Abstract Soil humidity is an important environmental factor that affect composition, diversity and structure of the vegetal communities. The objective of the present study was to determine the diversity changes that occur over an environmental gradient limited by the source of water of the oasis San Ignacio and the adjoining desert of Baja California Sur, Mexico. The study area was divided in nine strips of 100 m width. Over them, there were randomly selected 140 plots of 500, 20 and 1 m2 to register the vegetal species present in the tree, shrub and herbaceous layers, respectively. Species richness, Shannon-Weiner diversity, Simpson dominance, Pielou equity and true species value indexes were estimated and compared between established strips. The qualitative index of Sörensen was estimated to evaluate species similitude and similar communities were grouped applying dendrograms. The species richness of the herbaceous and shrub layers falls abruptly at 520 and 720 m far away from the source of water. Species richness and diversity in the tree layer presented an undefined tendency. The similitude index allowed to concentrate the herbaceous, shrub and tree vegetation layers in 4, 5 and 3 clusters. This diversity analysis suggests to determine that herbaceous and shrub species are more sensitive to humidity changes than arboreal species.

Resumen La humedad del suelo es un factor ambiental importante que afecta la composición, diversidad y estructura de las comunidades vegetales. Considerando lo anterior, el objetivo de este estudio fue determinar los cambios de diversidad vegetal que ocurren entre la fuente de humedad del Oasis San Ignacio y el desierto circundante de Baja California Sur. El área de estudio se dividió en nueve franjas de 100 m de ancho, sobre las cuales se seleccionaron aleatoriamente 140 sitios de 500, 20 y 1 m2 para registrar las especies vegetales de los estratos arbóreos, arbustivos y herbáceos, respectivamente. Se estimaron los índices de riqueza, diversidad de Shannon-Weiner, dominancia de Simpson, equidad de Pielou y valor verdadero de especies y se evaluaron los cambios entre las franjas establecidas. A su vez, se estimó el índice cualitativo de similitud de especies de Sörensen, generándose dendrogramas para agrupar comunidades vegetales similares establecidas sobre el gradiente estudiado. La riqueza y diversidad de las especies del estrato herbáceo y arbústivo decrecen abruptamente a los 520 y 720 m del cuerpo de agua, respectivamente. La riqueza y diversidad de la vegetación del estrato arbóreo no presenta una tendencia definida. El índice de similitud permitió concentrar las especies del estrato herbáceo, arbustivo y arbóreo en 4, 5 y 3 grupos, respectivamente. Los análisis de diversidad, sugieren que las especies herbáceas y arbustivas son más sensibles a los cambios de humedad que las arbóreas.

Resumen En este trabajo se determina la entomofauna benéfica asociada a especies arbóreas en escenarios de la agricultura urbana de Pinar del Río, Cuba. Entre septiembre de 2019 y marzo de 2020, se realizó un inventario florístico de la biodiversidad arbórea y se recolectaron muestras de los biorreguladores. Se inventariaron 23 especies arbóreas y 65% de ellas estuvo representado por frutales. La mayor riqueza de especies se detectó en los órdenes Diptera, Mesostigmata, Hymenoptera y Araneae. Los biorreguladores con mayor frecuencia fueron Condylostylus sp., Ocyptamus costatus y Phytoseiulus sp.; mientras que, las especies arbóreas con mayor proporción de artrópodos asociados fueron Persea americana, Citrus limon, Morinda citrifolia y Psidium guajava. Los resultados corroboran la necesidad de fomentar estratos arbóreos como reservorio de biorreguladores y profundizar en la actividad de estos organismos benéficos como alternativa para el manejo de plagas.

Abstract This work determines the beneficial entomofauna associated with tree species in urban agriculture scenarios of Pinar del Río, Cuba. Between September 2019 and March 2020, a floristic inventory of tree biodiversity was conducted and samples of bioregulators were collected. Twenty-three tree species were inventoried and 65% of them were represented by fruit trees. The greatest species richness was detected in the orders Diptera, Mesostigmata, Hymenoptera and Araneae. The most frequent bioregulators were Condylostylus sp., Ocyptamus costatus and Phytoseiulus sp.; while the tree species with the highest proportion of associated arthropods were Persea americana, Citrus limon, Morinda citrifolia and Psidium guajava. The results corroborate the need to promote tree strata as a reservoir of bioregulators and deepen the activity of these beneficial organisms as an alternative for pest management.

ABSTRACT Understanding the dynamics of endemic tree component species based on natural regeneration (NR) and adult trees (AT) is essential for formulating conservation strategies for protecting these species. The objective of the present study was to identify endemic species in a preserved area of secondary forest in the Atlantic Forest domain in Brazil and to evaluate their dynamics over 24 years. Based on inventories carried out from 1992 to 2016 of the NR (diameter at breast height - dbh ≤ 5 cm) and of the AT (dbh ≥ 5 cm) in ten sites with different characteristics (physiographic, edaphic, and successional), it was possible to, initially, identify 58 species classified as endemic to Brazil (EBR) and/or those exclusive to the Brazilian Atlantic Forest (EAF), among the 226 species in the entire survey. Subsequently, this classification was reassessed based on updated information on its occurrence, and only 38 of these species were maintained as endemic to Brazil and/or to the Atlantic Forest. Some species were recorded in the AT and NR strata, in different sites, throughout the study period, while others occurred in only one level (AT or NR), some with low abundance. Among these endemic species, eight are included in the endangered species lists, and 15 can be classified as rare, as there was only one individual in the survey. Considering the two arboreal strata it was observed that some species were abundant in the forest in all inventories and several sites, while others went throughout the study period with few individuals and, in some cases, disappeared due to mortality. These results contribute to understanding the factors that can affect the local abundance of endemic species over time, allowing the definition of conservation actions for protecting these vulnerable species, thus avoiding their extinction. (NR 2 years 199 201 diameter cm physiographic, physiographic (physiographic edaphic successional, successional , successional) initially EBR (EBR andor EAF, EAF (EAF) 22 survey Subsequently occurrence 3 NR, NR) lists 1 rare cases mortality time extinction 19 20 (EAF

