Batrachochytrium dendrobatidis (Bd) has contributed to population declines and extinction of amphibians worldwide. Disease-caused extinction is rare, but may occur where reservoirs exist or where transmission is independent of host density. Because some species persist after Bd epizootic events, they may act as potential reservoirs of the infection. I studied seasonal and elevational patterns of prevalence and intensity of Bd infection in eight pond-breeding species that persisted after an epizootic event at three low- and three mid-elevation ponds in Central America. I visited each pond three times over the rainy season to sample for Bd and to quantify frog density. I recorded air and water temperature at each pond. I analyzed 1,288 samples and detected Bd in all six ponds and in six of the eight species. Elevation and time affected Bd prevalence (F2,7 = 8.90, p = 0.01) and Bd intensity (F2,8 = 9.09, p = 0.008). Frog density was not correlated with Bd prevalence (F1,7= 4.75, p= 0.06), and temperature did not affect prevalence or intensity of the infection. Bd is enzootic at all 6 sites and six pond-breeding species are reservoirs. The presence of abundant reservoirs at enzootic conditions explains the persistence of Bd in areas where other species declined without showing evidence of recovery. Low intensities of infection explain the survivorship of these reservoir species. I suggest that temperature might not be the principal factor molding Bd dynamics in the humid Neotropical forests, and present evidence that ponds are ecosystems where frogs might clean or reduce their infections

Global biodiversity protection requires the development of protected areas that include representative samples of different ecosystems and their associated biodiversity (Dudley 1992, Scott et al. 2001a). I compared long-term decline and protection of forests in three major biomes; boreal, temperate and tropical. I found that forests in the temperate biome are less abundant and less protected than forests in the boreal and tropical biomes. I conducted regional analyses for five continents on the degree of protection of temperate forests across naturally occurring geographic and elevational ranges. My results indicate that protected temperate forests do not represent the full geographic and elevational range of naturally occurring temperate forests. Bias in location, elevation and slope of protected areas are present at both the regional and global scale. Better protection of temperate forests is needed if the diversity and resources associated with these forests types across their geographic range is to be preserved.

Esta dissertação trata da distribuição das aves no gradiente altitudinal dos municípios de Bertioga e Salesópolis, na Serra do Mar do Estado de São Paulo, Brasil. Está separada em três capítulos distintos, os quais, apesar de relacionados, podem ser lidos independentemente. O primeiro capítulo, Uma revisão do conhecimento ornitológico na Estação Biológica de Boracéia, faz uma revisão inédita sobre todos os registros avifaunísticos realizados ao longo de 68 anos de inventários na localidade e apresenta a importância dessa Unidade de Conservação localizada em Mata Atlântica Montana para a conservação das aves do Bioma. Foram registradas 323 espécies, sendo 117 endêmicas e 28 ameaçadas de extinção, motivos pelos quais a Estação pode ser considerada uma área prioritária para a conservação de aves no Brasil. O segundo capítulo, Análise dos padrões altitudinais das aves de Mata Atlântica: a influência do mid-domain effect , traz uma revisão sobre todas as publicações já realizadas sobre a distribuição altitudinal das aves da Mata Atlântica, determina o padrão da curva espécies-altitude de cada estudo e testa as previsões do modelo nulo chamado mid-domain effect (MDE) nos conjuntos de dados por eles apresentados. Dos oito estudos encontrados foram descritos três padrões de distribuição altitudinal, sendo que a robustez das previsões do MDE não foi consistente para nenhum deles. Provavelmente outros fatores moldam a distribuição das aves, porém a falta de padronização dos estudos não permite esse tipo de investigação. Finalmente, o terceiro capítulo, Distribuição altitudinal das aves na Serra do Mar: efeitos da altitude, área e mid-domain effect , apresenta o padrão de distribuição altitudinal encontrado ao longo do gradiente Bertioga-Salesópolis, na Serra do Mar de São Paulo e introduz pela primeira vez o estudo de variáveis explanatórias para a distribuição altitudinal das aves na Mata Atlântica. São testadas três variáveis espaciais (altitude, área e MDE) que possam ser responsáveis pelo padrão de distribuição encontrado e os resultados, comparados com padrões já estudados em outras regiões do mundo. A variável que mais explicou a distribuição altitudinal encontrada foi a área e, apesar de diversos estudos considerarem esta variável como secundária na determinação das curvas espécie-altitude, no gradiente altitudinal aqui amostrado, ela mostrou-se importante. / This master thesis aims to investigate the bird diversity along the elevational gradient of the cities of Bertioga and Salesópolis in the Serra do Mar from the state of São Paulo, Brazil. It is divided into three distinct chapters that, although related, may be independently read. The first chapter, A review of the ornithological history of the Boracéia Biological Station, reviews for the first time every ornithological record of more than 68 years of birding in that location and shows the importance of this Montane Atlantic forest Conservation Unit for the preservation of birds from this biome. During 68 years, investigators recorded 323 species of which 117 are endemic and 28 are threatened. For these reasons the Station may be considered an Important Bird Area for the conservation of birds in Brazil. The second chapter, The elevational diversity of Atlantic forest birds: influence of the mid-domain effect, reviews all published studies on bird elevational distribution in the Brazilian Atlantic Forest, establishes the species-altitude curve of each study and tests their data sets for the mid-domain effect (MDE) null model predictions. I found eight investigations from which three distinct altitudinal patterns could be determined. The MDE predictions were not consistently robust for none of them and the investigation of candidate factors that drive the elevational diversity of birds is not possible due to the lack of standardized procedures. Finally, the third chapter, Elevational diversity of birds of the Serra do Mar: implications of altitude, area and the mid-domain effect, deals with the diversity of birds along the Bertioga-Salesópolis elevational gradient in the Serra do Mar and explores for the first time three candidate variables (altitude, area and MDE) driving the elevational diversity of birds in the Atlantic forest; I further compare my results with patterns found elsewhere in the world. Area was the best predictor of the bird elevational diversity and, although a few investigators claimed this variable as secondary in determining the species-altitude curve, here it proved worth analyzing.

