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Determining how fully tropical forests regenerating on abandoned land recover characteristics of old-growth forests is increasingly important for understanding their role in conserving rare species and maintaining ecosystem services. Despite this, our understanding of forest structure and community composition recovery throughout succession is incomplete, as many tropical chronosequences do not extend beyond the first 50 years of succession. Here, we examined trajectories of forest recovery across eight 1-hectare plots in middle and later stages of forest succession (40-120 years) and five 1-hectare old-growth plots, in the Barro Colorado Nature Monument (BCNM), Panama. We first verified that forest age had a greater effect than edaphic or topographic variation on forest structure, diversity and composition and then corroborated results from smaller plots censused 20 years previously. Tree species diversity (but not species richness) and forest structure had fully recovered to old-growth levels by 40 and 90 years, respectively. However, rare species were missing, and old-growth specialists were in low abundance, in the mid- and late secondary forest plots, leading to incomplete recovery of species composition even by 120 years into succession. We also found evidence that dominance early in succession by a long-lived pioneer led to altered forest structure and delayed recovery of species diversity and composition well past a century after land abandonment. Our results illustrate the critical importance of old-growth and old secondary forests for biodiversity conservation, given that recovery of community composition may take several centuries, particularly when a long-lived pioneer dominates in early succession. Abstract in Spanish is available with online material.

Determinar en que medida los bosques tropicales que se regeneran en tierras abandonadas recuperan las características de los bosques primarios es cada vez más importante para comprender su papel en la conservación de especies raras y el mantenimiento de los servicios ecosistémicos. A pesar de ello, nuestro entendimiento sobre la recuperación de la estructura del bosque y la composición de la comunidad a lo largo de la sucesión es incompleta, ya que muchas cronosecuencias tropicales no van más allá de los primeros 50 años de sucesión. En este estudio, investigamos las trayectorias de recuperación del bosque en ocho parcelas de 1 hectárea en estadíos medios y tardíos de la sucesión forestal (40­120 años) y cinco parcelas de 1 hectárea de bosque primario, en el Monumento Natural Barro Colorado (MNBC), Panamá. En primer lugar, verificamos que la edad del bosque tenía un mayor efecto que la variación edáfica o topográfica en la estructura, diversidad y composición del bosque y luego corroboramos los resultados de parcelas más pequeñas estudiadas 20 años antes. La diversidad de especies arbóreas, pero no la riqueza de especies, y la estructura forestal se habían recuperado completamente hasta alcanzar los niveles de bosque primario a los 40 y 90 años, respectivamente. Sin embargo, los bosques secundarios carecían de especies raras y presentaban una escasa abundancia de especies especialistas del bosque antiguo, lo que condujo a una recuperación incompleta de la composición de especies, incluso a 120 años de sucesión. También encontramos pruebas de que el predominio de un pionero longevo en las primeras etapas de la sucesión provocó una alteración de la estructura forestal y retrasó la recuperación de la diversidad y composición de especies más allá de un siglo después el abandono de las tierras. Nuestros resultados ilustran la importancia crítica de los bosques primarios y secundarios más antiguos para la conservación de la biodiversidad, dado que la recuperación de la composición de la comunidad puede llevar varios siglos, especialmente cuando un pionero longevo domina en la sucesión temprana.

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Since the publication of the Solanaceae treatment in "Flora Argentina" in 2013 exploration in the country and resolution of outstanding nomenclatural and circumscription issues has resulted in a number of changes to the species of the Morelloid clade of Solanum L. (Solanaceae) for Argentina. Here we describe three new species: Solanum hunzikeri Chiarini & Cantero, sp. nov., from wet high elevation areas in Argentina (Catamarca, Salta and Tucumán) and Bolivia (Chuquisaca and Tarija), S. marmoratum Barboza & S. Knapp, sp. nov., from central Argentina in Catamarca, La Pampa, La Rioja, San Juan and San Luis, and S. tiinae Barboza & S. Knapp, sp. nov., from the mountains of Jujuy, La Rioja, Salta and Tucumán. We provide descriptions, illustrations and distribution maps for all new taxa. A table of nomenclatural changes and additional taxa now known to occur in Argentina summarizes additions and changes since the "Flora Argentina". We also provide an updated key, including all new taxa for the country, to facilitate identification and further exploration.