RESUMO A compreensão da dinâmica das espécies endêmicas do componente arbóreo, com base na regeneração natural (RN) e nas árvores adultas (AA) é fundamental para a formulação de estratégias de conservação dessas espécies. O objetivo do presente estudo foi identificar as espécies endêmicas em uma área preservada de floresta secundária, no domínio da Mata Atlântica, no Brasil, e avaliar sua dinâmica ao longo de 24 anos. Com base em inventários realizados de 1992 a 2016 da RN (diâmetro à altura do peito - dap ≤ 5cm) e das AA (dap ≥ 5 cm), em dez locais com diferentes características (fisiográficas, edáficas e sucessionais), foi possível identificar 58 espécies classificadas como endêmicas do Brasil e/ou àquelas exclusivas da Mata Atlântica brasileira, dentre as 226 espécies de todo o levantamento. Posteriormente, essa classificação foi reavaliada a partir de informações atualizadas de sua ocorrência, sendo que apenas 38 dessas espécies permaneceram como endêmicas do Brasil e/ou da Mata Atlântica. Algumas espécies foram registradas na AA e na RN, em diversos locais, em todo o período do estudo, enquanto outras ocorreram em apenas um nível (AA ou RN), inclusive com baixa abundância. Dentre essas espécies endêmicas, oito estão incluídas em listas de espécies ameaçadas de extinção e 15 podem ser classificadas como raras (apresentaram apenas um indivíduo). Considerando os dois estratos arbóreos, foi observado que algumas espécies permaneceram na floresta em todos os inventários, enquanto outras ingressaram ao longo do período do estudo, com poucos indivíduos, inclusive com elevada mortalidade, deixando de ocorrer na área. Esses resultados contribuem para o entendimento dos fatores que podem afetar a abundância local de espécies endêmicas ao longo do tempo, permitindo a definição de ações de conservação para proteger essas espécies vulneráveis, evitando assim, a sua extinção. arbóreo (RN secundária 2 anos 199 201 diâmetro 5cm cm cm, , cm) fisiográficas, fisiográficas (fisiográficas sucessionais, sucessionais sucessionais) eou brasileira 22 levantamento Posteriormente ocorrência 3 RN) 1 apresentaram indivíduo. indivíduo . indivíduo) arbóreos indivíduos mortalidade tempo vulneráveis assim 19 20

RESUMEN Sedimentos continentales del Mioceno temprano-medio de la Formación Cerro Boleadoras (FCB) afloran en el área de los cerros Boleadoras y Plomo, en la vertiente occidental de la meseta del lago Buenos Aires, noroeste de la provincia de Santa Cruz, Argentina. Los niveles inferiores de la FCB consisten en estratos de areniscas medianas a gruesas con estratificación entrecruzada, lateralmente extensos, interpretados como depósitos de canales fluviales, que se intercalan con depósitos finos de planicie de inundación. Trabajo de campo reciente permitió recuperar vertebrados fósiles de estos niveles, con una edad estimada entre ~16,5 y 15,1 Ma (Burdigaliano tardío-Langhiano temprano). Estos niveles se solapan temporalmente con las secciones media y superior de la Formación Santa Cruz (FSC) en la cuenca Austral-Magallanes de la Patagonia Austral, la Formación Río Frías en Chile y la parte inferior de la Formación Collón Curá en el norte de la Patagonia. En este trabajo se recopila una lista faunística actualizada para esta localidad, que incluye especímenes de colecciones previas, y se discuten sus implicaciones cronológicas y paleoambientales. La lista incluye la mayoría de los grupos registrados en la FSC: un anuro, tres aves y al menos 33 mamíferos (metaterios, xenartros, litopternos, notoungulados tipoterios y roedores caviomorfos), indicando una edad del Santacrucense sensu lato. También registramos un testudínido, que constituye el registro más austral de tortugas terrestres en América del Sur y en el mundo. La disimilitud faunística registrada con las secciones mencionadas de las formaciones Santa Cruz, Río Frías y Collón Curá reflejarían diferencias ecológicas, climáticas y geográficas más que temporales. La coocurrencia de mamíferos arbóreos o semiarbóreos, ramoneadores, frugívoros y pastadores sugiere la presencia de árboles y ambientes abiertos para el área ocupada por las rocas de la FCB. Sin embargo, no es posible discernir si estos 2 ambientes coexistieron o alternaron y si un ambiente predominó sobre el otro. Taxones claves, como los roedores chinchílidos Prolagostomus y Pliolagostomus y el tipoterio Pachyrukhos, indican una tendencia a la aridificación para el Mioceno de Patagonia Austral, como se reportó anteriormente para la parte superior de la FSC a lo largo del río Santa Cruz y al sur del río Coyle, a lo largo de la costa atlántica y el río Gallegos.

