Green deserts, but not always: A global synthesis of native woody species regeneration under tropical tree monocultures.

Tree monocultures constitute an increasing fraction of the global tree cover and are the dominant tree-growing strategy of forest landscape restoration commitments. Their advantages to produce timber are well known, but their value for biodiversity is highly controversial and context dependent. Therefore, understanding whether, and in which conditions, they can harbor native species regeneration is crucial. Here, we conducted meta-analyses based on a global survey of the literature and on a database created with local, unpublished studies throughout Brazil to evaluate the regeneration potential of native species under tree monocultures and the way management influences this regeneration. Native woody species regeneration under tree monocultures harbors a substantial fraction of the diversity (on average 40% and 68% in the global and Brazilian surveys, respectively) and abundance (on average 25% and 60% in the global and Brazilian surveys, respectively) of regeneration observed in natural forests. Plantations with longer rotation lengths, composed of native tree species, and located adjacent to forest remnants harbor more species. Pine plantations harbor more native individuals than eucalypt plantations, and the abundance of regenerating trees is higher in sites with higher mean temperatures. Species-area curves revealed that the number of woody species under pine and eucalypt plantations in Brazil is 606 and 598 species, respectively, over an aggregated sampled area of ca. 12 ha. We highlight that the understory of tree monocultures can harbor a considerable diversity of regenerating native species at the landscape and regional scales, but this diversity strongly depends on management. Long-rotation length and favorable location are key factors for woody regeneration success under tropical tree monocultures. Therefore, tree monocultures can play a role in forest landscape restoration and conservation, but only if they are planned and managed for achieving this purpose.

Species traits related to the invasion of woody plants in Patagonian deciduous forests.

The comparison of ecological, phenological, morphological and developmental traits between exotic invasive species and coexisting native species contributes to understand the driving mechanisms of successful invasions. This study aimed to examine which of these traits are related to the invasion of woody plants in the understory of deciduous North Patagonian forests of Argentina. We compared the phenology, shoot growth rate, number of leaves, biomass allocation, leaf herbivory, and recruitment type of two exotic deciduous trees, Crataegus monogyna and Sorbus aucuparia, with those of four coexisting native woody species (one deciduous, one semi-deciduous, and two evergreen species). Spring shoot growth took place several weeks earlier in both exotic species and in the deciduous native species than in the other native species; growth rates were higher in the exotics. Compared to coexisting native species, both exotic species developed shoots that were as long as or longer, had lower biomass allocation to leaves and higher allocation to roots, suffered lower leaf damage by herbivores and exhibited higher seed than vegetative recruitment. This study supports the idea that a combination of phenological, growth rate and mass allocation traits allow exotic species to preempt resources, thus favouring invasion processes.

Shading by giant kelp canopy can restrict the invasiveness of Undaria pinnatifida (Laminariales, Phaeophyceae).

The spread of non-indigenous and invasive seaweeds has increased worldwide, and their potential effects on native seaweeds have raised concern. Undaria pinnatifida is considered among the most prolific non-indigenous species. This species has expanded rapidly in the Northeast Pacific, overlapping with native communities such as the iconic giant kelp forests (Macrocystis pyrifera). Canopy shading by giant kelp has been argued to be a limiting factor for the presence of U. pinnatifida in the understory, thus its invasiveness capacity. However, its physiological plasticity under light limitation remains unclear. In this work, we compared the physiology and growth of juvenile U. pinnatifida and M. pyrifera sporophytes transplanted to the understory of a giant kelp forest, to juveniles growing outside of the forest. Extreme low light availability compared to that outside (~0.2 and ~4.4 mol photon ⋅ m-2 ⋅ d-1 , respectively) likely caused a "metabolic energy crisis" in U. pinnatifida, thus restricting its photoacclimation plasticity and nitrogen acquisition, ultimately reducing its growth. Despite M. pyrifera juveniles showing photoacclimatory responses (e.g., increases in photosynthetic efficiency and lower compensation irradiance, Ec ), their physiological/vegetative status deteriorated similarly to U. pinnatifida, which explains the low recruitment inside the forest. Generally, our results revealed the ecophysiological basis behind the limited growth and survival of juvenile U. pinnatifida sporophytes in the understory.

Novelties from the herbaceous stratum in a key region for the conservation of the Southern Amazon / Novidades do estrato herbáceo em uma região chave para a conservação da Amazônia Meridional

Abstract The contribution of the herbaceous stratum to tropical plant diversity is considerable, however this component remains undersampled. We investigated floristic, structural, ecological and conservation issues concerning the herbaceous component of a seasonal deciduous forest associated with granitic rock outcrops in the Cristalino Region, a key area for biodiversity conservation in the Brazilian Amazon. We installed a permanent plot of 1 ha, allocating 10 transect-lines of 20 m each. We identified the sampled individuals, measured height and projection, and verified cover and frequency per species, genera and family. We recorded 86 species, 62 genera and 25 families, with Orchidaceae being the family with the highest species richness. Among the 26 new species added to Cristalino Flora, we included Philodendron deflexum Poepp. ex Schott and Griffinia nocturna Ravenna, the latter 'Critically Endangered'. Furthermore, the occurrence of G. nocturna in an Amazonian forest matrix is a novelty in this study. The estimate of species diversity according to Shannon-Wiener (H') was 2.43 nats.ind.-1 (equivalent to 11.37 ± 0.90 IC95% equally common species), and according to Simpson (1/D), 6.82 (± 0.648 IC95%). The rarefaction and extrapolation curves for the diversity estimates tended to stabilize. Although the vegetation on rock outcrops usually presents a high number of endemic species, this pattern was not found in our study area, which can be explained by its continuous occurrence in the forest matrix. The understory of our study area consists in a mixture of floras, being composed mainly of species from the Amazon and/or Cerrado biomes. In view of the current anthropic pressure faced by the southern Amazon, we reinforce the importance of carrying out inventories of its herbaceous communities, since the risk of species loss is even more alarming when considering present undersampling of this component.