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Introduction: Glacierised catchments are remote and hostile environments, in which streams from different water sources (e.g., glacier melt, rain/snowmelt, groundwater) converge, creating a complex mosaic of stream sites with varying levels of glacial influence and environmental conditions. This environmental heterogeneity, in turn, influences the assemblage and composition of aquatic communities and produces complex patterns of species diversity at the catchment scale. Objectives: In this contribution, we assessed biodiversity and community composition of aquatic macroinvertebrate communities from 51 stream site types in a glacierised catchment in the tropical Andes. The aim of our study was to: (1) determine diversity, rarity, commonness and spatial distribution patterns of aquatic macroinvertebrate communities from sites with different water sources, and (2) identify which environmental variables influence the density and presence of macroinvertebrate taxa and, in particular, of the subfamilies of the ubiquitous chironomids. Methods: Our study sites were grouped according to their water source and to their percentage of glacier coverage in the catchment (GCC). At each site we sampled aquatic macroinvertebrates, measured environmental variables and assessed community differences and environmental influence with ordination analyses and generalized linear models. Results: Kryal and mixed sites had an important proportion of rare taxa. Mean richness was highest in the mixed sites and lowest in the sites with the highest glacier cover; while sites with an intermediate percentage of glacier cover, had the highest values of α and β diversity. We found that 13 taxa (15.9%) were common to all stream site types. SIMPER analysis showed that Orthocladiinae, Hyalella sp. and Andesiops sp. contributed the most to the dissimilarity between site types (˃ 45% of cumulative contribution). RDA showed that kryal sites were associated with high turbidity and density of Podonomids, and with low temperature, amount of CPOM and densities of both Anomalocosmoecus sp. and Andesiops sp. Orthocladinae was associated with high current velocity and chlorophyll a concentration, whereas Hyalella sp. had a positive relationship with higher pH and streambed stability. Generalized linear models showed that GCC was the main variable explaining all faunal metrics. Current velocity explained macroinvertebrate abundance, water temperature was related to chironomid density and chlorophyll a influenced Orthocladiinae presence-absence. Conclusions: Our results suggest that by favoring the presence of rare taxa and taxa turnover, glacier influence may increase biodiversity in glacierised catchments. In terms of biodiversity conservation, this study confirms an urgent need to increase knowledge of high-Andean stream biodiversity, especially in highly heterogenous glacierised catchments, to better describe regional biodiversity patterns and community composition of these highly vulnerable freshwater ecosystems. Detailed analyses of benthic communities and development of databases are key for conservation strategies. Water management municipalities and/or enterprises should consider water quality and stream types for more sustainable management of these important ecosystems.

Introducción: Las cuencas glaciares son entornos remotos y hostiles, en los que los arroyos de diferentes fuentes de agua (p.ej., deshielo de glaciares, lluvia/deshielo, agua subterránea) convergen, creando un mosaico complejo de tramos con diferentes niveles de influencia glacial y condiciones ambientales. Esta heterogeneidad ambiental influye, a su vez, en el ensamblaje y composición de las comunidades acuáticas y produce complejos patrones de diversidad a la escala de la cuenca. Objetivos: En esta contribución, evaluamos la biodiversidad y composición de comunidades de macroinvertebrados acuáticos en 51 sitios de una cuenca glaciar en los Andes tropicales. Los objetivos de nuestro estudio fueron: (1) determinar la diversidad, la contribución de taxones raros y comunes y los patrones de distribución espacial de las comunidades de macroinvertebrados acuáticos en sitios con diferentes fuentes de agua, y (2) identificar qué variables ambientales influyen en la densidad y presencia de taxones de macroinvertebrados y, en particular, de las subfamilias de los omnipresentes quironómidos. Métodos: Agrupamos a nuestros sitios de estudio según su fuente de agua y su porcentaje de cobertura de glaciar en la cuenca (GCC). En cada sitio donde muestreamos macroinvertebrados acuáticos, medimos variables ambientales y evaluamos las diferencias entre comunidades y la influencia ambiental con análisis de ordenación y modelos lineales generalizados. Resultados: Los sitios kryal y mixtos tuvieron una proporción importante de taxones raros. La riqueza media fue más alta en los sitios mixtos y más baja en los sitios con mayor cobertura glaciar; mientras que los sitios con un porcentaje intermedio de cobertura glaciar tuvieron los valores más altos de diversidad α y β. Encontramos que 13 taxones (15,9%) fueron comunes a todos los tipos de sitios de estudio. El análisis SIMPER mostró que Orthocladiinae, Hyalella sp. y Andesiops sp. contribuyeron más a la disimilitud entre tipos de sitios (˃ 45% de la contribución acumulada). El RDA mostró que los sitios kryal estaban asociados con alta turbidez y densidad de podonómidos, y con baja temperatura, cantidad de CPOM y densidad de Anomalocosmoecus sp. y Andesiops sp. Orthocladinae se asoció con una alta velocidad de corriente y concentración de clorofila a, mientras que Hyalella sp. tuvo una relación positiva con pH más alto y estabilidad del lecho del río. Los modelos lineales generalizados mostraron que GCC fue la variable principal para explicar todas las métricas de fauna. La velocidad de corriente explicó la abundancia de macroinvertebrados, la temperatura del agua estuvo relacionada con la densidad de los quironómidos y la clorofila influenció la presencia-ausencia de Orthocladiinae. Conclusiones: Nuestros resultados sugieren que, al favorecer la presencia de taxones raros y la rotación de taxones, la influencia de los glaciares puede aumentar la biodiversidad en cuencas con influencia glaciar. En términos de conservación de la biodiversidad, este estudio confirma la necesidad urgente de incrementar el conocimiento de la biodiversidad en arroyos de la región altoandina, especialmente en cuencas glaciares altamente heterogéneas, para describir mejor los patrones de biodiversidad regional y la composición de las comunidades en estos ecosistemas altamente vulnerables. Análisis detallados de las comunidades bentónicas y el desarrollo de bases de datos son claves para diseñar estrategias de conservación. Los municipios y/o empresas administradoras de agua deben considerar la calidad del agua y los tipos de arroyos para una gestión más sostenible de estos importantes ecosistemas.