Esta dissertação trata da distribuição das aves no gradiente altitudinal dos municípios de Bertioga e Salesópolis, na Serra do Mar do Estado de São Paulo, Brasil. Está separada em três capítulos distintos, os quais, apesar de relacionados, podem ser lidos independentemente. O primeiro capítulo, Uma revisão do conhecimento ornitológico na Estação Biológica de Boracéia, faz uma revisão inédita sobre todos os registros avifaunísticos realizados ao longo de 68 anos de inventários na localidade e apresenta a importância dessa Unidade de Conservação localizada em Mata Atlântica Montana para a conservação das aves do Bioma. Foram registradas 323 espécies, sendo 117 endêmicas e 28 ameaçadas de extinção, motivos pelos quais a Estação pode ser considerada uma área prioritária para a conservação de aves no Brasil. O segundo capítulo, Análise dos padrões altitudinais das aves de Mata Atlântica: a influência do mid-domain effect , traz uma revisão sobre todas as publicações já realizadas sobre a distribuição altitudinal das aves da Mata Atlântica, determina o padrão da curva espécies-altitude de cada estudo e testa as previsões do modelo nulo chamado mid-domain effect (MDE) nos conjuntos de dados por eles apresentados. Dos oito estudos encontrados foram descritos três padrões de distribuição altitudinal, sendo que a robustez das previsões do MDE não foi consistente para nenhum deles. Provavelmente outros fatores moldam a distribuição das aves, porém a falta de padronização dos estudos não permite esse tipo de investigação. Finalmente, o terceiro capítulo, Distribuição altitudinal das aves na Serra do Mar: efeitos da altitude, área e mid-domain effect , apresenta o padrão de distribuição altitudinal encontrado ao longo do gradiente Bertioga-Salesópolis, na Serra do Mar de São Paulo e introduz pela primeira vez o estudo de variáveis explanatórias para a distribuição altitudinal das aves na Mata Atlântica. São testadas três variáveis espaciais (altitude, área e MDE) que possam ser responsáveis pelo padrão de distribuição encontrado e os resultados, comparados com padrões já estudados em outras regiões do mundo. A variável que mais explicou a distribuição altitudinal encontrada foi a área e, apesar de diversos estudos considerarem esta variável como secundária na determinação das curvas espécie-altitude, no gradiente altitudinal aqui amostrado, ela mostrou-se importante. / This master thesis aims to investigate the bird diversity along the elevational gradient of the cities of Bertioga and Salesópolis in the Serra do Mar from the state of São Paulo, Brazil. It is divided into three distinct chapters that, although related, may be independently read. The first chapter, A review of the ornithological history of the Boracéia Biological Station, reviews for the first time every ornithological record of more than 68 years of birding in that location and shows the importance of this Montane Atlantic forest Conservation Unit for the preservation of birds from this biome. During 68 years, investigators recorded 323 species of which 117 are endemic and 28 are threatened. For these reasons the Station may be considered an Important Bird Area for the conservation of birds in Brazil. The second chapter, The elevational diversity of Atlantic forest birds: influence of the mid-domain effect, reviews all published studies on bird elevational distribution in the Brazilian Atlantic Forest, establishes the species-altitude curve of each study and tests their data sets for the mid-domain effect (MDE) null model predictions. I found eight investigations from which three distinct altitudinal patterns could be determined. The MDE predictions were not consistently robust for none of them and the investigation of candidate factors that drive the elevational diversity of birds is not possible due to the lack of standardized procedures. Finally, the third chapter, Elevational diversity of birds of the Serra do Mar: implications of altitude, area and the mid-domain effect, deals with the diversity of birds along the Bertioga-Salesópolis elevational gradient in the Serra do Mar and explores for the first time three candidate variables (altitude, area and MDE) driving the elevational diversity of birds in the Atlantic forest; I further compare my results with patterns found elsewhere in the world. Area was the best predictor of the bird elevational diversity and, although a few investigators claimed this variable as secondary in determining the species-altitude curve, here it proved worth analyzing.