Resumo A contribuição do estrato herbáceo para a diversidade de plantas tropicais é considerável, mas esse componente permanece subamostrado. Investigamos questões florísticas, estruturais, ecológicas e de conservação relacionadas ao componente herbáceo de uma floresta estacional decidual associada a afloramentos rochosos graníticos na região do Cristalino, que é uma área chave para a conservação da biodiversidade na Amazônia brasileira. Instalamos um plot permanente de 1 ha, alocando 10 linhas de 20 m cada. Identificamos os indivíduos amostrados, medimos altura e projeção e verificamos cobertura e frequência por espécie, gênero e família. Registramos 86 espécies, 62 gêneros e 25 famílias, sendo Orchidaceae a família com maior riqueza de espécies. Entre as 26 novas espécies adicionadas à Flora do Cristalino, incluímos Philodendron deflexum Poepp ex Schott e Griffinia nocturna Ravenna, esta última 'Criticamente Ameaçada'. Além disso, a ocorrência de G. nocturna em uma matriz florestal amazônica é uma novidade neste estudo. A estimativa da diversidade de espécies de acordo com Shannon-Wiener (H ') foi 2,43 nats / ind.-1 (equivalente a 11,37 ± 0,90 IC95% espécies igualmente comuns), e de acordo com Simpson (1/D), 6,82 (± 0,648 IC95%). As curvas de rarefação e extrapolação para as estimativas de diversidade tenderam à estabilização. Embora a vegetação associada a afloramentos rochosos em geral apresente um elevado número de espécies endêmicas, esse padrão não foi encontrado para a nossa área de estudo, o que pode ser explicado pela sua ocorrência contínua à matriz florestal. O sub-bosque da nossa área de estudo apresenta mistura de floras, sendo composto principalmente por espécies dos biomas Amazônia e/ou Cerrado. Diante das pressões antrópicas existentes no sul da Amazônia, reforçamos a importância da realização de inventários das comunidades herbáceas desse bioma, já que o risco de perda de espécies é ainda mais alarmante quando consideramos a subamostragem desse componente.

Monitoring the understory in eucalyptus plantations using airborne laser scanning

In eucalyptus plantations, the presence of understory increases the risk of fires, acts as an obstacle to forest operations, and leads to yield losses due to competition. The objective of this study was to develop an approach to discriminate the presence or absence of understory in eucalyptus plantations based on airborne laser scanning surveys. The bimodal canopy height profile was modeled by two Weibull density functions: one to model the canopy, and other to model the understory. The parameters used as predictor in the logistic model successfully discriminated the presence or absence of understory. The logistic model composed by ℽ canopy, ℽ understory, and ℽ understory showed higher values of accuracy (0.96) and kappa (0.92), which means an adequate classification of presence of understory and absence of understory. Weibull parameters could be used as input in the logistic regression to effectively identify the presence and absence of understory in eucalyptus plantation.(AU)

Birds associated with treefall gaps in a lowland forest in southwestern Brazilian Amazonia / Aves associadas a clareiras naturais em uma floresta de terras baixas no sudoeste da Amazônia brasileira

Natural communities are dynamic systems in time and space. The spatial distribution of plants and animals tends to coincide with the availability of resources needed for the survival and reproduction of each species. Natural treefall gaps offer a number of resources that influence the distribution of birds within the forest. We compared the understory bird assemblages of natural treefall gaps (15 sampling points) with those found in the adjacent forest (15 points) in the Humaitá Forest Reserve in southwestern Brazilian Amazonia. We used mist-nets to sample birds and obtained 700 captures of 105 species. Species richness, number of individuals, and species composition were all similar between gaps and forest, although six species presented some degree of association with the gaps, and nine with the forest. Nectarivores preferred gaps significantly over forest, whereas insectivores and frugivores were distributed equally between gaps and forest. Vegetation height and density differed between gaps and forest, and influenced the distribution of bird species in the two environments. Fruit availability was positively correlated with frugivore abundance in gaps. Overall, 33.3% of the birds associated with the treefall gaps are from lower forest canopy, while the others are understory species. We showed that the use of natural gaps by birds in a fragmented landscape of the Amazon forest contributes to the environmental heterogeneity and succession dynamics following natural events of habitat disturbance.(AU)

