Resumen Costa Rica es reconocido como el principal país exportador de piña fresca (Organización de las Naciones Unidas para la Alimentación y la Agricultura (FAO), 2020), lo que ha requerido un amplio conocimiento de la dinámica espacial de la producción del cultivo a escala nacional. Este estudio simuló el comportamiento espacial del cultivo de piña en los cantones de Upala y Los Chiles en la Región Huetar Norte de Costa Rica para el año 2028. Por medio de una entrevista a los productores de la zona, se identificaron las variables impulsoras del cambio en el periodo 2015-2018: “Condiciones del clima y suelo”, “Otros procesados industriales de la piña”, “La demanda de la piña”, “Exporta hacia Europa” y “Distancia a plantas empacadoras”. Con la utilización de QGis y DINAMICA EGO se espacializaron los resultados y se simuló la cobertura de piña al 2028. La comparación con el mapa real al 2018 (MOCUPP) mostró un coeficiente kappa de 0,55 e indicó una similitud moderada. La simulación proyectó 6 096,52 ha de piña para Upala y 10 568,78 ha de piña para Los Chiles. Se identificaron zonas de cambio sobre áreas silvestres protegidas y sobre cobertura arbórea para el año 2028.

Resumo A Costa Rica é reconhecida como o principal país exportador de abacaxi fresco (FAO, 2020), o que requereu um amplo conhecimento da dinâmica espacial da produção da cultura em escala nacional. Este estudo simulou o comportamento espacial do cultivo de abacaxi nos cantões de Upala e Los Chiles, na Região Huetar Norte da Costa Rica, para o ano de 2028. Por meio de uma entrevista com os produtores da região, foram identificadas as variáveis impulsionadoras da mudança no período 2015-2018: “Condições climáticas e do solo”, “Outros processamentos industriais do abacaxi”, “A demanda pelo abacaxi”, “Exportação para a Europa” e “Distância para instalações de embalagem”. Com o uso do QGis e do DINAMICA EGO, os resultados foram espacializados e a cobertura de abacaxi foi simulada até 2028. A comparação com o mapa real de 2018 (MOCUPP) mostrou um coeficiente kappa de 0,55 e indicou uma semelhança moderada. A simulação projetou 6.096,52 ha de abacaxi para Upala e 10.568,78 ha de abacaxi para Los Chiles. Foram identificadas áreas de mudança em áreas silvestres protegidas e cobertura arbórea para o ano de 2028.

Abstract Costa Rica is recognized as the main exporter of fresh pineapple (FAO, 2020), which has required extensive knowledge of the spatial dynamics of crop production on a national scale. This study simulated the spatial behavior of pineapple cultivation in the cantons of Upala and Los Chiles in the Huetar Norte Region of Costa Rica for the year 2028. Through an interview with producers in the area, the driving variables of change were identified in the period 2015-2018: “Climate and soil conditions”, “Other industrial pineapple processing”, and “The demand for pineapple”, “Exports to Europe” and “Distance to packing plants”. With the use of QGis and DINAMICA EGO, the results were specialized and pineapple coverage was simulated for 2028. The comparison with the real map for 2018 (MOCUPP) showed a kappa coefficient of 0.55 and indicated a moderate similarity. The simulation projected 6,096.52 ha of pineapple for Upala and 10,568.78 ha of pineapple for Los Chiles. Zones of change over forest coverage and protected areas were identified for the year 2028.

Abstract Introduction: The use of arthropods in ecological studies in the tropical dry forest (TDF) of Colombia focused mainly on spiders, butterflies, ants, and dung beetles; therefore, it is necessary to understand the seasonal dynamics of the other groups such as Geadephaga in this ecosystem. Objective: To evaluate the spatio-temporal variations and the effect of environmental conditions on the diversity of the Geadephaga communities in two TDF fragments in the Colombian Caribbean. Methods: This study was conducted during four sampling events between February and June 2018, each lasting four days, and four nights. Four sampling stations were selected in each locality (Reserva Campesina La Montaña = RCM and Reserva La Flecha = RLF), separated 350 m one from another, with square plots of 50 × 50 m. A light trap was installed in the center of each square, while pitfall traps were installed in the four vertices, and manual capture, beating sheets and leaf litter sieve were carried out. Results: A total of 348 Carabidae and 114 of Cicindelidae were captured. In both fragments, the richness and abundance presented the lowest values in dry season, while the highest values were observed during the rainy season. Tetracha affinis (Dejean, 1825) was the most abundant species in RCM during rainy season. Conclusions: The richness variation and abundance of Geadephaga corresponds to a seasonal pattern at both locations. A high dissimilarity between the communities of Geadephaga from the two fragments was found, despite having similar environmental conditions.