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Abstract: This study conducts a biogeographical review of Aniba in Brazil, including its actual and potential distribution, and a review on the species conservation status. The potential distribution of each Aniba species was modeled using the Brazilian Plants and Fungi Biogeography system, which is interconnected with the SpeciesLink network. A consensus model based on up to five algorithms was used to model the potential distribution of each species. The endemism, conservation status and rarity of each species in Brazil were also analyzed. A total of 3059 records of 30 Brazilian Aniba species were found. In total, 16.1% of the records were excluded because of the lack of valid names, and 53.4% were excluded because of the lack of georeference and name of the person who identified the record. The consensus model showed good results for species with 20 or more pixels. The other species had many errors, and their models could only be used to determine new areas for collections. Nine species were endemic to Brazil, and only three species showed no indicator of rarity. The geographical distribution of Brazilian Aniba species shows a predominantly Amazonian pattern. Only four species are not actually found in the Amazon. Some Amazonian species may also be found in Atlantic Forest areas, and many other species have the potential to live there. Our results indicate that only three species have no conservation problems, whereas 14 species have conservation problems, and 13 other species require further population studies to be best evaluated.

Resumo: Este estudo objetiva apresentar uma revisão biogeográfica de Aniba no Brasil, incluindo a distribuição real e potencial, além de uma revisão sobre o estado de conservação das espécies. A distribuição potencial de cada espécie de Aniba foi modelada através do sistema Biogeografia da Flora e Fungos do Brasil (Biogeo), interligado à Rede SpeciesLink que integra em tempo real dados primários de coleções científicas com os quais foram estabelecidas a distribuição real das espécies. Um modelo de consenso, baseado em até cinco algoritmos, foi usado para modelar a distribuição potencial de cada espécie. Também foram analisadas a situação de endemismo no Brasil, o estado de conservação e raridade de cada espécie. Foram encontrados 3059 registros de 30 espécies de Aniba no Brasil. Em média houve uma perda 16,1% dos registros por falta de nomes válidos e 53,4% dos registros por falta de georreferenciamento e identificador. A avaliação do modelo consenso mostrou bons resultados para as espécies com 20 ou mais pixels, as demais espécies apresentaram muitos erros; sendo que seus modelos servem apenas para orientar novas áreas para coletas. Nove espécies são endêmicas do Brasil. Apenas três espécies não apresentaram nenhum indicador de raridade. A distribuição geográfica das espécies de Aniba no Brasil mostra um padrão predominante amazônico. Apenas quatro espécies não possuem ocorrência conhecida na Amazônia. Algumas espécies amazônicas também podem ser encontradas em áreas da Mata Atlântica e muitas outras apresentam potencial para ocorrer lá. Nossos resultados indicam que apenas três espécies não possuem nenhum problema referente à conservação, 14 espécies possuem problemas e 13 outras espécies necessitam de mais estudos populacionais para melhor serem avaliadas.

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There is broad consensus that the diversity of functional traits within species assemblages drives several ecological processes. It is also widely recognized that rare species are the first to become extinct following human-induced disturbances. Surprisingly, however, the functional importance of rare species is still poorly understood, particularly in tropical species-rich assemblages where the majority of species are rare, and the rate of species extinction can be high. Here, we investigated the consequences of local and regional extinctions on the functional structure of species assemblages. We used three extensive datasets (stream fish from the Brazilian Amazon, rainforest trees from French Guiana, and birds from the Australian Wet Tropics) and built an integrative measure of species rarity versus commonness, combining local abundance, geographical range, and habitat breadth. Using different scenarios of species loss, we found a disproportionate impact of rare species extinction for the three groups, with significant reductions in levels of functional richness, specialization, and originality of assemblages, which may severely undermine the integrity of ecological processes. The whole breadth of functional abilities within species assemblages, which is disproportionately supported by rare species, is certainly critical in maintaining ecosystems particularly under the ongoing rapid environmental transitions.