As comunidades naturais são sistemas dinâmicos no tempo e no espaço. A distribuição espacial de plantas e animais coincide com a disponibilidade dos recursos necessários para a sobrevivência e reprodução de cada espécie. Clareiras naturais oferecem vários recursos que influenciam a distribuição de aves na floresta. Comparamos a assembleia de aves de sub-bosque de clareiras naturais (15 clareiras) com a encontrada na floresta adjacente (15 pontos) na Reserva Florestal Humaitá, no sudoeste da Amazônia brasileira. Amostramos aves com redes de neblina e contabilizamos 700 capturas de 105 espécies. A riqueza de espécies, o número de indivíduos e a composição de espécies foram semelhantes entre clareiras e floresta, mas seis espécies foram mais associadas com as clareiras e nove com a floresta. Os nectarívoros preferiram significativamente clareiras à floresta, enquanto os insetívoros e frugívoros se distribuíram igualmente entre clareiras e floresta. A altura e a densidade da vegetação variaram significativamente entre clareiras e floresta e influenciaram a distribuição das espécies nos dois ambientes. A disponibilidade de frutos foi correlacionada positivamente com a abundância de frugívoros nas clareiras. Em geral, 33,3% das aves associadas às clareiras são espécies de sub-dossel e as demais de sub-bosque. Mostramos que o uso de clareiras pelas aves em uma paisagem fragmentada da Amazônia contribui para a heterogeneidade ambiental e a dinâmica de sucessão após eventos naturais de perturbação do habitat.(AU)

Monitoring the understory in eucalyptus plantations using airborne laser scanning

In eucalyptus plantations, the presence of understory increases the risk of fires, acts as an obstacle to forest operations, and leads to yield losses due to competition. The objective of this study was to develop an approach to discriminate the presence or absence of understory in eucalyptus plantations based on airborne laser scanning surveys. The bimodal canopy height profile was modeled by two Weibull density functions: one to model the canopy, and other to model the understory. The parameters used as predictor in the logistic model successfully discriminated the presence or absence of understory. The logistic model composed by ℽ canopy, ℽ understory, and ℽ understory showed higher values of accuracy (0.96) and kappa (0.92), which means an adequate classification of presence of understory and absence of understory. Weibull parameters could be used as input in the logistic regression to effectively identify the presence and absence of understory in eucalyptus plantation.

Diversity and vertical distribution of psocids (Psocodea: Psocoptera) in two forests of the Colombian Amazon / Diversidad y distribución vertical de psócidos (Psocodea: Psocoptera) en dos bosques de la Amazonía colombiana

Introduction: The knowledge on the diversity of psocids in Colombia has increased, following the global trend, but the main interest of most of the studies has been oriented to solve taxonomic aspects, leaving aside other biological aspects, of which little is known, such as the ecological interactions of these organisms in tropical forests. Objective: To describe the psocid diversity in two Colombian Amazonian localities and provide the first data on their vertical distribution in tropical forests. Methods: Monthly samplings of Psocoptera were conducted during new moon periods, from July 2014 to May 2015. Surveys were carried out in two localities of the Putumayo department, Colombia (Puerto Asís and Mocoa), using LED light traps. Results: During the sampling period, 152 species, in 23 genera and nine families were collected. The richest family was Psocidae, followed by Epipsocidae and Lachesillidae. More than 80 % of the species found are still undescribed, and among the described ones, nine represent new records for Colombia, and are shared with neighboring countries in the Amazon basin. Fourteen (9.2 %) species are shared by the two localities surveyed. Puerto Asís is considerably richer than Mocoa. Vertical stratification of Psocoptera was found in both localities, with the canopy being the most species rich stratum. Conclusion: The relatively high diversity of psocidos found, as well as the high number of new species, is an indicator of the need to continue the exploration of these organisms in the rest of the Colombian territory and Andean countries, especially in the Amazon foothills. Stratification of the studied psocoptera community was evident, with the canopy stratum being the richest in species, a trend that continues throughout the year.

Introducción: El conocimiento que se tiene acerca de la diversidad de psócidos en Colombia ha ido en aumento, siguiendo la tendencia mundial, pero el interés principal de la mayoría de estudios se ha centrado en la resolución de aspectos taxonómicos dejando de lado otros aspectos de su biología tales como las interacciones ecológicas de estos organismos en bosques tropicales. Objetivo: Describir la diversidad de psócidos en dos localidades de la Amazonía colombiana y proporcionar los primeros datos sobre su distribución vertical en bosques tropicales. Métodos: Se realizaron muestreos mensuales de psócidos durante los periodos de luna nueva entre julio 2014 y mayo 2015, en dos localidades del departamento de Putumayo, Colombia, utilizando trampas de luz LED. Resultados: Durante el periodo de muestreo, se recolectaron 152 especies, 23 géneros y nueve familias. La familia más rica en especies fue Psocidae, seguida por Epipsocidae y Lachesillidae. Más del 80 % de las especies encontradas no están descritas y entre las descritas, nueve representan nuevos registros para Colombia y son compartidas con países vecinos de la cuenca del Amazonas. Catorce especies (9.2 %) son compartidas por las dos localidades de este estudio; Puerto Asís presentó mayores valores de diversidad que Mocoa. En ambas localidades se encontró una estratificación en la distribución vertical de Psocoptera, siendo el dosel el estrato más rico en especies. Conclusión: La relativamente alta diversidad de psócidos encontrada, así como el alto número de especies nuevas, es un indicador de la necesidad de continuar las exploraciones de estos organismos en el resto del territorio colombiano y países andinos, especialmente en el piedemonte amazónico. Fue evidente una estratificación de la comunidad de psocópteros estudiada, siendo el estrato dosel el más rico en especies, una tendencia que se mantiene a lo largo del año.