Resumen Introducción: El uso de artrópodos en estudios ecológicos en el bosque seco tropical (Bs-T) de Colombia se centra mayormente en arañas, mariposas, hormigas y escarabajos coprófagos; por lo tanto, es necesario comprender como es la dinámica estacional de otros grupos como Geadephaga en este ecosistema. Objetivo: Evaluar la variación espacio-temporal y el efecto de las condiciones ambientales sobre la diversidad de las comunidades de Geadephaga en dos fragmentos de Bs-T en el Caribe colombiano. Métodos: El estudio se llevó a cabo en cuatro eventos de muestreo entre febrero y junio de 2018; cada uno con una duración de cuatro días y cuatro noches. En cada localidad (Reserva Campesina La Montaña = RCM y Reserva La Flecha = RLF), se marcaron cuatro estaciones distanciadas 350 m, con parcelas de 50×50 m. En el centro de cada parcela se instaló una trampa de luz, mientras que en los cuatro vértices se instalaron trampas de caída, y se realizó captura manual, cernido de hojarasca y perturbación de follaje. Resultados: Se capturó un total de 348 ejemplares de Carabidae y 114 de Cicindelidae. La riqueza y la abundancia presentaron los valores más bajos durante el período seco, mientras que los mayores valores se observaron durante el período de lluvias, en ambos fragmentos. Tetracha affinis (Dejean, 1825) fue la especie más abundante en la RCM durante el período lluvioso. Conclusiones: La variación de la riqueza y abundancia de Geadephaga responde a un patrón estacional en ambos fragmentos. Se encontró una amplia disimilitud entre las comunidades de Geadephaga de ambos fragmentos, pese a tener condiciones ambientales parecidas.

ABSTRACT The livestock productive landscape encompassing Playada, La Piedad, San Francisco, and La Rafaela estates in the western region of Paraguay emerges as a representative model with capabilities for both production and conservation of ecosystem services. Through categorization using ArcGIS 10.3, it was identified that grasslands and savannas cover approximately 35% of the total area, around 5,716 hectares. The study, based on landscapescale homogeneity, allowed for the analysis of physical characteristics, distribution, coverage, and anthropogenic pressures in five Homogeneous Environmental Units (HEUs). The characterization of ecosystem services revealed that forest remnants provide regulation, provisioning, and cultural services, while grasslands are the primary providers of supporting services. Technical profiles were generated for each HEU, and conservation strategies such as agroforestry systems and land planning, derived from sustainable production, were proposed for the benefit of both producers and ecosystems, emphasizing the importance of understanding the dynamics of productive landscapes for resource optimization and long-term sustainability.

RESUMEN El paisaje productivo ganadero en las fincas Playada, La Piedad, San Francisco y La Rafaela, región occidental de Paraguay, se erige como modelo representativo con aptitudes para producción y conservación de servicios ecosistémicos. Mediante categorización con ArcGIS 10.3, se identificó que los pastizales y sabanas cubren aproximadamente el 35% del área total, alrededor de 5,716 hectáreas. El estudio, basado en homogeneidad a escala paisaje, permitió analizar características físicas, distribución, cobertura y presiones antrópicas en cinco Unidades Ambientales Homogéneas (UAH). La caracterización de servicios ecosistémicos reveló que los remanentes boscosos proveen servicios de regulación, provisión y culturales, mientras que los pastizales son los principales proveedores de servicios de soporte. Con fichas técnicas para cada UAH, se propusieron estrategias de conservación como sistemas silvopastoriles y planificación predial, derivadas de la producción sostenible, en beneficio de productores y ecosistemas, subrayando la importancia del conocimiento de la dinámica de paisajes productivos para la optimización de recursos y la sostenibilidad a largo plazo.

ABSTRACT The study of the structure and diversity of forest ecosystems is essential to understand the functioning and dynamics of forests. The structure and diversity of woody species in different types of watercourses along the Santa Catarina river in Nuevo Leon, Mexico were described. Three conditions were identified: permanent (I), semi-permanent (II) and temporary (III). In each condition, 14 rectangular sites of 1 000 m2 were established. All species were identified. The crown diameter of each individual was measured. The Importance Value Index (IVI) was determined for each condition. Species richness and diversity was calculated with the Margalef (D Mg ) and Shannon-Wiener (H') indices. In addition, the similarity between conditions was determined using the Sorensen index (Is). 32 species, 29 genus and 16 families were identified. Condition I recorded greater specific richness and greater diversity with 28 species and a diversity value H' = 2.41 ± 0.710, where Salix nigra presented the highest IVI. Condition II presented the highest Margalef richness with a D Mg value = 1.77 ± 0.22. In condition III Leucaena leucocephala turned out to be the most important species. The similarity between conditions was greater than 50%. The results demonstrate the structural variation of the vegetation in different hydrological regimes, which constitutes a solid base for future investigations on the development of the vegetation associated with the Santa Catarina river, and other riparian areas of north of Mexico.

