Abstract Introduction: The River Tambo basin is one of the main hydrographic systems of the Peruvian western watershed, being a source of development for agriculture, agroindustry, livestock, and domestic use in the Tambo Valley and Arequipa City. Objective: To analyze the structure of macroinvertebrates in River Tambo, Perú and assess the water quality through this community. Methods: Five sampling events were conducted between December 2018 and November 2019 in 12 stations, using a Surber net (500 μm). Macroinvertebrates were identified at a family level. To assess community structure, richness, Simpson’s dominance index (D), Pielou’s evenness (J’), and true diversity of order 1 were determined. A nMDS based on the Bray-Curtis index was used to evaluate dissimilarity. To check for differences in community structure, ANOSIM and two-way MANOVA were used. SIMPER was used to establish family contribution to sample similarity. Relations between physicochemical and biological variables were determined by CCA. ABI index was applied to assess ecological quality. Results: 32 families were recognized, being the most abundant: Baetidae, Chironomidae, Leptohyphidae, Simuliidae, Hydroptilidae, and Elmidae. The middle and low zones of the basin showed the highest and lowest diversity respectively. There were significant differences (P < 0.05) in the community structure indices among the 12 stations differed. There was a higher similarity among the 12 stations in December. ABI scores increased from the low to the middle part of the river, which showed the highest ecological quality. Conclusion: Macroinvertebrate communities from River Tambo reflect ecosystem conditions. Environments impacted by human activities show lower diversity and ecological quality, due to the structure, habitat, and water quality of the river being altered.

Resumen Introducción: La cuenca del rio Tambo es uno de los principales sistemas hidrográficos de la vertiente occidental del Perú y fuente de desarrollo para la agricultura, agroindustria, ganadería y consumo doméstico en el valle de Tambo y la ciudad de Arequipa. Objetivo: Analizar la estructura de macroinvertebrados en el río Tambo, Perú y evaluar la calidad del agua a través de esta comunidad. Métodos: Entre diciembre del 2018 y noviembre del 2019 se realizaron cinco muestreos en 12 estaciones, empleando una red Surber (500 μm). Los macroinvertebrados se identificaron a nivel de familia. Se registró la riqueza, dominancia de Simpson, equidad de Pielou, y diversidad verdadera de orden 1, para evaluar la estructura de la comunidad. Para estimar la similitud, se utilizó nMDS (índice de Bray-Curtis). Para verificar si existen diferencias en la estructura comunitaria, se empleó MANOVA de dos vías y ANOSIM. Para establecer la contribución de las familias a la similitud entre muestras, se utilizó SIMPER. La relación entre variables fisicoquímicas y biológicas se determinó con ACC. Se aplicó el índice ABI para evaluar la calidad ecológica. Resultados: se reconocieron 32 familias, siendo las más abundantes: Baetidae, Chironomidae, Leptohyphidae, Simuliidae, Hydroptilidae y Elmidae. La mayor y menor diversidad se presentó en la parte media y baja de la cuenca respectivamente. Existieron diferencias significativas (P < 0.05) de los índices de estructura comunitaria entre las 12 estaciones. Se evidenció mayor similitud entre las 12 estaciones en diciembre. Los puntajes del índice ABI se incrementan de la parte baja del río a la media, que se presentó la mejor calidad ecológica. Conclusión: Las comunidades de macroinvertebrados del río Tambo reflejan el estado del ecosistema. Los ambientes con impacto por actividad humana registran menor diversidad y calidad ecológica, ya que se altera la estructura, hábitat y calidad de agua del río.

Abstract Rice (Oryza sativa L.) is an important source of energy in the human diet; and, in Nicaragua, it constitutes a substantial component of the population's diet. The present study was exploratory, and aimed to determine the diversity of arthropods associated with rice cultivation in the municipality of Sébaco, an intensive rice production region, in the 2022-2023 agricultural cycle. Production systems with extensions over 100 hectares, where equal agronomic and phytosanitary management was used, were selected. For entomofauna monitoring, ten points were randomly selected in each production system, and at each point, and 20 double zigzag passes with entomological nets were used at each point. The number of individuals per order and family was quantified. For the diversity analysis, they were grouped according to their feeding habits. Abundance and richness information was analyzed using descriptive analysis, analysis of variance, and Shannon Weaver and Simpson's diversity index. Seven orders, 13 families, and 16 genera were found, most of them of the phytophagous habit. The highest abundance corresponded to the species T. orizicolus Muir (n = 46,663), reported in the reproductive and maturation phases. Likewise, Hydrellia sp (n = 5,229) presented the largest populations in the vegetative phase. Among the beneficial organisms, siders (n = 1,523) and Atrichopogum sp (n = 419) stood out. Diversity indices were low both in the production systems and in the different phenological phases of the crop.