Thinning Partially Mitigates the Impact of Atlantic Forest Replacement by Pine Monocultures on the Soil Microbiome.

Forest replacement by exotic plantations drive important changes at the level of the overstory, understory and forest floor. In the Atlantic Forest of northern Argentina, large areas have been replaced by loblolly pine (Pinus taeda L.) monocultures. Plant and litter transformation, together with harvesting operations, change microclimatic conditions and edaphic properties. Management practices such as thinning promote the development of native understory vegetation and could counterbalance negative effects of forest replacement on soil. Here, the effects of pine plantations and thinning on physical, chemical and microbiological soil properties were assessed. Bacterial, archaeal, and fungal community structure were analyzed using a metabarcoding approach targeting ribosomal markers. Forest replacement and, to a lesser extent, thinning practices in the pine plantations induced significant changes in soil physico-chemical properties and associated shifts in bacterial and fungal communities. Most measured physical and chemical properties were altered due to forest replacement, but a few of these properties reached values similar to natural forests under the thinning operation. Fungal alpha diversity decreased in pine plantations, whereas bacterial alpha diversity tended to increase but with little statistical support. Shifts in community composition were observed for both fungal and bacterial domains, and were mostly related to changes in plant understory composition, soil carbon, organic matter, water content, pH and bulk density. Among several other changes, highly abundant phyla such as Proteobacteria (driven by many genera) and Mortierellomycota (mainly driven by Mortierella) decreased in relative abundance in the plantations, whereas Acidobacteria (mainly driven by Acidothermus and Candidatus Koribacter) and Basidiomycota (mainly driven by the ectomycorrhiza Russula) showed the opposite response. Taken together, these results provide insights into the effects of forest replacement on belowground properties and elucidate the potentially beneficial effect of thinning practices in intensive plantation systems through promoting the understory development. Although thinning did not entirely counterbalance the effects of forest replacement on physical, chemical and biological soil properties, the strategy helped mitigating the effects and might promote resilience of these properties by the end of the rotation cycle, if subsequent management practices compatible with the development of a native understory vegetation are applied.

Richness of Chrysomelidae (Coleoptera) depends on the area and habitat structure in semideciduous forest remnants

The total area of a habitat patch can increase the local species richness both directly (through balance between immigration and extinction) and indirectly (by increasing the habitat heterogeneity and/or as an effect of sample effort). More heterogeneous environments present a wider variety of resources and conditions, allowing species to coexist through niche differentiation. This study shows that the diversity of Chrysomelidae depends on the area and habitat structure of semideciduous forest remnants. We sampled 16 remnants with Malaise traps in August 2012 to March 2013. In order to characterize the habitat, the area, structural heterogeneity of the understory, coverage and canopy height were measured. These variables were used in a path analysis to determine their direct and indirect effects on leaf beetle diversity. A total of 450 specimens from 99 species and five subfamilies were captured. The total area and the understory heterogeneity presented a positive effect on species richness, while canopy cover exerted a negative one. The canopy height only had a negative and indirect effect on leaf beetle richness. In such fragments with more area and more open spaces, plant abundance and richness tend to be higher and favor the coexistence of many Chrysomelidae species.(AU)

A área de uma mancha de habitat pode aumentar a riqueza local de espécies tanto diretamente (pelo balanço entre imigração e extinção) quanto indiretamente (por aumentar a heterogeneidade do habitat e/ou como efeito do esforço amostral). Ambientes mais heterogêneos apresentam maior variedade de recursos e condições permitindo a coexistência de espécies por diferenciação de nicho. Neste estudo mostramos que a riqueza de Chrysomelidae depende da área e da estrutura do habitat em remanescentes de floresta semidecidual. Realizamos amostragens com armadilhas Malaise em 16 remanescentes florestais entre agosto de 2012 e março de 2013. Para caracterizar o habitat, medimos a área, a heterogeneidade estrutural do sub-bosque, a cobertura e a altura do dossel. Estas variáveis foram utilizadas em uma análise de caminhos para determinar seus efeitos diretos e indiretos na riqueza de crisomelídeos. Capturamos 450 espécimes de 99 espécies e cinco subfamílias. A área total e a heterogeneidade do sub-bosque apresentaram um efeito positivo sobre a riqueza de espécies, enquanto a cobertura do dossel exerceu efeito direto negativo. A altura do dossel apresentou apenas efeito indireto e negativo sobre a riqueza de crisomelídeos. Em fragmentos com maior área e mais espaços abertos, provavelmente a abundância e a riqueza de plantas tendem a serem maiores, favorecendo a coexistência de muitas espécies de Chrysomelidae.(AU)

Richness of Chrysomelidae (Coleoptera) depends on the area and habitat structure in semideciduous forest remnants

The total area of a habitat patch can increase the local species richness both directly (through balance between immigration and extinction) and indirectly (by increasing the habitat heterogeneity and/or as an effect of sample effort). More heterogeneous environments present a wider variety of resources and conditions, allowing species to coexist through niche differentiation. This study shows that the diversity of Chrysomelidae depends on the area and habitat structure of semideciduous forest remnants. We sampled 16 remnants with Malaise traps in August 2012 to March 2013. In order to characterize the habitat, the area, structural heterogeneity of the understory, coverage and canopy height were measured. These variables were used in a path analysis to determine their direct and indirect effects on leaf beetle diversity. A total of 450 specimens from 99 species and five subfamilies were captured. The total area and the understory heterogeneity presented a positive effect on species richness, while canopy cover exerted a negative one. The canopy height only had a negative and indirect effect on leaf beetle richness. In such fragments with more area and more open spaces, plant abundance and richness tend to be higher and favor the coexistence of many Chrysomelidae species.