RESUMEN El estudio de la estructura y diversidad de los ecosistemas forestales es fundamental para comprender el funcionamiento y dinámica de los bosques. Se describió la estructura y diversidad de especies leñosas en diferentes tipos de curso de agua a lo largo del río Santa Catarina en Nuevo León, México. Se identificaron tres condiciones hidrológicas: permanente (I), semipermanente (II) y temporal (III). En cada condición se establecieron 14 sitios rectangulares de 1 000 m2, todas las especies de cada sitio fueron identificadas. Se midió el diámetro de la copa de cada individuo, el Índice de Valor de Importancia (IVI) de condición. La riqueza y diversidad de especies fue calculada con los índices de Margalef (D Mg ) y Shannon-Wiener (H'). Además, se determinó la similitud entre condiciones con el índice de Sorensen (Is). Se identificaron 32 especies, 29 géneros y 16 familias. La condición I registró mayor riqueza específica y diversidad con 28 especies y un valor de diversidad H' = 2.41 ± 0.710, en donde Salix nigra presentó el mayor IVI. La condición II presentó la mayor riqueza de Margalef con un valor D Mg de 1.77 ± 0.22. En la condición III Leucaena leucocephala fue la especie más importante. La similitud entre condiciones fue mayor al 50%. Los resultados demuestran la variación estructural de la vegetación en diferentes regímenes hidrológicos, lo cual constituye una base sólida para futuras investigaciones sobre el desarrollo de la vegetación asociada al río Santa Catarina, y otras áreas riparias del norte de México.

Abstract NDVI elucidates the ecophysiological mechanisms faced by vegetation. With the flexibility and versatility of unmanned aerial vehicles (UAVs), temporal, spatial and spectral resolutions have been useful in supporting decision-making. Here, we modeled diurnal change in the NDVI derived from UAV imagery for individual trees in a natural forest stand. Eight flights were conducted during daylight hours over one day to assess the dynamics of the NDVI of the genera Pinus, Juniperus, and Quercus. The results showed unstable NDVI values over time, with a parabolic quadratic trend in the model. The NDVI reached its maximum around 13:00 h and the values differed significantly according to genus: the highest value was found in Pinus with significant differences presented with Juniperus and Quercus, which showed similar values between them (p=0.533). As a validation strategy, we test the model generated using 124 trees independent of those that were sampled, which strengthened our results in terms of reliability. The similarities of statistical parameters confer a high variability of application of the results in models of simulation of similar forests ecosystems. We recommend to study more spectral indices of vegetation, including calibration of the sensor, particularly in longer-term seasonal studies. We conclude that the NDVI measured using UAV should consider image acquisition time to calibrate the records and thus improve the interpretation of results.

Resumen El NDVI dilucida los mecanismos ecofisiológicos a los que se enfrenta la vegetación. Gracias a la flexibilidad y versatilidad de los vehículos aéreos no tripulados (VANT), las resoluciones temporales, espaciales y espectrales han sido útiles para apoyar la toma de decisiones. En este trabajo se modelizó el cambio diurno en el NDVI derivado de imágenes de VANT para árboles individuales en un rodal forestal natural incoetáneo. Se realizaron ocho vuelos durante las horas diurnas a lo largo de un día para evaluar la dinámica del NDVI de los géneros Pinus, Juniperus y Quercus. Los resultados mostraron valores de NDVI inestables en el tiempo, con una tendencia cuadrática parabólica en el modelo. El NDVI alcanzó su máximo alrededor de las 13:00 h y los valores difirieron significativamente según el género: el valor más alto se encontró en Pinus con diferencias significativas presentadas con Juniperus y Quercus, que mostraron valores similares entre ellos (p=0.533). Como estrategia de validación, probamos el modelo generado utilizando 124 árboles independientes de los muestreados, lo que reforzó nuestros resultados en términos de confiabilidad. Las similitudes de los parámetros estadísticos confieren una alta variabilidad de aplicación de los resultados en modelos de simulación de ecosistemas forestales similares. Recomendamos estudiar más índices espectrales de vegetación, incluyendo la calibración del sensor, particularmente en estudios estacionales de más largo plazo. Concluimos que el NDVI medido mediante VANT debe considerar el tiempo de adquisición de la imagen para calibrar los registros y así mejorar la interpretación de los resultados.