Resumen El cultivo de arroz (Oryza sativa L.) representa una fuente de energía de importancia en la dieta humana, y en Nicaragua constituye un sustancial componente de la dieta de la población. El presente estudio fue exploratorio y tuvo como objetivo determinar la diversidad de artrópodos asociada al cultivo de arroz en el municipio de Sébaco, en el ciclo agrícola 2022-2023, una región intensiva en la producción de arroz. Se seleccionaron sistemas productivos con extensiones mayores a 100 hectáreas, en donde se empleó igual manejo agronómico y fitosanitario. Para el monitoreo de la entomofauna, en cada sistema productivo se seleccionaron diez puntos al azar y en cada punto se emplearon 20 pases dobles en forma de zig-zag con red entomológica. Se cuantifico el número de individuos por orden y familia; para el análisis de diversidad se agruparon por sus hábitos alimenticios. La información de la abundancia y riqueza se analizó mediante estudio descriptivo, análisis de varianza e índice de diversidad de Shannon Weaver y Simpson. Se encontraron siete órdenes, 13 familias y 16 géneros, la mayoría del hábito fitófago. La mayor abundancia correspondió a la especie T. orizicolus Muir (n=46.663), reportada en la fase reproductiva y maduración. Así mismo, Hydrellia sp (n=5.229), presentó las mayores poblaciones en la fase vegetativa. Dentro de los organismos benéficos sobresalieron las arañas (n=1.523) y Atrichopogum sp (n=419). Los índices de diversidad fueron bajos tanto en los sistemas productivos como en las diferentes fases fenológicas del cultivo.

Resumen Los cafetales (Coffea arabica) de la región de la Montaña de Guerrero mantienen las características de un bosque, además contribuyen a la generación de recursos económicos que ayudan a un gran número de familias a mitigar parte de sus necesidades básicas. El objetivo de este trabajo fue identificar la estructura y los usos de las especies de sombra de los cafetales en dos comunidades Me’phaa de la Montaña de Guerrero. Se muestrearon 12 parcelas en Tres Cruces (TC), Acatepec y La Ciénega (LC), Malinaltepec; se utilizó el método de punto-centro-cuadrado; a los árboles se les midió la distancia, altura, cobertura de copa y diámetro normal. Se estimó la diversidad alfa basada en la riqueza de especies (S), el Índice de Simpson, Shannon-Wiener y el número efectivo de especies (N0, N1 y N2), la similitud se calculó con el Coeficiente Jaccard (I J ) y se determinó el Índice de Valor de Importancia (IVI). Para reconocer los usos de los árboles se aplicaron entrevistas (50 en TC y 10 en LC) estructuradas a los cafeticultores. Se registraron 35 especies, 16 en Tres Cruces y 22 en La Ciénega, de las cuales 83.3 % fueron nativas, por lo que se clasifica como manejo tradicional. Alnus acuminata en LC y Myrsine juergensenii en TC fueron las de mayor IVI. Los cafeticultores señalaron a 24 especies en TC y 14 en LC que proporcionan sombra, generan materia orgánica, frutos, flores y combustibles; las especies más empleadas son Clethra mexicana y A. acuminata.

Abstract The coffee (Coffea arabica) plantations of the Montaña de Guerrero region preserve the characteristics of a forest and also contribute to the generation of economic resources that help a large number of families to meet some of their basic needs. The objective of this work was to identify the structure and uses of shade species in coffee plantations in two Me'phaa communities in the Montaña de Guerrero region. Twelve plots in Tres Cruces (TC), Acatepec and La Ciénega (LC), Malinaltepec, were sampled using the point-center-square method; trees were measured for distance, height, crown cover and normal diameter. The alpha diversity was estimated based on species richness (S), Simpson's Index, Shannon-Wiener’s Index, and the effective number of species (N0, N1 and N2); similarity was calculated with the Jaccard index (J I ), and the Importance Value Index (IVI) was determined. In order to identify the uses of the trees, structured interviews (50 in TC and 10 in LC) were carried out with coffee growers. Thirty-five species were recorded -16 in Tres Cruces and 22 in La Ciénega-, of which 83.3 % were native; therefore, the region is classified as under traditional management. Alnus acuminata in LC and Myrsine juergensenii in TC had the highest IVI. Coffee growers reported 24 species in TC and 14 in LC that provide shade, generate organic matter, fruits, flowers, and fuel. The most commonly used species are Clethra mexicana and A. acuminata.

Abstract Background: Research on weeds in rainfed maize crops in the state of Aguascalientes is scarce. Questions: What weed species are found in rainfed maize crops by biogeographic province? How are they controlled and managed? Study site and periods: One site in each of the three biogeographic provinces of the state of Aguascalientes: Sierra Madre Occidental (SMO), Altiplano Sur (AS) and Pacific Coast (CP), 2020 and 2021. Methods: Thirty semi-structured interviews were applied to describe the control and management of weeds. Forty-eight floristic inventories were carried out and the same number of sampling sites to obtain the richness and Shannon-Whiener and Simpson diversity indexes. Floristic similarity was evaluated with the Jaccard Index (I j). Results: Weed control is carried out mainly with tractor, animals and to a lesser extent herbicide. A total of 128 species were identified, 21 of which were introduced. SMO reported higher richness and diversity. There were not significant differences in average richness between the three provinces (P > 0.05) but there is a significant difference in diversity (H’) between SMO with AS and CP as well as (D Si) between CP and SMO (P < 0.05). Floristic similarity was less than 50 %. Conclusions: There is a great richness of weeds in rainfed maize crops. The floristic composition is differentiated by biogeographic province in the state of Aguascalientes. This work increases records and knowledge of weeds at local and national level.

