the effects of seasonally tropical dry forests (STDFs) conversion by anthropogenic disturbance by assessing diaspore fate of Enterolobium contortisiliquum. We compared 20 adult trees present in a STDFs preserved area and 20 adult trees present in a human-converted area. In general, diaspore fates from both areas were similar, i.e., there was no difference in the reproductive success of trees in STDFs and human-converted area. Habitat disturbance did not affect the length or width of fruits; only fruit thickness was larger in trees of STDFs habitat. None of the biometric seed measures differed between different habitat conditions. Likewise, the number of undamaged seeds, aborted seeds, pre-dispersal predated seeds, and seed production were independent of habitat conditions. Besides, we did not observe any effect of habitat disturbance on germination percentage. However, seeds from preserved STDFs germinated faster than seeds from the human-converted area. Even though the effects of human-modified habitats on the diaspore fate have already been studied, tree species exhibit different responses to habitat conversion regarding seed predation, seed dispersal, seed germination, and seedling establishment. Overall, our results show that habitat disturbance does not affect the diaspore fate of E. contortisiliquum. This study also highlights the importance of remnants trees in converted landscapes as the population’s connectors which maintain plant–animal mutualistic and antagonistic interactions that mitigate the effects of habitat disturbance.

Young successional tropical forests are crucial in the global carbon cycle because they can quickly sequester large quantities of atmospheric carbon. However, lianas (woody vines) can significantly decrease biomass accumulation in young regenerating forests. Lianas are abundant in tropical dry forests, and thus we hypothesized that lianas reduce biomass accretion in dry forests. Lianas may be particularly detrimental to the growth of young trees, which are vulnerable to competition from lianas. Alternatively, lianas may have a stronger negative effect on the largest trees because lianas seek the high-light environment at the top of the forest canopy. We tested these hypotheses using a liana-removal experiment in 13 dry forest stands that ranged from 1 to 70 years in southwestern Panama. We measured biomass accumulation annually for more than 10,000 stems from 2013 to 2017. Contrary to our expectations, liana removal had no effect on tree biomass accumulation across our successional forests and throughout our study period. Liana removal did not benefit smaller trees or larger trees. Lianas did not increase biomass accumulation on recruits, and did not increase biomass loss due to mortality. Surprisingly, removing lianas had a negative effect on three out of 41 tree species. Lianas had no effect on biomass accumulation and loss, possibly because: (1) trees allocated resources to roots instead of stems, (2) trees and lianas partitioned water, (3) higher irradiance after liana removal reduced soil moisture, or (4) low water availability might have been such a strong stressor that it reduced plant–plant competition.

The white-tailed deer (Odocoileus virginianus Zimmermann 1780) was an apex species for Precolumbian subsistence in the anthropogenic savannas and tropical dry forests bordering Parita Bay on the central Pacific coast of Panama. This paper focusses on Late Preceramic Cerro Mangote, a multi-component site whose domestic occupation corresponds to a maximum time-period of 7900 and 4600 cal BP. At this time, this site's inhabitants developed mixed subsistence strategies including farming and hunting, along with coastal fishing and invertebrate collection. Communities across the seasonally dry and windy plains and foothills of the central Pacific practiced swidden agriculture – a variety of plant food production that would have favored “garden hunting” (sensu Linares 1976), which, in this region, most likely involved white-tailed deer because of this species' acknowledged attraction to cultivated plots. Zooarchaeological and taphonomic analyses of white-tailed deer bone, tooth and antler samples from Cerro Mangote are based on two sequential Late Preceramic occupation layers. Results reveal that the same strategies for white-tailed deer hunting and for the treatment of their carcasses continued without change throughout the Late Preceramic period at Cerro Mangote.

Agricultural expansion has contributed to the loss and fragmentation of natural habitats and, as a consequence, the edge effect in these habitats has increased, leading to nest predation rates higher at the edge of fragments than in the interior. Living fences in abandoned croplands, however, add a structural component to the landscape which can help to mitigate the effects of disturbance. We used artificial nests to assess whether a living fence at the edge of a fragment of tropical dry forest, immersed in an agricultural landscape, can assuage the edge effect by decreasing predation rates. We identified the predators that attacked nests at several distances from the living fence and related the frequency of predator attacks with plant height, leaf height diversity, and tree and herb coverage. Vegetation structure of the living fence was vertically more complex than that found inside the fragment. 52% of nests were predated and we did not find a significant relationship between predation rates and the proximity of nests to the living fence, suggesting a null edge effect on predation. Birds were the most frequent predators, followed by rodents and carnivorous mammals, with the composition of predators varying among transects. The composition of predators and vegetation structure of the living fence were the factors that explained the null edge effect on nests predation. Our results indicate that the presence of a living fence at the edge of a fragment in agroforestry systems could mitigate the edge effects on nest predation.