Abstract Tropical wetland forests are fragile ecosystems facing critical risks due to global warming and other anthropogenic threats. Hence, gathering accurate and reliable information on them is urgent. Although remote sensing has demonstrated great potential in studying terrestrial ecosystems, remote sensing-based wetland forest research is still in an early stage of development. Mapping wetland forests, particularly mangrove forests, was an initial goal of this approach and is a task that still faces methodological challenges. Initially based on aerial photography only, wetland forest mapping through remote sensing underwent explosive diversification after the launching of artificial satellites in the 1970s. Later, precision in wetland forest mapping increased with the combination of hyperspectral, multispectral, and high and very high-resolution imagery. Accurate delimitation of wetland forest extent is also necessary to assess their temporal dynamics (losses, gains, and horizontal displacement). Despite the prevalence of mapping studies, current remote sensing-based research on wetland forests addresses new questions and novel aims, such as describing and predicting wetland forest attributes through mathematical modeling. Although this approach has made substantial progress in recent decades, modeling and predicting wetland forest attributes remain insufficiently explored fields of research. Combining active and passive sensors is a promising alternative to provide a more accurate picture of these communities’ attributes. In particular, LiDAR and radar-based technologies may help overcome difficulties encountered in older studies. In the future, we will witness conceptual and methodological progress that will enable us to surmount the remaining challenges.

Resumen Los humedales arbóreos tropicales están críticamente amenazados por el calentamiento global y otras amenazas antropogénicas; por ello, urge recopilar información confiable sobre estas comunidades vegetales. Aunque la percepción remota ha demostrado gran potencial en el estudio de ecosistemas terrestres, la investigación de los humedales arbóreos con este enfoque requiere mayor desarrollo. El mapeo de los humedales arbóreos (particularmente manglares), que fue el objetivo inicial de este enfoque, aún enfrenta desafíos metodológicos. Inicialmente basado solo en fotografías aéreas, el mapeo de humedales arbóreos se diversificó explosivamente con el lanzamiento de satélites artificiales y la interpretación de imágenes de percepción remota. La precisión de los mapas de estas comunidades aumentó con el uso combinado de imágenes multiespectrales, hiperespectrales, de alta y muy alta resolución. Para evaluar la dinámica temporal (pérdidas, ganancias, desplazamiento horizontal) de los humedales arbóreos necesitamos delimitar de manera precisa su extensión. Aunque todavía se están cartografiando numerosos humedales arbóreos, la investigación actual de estos ecosistemas por percepción remota aborda nuevas preguntas y objetivos (e.g., predecir los atributos comunitarios por medio de modelos matemáticos). A pesar de sustanciales avances recientes, el modelado y la predicción de los atributos de los humedales arbóreos siguen siendo temas poco explorados. La combinación de sensores activos y pasivos es una alternativa promisoria para evaluar con precisión los atributos de estas comunidades, y las tecnologías de radar y LiDAR pueden ayudar a superar dificultades enfrentadas en el pasado. Los avances conceptuales y metodológicos en el futuro permitirán superar los desafíos que aún persisten.

Abstract The objective of the study was to determine the spatial distribution patterns of Pinus and Quercus species along an altitudinal gradient in a temperate forest in northwestern Mexico. Individual uniformity (W i ), species mixture (M i ), and size dominance (U i ) were analyzed using structural parameters based on the relationships with the four nearest neighbors. Data were obtained from 37 sampling sites at three different altitude levels (Level 1: 2 200-2 600 m, Level 2: 2 600-2 800 m, and Level 3: 2 800-3 200 m), generating a total of 979 structural groups for all species. Pinus contributed 191, 51, and 41 groups at levels 1, 2, and 3, while Quercus contributed 192, one and zero, respectively. Pinus showed a tendency towards randomness, as did the oaks at Level 1; although, in this analysis, it was observed that at higher altitudes, Pinus tends towards a regular distribution. The species mix was medium to high for Pinus, which indicates that its individuals are surrounded by trees of different species, unlike Quercus. Size dominance revealed that Pinus specimens are taller than those of the Quercus genus throughout the gradient, especially at Level I. This approach provides an accurate understanding of the role of species in forest ecosystem dynamics.