A área de uma mancha de habitat pode aumentar a riqueza local de espécies tanto diretamente (pelo balanço entre imigração e extinção) quanto indiretamente (por aumentar a heterogeneidade do habitat e/ou como efeito do esforço amostral). Ambientes mais heterogêneos apresentam maior variedade de recursos e condições permitindo a coexistência de espécies por diferenciação de nicho. Neste estudo mostramos que a riqueza de Chrysomelidae depende da área e da estrutura do habitat em remanescentes de floresta semidecidual. Realizamos amostragens com armadilhas Malaise em 16 remanescentes florestais entre agosto de 2012 e março de 2013. Para caracterizar o habitat, medimos a área, a heterogeneidade estrutural do sub-bosque, a cobertura e a altura do dossel. Estas variáveis foram utilizadas em uma análise de caminhos para determinar seus efeitos diretos e indiretos na riqueza de crisomelídeos. Capturamos 450 espécimes de 99 espécies e cinco subfamílias. A área total e a heterogeneidade do sub-bosque apresentaram um efeito positivo sobre a riqueza de espécies, enquanto a cobertura do dossel exerceu efeito direto negativo. A altura do dossel apresentou apenas efeito indireto e negativo sobre a riqueza de crisomelídeos. Em fragmentos com maior área e mais espaços abertos, provavelmente a abundância e a riqueza de plantas tendem a serem maiores, favorecendo a coexistência de muitas espécies de Chrysomelidae.

Richness of Chrysomelidae (Coleoptera) depends on the area and habitat structure in semideciduous forest remnants

ABSTRACT The total area of a habitat patch can increase the local species richness both directly (through balance between immigration and extinction) and indirectly (by increasing the habitat heterogeneity and/or as an effect of sample effort). More heterogeneous environments present a wider variety of resources and conditions, allowing species to coexist through niche differentiation. This study shows that the diversity of Chrysomelidae depends on the area and habitat structure of semideciduous forest remnants. We sampled 16 remnants with Malaise traps in August 2012 to March 2013. In order to characterize the habitat, the area, structural heterogeneity of the understory, coverage and canopy height were measured. These variables were used in a path analysis to determine their direct and indirect effects on leaf beetle diversity. A total of 450 specimens from 99 species and five subfamilies were captured. The total area and the understory heterogeneity presented a positive effect on species richness, while canopy cover exerted a negative one. The canopy height only had a negative and indirect effect on leaf beetle richness. In such fragments with more area and more open spaces, plant abundance and richness tend to be higher and favor the coexistence of many Chrysomelidae species.

RESUMO A área de uma mancha de habitat pode aumentar a riqueza local de espécies tanto diretamente (pelo balanço entre imigração e extinção) quanto indiretamente (por aumentar a heterogeneidade do habitat e/ou como efeito do esforço amostral). Ambientes mais heterogêneos apresentam maior variedade de recursos e condições permitindo a coexistência de espécies por diferenciação de nicho. Neste estudo mostramos que a riqueza de Chrysomelidae depende da área e da estrutura do habitat em remanescentes de floresta semidecidual. Realizamos amostragens com armadilhas Malaise em 16 remanescentes florestais entre agosto de 2012 e março de 2013. Para caracterizar o habitat, medimos a área, a heterogeneidade estrutural do sub-bosque, a cobertura e a altura do dossel. Estas variáveis foram utilizadas em uma análise de caminhos para determinar seus efeitos diretos e indiretos na riqueza de crisomelídeos. Capturamos 450 espécimes de 99 espécies e cinco subfamílias. A área total e a heterogeneidade do sub-bosque apresentaram um efeito positivo sobre a riqueza de espécies, enquanto a cobertura do dossel exerceu efeito direto negativo. A altura do dossel apresentou apenas efeito indireto e negativo sobre a riqueza de crisomelídeos. Em fragmentos com maior área e mais espaços abertos, provavelmente a abundância e a riqueza de plantas tendem a serem maiores, favorecendo a coexistência de muitas espécies de Chrysomelidae.