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Spatial and temporal distribution of stream macroalgae in streams from southeastern Brazil were assessed for one year. The fluctuations in macroalgal species composition and environmental factors were monitored monthly. The region exhibit a tropical climate, with defined rainy and dry seasons. Nineteen species were found, with a predominance of Chlorophyta (52.7% of the species), followed by Cyanobacteria (26.3%), Ochrophyta and Rhodophyta (10.5% each). Scytonema arcangeli had the highest number of records (63.6%), while Mougeotia capucina occurred in all sampling sites. Community structure had low similarity (20-26%) and the environmental factors showed a weak contribution to the distribution pattern observed. Despite this, the light availability at the stream-bed seems to be a major influence on the macroalgal seasonal dynamics. We suggest that macroalgae communities are predominantly composed of rare species, and this could explain the lack of a clear spatial and temporal variation pattern of these organisms.

A distribuição espacial e temporal das macroalgas lóticas em riachos do sudeste do Brasil foram avaliadas por um ano. As flutuações na composição de espécies de macroalgas e fatores ambientais foram monitorados mensalmente. A região apresenta um clima tropical, com estações chuvosas e secas definidas. Dezenove espécies foram encontradas, com predomínio de Chlorophyta (52,7% das espécies), seguido por Cianobactérias (26,3%), Ochrophyta e Rhodophyta (10,5% cada). Scytonema arcangeli teve o maior número de registros (63,6%), enquanto Mougeotia capucina ocorreu em todos os pontos de amostragem. A estrutura da comunidade teve baixa similaridade (20-26%) e os fatores ambientais mostraram uma fraca contribuição para o padrão de distribuição observado. Apesar disso, a disponibilidade de luz no leito do riacho parece ser de grande influência sobre a dinâmica sazonal de macroalgas. Nós sugerimos que as comunidades de macroalgas são predominantemente compostas por espécies raras, e isso poderia explicar a falta de um padrão claro de variação espacial e temporal desses organismos.

RESUMO

The conversion of natural habitats to farmland is a major driver of the global extinction crisis. Two strategies are promoted to mitigate the impacts of agricultural expansion on biodiversity: land sharing integrates wildlife-friendly habitats within farmland landscapes, and land sparing intensifies farming to allow the offset of natural reserves. A key question is which strategy would protect the most phylogenetic diversity--the total evolutionary history shared across all species within a community. Conserving phylogenetic diversity decreases the chance of losing unique phenotypic and ecological traits and provides benefits for ecosystem function and stability. Focusing on birds in the threatened Chocó-Andes hotspot of endemism, we tested the relative benefits of each strategy for retaining phylogenetic diversity in tropical cloud forest landscapes threatened by cattle pastures. Using landscape simulations, we find that land sharing would protect lower community-level phylogenetic diversity than land sparing and that with increasing distance from forest (from 500 to >1,500 m), land sharing is increasingly inferior to land sparing. Isolation from forest also leads to the loss of more evolutionarily distinct species from communities within land-sharing landscapes, which can be avoided with effective land sparing. Land-sharing policies that promote the integration of small-scale wildlife-friendly habitats might be of limited benefit without the simultaneous protection of larger blocks of natural habitat, which is most likely to be achieved via land-sparing measures.

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The Cinereous Warbling-finch Poospiza cinerea is a globally vulnerable Emberizidae passerine, patchily distributed and rare in the open savannah of central South America. Attributes of rare species include niche specificity such as feeding habits. To verify possible niche specialization in this species we aimed to describe its foraging habits related to substrate use, foraging and substrate height, attack maneuvers, and consumed food items. We monitored two groups at two study sites and sampled foraging events with intervals of 15 minutes. The substrates used in greater frequency were foliage and reproductive organs. Foraging and substrate height varied widely with study area. The attack maneuver adopted in greater frequency was glean. Most food items attacked were small invertebrates. Big invertebrates included Lepidoptera, Hemiptera, Coleoptera, Hymenoptera and Orthoptera. Poospiza cinerea was also recorded foraging in mixed bird flocks with seven other species. The generalist foraging behavior of the species cannot be associate to its rarity.(AU)