ABSTRACT The early-middle Miocene continental Cerro Boleadoras Formation (CBF) crops out in the area of Cerro Boleadoras and Cerro Plomo on the western slope of the Meseta del Lago Buenos Aires, northwestern Santa Cruz Province, Argentina. The lower levels of the CBF consist of laterally extensive medium to pebbly sandstone beds with trough cross-bedding, interpreted as fluvial channel deposits, interbedded with tabular fine-grained floodplain deposits. Recent fieldwork provided fossil vertebrates from these levels with an estimated age between ~16.5 Ma and 15.1 Ma (late Burdigalian-early Langhian). The studied section temporally overlaps with the middle or upper sections of the Santa Cruz Formation (SCF) in the Austral-Magallanes Basin of southern Patagonia, the Río Frías Formation in Chile, and the lower Collón Curá Formation of northern Patagonia. We compile an integrated faunal list for this locality, including specimens from previous collections, and discuss its chronological and paleoenvironmental implications. The taxa list includes most of the groups recorded in the SCF: one anuran, three birds, and at least 33 mammals (metatherians, xenarthrans, litopterns, notoungulate typotheres and caviomorph rodents), indicating a Santacrucian age sensu lato. We also recorded a testudine, which constitutes the southernmost record of tortoises in South America and worldwide. Faunal dissimilarities between the vertebrate fossil content of the CBF and the mentioned sections of the Santa Cruz, Río Frías and Collón Curá formations may reflect ecologic, climatic and geographic differences rather than temporal ones. The co-occurrence of arboreal or semiarboreal, browsing, frugivorous, and grazing mammals suggests the presence of both forested and open environments for the area occupied by the CBF rocks. However, it is not possible to discern whether these two environments coexisted or alternated, and whether one environment predominated over the other. Marker taxa, such as the chinchillid rodents Prolagostomus and Pliolagostomus, and the typothere Pachyrukhos indicate a trend to aridification during the Miocene in southern Patagonia, as previously reported for the upper part of the SCF along the Río Santa Cruz and south to the Río Coyle, along the Atlantic coast and the Río Gallegos.

RESUMO O objetivo deste estudo foi avaliar as relações de escala de artrópodes do solo e da estrutura da vegetação de fitofisionomias de Cerrado. As parcelas experimentais foram alocadas em áreas com Cerrado denso (T1), Cerrado típico (T2) e Cerrado ralo (T3). A fauna edáfica foi coletada em 128 pontos, por meio de armadilhas de queda e a vegetação avaliada em subparcelas de 9 m2. Os dados foram avaliados por meio da estatística descritiva, geoestatística, análise multifractal e joint multifractal. Os artrópodes do solo e a estrutura de vegetação se ajustaram a um modelo geoestatístico, exceto, plantas arborescentes (T1), abundância de artrópodes (T2) e plantas arbóreas (T2), que apresentaram efeito pepita puro. As variáveis estudadas apresentaram diferentes graus de multifratalidade. Os gráficos da dimensão joint multifractal mostraram linhas circulares com altos valores de correlação conjunta para riqueza de artrópodes versus abundância dos estratos vegetais (r = -0,498), riqueza de artrópodes versus herbáceos (r = 0,323) e riqueza de artrópodes versus arbóreo (r = 0,451) em T1. A fauna do solo foi influenciada pela composição dos estratos arbóreos em maior ou menor grau. As parcelas com Cerrado denso (T1) e Cerrado ralo (T3) apresentaram a maior dependência espacial entre as amostras. A análise multifractal demonstrou que a parcela com Cerrado ralo (T3) foi o sistema com maior heterogeneidade de medida ao longo do suporte geométrico; enquanto a maior assimetria do espectro de singularidade foi descrita para a parcela com Cerrado denso (T1). A utilização de ferramentas de geoestatística e análise multifractal permitiu caracterizar as relações de escala entre as variáveis.

ABSTRACT The objective of this study was to assess the scale relationships of soil arthropods and the vegetation structure of Cerrado phytophysiognomies. The experimental plots were set in areas with dense Cerrado (T1), typical Cerrado (T2), and sparse Cerrado (T3). The edaphic fauna was collected at 128 points through pitfall traps, and the vegetation was evaluated in subplots of 9 m2. The data were evaluated using descriptive statistics, geostatistics, multifractal analysis, and joint multifractal analysis. The soil arthropods and vegetation structure were adjusted to a geostatistical model, except for arborescent plants (T1) and arthropod abundance and arboreal plants (T2), which showed a pure nugget effect. The studied variables showed different degrees of multifractality. The graphs of joint multifractal dimension showed circular lines with high values of joint correlation for the pairs of arthropod richness versus the abundance of plant strata (r = -0.498), arthropod richness versus herbaceous plants (r = 0.323), and arthropod richness versus arboreal plants (r = 0.451) at T1. The soil fauna was influenced by the composition of the plant strata. The plots with dense Cerrado (T1) and sparse Cerrado (T3) showed the greatest spatial dependence between the samples. The multifractal analysis showed that the plot with sparse Cerrado (T3) had the greatest heterogeneity of measurement along the geometric support. In contrast, the greatest asymmetry of the singularity spectrum was described for the plot with dense Cerrado (T1). The use of geostatistical and multifractal analysis tools enabled us to characterize the scale relationships between the variables.