Resumen El objetivo del estudio fue determinar los patrones de distribución espacial de las especies de Pinus y Quercus a lo largo de un gradiente altitudinal en un bosque templado del noroeste de México. Se analizó la uniformidad de los individuos (W i ), la mezcla de especies (M i ) y la dominancia dimensional (U i ) mediante parámetros estructurales basados en las relaciones con los cuatro vecinos más cercanos. Los datos se obtuvieron de 37 sitios de muestreo en tres niveles altitudinales (Nivel 1: 2 200-2 600 m, Nivel 2: 2 600-2 800 m y Nivel 3: 2 800-3 200 m), lo que generó un total de 979 grupos estructurales para todas las especies. Pinus contribuyó con 191, 51 y 41 grupos en los niveles 1, 2 y 3; mientras que Quercus aportó 192, uno y cero, respectivamente. Pinus evidenció tendencia hacia la aleatoriedad, y los encinos también en el Nivel 1, aunque en este análisis se observó que a mayor altitud Pinus tiende hacia una distribución regular. La mezcla de especies fue de media a alta para Pinus, lo cual indica que sus individuos están rodeados de árboles de especies diferentes, y con Quercus ocurrió al contrario. La dominancia dimensional reveló que los ejemplares de Pinus tienen mayor altura que los del género Quercus en todo el gradiente, especialmente en el Nivel 1. Este enfoque proporciona una comprensión exacta de la función que cumplen las especies en la dinámica de los ecosistemas forestales.

Abstract The forests of the Yucatán Peninsula have been periodically subjected to various natural and anthropogenic disturbance factors, among these are the occurrence of hurricanes and logging, the latter with a history of more than 300 years. The use of remote sensing has been widely employed for forest cover management and other land uses. Satellite information allows the calculation of several indexes that are useful for purposes of forest management, one of the most widely used is the Normalized Difference Vegetation Index (NDVI), which is associated with the fraction of solar radiation absorbed by plants. The objective of this study was to analyze the spatial-temporal dynamics of the NDVI changes in a region under forest harvesting in the state of Quintana Roo and determine their possible causes during the 1985-2022 period. A time series of NDVI values was generated from Landsat sensor images for the years 1985, 1993, 2000, 2010 and 2022. Differences in NDVI values were wide and appear to follow the recurrence of hurricanes in the region. Logging did not explain the upward and downward patterns in NVDI values, nor did these patterns coincide with the changes in vegetation, as they do not change the land cover characteristics. These results provide partial evidence that significant changes in vegetation characteristics occur only after major and extensive disturbances such as hurricanes.

Resumen Las selvas de la Península de Yucatán han estado sujetas periódicamente a diferentes factores de perturbación natural y antropogénica, entre ellos la ocurrencia de huracanes y el aprovechamiento maderable, este último con una historia de más de 300 años. El uso de sensores remotos se ha empleado ampliamente para la gestión de coberturas forestales y otros usos del suelo. La información satelital permite el cálculo de diversos índices útiles para la administración forestal, uno de los más usados es el Índice de Vegetación de Diferencia Normalizada (NDVI) que se asocia a la fracción de la radiación solar absorbida por las plantas. El objetivo del presente estudio fue analizar la dinámica espacio-temporal de los cambios en el NDVI en una región con aprovechamiento maderable en el estado de Quintana Roo y determinar sus posibles causas durante el periodo 1985-2022. Se generó una serie de tiempo de valores de NDVI en imágenes de los sensores Landsat para los años 1985, 1993, 2000, 2010 y 2022. Las diferencias en los valores del NDVI fueron amplias y parecen seguir la recurrencia de huracanes en la región. La tala forestal no explicó los patrones al alza y a la baja en los valores del NVDI, ni coincidieron con las modificaciones en la vegetación, ya que no cambian las características de la cobertura del suelo. Estos resultados proporcionan evidencia parcial de que cambios significativos en las características de la vegetación solo ocurren después de perturbaciones importantes y extensas como los huracanes.

Abstract Vegetation dynamics in forest ecosystems are commonly attributed to climatic factors. However, there is still limited knowledge on how topography influences the climatic sensitivity of forest species. The response of dendroecological indicators of Pinus arizonica to exposure and climatic variability was determined. Indices of ring width (RWI) and Basal area increments (BAI) were obtained. The correlation between RWI and monthly records of accumulated precipitation (PP) and mean temperatures (Tmax and Tmin) was calculated for three periods: 1990-2000 (B1), 2001-2011 (B2), and 2012-2021 (B3). Mann-Whitney and Kruskall-Wallis tests were performed to test for differences in BAI by exposure (northwest, NW and northeast, NE) and by time period, respectively. Tmax limited growth in all three periods, Tmin restricted it in B2 and PP favored it in B1 and B2. A higher BAI was detected in the NW exposure (224.7 mm2 yr-1) compared to the NE (143.9 mm2 yr-1). There was a significant increase in BAI in periods B2 (62.1 mm2 yr-1) and B3 (56.9 mm2 yr-1) compared to B1 (51.2 mm2 yr-1). This highlights the importance of considering topography when analyzing climate-growth associations of forest species. Considering the interaction of climatic factors and microclimates associated with site-specific topography generates an integrated view of ecological processes. This allows proposing better forest management strategies to mitigate the effects of Climate Change.