O capacetinho-do-oco-do-pau Poospiza cinerea é um passeriforme da família Emberizidae globalmente vulnerável, irregularmente distribuído e raro no Cerrado do centro da América do Sul. Atributos de espécies raras incluem especificidades de nicho tais como hábitos de forrageamento. Para verificar possível especialização de nicho dessa espécie, buscamos descrever seu comportamento de forrageamento relacionado a uso de substrato, altura de forrageamento e do substrato, manobras de ataque e itens alimentares consumidos. Nós monitoramos dois grupos em duas áreas de estudo e amostramos eventos de forrageamento com intervalos de 15 minutos. Os substratos utilizados em maior frequência foram folhagem e órgãos reprodutivos. Alturas de forrageamento e dos substratos variaram amplamente com a área de estudo. A manobra de ataque adotada em maior frequência foi respigar. A maioria dos itens alimentares foi pequenos invertebrados. Grandes invertebrados incluíram Lepidoptera, Hemiptera, Coleoptera, Hymenoptera e Orthoptera. Poospiza cinerea foi registrado forrageando em bandos mistos com outras sete espécies. O comportamento de forrageamento generalista da espécie não pode ser associado com sua raridade.(AU)

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The Cinereous Warbling-finch Poospiza cinerea is a globally vulnerable Emberizidae passerine, patchily distributed and rare in the open savannah of central South America. Attributes of rare species include niche specificity such as feeding habits. To verify possible niche specialization in this species we aimed to describe its foraging habits related to substrate use, foraging and substrate height, attack maneuvers, and consumed food items. We monitored two groups at two study sites and sampled foraging events with intervals of 15 minutes. The substrates used in greater frequency were foliage and reproductive organs. Foraging and substrate height varied widely with study area. The attack maneuver adopted in greater frequency was glean. Most food items attacked were small invertebrates. Big invertebrates included Lepidoptera, Hemiptera, Coleoptera, Hymenoptera and Orthoptera. Poospiza cinerea was also recorded foraging in mixed bird flocks with seven other species. The generalist foraging behavior of the species cannot be associate to its rarity.

O capacetinho-do-oco-do-pau Poospiza cinerea é um passeriforme da família Emberizidae globalmente vulnerável, irregularmente distribuído e raro no Cerrado do centro da América do Sul. Atributos de espécies raras incluem especificidades de nicho tais como hábitos de forrageamento. Para verificar possível especialização de nicho dessa espécie, buscamos descrever seu comportamento de forrageamento relacionado a uso de substrato, altura de forrageamento e do substrato, manobras de ataque e itens alimentares consumidos. Nós monitoramos dois grupos em duas áreas de estudo e amostramos eventos de forrageamento com intervalos de 15 minutos. Os substratos utilizados em maior frequência foram folhagem e órgãos reprodutivos. Alturas de forrageamento e dos substratos variaram amplamente com a área de estudo. A manobra de ataque adotada em maior frequência foi respigar. A maioria dos itens alimentares foi pequenos invertebrados. Grandes invertebrados incluíram Lepidoptera, Hemiptera, Coleoptera, Hymenoptera e Orthoptera. Poospiza cinerea foi registrado forrageando em bandos mistos com outras sete espécies. O comportamento de forrageamento generalista da espécie não pode ser associado com sua raridade.

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Este artigo visa apresentar, com exemplos empíricos, três índices calculáveis a partir de dados de evocações livres. Dois desses índices foram elaborados por Flament e Rouquette (2003) e indicam o grau de diversidade e de raridade das evocações. O terceiro índice permite o estudo da proporção de elementos comuns a dois corpora de evocações, por isso foi nomeado de índice de comunidade. A partir desses três indicadores, é possível ter informações sobre o grau de compartilhamento social de cada objeto, seu nível de idiossincrasia e a proporção de comunidade entre dois corpora. Essas informações, quando associadas a outras técnicas, podem ser úteis para uma melhor compreensão da relação população-objeto.

This paper aims at presenting three indexes that can be calculated from free evocation data. Two of those indexes were elaborated by Flament and Rouquette (2003), and they indicate the diversity and rarity degrees of evocations. The third index allows for the study of the proportion of elements common to two evocation corpora. From these three indicators it is possible to have information about the degree of social sharing of each object, their idiosyncrasy level and the community proportion between two corpora. When associated with other techniques, such information might be useful for a better understanding of the population-object relationship.