Summary: Agroforestry systems (SAF) of coffee are considered areas that increase the biodiversity of species of both flora and fauna, are sources of economic income for the communities that work them, as well as multiple environmental services. In order to know the influence of coffee SAF management on the diversity of tree species, the composition, structure and diversity of the tree stratum in two rustica coffee plantations was described, under management conditions: active coffee (CA) and abandoned coffee plantation (CAb), in Jocotepec, region Coast of Oaxaca. In each driving condition four study units of 20 × 30 m (0.06 ha) were placed. All trees individuals from 1.30 m above the ground were registered with the normal diameter (DN) ≥ 2.5 cm, total height and canopy cover. Wealth, vertical, horizontal structure, Importance and Forest Value Indices (IVI and IVF) were evaluated; diversity with the Simpson Indices modified by Pielou (1-D) and Shannon-Weaver (H´) and equity (E), dominance (D) and Similarity. A wealth of 35 species was obtained for the CA and 31 in CAb; The main taxonomic families were Fabaceae, Lauraceae and Moraceae. In both driving conditions, the diameter category 5 (2.5 - 7.5 cm) exceeded the number of tree individuals, with a distribution of heights that revealed the existence of two vertical strata. The species that presented a high IVI and IVF in CA were: Cedrela odorata, Tabebuia rosea and Quercus crispifolia and for the CAb: Quercus sp., Ficus tecolutensis and Ocotea helicterifolia. Between CA and CAb there were no differences in the evaluated variables, 1-D, H´, E and D. The floristic similarity between conditions was 52%.

Resumen: Los sistemas agroforestales (SAF) de café son consideradas áreas que incrementan la biodiversidad de especies tanto de flora y fauna, son fuentes de ingresos económicos para las comunidades que los trabajan, así como de múltiples servicios ambientales. Con el objetivo de conocer la influencia del manejo en los SAF de café en la diversidad de especies arbóreas, se describió la composición, estructura y diversidad del estrato arbóreo en dos cafetales rusticanos, bajo condiciones de manejo: cafetal activo (CA) y cafetal abandonado (CAb), en Jocotepec, región Costa de Oaxaca. En cada condición de manejo se situaron cuatro unidades de estudio de 20 × 30 m (0.06 ha). A todos los individuos arbóreos a partir de 1.30 m del suelo se les registró el diámetro normal (DN) ≥ 2.5 cm, altura total y cobertura de copa. Se evaluó la riqueza, estructura vertical, horizontal, Índices de Valor de Importancia y Forestal (IVI e IVF); diversidad con los Índices de Simpson modificado por Pielou (1-D) y Shannon-Weaver (H´) y la equidad (E), dominancia (D) y Similitud. Se obtuvo una riqueza de 35 especies para el CA y 31 en CAb; las principales familias taxonómicas fueron Fabaceae, Lauraceae y Moraceae. En ambas condiciones de manejo la categoría diamétrica 5 (2.5‑7.5 cm) superó en número de individuos arbóreos, con una distribución de alturas que reveló la existencia de dos estratos verticales. Las especies que presentaron un alto IVI e IVF en CA fueron: Cedrela odorata, Tabebuia rosea y Quercus crispifolia y para el CAb: Quercus sp., Ficus tecolutensis y Ocotea helicterifolia. Entre CA y CAb no se presentaron diferencias en las variables evaluadas, 1-D, H´, E y D. La similitud florística entre condiciones fue del 52%.

Resumen Introducción. Los sistemas silvopastoriles se presentan como una alternativa para el uso sostenible de los recursos naturales, por ello, surge la necesidad de identificar especies potenciales para su establecimiento en el trópico de altura. Objetivo. El objetivo fue evaluar el crecimiento inicial de ocho especies leñosas en un diseño silvopastoril para protección de fuente hídrica. Materiales y métodos. El estudio se realizó en el centro de investigación Obonuco de la Corporación Colombiana de Investigación Agropecuaria (Pasto, Colombia) entre septiembre 2017 y junio 2018, se desarrolló un diseño de bloques al azar en arreglo factorial, donde interactuaron especies arbóreas/arbustivas diferenciadas por su hábito de crecimiento (estrato alto: Cedrela montana, Quercus humboldtii, Ficus andicola; estrato medio: Salix babylonica, Alnus acuminata, Smallanthus pyramidalis; estrato bajo: Morella pubescens y Sambucus nigra) y altitud (2750, 2770 y 2800), con cuatro repeticiones para evaluar variables morfométricas y calidad de plántulas. Resultados. En la variable altura, el mejor comportamiento se presentó en Ficus andicola a 2750 msnm con 191,37 cm y Alnus acuminata a 2800 msnm con 181,83 cm. En diámetro de tallo sobresalieron Ficus andicola a 2750 msnm con 42,98 mm, Smallanthus pyramidalis a 2800 msnm con 37,24 mm y Sambucus nigra a 2800 msnm con 8,16 mm. El número de rebrotes no evidenció efecto significativo de la interacción y, en calidad de plántulas, Quercus humboldtii a 2750 y 2700 msnm y Ficus andicola a 2750 msnm, presentaron la mejor calidad de individuos; mientras que, Cedrela montana mostró mortalidad en las tres altitudes evaluadas. Conclusiones. Las especies nativas sobresalieron por su capacidad de adaptación, reflejada en un rápido y óptimo crecimiento y desarrollo; lo cual evidencia su gran potencial para ser evaluadas en sistemas silvopastoriles de manera asociada, para determinar sus beneficios y potencial contribución con el desarrollo sostenible de la ganadería en la región.