Resumen La dinámica de la vegetación en ecosistemas forestales, comúnmente, se atribuye a factores climáticos. Sin embargo, aún existe un conocimiento limitado sobre cómo la topografía influye en la sensibilidad climática de especies forestales. Se determinó la respuesta de indicadores dendroecológicos de Pinus arizonica a la exposición y la variabilidad climática. Se obtuvieron índices de ancho de anillo (IAA) e incrementos de área basal (IAB). Se calculó la correlación entre los IAA, registros mensuales de precipitación acumulada (PP) y temperaturas medias (Tmáx y Tmín) en tres periodos: 1990-2000 (B1), 2001-2011 (B2) y 2012-2021 (B3). Se realizaron las pruebas de Mann-Whitney y de Kruskall-Wallis para comprobar diferencias en el IAB por exposición (noroeste, NO y noreste, NE) y por bloque temporal, respectivamente. La Tmáx limitó el crecimiento en los tres periodos, la Tmín lo restringió en el B2 y la PP lo favoreció en los B1 y B2. Se detectó un mayor IAB en la exposición NO (224.7 mm2 año-1) en comparación con la NE (143.9 mm2 año-1). Existió un aumento significativo en el IAB en los periodos B2 (62.1 mm2 año-1) y B3 (56.9 mm2 año-1) en comparación con el B1 (51.2 mm2 año-1). Esto resalta la importancia de considerar la topografía al analizar las asociaciones clima-crecimiento de especies forestales. Considerar la interacción de factores climáticos y microclimas asociados a la topografía específica del sitio, genera una visión integral de los procesos ecológicos, lo que permite proponer mejores estrategias de manejo forestal para la mitigación de los efectos del Cambio Climático.

Resumen Las tierras secas representan el principal bioma terrestre, proveyendo numerosos servicios ecosistémicos a un ingente número de personas. En estos ambientes, los bosques son a menudo dominados por árboles de porte multi-fustal, explotados por los habitantes locales para obtener productos forestales útiles para su sustento. En los territorios del centro-oeste de Argentina, los bosques de Neltuma flexuosa (algarrobo) están distribuidos en diferentes unidades de paisaje, los que presentan variaciones en las características topográficas y edáficas. En este estudio reconstruimos, a través de métodos dendrocronológicos, el crecimiento, el intervalo para obtener productos maderables, y el turno biológico de corta en función de la variabilidad topo-edáfica en tres bosques diferentes de algarrobo. Los resultados indican que la heterogeneidad del paisaje modula el crecimiento radial de la especie, influenciando el incremento diamétrico y el turno de corta. En este sentido, se evidencia una tendencia decreciente en valores de productividad según un gradiente edáfico desde textura limosa a arenosa. Estos hallazgos proveen información novedosa y de utilidad para los planes de manejo forestal de los bosques de N. flexuosa, indicando la necesidad por considerar la heterogeneidad espacial establecidas por las unidades de paisaje/suelos en estudios relativos a la dinámica forestal de los bosques de tierras secas.

Abstract Drylands represent the main earth biome, providing ecosytemic services to a large number of people. Along these environments, woodlands are often dominated by multi-stemmed trees, which are exploited by local inhabitants to obtain forest products for their livelihood. In central-west Argentina, Neltuma flexuosa (algarrobo) woodlands are distributed across different landform units, varying in topographical and soil characteristics. This research aimed to reconstruct stem-growth time until harvestable diameter was achieved, and biological rotation age according to topo-edaphic variability in three algarrobo forests using dendrochronological methods. Results indicated that landform heterogeneity modulated species radial growth, influencing stem increments and cutting cycle period. In this sense, a decreasing trend in tree productivity emerged along a loamy-to-sandy textured soil gradient. These findings provide useful novel information for N. flexuosa forest management, suggesting the need to account for spatial landform/soil heterogeneity when examining desert forest dynamics.