Este artículo tiene como objetivo presentar, con ejemplos empíricos, tres índices estimados a partir de datos de evocaciones libres. Dos de estos índices fueron desarrollados por Flament y Rouquette (2003) e indican el grado de diversidad y rareza de las evocaciones. El tercer índice permite estudiar la proporción de elementos comunes a los dos corpora de evocaciones, por lo que fue llamado el índice de la comunidad. A partir de estos tres indicadores es posible tener información sobre el grado de participación social de cada objeto, su nivel de la idiosincrasia y la proporción de comunidad entre los dos corpora. Esta información, cuando se combina con otras técnicas, puede ser útil para una mejor comprensión de la relación población-objeto.

RESUMO

We surveyed the herpetofauna from the Complex of Planalto da Ibiapaba (CPI), CE, Brazil, during two years, using five sampling methods and information available in the literature. The amphibians are represented by 38 species distributed into nine families. The reptiles found summed 84 species, distributed into 25 families. Most amphibians collected exhibited wide occurrence along CPI, where we recorded 24 species (63.2 percent), which occurred at least in 60 percent of the sampled environments. Reptiles showed a different pattern, since 52 species (62.6 percent) had a restricted distribution (up to two environments). Sixteen species out of 25 considered as rare in CPI are restricted to relict moist forests. We also applied a rarity-vulnerability index to determine the most susceptible species. Pristimantis sp., Adelophryne baturitensis Hoogmoed, Borges, and Cascon, 1994, Pseudopaludicola sp. (aff. saltica), Scinax fuscomarginatus (A. Lutz, 1925), and Odontophrynus carvalhoi Savage & Cei, 1965 were the most vulnerable amphibians in CPI. Reptiles showed a more diverse range in the scale of rarity with 40 species considered vulnerable. Among the vulnerable reptiles Leposoma baturitensis Rodrigues & Borges, 1997, Bothrops sp. (gr. atrox), Atractus ronnie Passos, Fernandes & Borges-Nojosa, 2007, Apostolepis sp. (gr. pimy), and Mesoclemmys perplexa Bour & Zaher, 2005 were the rarest species found in the whole complex of Ibiapaba mountain range. Results indicate that about 70 percent of the species found in Ceará are present in this complex. Also, CPI is the area of the Caatinga biome with the highest species richness, including rare and threatened species.

A herpetofauna do Complexo do Planalto da Ibiapaba (CPI), CE, Brasil, foi estudada durante dois anos, usando cinco métodos de amostragem e informação disponível na literatura. Os anfíbios estavam representados por 38 espécies distribuídos em nove famílias. Os répteis encontrados somaram 84 espécies, distribuídos em 25 famílias. A maioria dos anfíbios coletados apresentou ampla ocorrência ao longo do CPI, sendo 24 espécies (63,2 por cento) ocorrendo em pelo menos 60 por cento dos ambientes amostrados. Répteis tiveram um padrão diferente uma vez que 52 espécies (62.6 por cento) tiveram uma distribuição restrita (até dois ambientes). Dezesseis das 25 espécies consideradas como rara no CPI são restritas as áreas de floresta úmida relictuais. Foi aplicado um índice de raridade/vulnerabilidade para determinar as espécies mais susceptíveis. Pristimantis sp., Adelophryne baturitensis Hoogmoed, Borges, and Cascon, 1994, Pseudopaludicola sp. (aff. saltica), Scinax fuscomarginatus (A. Lutz, 1925) e Odontophrynus carvalhoi Savage & Cei, 1965 foram os anfibios mais vulneráveis no CPI. Répteis mostraram uma variação mais diversa na escala de raridade com 40 espécies consideradas vulneráveis. Entre os répteis vulneráveis Leposoma baturitensis Rodrigues & Borges, 1997, Bothrops sp. (gr. atrox), Atractus ronnie Passos, Fernandes & Borges-Nojosa, 2007, Apostolepis sp. (gr. pimy) e Mesoclemmys perplexa Bour & Zaher, 2005 foram as espécies mais raras na encontradas ao longo do Complexo do Planalto da Ibiapaba. Os resultados indicam que aproximadamente 70 por cento dos répteis encontrados no Ceará estão presentes nesse complexo. O CPI é também a área do Bioma Caatinga com a maior riqueza de espécies, incluindo espécies raras e ameaçadas.