Abstract Introduction. Silvopastoral systems are presented as an alternative for the sustainable use of natural resources, so there is a need to identify potential species for their establishment in the high tropics. Objective. The objective was to evaluate the initial growth of eight woody species in a silvopastoral design for water source protection. Materials and methods. The study was carried out in the Obonuco research center of Corporacion Colombiana de Investigacion Agropecuaria (Pasto, Colombia) between September 2017 and June 2018. A randomized block design was developed in a factorial arrangement, where tree/bush species differentiated by their growth habit interacted (high stratum: Cedrela montana, Quercus humboldtii, Ficus andicola; middle stratum: Salix babylonica, Alnus acuminata, Smallanthus pyramidalis; lower stratum: Morella pubescens and Sambucus nigra) and altitude (2750, 2770 and 2800 masl) with four repetitions to evaluate morphometric variables and seedling quality. Results. In the variable height the best behavior was presented in Ficus andicola at 2750 masl with 191.37 cm and Alnus acuminata at 2800 masl with 181.83 cm. In stem diameter Ficus andicola stood out at 2750 masl with 42.98 mm, Smallanthus pyramidalis at 2800 masl with 37.24 mm, and Sambucus nigra at 2800 masl with 8.16 mm. The number of regrowths did not show a significant effect of the interaction, and as seedlings, Quercus humboldtii at 2750 and 2700 masl and Ficus andicola at 2750 masl showed the best quality of individuals; while Cedrela montana showed mortality at the three altitudes evaluated. Conclusions. Native species stood out for their adaptibility, reflected in fast and optimal growth and development, which evidences its great potential to be evaluated in silvopastoral systems in an associated way to decide its multiple benefits and potential contribution to the sustainable development of the livestock in the region.

Abstract: Background and Aims: The studies of plant communities allow to know the impacts caused by the agricultural and livestock activities, especially in arid zones. The objective of this work was to contrast the diversity, composition and structure of the arboreal and shrub strata of three areas (Agroforestry, Regenerated and Reference) of the xerophilous scrub. Methods: In each area four sampling sites of 1600 m2 each one were established randomly, where all arboreal and shrubby individuals were registered and censused. In each area, ecological parameters were calculated, as well as the Shannon and Margalef indices. Key results: In the three areas, a total of 25 species of vascular plants belonging to 22 genera and 15 families were registered. The best represented family was Fabaceae with nine species, being the genus Acacia the one that presented the largest species number (three). The observed values of species richness, the Shannon index, Margalef index and abundance between the Reference and Agroforestry area were similar, and both were significantly higher than the values of the Regenerated area. The Agroforestry area presented lower abundance but greater dominance compared with the other two areas studied, and it was the area that reached the highest percentage of similarity with the Reference area. Conclusions: The Agroforestry activity contributes in a certain way in the maintenance of the diversity and composition of vascular plants of the Tamaulipan thorn scrub studied; and this activity does not allow to change to a large extent the composition and structure of this type of vegetation.

Resumen: Antecedentes y Objetivos: Los estudios de comunidades vegetales permiten conocer los impactos causados por las actividades agrícolas y pecuarias, especialmente en las zonas áridas. El objetivo de este trabajo fue contrastar la diversidad, composición y estructura de los estratos arbóreo y arbustivo de tres áreas (Agroforestal, Regenerada y Referencia) del matorral xerófilo. Métodos: Se establecieron tres áreas con cuatro sitios de muestreo de 1600 m2 cada una, elegidos al azar, en donde se censaron y registraron los individuos arbóreos y arbustivos. En cada área se calcularon parámetros ecológicos, así como los índices de Shannon y Margalef. Resultados clave: Considerando las tres áreas, se registró un total de 25 especies de plantas vasculares pertenecientes a 22 géneros y 15 familias. Fabaceae fue la familia mejor representada con nueve especies, siendo el género Acacia el que tuvo un mayor número (tres). Los valores de riqueza de especies, el índice de Shannon, índice de Margalef y abundancia, entre el área Referencia y Agroforestal, fueron similares, y en ambos los resultados fueron significativamente mayores que los valores del área Regenerada. El área Agroforestal presentó menor abundancia pero mayor dominancia comparada con las otras dos áreas estudiadas y fue el área que alcanzó el mayor porcentaje de similitud con el área de Referencia. Conclusiones: La actividad Agroforestal contribuye en cierta manera con el mantenimiento de la diversidad y la composición de plantas vasculares del matorral espinoso tamaulipeco estudiado; y dicha actividad no permite cambiar en gran medida la composición y estructura de este tipo de vegetación.

RESUMEN Se estudiaron las condiciones fisionómicas, ecológicas y fitosociológicas de las fitocenosis observadas en los dos tipos de pluvisilvas sobre ofiolitas presentes en el Parque Nacional Alejandro de Humboldt; ellas son las más desarrolladas, extensas, conservadas y típicas del archipiélago cubano. Algunas tienen tres estratos arbóreos y alcanzan hasta 45 m de altura. Se presentan desde cerca del nivel del mar hasta los 900 m, con precipitaciones de alrededor de 2000 mm a 3600 mm. Se describen por primera vez dos alianzas, cuatro asociaciones y siete subasociaciones, lo que fortalece los valores del parque como Patrimonio de la Humanidad.

ABSTRACT Physiognomic, ecological and phytosociological characteristics of the sintaxa of two types of rain forests on ophiolites in the Alejandro de Humboldt National Park were studied; these are the most developed, extensive, varied, best conserved and typical rain forests of the Cuban archipelago. Some of them reach a height of 45 m with three tree layers. They occur from near sea level to over 900 m and rainfall ranges from 2000 to 3600 mm. Two alliances, four associations and seven subassociations are described for the first time, thereby increasing the park's value as a natural heritage site.