Resumen Antecedentes: Las investigaciones sobre arvenses en cultivo de maíz de temporal en el estado de Aguascalientes son escasas. Preguntas: ¿Qué especies arvenses se encuentran en cultivos de maíz de temporal por provincia biogeográfica en el estado de Aguascalientes? ¿Cómo es su control y manejo? Sitio y años de estudio: Un sitio en cada una de las tres provincias biogeográficas del estado de Aguascalientes: Sierra Madre Occidental (SMO), Altiplano Sur (AS) y Costa del Pacífico (CP); durante los ciclos agrícolas 2020 y 2021. Métodos: Se aplicaron 30 entrevistas semiestructuradas para describir el control y manejo de arvenses. Se realizaron 48 inventarios florísticos y mismo número de muestreos para estimar riqueza e índices de diversidad de Shannon-Whiener (H’) y Simpson (D Si). La similitud florística se evaluó con el Índice de Jaccard (Ij). Resultados: El control de arvenses se realiza principalmente con tractor, yunta y en menor proporción herbicida. Se identificaron 128 especies, 21 introducidas. Aunque en SMO se registró mayor riqueza y diversidad, no existe diferencia significativa en la riqueza promedio entre las tres provincias (P > 0.05), pero sí en diversidad (H’) entre SMO con AS y CP y (D Si) entre CP y SMO (P < 0.05). La similitud florística fue menor al 50 %. Conclusiones: En el estado de Aguascalientes existe gran riqueza de arvenses en cultivos de maíz de temporal y la composición florística está diferenciada por provincia biogeográfica. Los resultados de la investigación suman al registro y conocimiento de las arvenses a nivel local y nacional.

We value comments on our research paper in a Commentary in this issue (Simpson, S Afr J Sci. 2024;120(1/2), Art. #16445). Acknowledging the Universal Thermal Comfort Index (UTCI)'s limitations in capturing individual physiological responses remains important; however, we argue for its appropriateness based on recent thermophysiology and heat exchange advancements during its development and broader alignment with standardised indexing efforts. Our original research paper set out with these considerations in mind, and our conclusions remain valid. We further argue for refinement of the UTCI for specific activities instead of using the RET. Finally, future efforts should focus on monitoring data in real-world scenarios to validate and improve thermal indices

ABSTRACT: The aim of this research was to determine the alpha and beta diversity of mangrove trees in the Tumbes mangrove forest. The mangrove forest area was divided into three zones: A, B and C, in which 41 sampling points (PM) were taken. Mangrove trees were counted and measured, and the alpha diversity indices were determined: Shannon-Wiener (H'), Simpson (DS) and Pielou (J’), as well as the similarity of the PM. Beta diversity is determined with the indices: Jackard (IJ) and quantitative Sorensen (S). It is considered that the alpha diversity of the mangrove forest was low (H'=1.0260, SD =0.6158 and J’=0.9339), with zone A being the one with the lowest diversity (H'=0.3048, SD=0.8531 and J’=0.2774), due to its less anthropic impact and due to the dominance of Rhizophora mangle over the other species, it was observed that the PM were very similar within each zone, with lower diversity in zone A. The beta diversity evaluated using IJ was 1, indicating that the diversity of species does not change between the zones, while the S index showed that there is a greater change in diversity between zone A and the remaining zones. These results can allow local and regional authorities to make decisions to protect said mangrove forest. On the other hand, it would also be advisable to carry out research to determine the impact that alterations in mangrove species biodiversity may have on the organisms that inhabit this mangrove forest.

RESUMEN: El objetivo de la investigación fue determinar la diversidad alfa y beta de los árboles de mangle en el manglar de Tumbes. El área del manglar se dividió en tres zonas: A, B y C, en ellas se tomaron 41 puntos de muestreo (PM). Se contaron y midieron los árboles de mangle y se determinaron los índices de diversidad alfa: Shannon-Wiener (H’), Simpson (DS) y Pielou (J’), así como la similitud de los PM. La diversidad beta se determinó con los índices: de Jackard (IJ) y cuantitativo de Sorensen (S). Se determinó que la diversidad alfa del manglar fue baja (H’=1,0260, DS=0,6158 y J’=0,9339), siendo la zona A la de menor diversidad (H’=0,3048, DS=0,8531 y J’=0,2774), por su menor impacto antrópico y por el dominio de Rhizophora mangle sobre las otras especies, se observó que los PM fueron muy similares dentro de cada zona, con menor diversidad en la zona A. La diversidad beta evaluada mediante IJ fue de 1, indicando que la diversidad de especies no cambia entre las zonas, en tanto que el índice S mostró que hay un mayor cambio en diversidad entre la zona A y las restantes zonas. Estos resultados pueden permitir a las autoridades locales y regionales tomar decisiones a fin de poder proteger a dicho manglar. Por otro lado, también sería conveniente realizar investigación para determinar el impacto que la alteración de la biodiversidad de las especies de mangles pueda tener en los organismos que habitan en este manglar.