Biodiversity maintenance in human-modified landscapes largely depends on spatial variations in species composition (β-diversity), but the impact of human disturbance on β-diversity remains poorly understood. We examined how taxonomic and phylogenetic β-diversity of woody plant communities in the Brazilian Caatinga dry forest respond to two emerging threats—chronic anthropogenic disturbance and water scarcity. We separately assessed diversity metrics that give a disproportionate weight to rare species, and metrics weighted by dominant species. We recorded a total of 5118 individuals from 104 species across 19 0.1-ha plots into a 21,430-ha human-modified landscape exposed to chronic disturbances and a high variation in climatic water deficit. At the landscape scale, β-diversity was higher when considering rare species than when focusing on dominant species, especially for the phylogenetic dimension of β-diversity. Water deficit was the primary driver of plant taxonomic and phylogenetic β-diversity, followed by the number of cattle and inter-site isolation; however, rare species seem to depend more strongly on these factors than the dominant ones. Therefore, preserving as much forest as possible, including areas exposed to different disturbance level and climate variables, is critical to prevent the loss of rare species and maintain the compositional differentiation of biotic assemblages. Such forest cover should be maintained in a large number of forest patches scattered through the landscape to preserve biologically and functionally distinct components of this ecosystem, avoid landscape-scale biotic homogenization, and thus favor its ecological resilience.

Los inventarios locales constituyen la base para entender la distribución de las especies y los procesos ecológicos e históricos subyacentes. Esta información, en asociación con la documentación de los motivos de caza de las especies, es necesaria para el diseño de estrategias de conservación. Este estudio provee datos nuevos de las especies de mamíferos medianos y grandes del Cerro Piedra Larga (CPL), un macizo montañoso interior en Oaxaca, México. Obtuvimos datos de observaciones directas en transectos, búsqueda de rastros y fototrampeo en bosque tropical caducifolio, bosque seco de pino-encino y en bosque de pino-encino. Registramos los motivos de caza de los mamíferos por la gente local a través de entrevistas informales. Cuantificamos el número de especies e identificamos aquellas que están en alguna categoría de riesgo para su conservación. Reportamos la presencia de 26 especies de mamíferos medianos y grandes en el CPL. Siete especies están en alguna categoría de riesgo. Los habitantes reconocieron la presencia de 23 especies, de las cuales 14 son cazadas para prevenir daños sobre animales domésticos y cultivos. Cinco especies son cazadas por su carne. Las observaciones directas, el fototrampeo y las entrevistas fueron métodos complementarios que ayudaron a tener una mejor lista de las especies. Siete especies constituyen los primeros registros para toda la subprovincia. El registro de Cuniculus paca representa una extensión de su distribución hacia el centro-sur de Oaxaca. Considerando a los mamíferos pequeños, los voladores y los medianos y grandes, el CPL tiene el 24.9 % del total de mamíferos terrestres registrados en Oaxaca. Este estudio destaca la importancia de este macizo montañoso por su diversidad de mamíferos, la cual es amenazada por agricultura de roza-tumba y quema, y actividades de desarrollo carretero.

Seasonal dry tropical forest (STDF) is a widespread vegetation type in western Mexico. Generally, this type of forest develops in semihumid habitats where lacustrine basins are scarce, preventing documentation of the vegetation history and forest dynamics using a paleoecological approach. Here, we present a palynological record from the Santa Maria del Oro crater lake, located within the distribution area of the STDF and the adjacent dry oak forest which gives insight into the changes in diversity and human impact at this tropical site. Pollen data, in combination with geochemical analysis and microcharcoal data from a lacustrine sequence, are used to discuss vegetation change and diversity in the plant assemblages related to drought or anthropogenic activity over the last 5000 years. Our results show three distinct periods of drought in the basin, from 4200 to 3850, 3100 to 2300, 1570 to 1100 and 300 cal year BP, with changes in vegetation composition mainly related to a decrease in taxa diversity during these periods. Based on the presence of maize pollen, two periods of human activity (3790–2160 and 280 cal year BP to present) were detected with an increase in herbaceous pollen used as a surrogate for deforestation. These two disturbance periods, pre-Columbian and postcolonial, occurred during wet conditions in the basin. Our results highlight the correlation between El Niño events, drought and fire with changes in the composition and diversity of STDF.

Zanthoxylum magnifructum is a recently described species based on only a fruiting specimen collected in tropical dry forests in the department of Huila in Colombia. An emended description and illustration are presented, including flowers and seeds, which were previously unknown. Comments on its geographical distribution, conservation status, taxonomic affinities, and sexual dimorphism are made. A key for the species of Zanthoxylum that occur in tropical dry forest in Colombia is provided.