Nothofagus antarctica is a species of the Andean-Patagonian forest with a wide distribution from the north of Neuquén to Tierra del Fuego. Although the N. antarctica forests are of great economic importance for the region, they are intensely affected nowadays by human activities such as grazing, firewood extraction, conversion into pastures and the replacement by coniferous plantations. These activities produce changes in the N. antarctica forest, mainly by the alteration of its original structure affecting the performance of the ecosystem as a whole, resulting in the loss of biodiversity. Since July 2008 up to May 2010 in the northwest of Chubut, Patagonia, we analyzed the effect of disturbances associated with different management strategies on species composition and structure of N. antarctica forest. The disturbances on N. antarctica forest considered in this study are derived from extraction of firewood by patches and landscapes, conversion of forests into pastures, forest fires occurred 15 and 25 years ago. Pristine forest was considered a control. The structure, composition and species diversity differ between forests affected by different disturbances. The higher arboreal and shrub stratum cover was observed in pristine sites (PR) while the largest herbaceous cover was observed in sites converted into pasture. The diameter at breast height (DAP) and the basal area (BA) of individuals of N. antarctica was larger than in those sites affected by firewood extraction at the landscape scale (FWL) than at the patch scale (FWP), while the density (number of individuals) was higher in the sites burned 25 years ago (B25). The canopy cover was higher in PR and FWL compared with those in the remaining sampling sites. Although some differences were found in the richness among the sampling sites, being higher in firewood extraction by patches and landscaped sites (FWP and FWL), there were no differences of diversity and dominance among sampling sites. Our results are compared with those obtained in previous studies in Patagonia and are of importance in the improvement of the management of N. antarctica forest and its conservation.

Efectos de los disturbios generados por diferentes estrategias de manejo sobre los estratos vegetales de bosques de Nothofagus antarctica de Chubut, Argentina. Nothofagus antarctica es una especie de los bosques Andino-Patagónicos, con una amplia distribución que se extiende desde el norte de Neuquén hasta Tierra del Fuego. Si bien los bosques de N. antartica son de gran importancia económica para la región, en la actualidad son muy afectados por actividades humanas como el pastoreo, la extracción de leña, la conversión en pastos y el reemplazo por plantaciones de coníferas. Estas actividades alteran la estructura original del bosque de N. antartica, lo cual afecta el funcionamiento de los ecosistemas en su conjunto y determina la pérdida de biodiversidad. Desde julio de 2008 a mayo de 2010, en el noroeste de Chubut, Patagonia, analizamos el efecto de las perturbaciones asociadas con distintas estrategias de manejo sobre la composición de especies y la estructura de los bosques de N. antartica. Los disturbios de los bosques de N. antartica considerados en este estudio se derivan de la extracción de leña por manchones y parquizado, la conversión de bosques en pasturas, los incendios ocurridos hace 15 y 25 años y, a modo de control, también se consideraron los bosques prístinos. La estructura, composición y diversidad de especies se diferenciaron entre bosques afectados por diversos disturbios. La mayor cobertura de los estratos arbóreos y arbustivos se observó en los sitios prístinos (PR), mientras que la mayor cobertura del estrato herbáceo se observó en los sitios convertidos en pasturas. El diámetro a la altura del pecho (DAP) y el área basal (BA) de los individuos de N. antarctica fue mayor en los sitios afectados por la extracción de leña por parquizado (FWL) que por parche (FWP), mientras que la densidad (número de individuos) fue mayor en los sitios quemados hace 25 años (B25). La cobertura del dosel fue mayor en PR y FWL, en comparación con los restantes sitios de muestreo. Aunque se encontraron diferencias en riqueza entre los sitios de muestreo (fue mayor en los sitios sometidos a extracción de leña por manchones y parquizado [FWP y FWL]), no se encontraron diferencias de diversidad y dominancia entre sitios de muestreo. Nuestros resultados son comparados con los obtenidos en estudios previos en la Patagonia y resultan de importancia en la mejora en la gestión de los bosques de N. antarctica y su conservación.

El presente trabajo tuvo como objetivo establecer la diversidad de Psocoptera en cuatro hábitats (Playas, Poblado, Senderos y Estratos arbóreos) del Parque Nacional Natural Gorgona, Colombia. Se realizaron dos campañas de recolecta durante los meses de noviembre de 2009 y octubre de 2010, con un total de 30 horas/hombre. Se revisó además el material de artrópodos arbóreos del muestreo realizado en el parque en noviembre de 2007, depositado en el Museo de Entomología de la Universidad del Valle (MUSENUV). Los especímenes recolectados en los cuatro sitios, se identificaron como mínimo a nivel de género, y posteriormente se cuantificaron para comparar la riqueza específica y diversidad entre los sitios. Aunque no hubo diferencia significativa en la diversidad estimada por el índice de Shannon-Wiener, se registró una alta riqueza de especies y abundancia para los hábitats “Playas” y “Poblado”. Se observó una tendencia de los Psocoptera del PNN Gorgona a ocupar espacios donde la cubierta vegetal es baja.

Diversity of Psocoptera (Insecta: Psocodea) at the National Natural Park Gorgona (Pacific Ocean, Colombia). Psocopterans are insects that have been recorded from all zoogeographic regions but have more species in the tropics. We studied their diversity of in four habitats (Beaches, Village, Trails and Arboreal strata) at the Gorgona National Natural Park, Colombia, from samples collected during November 2009 and October 2010. We added the arboreal Psocoptera collected by canopy fogging in November 2007. The specimens collected were identified to genus and/or to species or morphospecies level. Comparisons were made of the richness and diversity among sites. Although there was no significant difference in the diversity estimated by the Shannon-Wiener index, high species richness and abundance were recorded for the Beaches and Village habitats. The psocid community of Gorgona occurs mainly where vegetation cover is low. Rev. Biol. Trop. 62 (Suppl. 1): 257-264. Epub 2014 February 01.