Resumo O objetivo básico deste estudo foi determinar a diversidade ictiofaunística do rio Panjkora nos distritos de Lower e Upper de Dir, na província de Khyber Pakhtunkhwa, no Paquistão. Amostras de peixes foram coletadas com redes de arrasto de março a setembro de 2020. Foram coletados 724 espécimes, classificados em 5 famílias, 14 gêneros e 18 espécies. Os resultados gerais revelaram que a maioria da ictiofauna do rio Panjkora contém 8 espécies da família Cyprinidae (56,49%), seguidas por 4 espécies de Nemacheilidae (24,44%), 2 espécies de Channidae (10,63%) e Sisoridae (7,04%) e 1 espécie de Mastacembelidae (1,38%). Entre todas as espécies de peixes, Schizothorax plagiostomus (16,57%) foi altamente predominante, seguida por Carassius auratus (11,87%) e Racoma labiata (9,66%), e elas foram relatadas como altamente abundantes, especialmente nos meses de abril, maio e junho. As espécies menos abundantes foram Glyptothorax punjabensis, Glyptothorax sufii e Mastacembelus armatus, que constituíram 2,48%, 2,20% e 1,38%, respectivamente, do total de peixes amostrados. O índice de diversidade de Simpson (1-D = 0,919), o índice recíproco de Simpson (1/D = 12,3876) e o índice de Shannon (H = 2,68) indicaram que o rio Panjkora contém um grupo bastante rico e diversificado de espécies de peixes. Os microplásticos mais altos foram observados no local 7 em comparação com outra área de estudo. Medidas de conservação devem ser tomadas como prioridade máxima para proteger e conservar o ambiente marinho e o patrimônio natural de novas perdas e extinção e para parar ou minimizar as perdas ocorridas por práticas de pesca irresponsáveis.

Abstract The basic aim of this study was aimed to determine the ichthyofaunal diversity of River Panjkora in both upper and lower Dir districts in Khyber Pakhtunkhwa province of Pakistan.Fish samples were collected by using fishnets from March to September 2020. A total of 724 specimens were collected and classified into 5 families, 14 genera, and 18 species. The overall results revealed that most fish fauna of river Panjkora contains 8 species of family Cyprinidae (56.49%) followed by 4 species of Nemacheilidae (24.44%), 2 species of Channidae (10.63%), and Sisoridae (7.04%), and 1 species of Mastacembelidae (1.38%), respectively. Among all kinds of fish species, Schizothorax plagiostomus (16.57%) was highly dominated and followed by Carassius auratus (11.87%) and Racoma labiata (9.66%) and were reported as highly abundant, especially during April, May, and June. The least abundant species were Glyptothorax punjabensis, Glyptothorax sufii, and Mastacembelus armatus, that constituting 2.48%, 2.20%, and 1.38% of the total fish samples. The Overall Simpson’s diversity (1-D= 0.919) and Simpson’s Reciprocal index values (1/D= 12.3876), and Shannon’s index (H= 2.68) were indicating that river Panjkora contains a quite rich and diverse group of fish species. The highest microplastics observed in site 7 compared to other study area. Conservation steps should be taken as a top priority to protect and conserve the marine environment and natural heritage from further loss, extinction and stop or minimize losses incurred through irresponsible fishery practices

Resumo A fauna aquática de insetos continua sendo uma ferramenta importante para a bioindicação de distúrbios ambientais, ao mesmo tempo em que mantém um sistema aquático saudável. O objetivo do estudo foi documentar e identificar a diversidade e os padrões de distribuição dos insetos aquáticos, um aspecto altamente ignorado no Catar. Seguindo os procedimentos padrão, as amostras foram coletadas em hábitats aquáticos durante o período de outubro de 2015 a maio de 2017, mensalmente. Um total de 11.287 indivíduos, pertencentes a seis ordens, foram capturados. Dípteros foram os mais abundantes, com as porcentagens de 71,01 (n = 8.015), enquanto a menor porcentagem foi observada para Coleópteros 0,04 (n = 05). Doze famílias de insetos foram identificadas, destas, cinco foram registradas sob Diptera, seguido por Hemiptera (03), enquanto Coleoptera, Tricoptera, Odonata e Ephemeroptera foram representados por famílias únicas. Dentre as localidades selecionadas, Dipterans foram coletados em 10 estações, seguidos por Hemiptera (9), Coleoptera (4), Odonota (4), Ephemeroptera (3) e Trichoptera (1), respectivamente. Entre as amostras de corpos d'água, os riachos foram os hábitats mais preferidos (n = 2.767), enquanto as piscinas de água potável foram os menos (27). Além disso, o maior índice de diversidade de Simpson de 1,48 e o menor de 0,47 foi registrado para piscina de esgoto inundada e recipientes de plástico, respectivamente, enquanto os valores de baixa uniformidade foram observados para lagoas e menos de 1 valores de diversidade de Margalef foram observados para todos os hábitats. Este estudo documenta os padrões de diversidade e distribuição de insetos aquáticos e fornece uma linha de base para os estudos futuros do Catar.

Abstract Aquatic insect fauna remains an important tool for bio indication of environmental disturbance, while maintaining a healthy aquatic system. The purpose of the study was to document and to identify the diversity and distribution patterns of aquatic insect, a highly ignored aspect from the Qatar. Following the standard procedures, the samples were collected from aquatic habitats during the period October 2015 to May 2017 on monthly basis. A total of 11,287 individuals, belonging to 6 orders were captured. Dipterans were the abundant with the percentages of 71.01 (n=8,015), while the lowest percentage was observed for Coleoptera 0.04 (n=05). Twelve insects families were identified, among these five were reported under Diptera, followed by Hemiptera (03), while Coleoptera, Tricoptera, Odonata, and Ephemeroptera were represented by single families. Among the selected localities, Dipterans were collected from 10 stations, followed by Hemiptera (9), Coleoptera (4), Odonota (4), Ephemeroptera (3) and Trichoptera (1) respectively. Among the water bodies samples, streams were the most preferred habitats (n=2,767), while drinking water pools were the least (27). Moreover, the highest Simpson diversity index of 1.48 and lowest of 0.47 was recorded for flooded sewage pool and plastic containers respectively, while the low evenness values were observed for ponds, and less than 1 Margalef’s diversity values were seen for all habitats. This study documents the patterns of the diversity and distribution of aquatic insects, and provides a baseline for the future studies from Qatar.