RESUMO

El presente estudio se llevó a cabo en cinco hectáreas de una parcela permanente establecida en el Parque Nacional Amacayacu, Amazonia colombiana. En éste, se evaluó el efecto de la variación ambiental y la configuración espacial sobre los patrones florísticos de las especies arbóreas (DAP>10 cm) a escala local en un bosque de tierra firme. Se estudió la variación florística y ambiental en cuadrantes de 20x20 m. Adicionalmente, se consideraron diferentes categorías de abundancia (total, alta, media y baja). Se utilizó el Análisis de Correspondencia Linealizado y el Análisis de Correspondencia Canónica, seguido de una partición de la variación, para cuantificar la magnitud a la cual el ambiente y la limitación en dispersión determinan la variación florística. La fracción espacial, representando procesos de autocorrelación como la limitación en dispersión, se analizó mediante dos métodos: Asumiendo un polinomio de tercer grado y por el método de Coordenadas Principales de Matrices Vecinas (PCNM). La diversidad beta de la parcela fue baja. El PCNM aparece como el método de análisis más apropiado para estudios a esta escala. Las diferencias florísticas explicadas a lo largo de la parcela de 5-ha fueron principalmente asociadas con procesos biológicos como la limitación en dispersión. La mayor parte de la variación florística, no obstante, no fue explicada por las variables ambientales o espaciales consideradas. En conclusión, estos resultados sugieren que procesos aleatorios son determinantes esenciales de la variación espacial de las especies arbóreas a escala local en tierra firme en los bosques en el Parque Nacional Amacayacu.

This study was carried out in a 5-ha permanent plot established in the Amacayacu National Park, Colombian Amazonia. We assessed the extent at which floristic patterns of tree species were determined by either the environmental variation or the spatial configuration in tierra firme forests. Floristic and environmental variation was assessed on quadrants of 20x20 m. To run the analysis, four different categories of abundance (all, high, medium and low) were considered. We used Detrended Correspondence Analysis and Canonical Correspondence Analysis, followed by a variation partitioning, to analyze the patterns of species distribution in order to quantify the role played by both environmental filtering and dispersal limitation. The spatial template, which represents dispersal limitation, was evaluated in two different ways: using a third degree polynomial and using the Principal Coordinates of Neighbour Matrix (PCNM) method. Beta diversity was relatively low within the plot. PCNM appears as the most appropriate method to analyze the spatial template at this scale. The floristic differences explained along the 5-ha plot were mainly associated to biological processes, such as dispersal limitation. The largest proportion of community variation in our dataset was unexplained by either environmental or spatial data. In conclusion, these results support random processes as the major drivers of the spatial variation of tree species at a local scale on tierra firme forests in the Amacayacu National Park.

Assuntos

RESUMO

El presente estudio se llevó a cabo en cinco hectáreas de una parcela permanente establecida en el Parque Nacional Amacayacu, Amazonia colombiana. En éste, se evaluó el efecto de la variación ambiental y la configuración espacial sobre los patrones florísticos de las especies arbóreas (DAP>10 cm) a escala local en un bosque de tierra firme. Se estudió la variación florística y ambiental en cuadrantes de 20x20 m. Adicionalmente, se consideraron diferentes categorías de abundancia (total, alta, media y baja). Se utilizó el Análisis de Correspondencia Linealizado y el Análisis de Correspondencia Canónica, seguido de una partición de la variación, para cuantificar la magnitud a la cual el ambiente y la limitación en dispersión determinan la variación florística. La fracción espacial, representando procesos de autocorrelación como la limitación en dispersión, se analizó mediante dos métodos: Asumiendo un polinomio de tercer grado y por el método de Coordenadas Principales de Matrices Vecinas (PCNM). La diversidad beta de la parcela fue baja. El PCNM aparece como el método de análisis más apropiado para estudios a esta escala. Las diferencias florísticas explicadas a lo largo de la parcela de 5-ha fueron principalmente asociadas con procesos biológicos como la limitación en dispersión. La mayor parte de la variación florística, no obstante, no fue explicada por las variables ambientales o espaciales consideradas. En conclusión, estos resultados sugieren que procesos aleatorios son determinantes esenciales de la variación espacial de las especies arbóreas a escala local en tierra firme en los bosques en el Parque Nacional Amacayacu.

This study was carried out in a 5-ha permanent plot established in the Amacayacu National Park, Colombian Amazonia. We assessed the extent at which floristic patterns of tree species were determined by either the environmental variation or the spatial configuration in tierra firme forests. Floristic and environmental variation was assessed on quadrants of 20x20 m. To run the analysis, four different categories of abundance (all, high, medium and low) were considered. We used Detrended Correspondence Analysis and Canonical Correspondence Analysis, followed by a variation partitioning, to analyze the patterns of species distribution in order to quantify the role played by both environmental filtering and dispersal limitation. The spatial template, which represents dispersal limitation, was evaluated in two different ways: using a third degree polynomial and using the Principal Coordinates of Neighbour Matrix (PCNM) method. Beta diversity was relatively low within the plot. PCNM appears as the most appropriate method to analyze the spatial template at this scale. The floristic differences explained along the 5-ha plot were mainly associated to biological processes, such as dispersal limitation. The largest proportion of community variation in our dataset was unexplained by either environmental or spatial data. In conclusion, these results support random processes as the major drivers of the spatial variation of tree species at a local scale on tierra firme forests in the Amacayacu National Park.