Understory bird community from Wildlife Protected Areas of the Quedas do Rio Bonito Ecological Park / Comunidade de aves de sub-bosque do Parque Ecológico Quedas do Rio Bonito

The bird diversity is threatened and many studies have focused on preservation and conservation efforts. For example, few public Wildlife Protected Areas are created, which increase the requirement for private initiatives to support the conservation challenge. The Quedas do Rio Bonito Ecological Park is a private protected areas located in the south of Minas Gerais, Brazil. Here, we present the median richness (54 bird species, 20 families and seven orders) of this protected area in relation to other studies in southeastern Brazil, as well as seasonal variations, similarities between areas and the estimation of understory stratum richness. Therefore, this article presents arguments to support future studies, since knowledge about the community in different areas is primordial to Biological Conservation projects.(AU)

A diversidade de aves está ameaçada e muitos estudos têm se concentrado em esforços de preservação e conservação. No entanto, poucas áreas protegidas públicas de vida selvagem são criadas, o que aumenta a necessidade de iniciativas privadas para apoiar o desafio da conservação. O Parque Ecológico Quedas do Rio Bonito é uma dessas áreas privadas protegidas localizada no sul de Minas Gerais, Brasil. Aqui, apresentamos a riqueza mediana (54 espécies, 20 famílias alocadas em sete ordens) desta área protegida em relação a outros estudos no sudeste do Brasil, bem como foram observadas variações sazonais, semelhanças entre áreas e a estimativa de riqueza do estrato do subbosque. Portanto, este artigo apresenta argumentos para auxiliar futuros estudos, uma vez que o conhecimento sobre a comunidade em diferentes áreas é primordial para projetos de Conservação Biológica.(AU)

Understory bird community from Wildlife Protected Areas of the Quedas do Rio Bonito Ecological Park / Comunidade de aves de sub-bosque do Parque Ecológico Quedas do Rio Bonito

The bird diversity is threatened and many studies have focused on preservation and conservation efforts. For example, few public Wildlife Protected Areas are created, which increase the requirement for private initiatives to support the conservation challenge. The Quedas do Rio Bonito Ecological Park is a private protected areas located in the south of Minas Gerais, Brazil. Here, we present the median richness (54 bird species, 20 families and seven orders) of this protected area in relation to other studies in southeastern Brazil, as well as seasonal variations, similarities between areas and the estimation of understory stratum richness. Therefore, this article presents arguments to support future studies, since knowledge about the community in different areas is primordial to Biological Conservation projects.

A diversidade de aves está ameaçada e muitos estudos têm se concentrado em esforços de preservação e conservação. No entanto, poucas áreas protegidas públicas de vida selvagem são criadas, o que aumenta a necessidade de iniciativas privadas para apoiar o desafio da conservação. O Parque Ecológico Quedas do Rio Bonito é uma dessas áreas privadas protegidas localizada no sul de Minas Gerais, Brasil. Aqui, apresentamos a riqueza mediana (54 espécies, 20 famílias alocadas em sete ordens) desta área protegida em relação a outros estudos no sudeste do Brasil, bem como foram observadas variações sazonais, semelhanças entre áreas e a estimativa de riqueza do estrato do subbosque. Portanto, este artigo apresenta argumentos para auxiliar futuros estudos, uma vez que o conhecimento sobre a comunidade em diferentes áreas é primordial para projetos de Conservação Biológica.

Targeted habitat restoration can reduce extinction rates in fragmented forests.

The Eastern Arc Mountains of Tanzania and the Atlantic Forest of Brazil are two of the most fragmented biodiversity hotspots. Species-area relationships predict that their habitat fragments will experience a substantial loss of species. Most of these extinctions will occur over an extended time, and therefore, reconnecting fragments could prevent species losses and allow locally extinct species to recolonize former habitats. An empirical relaxation half-life vs. area relationship for tropical bird communities estimates the time that it takes to lose one-half of all species that will be eventually lost. We use it to estimate the increase in species persistence by regenerating a forest connection 1 km in width among the largest and closest fragments at 11 locations. In the Eastern Arc Mountains, regenerating 8,134 ha of forest would create >316,000 ha in total of restored contiguous forest. More importantly, it would increase the persistence time for species by a factor of 6.8 per location or ∼2,272 years, on average, relative to individual fragments. In the Atlantic Forest, regenerating 6,452 ha of forest would create >251,000 ha in total of restored contiguous forest and enhance species persistence by a factor of 13.0 per location or ∼5,102 years, on average, relative to individual fragments. Rapidly regenerating forest among fragments is important, because mean time to the first determined extinction across all fragments is 7 years. We estimate the cost of forest regeneration at $21-$49 million dollars. It could provide one of the highest returns on investment for biodiversity conservation worldwide.

Carbon allocation to growth and storage in two evergreen species of contrasting successional status.

PREMISE OF THE STUDY: A prevailing hypothesis in forest succession is that shade-tolerant species grow more slowly than shade-intolerant species, across light conditions, because they prioritize carbon (C) allocation to storage. We examined this hypothesis in a confamilial pair of species, including one of the fastest-growing tree species in the world (Eucalyptus globulus) and a shade-tolerant, slow-growing species (Luma apiculata). METHODS: Seedlings were subjected to one out of four combinations of light (high vs. low) and initial defoliation (90% defoliated vs. nondefoliated) for four months. Growth, C storage concentration in different organs, leaf shedding, and lateral shoot formation were measured at the end of the experiment. KEY RESULTS: Eucalyptus globulus grew faster than L. apiculata in high light, but not in low light. Both species had lower C storage concentration in low than in high light, but similar C storage concentrations in each light condition. Defoliation had no effect on C storage, except in the case of the old leaves of both species, which showed lower C storage levels in response to defoliation. Across treatments, leaf shedding was 96% higher in E. globulus than in L. apiculata while, in contrast, lateral shoot formation was 87% higher in L. apiculata. CONCLUSIONS: In low light, E. globulus prioritized C storage instead of growth, whereas L. apiculata prioritized growth and lateral branching. Our results suggest that shade tolerance depends on efficient light capture rather than C conservation traits.