Abstract: Aim We investigated the ichthyofauna parasite component community across a gradient of anthropogenic pressures of the Guaraguaçu River, south Brazil, a Neotropical river of central importance for biodiversity conservation. Methods After fish sampling, all fish were identified, measured, weighed and eviscerated. The viscera and gills were inspected for parasite screening and subsequent identification. Parasite diversity estimators were calculated for the most abundant host species. Results A total of 159 host specimens from 12 species were examined, being 140 (88.05%) found to be infected with at least one parasite, including 14 new parasite occurrences. The most widely distributed parasite was the nematode Contracaecum sp., found in 8 host species. The highest mean infection intensity and mean abundance was observed for the monogenean Aphanoblastella mastigatus, infecting the Silver catfish Rhamdia quelen. The Shannon-Wiener, Jost and Simpson indexes were higher for the more abundant fishes, except for the Trahira Hoplias malabaricus. Most host species harbored parasites in poorly aggregated distribution, according to the discrepancy index. The Berger-Parker index showed monogenean dominance in all hosts except for H. malabaricus. We found little evidence for parasite infracommunity changes across the gradient of the river. Conclusions We described the infection patterns in an important Neotropical river. The new parasite occurrences highlight the contribution of our study. Fish-parasite interactions changed throughout the river stretches, and we argue that it does not necessarily means changes in diversity and abundance of parasite within species, but the rearrange of interactions. Moreover, it seems that parasites are more abundant in most impacted sites, another reason to continue the monitoring. Abstract River Brazil conservation sampling identified measured eviscerated identification 15 1 examined 88.05% 8805 88 05 (88.05% sp sp. mastigatus quelen ShannonWiener, ShannonWiener Shannon Wiener, Wiener Shannon-Wiener fishes malabaricus distribution BergerParker Berger Parker H study Fishparasite Fish stretches Moreover sites monitoring 88.05 880 0 (88.05 88.0 (88.0 88. (88. (88 (8 (

Resumo: Objetivo A comunidade componente de parasitas da ictiofauna foi investigada ao longo de um gradiente de pressões antropogênicas no Rio Guaraguaçu, sul do Brasil, um rio Neotropical com grande importância para a conservação da biodiversidade. Métodos Após a coleta, todos os peixes foram identificados, medidos, pesados e eviscerados. As vísceras e brânquias foram inspecionadas para coleta e subsequente identificação de parasitas. Estimadores de diversidade de parasitas foram calculados para as espécies de hospedeiros mais abundantes. Resultados Um total de 159 espécimes de hospedeiros de 12 espécies foram examinados, sendo 140 (88,05%) infectados com pelo menos um parasita, incluindo 14 novas ocorrências de parasitas. O parasita mais amplamente distribuído foi o nematoide Contracaecum sp., encontrado em 8 espécies de hospedeiros. As maiores intensidades de infecção e abundância foram observadas para o monogenético Aphanoblastella mastigatus, infectando o Jundiá Rhamdia quelen. Os índices de Shannon-Wiener, Jost e Simpson foram maiores para os peixes mais abundantes, exceto para a Traíra Hoplias malabaricus. A maioria das espécies de hospedeiros abrigava parasitas com distribuição pouco agregada, de acordo com o índice de discrepância. O índice de Berger-Parker mostrou a dominância de monogenéticos em todos os hospedeiros, exceto H. malabaricus. Encontramos poucas evidências de mudanças nas infracomunidades de parasitas ao longo do gradiente do rio. Conclusões Descrevemos os padrões de infecção em um importante rio Neotropical. As novas ocorrências de parasitas destacam a importância de nosso estudo. Interações entre parasitos e peixes mudaram ao longo dos setores do rio, e isso não necessariamente resulta em mudanças na diversidade e abundância de parasitos dentro de cada espécie, mas um rearranjo das interações. Além disso, parece que os parasitas são mais abundantes na maioria dos locais impactados, o que é mais uma razão para continuar o monitoramento. Resumo Guaraguaçu Brasil biodiversidade identificados medidos eviscerados 15 1 examinados 88,05% 8805 88 05 (88,05% sp sp. mastigatus quelen ShannonWiener, ShannonWiener Shannon Wiener, Wiener Shannon-Wiener malabaricus agregada discrepância BergerParker Berger Parker H estudo espécie interações disso impactados monitoramento 88,05 880 0 (88,05 88,0 (88,0 88, (88, (88 (8 (

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.