In tropical dry forest conditions, small ruminant production is an alternative for small farmers. Even so, the quality of the forages does not meet the nutritional requirements of the animals. However, the high biodiversity of trees that exist in the region offers a supplementation alternative especially during the dry season. The objective of this research work was to evaluate the quality and the profile effect of fatty acids in Colombian creole lamb meat supplemented with tree species from the tropical dry forest. A total of 35 lambs were used which were randomly distributed in 5 treatments as follows: T1: Botriochloa pertusa; T2: Botriochloa pertusa + 300 g/day of Leucaena leucocephala; T3: Botriochloa pertusa + 300 g/day of Gliricidia sepium; T4: Botriochloa pertusa + 300 g/day of Guazuma ulmifolia and T5 (BpSs): Botriochloa pertusa + 300 g/day of Senna spectabilis. The experimental units were brought to a final slaughter weight of ±32 kg and the pH, color, and fatty acid composition of the carcasses were evaluated at 24 hours. The meat quality parameters did not present significant differences (P>0.05) in the different supplements and obtained acceptable parameters for their consumption. It was evidenced that the proportions of saturated fatty acids (C 16: 0, C 18: 0, total SFA) in lambs supplemented with Senna spectabilis and Gliricidia sepium were lower (P< 0.05). It is concluded that under the conditions of the study the supplementations with Senna spectabilis and Gliricidia sepium can induce a favorable change in the fatty acid content of lamb meat. Resumen En condiciones de bosque seco tropical, la producción de pequeños rumiantes es una alternativa para los pequeños agricultores. No obstante, la calidad de los forrajes no atiende a los requerimientos nutricionales de los animales. Sin embargo, la alta biodiversidad de árboles que existe en la región ofrece una alternativa de suplementación especialmente en la época seca. El objetivo de este trabajo de investigación fue evaluar la calidad y el perfil de ácidos grasos en carnes de corderos criollos colombianos suplementados con especies arbóreas del bosque seco tropical. Se utilizaron 35 corderos los cuales fueron distribuidos aleatoriamente en 5 tratamientos: T1 (control) = pastoreo en Botriochloa pertusa; T2= pastoreo en Botriochloa pertusa + 300 gr/día de suplemento a base de Leucaena leucocephala; T3= pastoreo en Botriochloa pertusa + 300 gr/día de Gliricidia sepium; T4= pastoreo en Botriochloa pertusa + 300 gr/día de Guazuma ulmifolia y T5= pastoreo en Botriochloa pertusa + 300 gr/día de Senna spectabilis. Las unidades experimentales fueron llevadas a un peso final de sacrificio de ± 32 kg y se evaluó el pH a las 24 horas, el color y el perfil lipídico de las canales. Los parámetros de calidad de la carne no presentaron diferencias estadísticas significativas (P>0.05) en las diferentes suplementaciones y obtuvieron parámetros aceptables para su consumo. Se evidencio que las proporciones de ácidos grasos saturados (C 16:0, C 18:0, total de SFA) en los corderos suplementados con Senna spectabilis y Gliricidia sepium fueron menores (P< 0.05). Se concluye que bajo las condiciones del estudio las suplementaciones con Senna spectabilis y Gliricidia sepium pueden inducir un cambio favorable en el contenido de ácidos grasos de la carne de corderos.

Leaf traits are analyzed as essential drivers for the evolutionary and ecological role of plant defense mechanisms. Plants show leaf trait variation as a response to the diverse environmental conditions, like different successional stages. Those variations can impact leaf herbivory rates and drive changes in the allocation of plant resources. In this study, we aimed at comparing the expression of leaf defenses in established plants over different successional stages in a tropical dry forest to understand how these defenses modify the plant–herbivore interactions based on herbivory rates. We analyzed physical leaf traits (specific leaf area, thickness, and density), nutrient content (N, P, and K), total phenolic compounds, and leaf herbivory, of the native tree species Aspidosperma pyrifolium and Cenostigma pyramidale, in early- and late-successional stage areas. Results showed that the plant investment in defenses varies according to the successional stage and that both species have similar defense strategies, confirming the resource availability hypothesis. Individuals from the early stage adopt a strategy to lower sclerophylly, higher nutrient content and less phenolic compounds, while the late-stage individuals showed an opposite behaviour. For both species in this study, the average percentage of leaf herbivory observed was 40% higher in the early compared to the late-stage area. Our data indicate that plant defenses are tightly coupled to sclerophylly and investments in secondary metabolites, and the environmental conditions of different successional stage drive that plasticity in such leaf traits.