Convergence in relationships between leaf traits, spectra and age across diverse canopy environments and two contrasting tropical forests.

Leaf age structures the phenology and development of plants, as well as the evolution of leaf traits over life histories. However, a general method for efficiently estimating leaf age across forests and canopy environments is lacking. Here, we explored the potential for a statistical model, previously developed for Peruvian sunlit leaves, to consistently predict leaf ages from leaf reflectance spectra across two contrasting forests in Peru and Brazil and across diverse canopy environments. The model performed well for independent Brazilian sunlit and shade canopy leaves (R2  = 0.75-0.78), suggesting that canopy leaves (and their associated spectra) follow constrained developmental trajectories even in contrasting forests. The model did not perform as well for mid-canopy and understory leaves (R2  = 0.27-0.29), because leaves in different environments have distinct traits and trait developmental trajectories. When we accounted for distinct environment-trait linkages - either by explicitly including traits and environments in the model, or, even better, by re-parameterizing the spectra-only model to implicitly capture distinct trait-trajectories in different environments - we achieved a more general model that well-predicted leaf age across forests and environments (R2  = 0.79). Fundamental rules, linked to leaf environments, constrain the development of leaf traits and allow for general prediction of leaf age from spectra across species, sites and canopy environments.

Effect of a major highway on the spatial and temporal variation in the structure and diversity of the avifauna of a tropical premontane rain forest / Efecto de una carretera principal en la variación espacial y temporal en la estructura y la diversidad de la avifauna de un bosque lluvioso tropical premontano

Abstract:Roads immersed in conservation areas will increase in number, size, and traffic over the next decade, and thus, understanding their effects on forest-dependent wildlife is crucial for improving current management practices and reducing the negative impacts of roads on sensitive species. We examined the influence of route 32 (a.k.a. Guápiles Highway) on temporal and spatial changes in the structure of the avifauna of Braulio Carrillo National Park, Costa Rica, a site crossed by this road along 25 km. The highway connects the capital city of San José with the Harbor of Limón in the Caribbean Sea (142 km). Although the road is narrow (12 m in width and comprised by two lanes along most of the route) it services over 1.5 million motor vehicles per year, 12 % are heavy trucks and trailers. We expected the highway to divide the avifauna, and thus to observe significant differences in species structure on opposite sides of the road. We described changes in bird diversity between wet and dry seasons at Las Palmas and Ceibo trails located on opposite sides of the highway (14 point counts per trail), and evaluated how abundance and diversity varied with road distance. Censuses took place during wet and dry seasons from 2002 to 2005. We listed 245 species and 6 035 observations during the 4-yr survey. Rare species dominated the avifauna (65 % of species < 5 observations), and species overlap between trails was high (Sorensen= 71 %; Morisita= 0.96). Species accumulation curves varied little among trails, yielding 190 species. Resident species represented 70 % of observations, followed by elevational (15 %) and long-distance migrants (1-2 %). Understory species were the most abundant (60 %) followed by canopy birds (30 %). Species turnover rate was 55 % between seasons, but species composition between trails remained homogeneous. Overall, birds were avoiding the road (abundance increased away from the road) although other diversity parameters (richness, dominance, Shannon index, and equitability) were not influenced by road proximity. Although the avifauna remained homogeneous on both sides of the road, which did not support the fragmentation hypothesis, the highway reduced the abundance and diversity of specialized understory insectivores associated with primary forests near the road. This highway will expand outside the National Park (from 2 to 4 lanes along 107 km from Río Frío to Limón) in the next years, which will increase traffic volume and road impacts within the Park. Roads are increasing across highly diverse tropical areas justifying the need for management practices based on the identification of sensitive groups. Rev. Biol. Trop. 64 (4): 1383-1399. Epub 2016 December 01.