Abstract The objective of this research was to evaluate the diversity, horizontal structure and vertical structure of tree species in three types of forest vegetation in the Adolfo Ruiz Cortines ejido in the south of the state of Durango, Mexico. The data analyzed corresponds to 665 circular sites of 0.1 ha; 56 sites correspond to pine forests (BP), 511 to pine oak forests (BPQ) and 98 to pine oak forests (BQP). For each site, the name of the species, the normal diameter (>7.5 cm) and the total height (m) of the trees were recorded. For the tree species in each type of vegetation, their diversity was determined using the Shannon index, their dominance with the Simpson index and their specific richness using the Margalef index. Subsequently, a test of over similarity or difference in the diversity-abundance Hutchenson's t was carried out to compare the diversity of species between the vegetation types using the Shannon index, to know if there are significant statistical differences between the diversity of species of the types of vegetation. To know the horizontal structure, the importance value index (IVI) was obtained, which is a hierarchical index that measures the dominance of the species through percentage values, which are obtained with the abundance Ai, dominance Di and frequency Fi of the species. species, these ecological parameters were analyzed with the non-parametric Kruskal-Wallis test to determine if there are significant statistical differences. The vertical structure was determined with the species vertical distribution index A. Hutchenson's t test demonstrated that there are significant statistical differences in the tree diversity of the forest types. According to the horizontal structure, only the absolute frequencies recorded significant statistical changes between the three vegetation types (BP-BPQ-BQP). The values of the vertical index of species A indicated that for the three types of vegetation there is a non-uniform plant community in terms of height, presenting a greater number of individuals in the lower stratum, followed by the middle stratum, to finally have a smaller amount in the higher altitude stratum. The information generated in this research provides a frame of reference on how the tree structure is formed in the vegetation types of the ejido, as well as the basis for future decision-making on forest management plans.

Resumen El objetivo de la presente investigación fue evaluar la diversidad, estructura horizontal y estructura vertical de especies arbóreas en tres tipos de vegetación forestal en el ejido Adolfo Ruíz Cortines al sur del estado de Durango, México. Los datos analizados corresponden a 665 sitios circulares de 0.1 ha; 56 sitios correspondientes a bosques de pino (BP), 511 a bosques de pino encino (BPQ) y 98 a bosques de encino pino (BQP). Para cada sitio se registró el nombre de la especie, el diámetro normal (>7.5 cm) y la altura total (m) de los árboles. Para las especies, en cada tipo de vegetación, se determinó su diversidad mediante el índice de Shannon, dominancia con el índice de Simpson y riqueza específica utilizando el índice de Margalef. Se realizó una prueba de similitud o diferencia en la diversidad-abundancia t de Hutchenson para comparar la diversidad de especies entre los tipos de vegetación utilizando el índice de Shannon, para conocer si existen diferencias estadísticas significativas entre la diversidad de especies de los tipos de vegetación. Para conocer la estructura horizontal se obtuvo el índice de valor de importancia (IVI), el cual es un índice jerárquico que mide la dominancia de las especies mediante valores porcentuales, los cuales son obtenidos con la abundancia A i , dominancia D i y frecuencia F i de las especies, dichos parámetros ecológicos se analizaron con la prueba no paramétrica de Kruskal-Wallis para determinar si existen diferencias estadísticas significativas. La estructura vertical se determinó con el índice de distribución vertical de especies A. La prueba de t de Hutchenson demostró que existen diferencias estadísticas significativas en la diversidad arbórea de los tipos de bosque. De acuerdo con la estructura horizontal, sólo las frecuencias absolutas registraron cambios estadísticos significativos entre los tres tipos de vegetación (BP-BPQ-BQP). Los valores del índice vertical de especies A, indicaron que para los tres tipos de vegetación se presenta una comunidad vegetal no uniforme en cuanto a sus alturas, presentando un mayor número de individuos en el estrato inferior, seguido del estrato medio, para finalmente tener una cantidad menor en el estrato de altura mayor. La información generada en esta investigación proporciona un marco de referencia sobre cómo se conforma la estructura arbórea en los tipos de vegetación del ejido, así como la base para futuras tomas de decisión sobre planes de manejo forestal.

Summary Climatic variations modify the distribution of species in temperate forests, affecting their composition, structure, richness, growth and regeneration. Cerro El Potosí has experienced multiple anthropogenic events that have caused a degradation and reduction in vegetation cover, affecting and reducing the populations of Pinus culminicola Andresen & Beaman. The objective was to determine the composition, structure, diversity, dasometry and regeneration of species in the distribution area of Pinus culminicola in an altitudinal gradient (3190 to 3700 masl) in Cerro El Potosí. Twelve circular sites of 400 m2 distributed in 4 altitudinal levels were established. The importance value indexes (IVI), species richness (Simpson, Shannon-Weiner and Margalef), dasometric parameters (height, stem diameter and crown area) and natural regeneration were determined. Levene, Shapiro-Wilk, ANOVA and Tukey tests were used for data analysis. The Pinaceae family was found to be the most abundant, with four species. Species diversity is low at higher altitudes and gradually increases as altitude decreases. The species with the highest IVI at each altitudinal level were the following: 1) at 3190 masl: Pinus hartwegii; 2) at 3300 masl: Pinus culminicola; 3) at 3500 and 3700 masl: Pinus hartwegii and Pinus culminicola had similar values. The dasometric parameters showed that the sizes of P. culminicola and P. hartwegii decreased with altitude, with the largest individuals occurring at 3500 masl. The density of adult trees is higher than young trees at all altitudes, so the state of regeneration is low. It is concluded that in Cerro El Potosí, the increase in altitude influences the studied variables of abundance and richness. The findings of this study could guide future studies that include management and conservation plans.