ABSTRACT Considering the importance of evaluating the compatibility between the exploration system usually used in the Caatinga and the vegetation regeneration process, this study aimed to evaluate the feasibility of recovering structural parameters in an experimental unit subjected to different management systems aged 9, 12, 16, 20 and 26 years post-exploitation. The area was subjected to clearcutting (CC) regimes and three types of selective cuttings (SC1 – selective cutting 1, cut of trees with diameter at the base – DAB < 15 cm; SC2 – selective cutting 2, cut of trees with DAB > 10 cm; and SC3 – selective cutting 3, cut of trees with DAB between 5 and 10 cm). In permanent plots of 20 m × 20 m, individuals with a circumference at breast height (CBH) ≥ 6 cm and a total height greater than 1.0 m were measured. Over the years of monitoring, the CC presented the lowest values of density, dominance, and volume, not obtaining a recovery in basal area and volume even after 26 years of regeneration. Treatments SC2 and SC3 stood out regarding recovery of the original woody biomass stock, presenting values higher than the original ones and indicating that the initial data did not correspond to the site's maximum potential. The forest dynamics pointed to the insufficiency of the 15-year clearcutting cycle in terms of recovering this region forest composition and structure. process 9 12 16 2 postexploitation. postexploitation post exploitation. exploitation post-exploitation (CC SC1 SC (SC 1 3 cm. . cm) CBH (CBH 0 1. measured monitoring density dominance stock sites site s potential 15year year structure

RESUMO Considerando a importância de se avaliar a compatibilidade entre o sistema de exploração usualmente empregado na Caatinga e o processo de regeneração da vegetação, este estudo objetivou avaliar a viabilidade de recuperação dos parâmetros estruturais em uma unidade experimental submetida a diferentes sistemas de manejo com idades de 9, 12, 16, 20 e 26 anos pós-exploração. A área foi submetida aos regimes de corte raso (CR) e três tipos de cortes seletivos (SC1 – corte seletivo 1, de árvores com diâmetro na base – DNB < 15 cm; SC2 – corte seletivo 2, de DNB > 10 cm; e SC3 – corte seletivo 2, de DNB entre 5 e 10 cm). Em parcelas permanentes de 20 m × 20 m, foram mensurados os indivíduos com CAP ≥ 6 cm e altura total superior a 1,0 m. Ao longo dos anos de monitoramento, o CR apresentou os menores valores de densidade, dominância e volume, não obtendo recuperação em área basal e volume mesmo após 26 anos de regeneração. Os tratamentos SC2 e SC3 se sobressaíram quanto à recuperação do estoque original de biomassa lenhosa, apresentando valores superiores aos originais e indicando que os dados iniciais não correspondiam ao potencial máximo do sítio. A dinâmica florestal apontou à insuficiência do ciclo de corte raso de 15 anos quanto à recuperação da composição e estrutura florestal nesta região. vegetação 9 12 16 2 pósexploração. pósexploração pós exploração. pós-exploração (CR SC1 SC (SC 1 cm. . cm) 0 monitoramento densidade lenhosa sítio região

Abstract The Neotropics are one of the most biodiverse regions of the world, where environmental dynamics, climate and geology resulted in a complex diversity of fauna and flora. In such complex and heterogeneous environments, widely distributed species require deep investigation about their biogeographic history. The gray-breasted sabrewing hummingbird Campylopterus largipennis is a species complex that occurs in forest and open ecosystems of South America, including also high-altitude grasslands. It has been recently split into four distinct species distributed in Amazonia (rainforest) and Cerrado (savanna) biomes with boundaries marked by ecological barriers. Here, we investigated the evolutionary dynamics of population lineages within this neotropical taxon to elucidate its biogeographical history and current lineage diversity. We used a reduced-representation sequencing approach to perform fine-scale population genomic analyses of samples distributed throughout Amazonia and Cerrado localities, representing all four recently recognized species. We found a deep genetic structure separating species from both biomes, and a more recent divergence between species within each biome and from distinct habitats. The population dynamics through time was shown to be concordant with known vicariant events, isolation by distance, and altitudinal breaks, where the Amazon River and the Espinhaço Mountain Range worked as important barriers associated to speciation. world flora environments graybreasted gray breasted America highaltitude high altitude grasslands rainforest (rainforest savanna (savanna Here reducedrepresentation reduced representation finescale fine scale localities habitats events distance breaks speciation

Abstract The impact of forestry practices was evaluated on Eucalyptus’s growth variables and mortality dynamics. An experiment was conducted in Uruguay over sixteen years, sixteen spacing and thinning treatments were compared depending on the genetic material and productive objective. Tree height and diameter at breast height were assessed annually. All variables were analyzed using linear mixed models. Kaplan-Meier survival analysis and the Log Rank test were used to compare tree survival. 460 trees ha-1 from seed material resulted in the highest individual basal area (0.023 m2), while treatments with 2000 trees ha-1, without thinning, generated a greater yield per hectare (1014 m3 ha-1). Variations in mortality were detected in higher-density treatments (above 800 trees ha-1). This study underscores the critical importance of managing spacing, genetic material, and thinning practices to optimize Eucalyptus growth. Eucalyptuss s dynamics years objective annually models KaplanMeier Kaplan Meier 46 ha1 ha 1 ha- 0.023 0023 0 023 (0.02 m2, m2 m , m2) 200 ha1, 1, 1014 (101 ha1. . ha-1) higherdensity higher density above 80 4 0.02 002 02 (0.0 20 101 (10 8 0.0 00 (0. 2 10 (1 0. (0 (