With the objective of ecologically characterize the woody plant communities, twelve sampling sites were randomly selected based on cartographic material and digital ortophotos from the Tamaulipan matorral located in Northeastern Mexico. In each site, the minimum sampling area was determined. Thereafter quadrats of 10 x 10 m were used in variable numbers for the evaluation of the tree and shrub layers, and of 1 m² for the herbaceous layer. In each quadrat, all individuals of any species were registered, measuring its height and crown projection for the determination of density, canopy cover, frequency and importance value for each species. In order to evaluate the overall community a series of ecological indices were used: richness (Margalef), diversity (Shannon-Weiner), equitativity (Shannon), dominance (Simpson) and similarity (Sorensen and Jaccard). A total of 160 taxa pertaining to 46 families were found. The families with a greater number of taxa were the Poaceae, Asteraceae and Cactaceae with 19, 18 and 14 taxa, respectively, followed by the Fabaceae with 9 taxa, and the Euphorbiaceae and Acanthaceae with 8 taxa. The rest of the families mostly presented less than 3 taxa, and 23 of them were represented by a single taxon. The estimation of the diversity according to the Index of Shannon-Weiner (H') showed that in the herbaceous and shrub strata the communities with greater H' were the same than those of greater richness. The greater values of H' varied between 1.23-1.56. The equitativity index showed a large variation in the tree stratum of the study communities, reaching values between 0.20-0.90.

Con el objetivo de determinar las características ecológicas de comunidades vegetales maderables, doce sitios fueron aleatoriamente seleccionados en base a material cartográfico y ortofotos digitales correspondientes al matorral tamaulipeco localizado en el noreste de México. En cada sitio, se determinó el área mínima de muestreo sobre la base de cuadrantes de 100 m2 (10 x 10 m) donde se evaluaron los estratos arbóreos y arbustivos. Para la evaluación del estrato herbáceo se utilizaron cuadrantes de 1 m2 (1 x 1 m). En cada cuadrante todas las plantas fueron identificadas, registrando la altura, proyección de la corona, y la densidad, frecuencia, abundancia y valor de importancia de cada una de las especies. Para poder evaluar el índice de similitud de comunidades vegetales, se usaron una serie de índices ecológicos: índice de riqueza de Malgalef, índice de diversidad de Shannon-Wiener, índice de equitatividad, índice de dominancia de Simpson e índice de similitud de Sörensen-Jaccard. Se registraron un total de 160 taxa perteneciendo a 46 familias. Las familias con un número mayor de taxa fueron Poaceae, Asteraceae y Cactaceae con 19, 18 y 14 taxa, respectivamente, seguido por Fabaceae con 9 taxa, Euphorbiaceae y Acanthaceae con 8 taxa cada uno; el resto de las familias presentaron menos de 3 taxa, y 23 de ellas presentaron solo un taxón. En relación a la diversidad florística, los estratos herbáceos y arbustivos mostraron mayor índice de Shannon-Weiner (H') en comparación al estrato arbóreo, y por ende mayor riqueza en especies. El valor de H' varió entre 1,23-1,56; el índice de equitatividad mostró una mayor variación en el estrato arbóreo alcanzando valores entre 0,20-0,90.

RESUMO O presente estudo foi realizado em um fragmento de Floresta Estacional Semidecidual de 52 ha, conhecido como Floresta do Rosal, no município de Guaçuí-ES e teve como objetivo testar metodologias de estratificação vertical, avaliando a adequação dessas metodologias baseada na classificação sucessional ecológica das espécies. Para tanto, empregou-se o método de amostragem de área fixa, sendo distribuídas 16 parcelas de 600 m2, de forma sistemática no campo. Todos os indivíduos com DAP ≥ 5 cm tiveram suas alturas totais medidas de forma direta. As árvores passaram por processo de identificação botânica e classificação quanto ao grupo ecológico. A análise da estrutura vertical de espécies arbóreas foi feita pela distribuição do número de árvores nos estratos, utilizando-se quatro métodos: Método 1 - Souza (1990), Método 2 - Souza et al. (2003), Método 3 - IUFRO, e Método 4 - Calegário et al. (1994). Os resultados das classificações obtidas foram comparados à classificação sucessional das espécies, de acordo com os grupos ecológicos a que pertencem. O Método 1 não permitiu análise detalhada sobre o comportamento das espécies no estrato II por apresentar tendências fortes em concentrar um maior número de indivíduos no referido estrato, já o Método 2 permitiu um maior detalhamento. O Método 3 minimizou o problema encontrado no Método 1, porém, a mudança da altura dominante da amostragem pode mudar toda a discussão, demonstrando fragilidade do método. O Método 4 não trouxe bons resultados para a estratificação da floresta em estudo, pois a dividiu em apenas dois estratos de altura total.