Resumen Las variaciones climáticas modifican la distribución de las especies en los bosques templados, afectando su composición, estructura, riqueza, crecimiento y regeneración. El Cerro El Potosí ha experimentado múltiples eventos de origen antrópico que han ocasionado una degradación y reducción en la cobertura vegetal, afectando y aminorando las poblaciones de Pinus culminicola Andresen & Beaman. El objetivo fue determinar la composición, estructura, diversidad, dasometría y regeneración de especies en el área de distribución del Pinus culminicola en un gradiente altitudinal (3190 a 3700 msnm) en el Cerro El Potosí. Se establecieron 12 sitios circulares de 400 m2 distribuidos en 4 pisos altitudinales. Se determinaron los índices de valor de importancia (IVI), de riqueza de especies (Simpson, Shannon-Weiner y de Margalef), los parámetros dasométricos (altura, diámetro de fuste y área de copa) y la regeneración natural. Para el análisis de la información se utilizaron las pruebas de Levene, Shapiro-Wilk, ANOVA y Tukey. Se encontró que la familia Pinaceae es la más abundante, con cuatro especies. La diversidad de especies es baja en las altitudes más altas y aumenta gradualmente a medida que la altitud disminuye. Las especies con mayor IVI en cada piso altitudinal fueron las siguientes: 1) a 3190 msnm: Pinus hartwegii; 2) a 3300 msnm: Pinus culminicola; 3) a 3500 y 3700 msnm: Pinus hartwegii y Pinus culminicola tuvieron valores similares. Los parámetros dasométricos mostraron que los tamaños P. culminicola y P. hartwegii disminuyen con la altitud, siendo los 3500 msmn en donde se presentaron los individuos más grandes. La densidad de árboles adultos es mayor que los jóvenes en todas las altitudes, por lo que el estado de regeneración es bajo. Se concluye que en el Cerro El Potosí, el aumento de la altitud tiene un efecto en las variables estudiadas de abundancia y riqueza. Lo encontrado en el presente trabajo pudieran orientar futuros estudios que incluyan planes de manejo y conservación.

Abstract Introduction: Trees in urban and peri-urban areas produce goods and services for society; therefore, it is important to know about their ecological characteristics. Objective: We aimed to determine trees’ ecological characteristics in the peri-urban forest at the Molino de Flores Netzahualcóyotl National Park (MFNNP) in Texcoco, Estado de México. Materials and methods: A stratified tree sampling was developed to register tree species, diameter at breast height, height, crown diameter, percentage of live crown and crown density. Species richness and diversity were calculated using Margalef, Simpson (1-D) indexes and Santamour's 10-20-30 rule; in addition, the urban importance value index (UIVI) was determined. Results and discussion: Seventeen families and 22 species were identified. Eucalyptus camaldulensis Dehnh., Schinus molle L. and Casuarina equisetifolia L. represented 55 % of the sampled trees. We estimated 7 983 ± 806 trees with a density of 163 trees∙ha-1. Diameter at breast height is 26.56 ± 2.33 cm, height 10.52 ± 0.6 m and canopy cover equals 48.2 % of the park area (4 819.88 m2∙ha-1). Richness (≤1.67) and diversity (≤0.61) were low; the species with the highest IVIU were E. camaldulensis, S. molle and Fraxinus uhdei (Wenz.) Lingelsh. with 38.53 %, 13.89 % and 10.62 %, respectively. Conclusions: The tree composition of the MFNNP is similar to that of an urban forest, a situation that contrasts with other natural protected areas. Areas with very low densities were identified with potential to be reforested and could increase the diversity and canopy cover to provide greater protection to the soil.

Resumen Introducción: El arbolado de las zonas urbanas y periurbanas genera bienes y servicios para la sociedad; por tanto, es importante conocer sus características ecológicas. Objetivo: Determinar las características ecológicas del arbolado del bosque periurbano Parque Nacional Molino de Flores Netzahualcóyotl (PNMFN) en Texcoco, Estado de México. Materiales y métodos: Se realizó un muestreo arbóreo estratificado donde se registró la especie, diámetro normal, altura, diámetro de copa, porcentaje de copa viva y densidad de copa. La riqueza y diversidad de especies se calculó con los índices de Margalef, Simpson (1-D) y la regla 10-20-30 de Santamour; además, se determinó el índice de valor de importancia urbano (IVIU). Resultados y discusión: Se identificaron 17 familias y 22 especies. Eucalyptus camaldulensis Dehnh., Schinus molle L. y Casuarina equisetifolia L. representaron 55 % de los árboles muestreados. Se estimaron 7 983 ± 806 árboles con una densidad de 163 árboles∙ha-1. El diámetro normal es de 26.56 ± 2.33 cm, la altura de 10.52 ± 0.6 m y la cobertura de copa equivale a 48.2 % de la superficie del parque (4 819.88 m2∙ha-1). La riqueza (≤1.67) y diversidad (≤0.61) fueron bajas; las especies con mayor IVIU fueron E. camaldulensis, S. molle y Fraxinus uhdei (Wenz.) Lingelsh. con 38.53 %, 13.89 % y 10.62 %, respectivamente. Conclusiones: La composición arbórea del PNMFN es similar a la de un bosque urbano, situación que contrasta con otras áreas naturales protegidas. Hay zonas con densidades muy bajas que pueden ser objeto de reforestación, la cual podría incrementar la diversidad y cobertura de copa que brinde mayor protección al suelo.