Resumen:Las carreteras inmersas en áreas de conservación van a aumentar en número, tamaño, y volumen de tráfico en la próxima década, por lo que comprender los efectos de las mismas sobre la fauna dependiente de bosque es crucial para mejorar las prácticas de manejo y reducir los impactos negativos de los caminos sobre las especies más frágiles. Examinamos la influencia de la ruta 32 (conocida como la carretera a Guápiles) sobre los cambios temporales y espaciales en la estructura de la avifauna del Parque Nacional Braulio Carrillo, Costa Rica, el cual es atravesado por esta carretera a lo largo de 25 km. La carretera conecta la ciudad capital de San José con el puerto de Limón en el Caribe (142 km). Aunque la calle es estrecha (12 m de ancho en dos carriles en la mayor parte de la ruta) da servicio a más de 1.5 millones de vehículos por año, 12 % de los cuales es transporte pesado. Esperábamos que la carretera fragmentara a la avifauna, y por lo tanto que hubieran diferencias significativas en la estructura de las especies en lados opuestos de la ruta. Describimos los cambios en la diversidad de aves entre las estaciones secas y húmedas en los senderos Las Palmas y Ceibo situados en lados opuestos de la carretera (14 puntos de conteo por sendero), y evaluamos cómo la abundancia y la diversidad variaron con la distancia hacia la carretera. Los censos se realizaron durante las estaciones húmedas y secas desde el 2002 al 2005. Encontramos 245 especies y 6 035 observaciones durante el período de 4 años. Las especies raras dominaron la avifauna (65 % de las especies < 5 observaciones), y mostraron un alto traslape entre senderos (Sorensen= 71 %; Morisita= 0.96). Las curvas de acumulación de especies variaron poco entre senderos, generando 190 especies. Las especies residentes representaron el 70 % de las observaciones, seguidas migrantes de elevación (15 %) y especies migratorias latitudinales (1-2 %). Las especies de sotobos que fueron las más abundantes (60 %), seguidas por las aves de dosel (30 %). La tasa de recambio de especies fue del 55 % entre estaciones, pero la composición de especies entre senderos permaneció homogénea. El patrón general consistió en que las aves evitaron la carretera (la abundancia aumentó lejos de la carretera), aunque otros parámetros de diversidad (riqueza, dominancia, el índice de Shannon y la equidad) no fueron influenciados por la proximidad de la calle. Si bien los resultados no apoyaron la hipótesis de la fragmentación, la carretera redujo la abundancia y diversidad de insectívoros especializados de sotobosque asociados a bosque primario. Esta carretera se expandirá fuera del Parque Nacional (de 2 a 4 carriles a lo largo de 107 km de Río Frío a Limón) en los próximos años, lo que aumentará el impacto del volumen de tráfico dentro del parque. Las carreteras cercanas a zonas protegidas están aumentando en los trópicos, por lo que es crucial desarrollar alternativas de manejo basadas en la respuesta de los grupos sensibles a estos impactos.

Targeted reforestation could reverse declines in connectivity for understory birds in a tropical habitat corridor.

Re-establishing connectivity between protected areas isolated by habitat clearing is a key conservation goal in the humid tropics. In northeastern Costa Rica, payments for environmental services (PES) and a government ban on deforestation have subsidized forest protection and reforestation in the San Juan-La Selva Biological Corridor (SJLSBC), resulting in a decline in mature forest loss and the expansion of tree plantations. We use field studies and graph models to assess how conservation efforts have altered functional connectivity over the last 25 years for four species of insectivorous understory birds. Field playback studies assessed how reforestation habitat quality affected the willingness of Myrmeciza exsul, Henicorhina leucosticta, Thamnophilus atrinucha, and Glyphorynchus spirurus to travel outside forest habitat for territorial defense. Observed travel distances were greatest in nonnative and native tree plantations with high understory stem density, regardless of overstory composition. In contrast, tree plantations with low stem density had travel responses comparable to open pasture for three of the four bird species. We modeled landscape connectivity for each species using graph models based on varying possible travel distances in tree plantations, gallery forests, and pastures. From 1986 to 2011, connectivity for all species declined in the SJLSBC landscape (5825 km2 ) by 14% to 21% despite only a 4.9% net loss in forest area and the rapid expansion of tree plantations over 2% of the landscape. Plantation placement in the landscape limited their potential facilitation of connectivity because they were located either far from forest cover or within already contiguous forest areas. We mapped current connectivity bottlenecks and identified priority areas for future reforestation. We estimate that reforestation of priority areas could improve connectivity by 2% with only a 1% gain in forest cover, an impressive gain given the small area reforested. Results indicate key locations where spatial targeting of PES within the SJLSBC study region would protect existing forest connectivity and enhance the connectivity benefits of reforestation.

Carbon dynamics of Acer pseudoplatanus seedlings under drought and complete darkness.

Carbon (C) storage is considered a key component to plant survival under drought and shade, although the combined effects of these factors on survival remain poorly understood. We investigated how drought and shade alter the C dynamics and survival of tree seedlings, and whether drought limits the access to or usage of stored C. We experimentally applied two levels of soil humidity (well-watered versus drought, the latter induced by dry-down) and light availability (light versus complete darkness) on 1-year-old seedlings of Acer pseudoplatanus L. for 3 months. We quantified the survival, biomass, growth rate and non-structural carbohydrates (NSC) of seedlings at their time of death or at the end of the experiment for those that survived. We found that the soil dried out faster when drought was combined with light than when it was combined with complete darkness. Seedlings subjected to both drought and light showed reduced growth and reached 100% mortality earlier than any other treatment, with the highest NSC concentrations at the time of death. Seedlings exposed to both drought and complete darkness died significantly earlier than seedlings exposed to complete darkness only, but had similar NSC concentrations at time of their death, suggesting that drought accelerated the use of stored C under complete darkness. Complete darkness significantly reduced seedling growth and whole-plant NSC concentrations regardless of soil humidity, while root NSC concentrations were significantly more reduced when complete darkness was combined with drought conditions. Thus, the C dynamics in A. pseudoplatanus seedlings under complete darkness was not hindered by drought, i.e., the access and use of stored C was not limited by drought. The contrasting growth and C storage responses driven by drought under light versus complete darkness are consistent with a key role of the drought progression in the C dynamics of trees.