ABSTRACT This study was conducted in a semideciduous forest fragment of 52 hectares, known as Rosal Forest, in the municipality of Guaçuí, Espírito Santo state. It had the objective to test vertical stratification methodologies, evaluating the appropriateness of these methodologies based on the ecological successional classification of the species. To do so, the method of sampling fixed area was used, and distributed 16 plots of 600 m², in a systematic way. All individuals with DBH ≥ 5 cm, had their total height measures directly. The trees went through the botanical classification identification process and had their classifications in accordance with their ecological groups. The analysis of the tree vertical structure was made by the distribution of the number of trees in the strata, using four methods: Method 1 - Souza (1990), Method 2 - Souza et al. (2003), Method 3 - IUFRO, and Method 4 - Calegário et al. (1994). The classification results were compared to the successional classification of species, according to the ecologic groups that they belong to. The method 1 did not allow a detailed analysis about the behavior of stratum II species, because of the strong tendencies to concentrate a greater number of individuals in this stratum, already the Method 2 has allowed a greater detail. The Method 3 minimized the problem encountered in Method 1, but the dominant height change of the sample can change the whole discussion, demonstrating the method weakness. Method 4 did not bring good results for the forest stratification under study, because this method only divided in two height strata.

RESUMO As Florestas Estacionais Semideciduais ocorrem em alguns locais no Bioma Cerrado, mas estão sendo suprimidas em meio à ampla matriz agropecuária no Brasil Central. O objetivo do trabalho foi caracterizar a estrutura horizontal e vertical, as síndromes de dispersão, os grupos sucessionais e a similaridade florística do estrato arbóreo e regenerativo de um trecho de fragmento de Floresta Estacional Semidecidual no município de Itumbiara, GO. Todos os indivíduos arbóreos vivos com circunferência do tronco a altura do peito (CAP) ≥15 foram identificados e medidos quanto à altura e circunferência do tronco em 25 parcelas de 20 x 20 m. A amostragem do estrato regenerativo foi realizada em 25 subparcelas de 10 m x 10 m, totalizando 0,25 ha, alocadas no vértice inferior direito das parcelas utilizadas para a amostragem do estrato arbóreo. Nestas subparcelas foram identificados e contados todos os indivíduos regenerantes de espécies arbóreas com altura maior ou igual a 1 m até aqueles com CAP < 15 cm. Para o estrato arbóreo foi calculado: a densidade, frequência, dominância, valor de importância e a estratificação vertical. Nos dois estratos foram amostradas 100 espécies. A espécie com maior valor de importância no estrato arbóreo foi Nectandra megapotamica (Spreng) Mez, e no estrato regenerativo Siparuna guianensis Aubl teve maior número de indivíduos. Ambos os estratos apresentaram maior proporção de espécies secundárias iniciais e a zoocoria foi a síndrome de dispersão mais frequente. A estrutura fitossociológica atual mostra que o fragmento contém diversas espécies pouco representadas em outras Florestas Semideciduais, o que mostra a sua importância como área de preservação permanente.

ABSTRACT Semideciduous forests occur in a few places in the Cerrado biome, but are being suppressed through by agriculture and livestock in central Brazil. The objective of this study was characterize the horizontal and vertical structures, the dispersal syndromes, successional groups and floristic similarity of the tree layer and regeneration in a semideciduous forest fragment in Itumbiara, Goiás state. All trees alive with circumference at breast height (CAP) ≥ 15 were identified and measured for height and diameter in 25 plots of 20 x 20 m. To the regenerative stratum the criteria was the inclusion of individuals with height ≥ 1m until CAP = 14.9 cm in 25 plots of 10 × 10 m. In both layers were sampled 100 species. The species with the highest importance in the tree layer were Nectandra megapotamica (Spreng.) Mez, and in the regenerative stratum, Siparuna guianensis Aubl. Both layers had a higher proportion of early secondary species and the zoochory dispersion syndrome was more frequent. Several important species are not represented in other semideciduous forests, and then this forest is an important permanent conservation area.

La exuberante selva tropical que se desarrolla en el Chocó biogeográfico lo convierte en uno de los principales centros de diversidad del planeta. Dentro de este tipo de ambientes los mamíferos arbóreos cumplen un importante papel enlazando los diferentes estratos del bosque. Este trabajo se desarrolló en la localidad de Isla Palma (Bahía Málaga, Valle del Cauca) en donde Bradypus variegatus (Perezoso de tres dedos) es el único mamífero arbóreo reportado. Con el propósito de ampliar el conocimiento de la especie en zonas insulares del Chocó biogeográfico se realizaron 5 campañas de muestreo durante el 2008, en las cuales se registraron aspectos relacionados con el uso del hábitat y se estimó la densidad poblacional utilizando el programa Distance 6.0. Probablemente, la ausencia de predadores naturales, la ausencia de competidores directos, y el acceso restringido de los seres humanos a esta localidad insular han favorecido el registro de una densidad poblacional de B. variegatus en Isla Palma de 71,7 ind/Km² (IC 95 %= 43,1- 119,3 ind/Km²), siendo la segunda más alta reportada para la especie.

The exhuberant tropical rain forest present in the biogeographic area of Chocó is one of the main diversity hot spots in the planet. In this environment, the arboreal mammals suit an important role by connecting the different forest stratums. This research was carried out in Isla Palma (Bahía Malaga, Valle del Cauca) where the unique arboreal mammal reported is Bradypus variegatus (Three toed sloths). With the purpose of widening knowledge of this species in insular areas of the biogeographic Choco, five sampling field trips were conducted during 2008, in which aspects related with the habitat use were recorded and population density was estimated using the Distance 6.0 software. Probably, the absence of natural predators, the absence of direct competitors, and the restricted access of human beings to this insular locality have favored the recordings of population density of B. variegates, in Isla Palma in 71,7 ind/Km² (IC 95 %= 43,1- 119,3 ind/Km²),being the highest second population recorded for the especies.