RESUMO

Spatial patterns in biodiversity variation at a regional scale are rarely taken into account when a natural reserve is to be established, despite many available methods for determining them. In this paper, we used dimensions of occurrence of 105 species of Anura (Amphibia) in the cerrado region of central Brazil to create a regional system of potential areas that preserves all regional diversity, using three different algorithms to establish reserve networks: "greedy", rarity, and simulated annealing algorithms. These generated networks based on complementarity with 10, 12, and 8 regions, respectively, widely distributed in the biome, and encompassing various Brazilian states. Although the purpose of these algorithms is to find a small number of regions for which all species are represented at least once, the results showed that 67.6%, 76.2%, and 69.5% of the species were represented in two or more regions in the three networks. Simulated annealing produced the smallest network, but it left out three species (one endemic). On the other hand, while the greedy algorithm produce a smaller solution, the rarity-based algorithm ensured that more species were represented more than once, which can be advantageous because it takes into consideration the high levels of habitat loss in the cerrado. Although usually coarse, these macro-scale approaches can provide overall guidelines for conservation and are useful in determining the focus for more local and effective conservation efforts, which is especially important when dealing with a taxonomic group such as anurans, for which quick and drastic population declines have been reported throughout the world.

Os padrões espaciais da variação da biodiversidade em escalas regionais raramente são considerados na escolha de uma reserva (unidades de conservação), a despeito dos diversos métodos disponíveis para esse fim. Neste trabalho, usamos dados da extensão de ocorrência de 105 espécies de Anura (Amphibia) na região de Cerrado, no Brasil Central, para estabelecer um sistema regional de áreas potenciais que preserve toda a diversidade da região. Para tanto, três algoritmos de seleção de redes de reservas foram testados: "greedy", raridade e "annealing" simulado. Com base na complementação, esses algoritmos geraram redes com 10, 12 e 8 regiões, respectivamente, sendo estas amplamente distribuídas no bioma e contemplando diferentes Estados da União. Esses algoritmos buscam o menor número de regiões que representem todas as espécies pelo menos uma vez. No entanto, 67,6%, 76,2% e 69,5% das espécies foram representadas ("preservadas") em duas ou mais regiões nas três redes de reservas selecionadas pelos métodos citados. O algoritmo "annealing" simulado resultou na menor rede, no entanto, não incluiu áreas para a preservação de três espécies (sendo uma delas endêmica). Por outro lado, embora o algoritmo de "greedy" tenha resultado em menor solução, o método baseado na raridade garante que mais espécies sejam representadas mais de uma vez, o que pode ser vantajoso considerando a elevada taxa de perda de habitat no Cerrado. Embora imprecisas, as abordagens em grandes escalas espaciais podem indicar estratégias gerais para a conservação e definir esforços de conservação locais e mais efetivos. Isto é especialmente importante quando se trata de um grupo taxonômico como os anuros, com declínios populacionais acentuados registrados mundialmente.

RESUMO

Maxipiñon (Pinus maximartinezii Rzedowski), which is confined to a single population of approximately 2000 to 2500 mature trees, covers about 400 ha in southern Zacatecas, Mexico. Genetic diversity measured by expected heterozygosity was 0.122, which is moderate for pines. However, percentage polymorphic loci was low, 30.3%. The fixation index (F) of 0.081 indicated only slight heterozygote deficiency. Mating system analysis indicated a significant but low level of selling; the multilocus outcrossing rate, tm , was 0.816. The mean of single locus estimates, ts , was smaller (0.761), perhaps suggesting mating among relatives, although the difference between tm and ts was not statistically significant. The most striking features of maxipiñon's genetic structure were that no polymorphic locus had more than two alleles and most alleles at polymorphic loci were at intermediate frequencies. This is in contrast to other pines, which often have three to five or more alleles at some loci and in which the distribution of allele frequencies is U-shaped, most alleles being present at frequencies less than 10% or greater than 90%. A population with only two alleles per locus and at intermediate frequencies could occur if the population had been reduced to an extreme bottleneck and then expanded rapidly before random drift modified allele frequencies. A novel origin from a hybridization event would also explain the results. Significant gametic disequilibrium was detected at several pairs of loci in both maternal and paternal gametes. The presence of disequilibrium is in agreement with an origin from an extreme bottleneck, perhaps even a single seed. Furthermore, it demands that the event be relatively recent. The number of generations, as calculated from the observed mean disequilibrium, suggested that maxipiñon derived from an extreme bottleneck four to five generations ago, which is less than 1000 years in this species.