Abstract Introduction: Sustainable management of oases needs knowledge of the conditions of composition and diversity of the species living there. Objective: Estimating and comparing the diversity and structure of vegetation in the tree, shrub and herbaceous strata of the San Ignacio oasis, Baja California Sur, Mexico. Materials and methods: A total of 140 circular sites (500 m2) were randomly located, where 20 m2 and 1 m2 sites were nested to record the vegetation in the herbaceous, shrub and tree strata. Species richness, Shannon-Wiener, Simpson, Pielou and species importance value indices were used to estimate plant diversity in the strata and to characterize their structure. Results and discussion: A total of 53 taxa were distributed in 17 orders, 25 families and 47 genera. Richness, diversity and homogeneity were higher in the herbaceous stratum (S = 41, H´ = 3.21, J´ = 8.64, respectively) and lower in the arboreal stratum (S = 21, H´ = 2.01, J´= 0.688). Regarding the importance value index, the species with the highest ecological weight was Prosopis articulata S. Watson (33.35 %) for the herbaceous stratum, Cylindropuntia alcahes (F. A. B. Weber) F. M. Kunth (65.60 %) for shrub and Phoenix dactylifera L. (92.94 %) for the arboreal stratum. Conclusions: Vegetation richness and diversity were higher in the herbaceous stratum. This study represents a baseline of indicators useful for the evaluation of changes generated by natural or anthropogenic events in the San Ignacio oasis.

Resumen Introducción: El manejo sustentable de los oasis requiere conocimiento de las condiciones de composición y diversidad de las especies que lo habitan. Objetivo: Estimar y comparar la diversidad y estructura de la vegetación en los estratos arbóreo, arbustivo y herbáceo del oasis San Ignacio, Baja California Sur, México. Materiales y métodos: Se ubicaron 140 sitios circulares (500 m2) de manera aleatoria, sobre los cuales se anidaron sitios de 20 m2 y 1 m2 para el registro de la vegetación en los estratos herbáceo, arbustivo y arbóreo. Los índices riqueza de especies, Shannon-Wiener, Simpson, Pielou y valor de importancia de las especies se utilizaron para estimar la diversidad vegetal en los estratos y caracterizar su estructura. Resultados y discusión: Se contabilizaron 53 taxones distribuidos en 17 órdenes, 25 familias y 47 géneros. La riqueza, diversidad y homogeneidad fueron mayores en el estrato herbáceo (S = 41, H´ = 3.21, J´ = 8.64, respectivamente) y menores en el estrato arbóreo (S = 21, H´ = 2.01, J´= 0.688). En lo que respecta al índice del valor de importancia, la especie con mayor peso ecológico en el estrato herbáceo fue Prosopis articulata S. Watson (33.35 %), en el arbustivo Cylindropuntia alcahes (F. A. B. Weber) F. M. Kunth (65.60 %) y en el arbóreo Phoenix dactylifera L. (92.94 %). Conclusiones: La riqueza y diversidad de la vegetación fueron superiores en el estrato herbáceo. Este estudio representa una línea base de indicadores útil para la evaluación de los cambios generados por eventos naturales o antropogénicos en el oasis San Ignacio.

Resumen La vegetación de un ecosistema puede ser degradada por los incendios forestales; estos se originan por acciones humanas o de manera natural y por lo general reducen la diversidad y composición de especies, así como su regeneración natural. El presente trabajo se desarrolló en un bosque templado degradado por incendios forestales en el Área Natural Protegida El Tejocote, municipio Santiago, Nuevo León. Los objetivos fueron calcular el Índice de Valor de Importancia, analizar la diversidad de especies y determinar el porcentaje de germinación. El muestreo se realizó en 10 parcelas al azar de 1 000 m2. El Índice de Valor de Importancia (IVI), índices de diversidad (Margalef, Shannon-Weiner y Simpson) y los porcentajes de germinación se determinaron para cada especie. Pinus teocote tuvo el mayor IVI (45.5 %), también fue la más dominante al cubrir 69 % de la superficie muestreada. Quercus laeta tuvo 25 % de IVI y fue la más abundante de todas las especies (39 %). Agave scabra y Arbutus xalapensis tuvieron IVI de 7.9 % y 6.9 %, respectivamente; ambas se clasificaron como arbustivas. Se obtuvo una baja diversidad en todos los sitios muestreados, y los valores promedio fueron: Margalef (0.74), Shannon-Weiner (0.46) y Simpson (0.77). Los porcentajes de germinación más altos los presentaron Pinus pseudostrobus (97.40 %) y Agave scabra (84 %). La diferencia en la capacidad germinativa de los taxones podría cambiar la diversidad y composición de las especies de la comunidad El Tejocote después de su degradación por incendio.

Abstract The vegetation of an ecosystem can be degraded by forest fires; which are caused by human or natural actions and generally reduce the diversity and composition of species, as well as their natural regeneration. This work was carried out in a temperate forest degraded by forest fires in the El Tejocote Natural Protected Area, Santiago municipality, Nuevo León State. The objectives were to calculate the Importance Value Index, analyze species diversity and determine the percentage of germination. Sampling was carried out in 10 random plots of 1 000 m2. The Importance Value Index (IVI), diversity indexes (Margalef, Shannon-Weiner and Simpson) and the germination percentages were determined for each species. Pinus teocote had the highest IVI (45.5 %), it was also the most dominant, covering 69 % of the sampled area. Quercus laeta had 25 % IVI and was the most abundant of all species (39 %). Agave scabra and Arbutus xalapensis had IVIs of 7.9 % and 6.9 %, respectively; both were classified as shrubs. A low diversity was obtained in all the sites sampled; the average values were: Margalef (0.74), Shannon-Weiner (0.46), and Simpson (0.77). The highest germination percentages were presented by Pinus pseudostrobus (97.40 %) and Agave scabra (84 %). The difference in the germination capacity of taxa could change the diversity and species composition of the El Tejocote community after its degradation by fire.