ABSTRACT The partitioning of precipitation into interception, throughfall and stemflow is essential for the hydrological balance in forests, particularly in the Brazilian forest system, regulating the amount of water input and leaf distribution in the ecosystem. This study aimed to present the dynamics of interception loss in yerba mate monoculture, agroforestry and native mixed ombrophilous forest systems, in experimental producing areas in the municipality of Guarapuava, Southern Brazil. The total gross rainfall was 788 mm, distributed in 33 events between July 2019 and March 2020. The throughfall, stemfow and interception loss of rainfall were respectively 78.7, 0.2 and 21.1 % in the native mixed ombrophilous forest; 85.3, 0.1 and 14.6 % in the agroforestry system; and 86.1, 0.3 and 13.6 % in the monoculture system. It was observed that diferent canopy characteristics infuence the variability of rainfall partitioning. The mixed ombrophilous forest showed a higher interception capacity, when compared to the monoculture and agroforestry systems, determined by plant density and meteorological conditions. forests system ecosystem systems Guarapuava Brazil 78 mm 3 201 2020 787 7 78.7 02 0 2 0. 211 21 1 21. 853 85 85.3 01 146 14 6 14. 861 86 86.1 03 136 13 13. capacity conditions 20 202 78. 8 85. 86.

RESUMO A partição da precipitação em interceptação, precipitação interna e escoamento pelo tronco é essencial para o equilíbrio hídrico em forestas, especialmente no sistema forestal brasileiro, regulando a quantidade de entrada de água e a distribuição de folhas no ecossistema. Objetivou-se apresentar a dinâmica de perda por interceptação em sistemas de monocultura, agroforesta e foresta ombrófla mista nativa de erva-mate, em áreas experimentais de produção no município de Guarapuava, no Sul do Brasil. A chuva total foi de 788 mm, distribuída em 33 eventos entre julho de 2019 e março de 2020. A precipitação interna, escoamento pelo tronco e perda por interceptação da precipitação foram, respectivamente, de 78,7; 0,2; e 21,1 % na foresta ombrófla mista nativa; 85,3; 0,1; e 14,6 % no sistema agroforestal; e 86,1; 0,3; e 13,6 % no sistema de monocultura. Observou-se que diferentes características de dossel infuenciam a variabilidade na partição da precipitação. A foresta ombrófla mista apresentou capacidade de interceptação superior, em comparação aos sistemas de monocultura e agroforesta, determinada pela densidade de plantas e condições meteorológicas. forestas brasileiro ecossistema Objetivouse Objetivou se ervamate, ervamate erva mate, mate erva-mate Guarapuava Brasil 78 mm 3 201 2020 foram respectivamente 78,7 787 7 0,2 02 0 2 211 21 1 21, 85,3 853 85 0,1 01 146 14 6 14, agroforestal 86,1 861 86 0,3 03 136 13 13, Observouse Observou superior meteorológicas 20 202 78, 0, 85, 8 86,

Abstract Soil organic matter is closely linked to the quality of Agroecosystems and directly influences the agricultural production and the environmental conditions. Understanding of soil organic matter dynamics in agroforestry systems requires studies with a temporal focus, since the changes in its chemical composition tend to follow a gradual behavior. The aim of this study was to investigate the dynamics of changes in stocks and chemical composition of soil organic matter under agroforestry, using systems in different stages of vegetation succession. The soil sampling was carried out from trenches, and litter fractions were also sampled. The samples were collected from different layers of the soil profile under the following conditions: Control; agroforestry with 1 year; agroforestry with 3 years; agroforestry with 7 years and Forest in natural regeneration. The following attributes/parameters were determined/calculated: i) C and N contents and stocks and C/N ratio; ii) C and N proportions in soil granulometric fractions and iii) kinetics of organic matter accumulation in soil with the time of systems evolution. The results showed: i) The C/N ratio tended to increase in depth but did not show a clear variation between the systems evaluated; ii) the adoption of successive agroforestry practices has the potential to increase the C and N stocks in soil; iii) the soil organic matter accumulation occurs gradually during the systems evolution and is mainly related to the particulate fraction (> 0.053 mm). conditions focus behavior succession trenches sampled Control year regeneration attributesparameters attributes parameters determined/calculated determinedcalculated determined calculated i CN ii iii showed evaluated > ( 0053 0 053 0.05 mm. mm . mm) 005 05 0.0 00 0.