Subalpine ecosystems are experiencing rapid changes in snow pack, temperature, and precipitation regime as a result of anthropogenic climate forcing. These changes in climate can have a profound effect on subalpine ecosystem structure and functioning, which may ultimately feed back to climate change. In this study, I examined the response of the subalpine meadow plant communities at the Rocky Mountain Biological Laboratory to natural and simulated climate change. First, I looked at whether changes in growing season precipitation or temperature regime would have the larger effect on subalpine ecosystem carbon flux. In a simulated warming experiment, changes in growing season precipitation had a tenfold larger effect on cumulative carbon flux than did the warming treatment. Along a natural climatic and elevational gradient, precipitation stimulates carbon uptake, particularly at higher elevations. Given projected decreases in summer precipitation in the high elevation Rockies, we predict a 20% decrease in carbon uptake from subalpine meadows. Second, I compared the taxonomic, phylogenetic and functional structure of plant communities along an elevational gradient to infer which climatic and biotic factors influence community assembly at each elevation. Floral and phenology traits become overdispersed at high elevation, mirroring phylogenetic relatedness, and suggesting pressure to diversify to attract pollinators during the abbreviated growing season. At the same time, leaf functional traits become clustered at high elevation, indicating multiple opposing assembly mechanisms in subalpine communities. Finally, I studied the natural history of sagebrush, Artemisia tridentate ssp. vaseyana, at its elevational range limit in subalpine meadows. In particular, I focused on the importance of warming and species interactions in elevational advance of the species. I found that facilitation by neighboring forbs was critical for sagebrush seedling survival, decreasing mortality by 75%. Seedling mortality was overwhelmingly due to desiccation of seedlings; therefore, neighboring forbs moderate temperature and water stress for seedlings. Despite the extremely limited growing season at high elevation caused by subfreezing temperatures, subalpine ecosystem structure and function are closely tied to water availability during the growing season. Therefore, improved predictions of future precipitation regimes over the Rocky Mountains will be our best tool for conservation of these fragile habitats.

Com o objetivo de investigar a influência da elevação topográfica na distribuição da fauna mirmecológica da serapilheira e de verificar se há um padrão de riqueza para o gradiente investigado, estudei a distribuição das formigas ao longo de um gradiente elevacional no Núcleo Picinguaba do Parque Estadual da Serra do Mar, Ubatuba, SP. Para isso, adotei seis faixas elevacionais (50, 200, 400, 600, 800 e 1000 metros) na costa leste dos Morros do Corisco e do Cuscuzeiro, coletando 20 amostras de 1 m2 de serapilheira em cada uma delas ao longo de dois transectos de 225 m cada e medindo a espessura de cada amostra. As 120 amostras foram submetidas ao extrator mini-Winkler para retirada das formigas. A riqueza observada em todo o gradiente foi de 176 espécies e a estimada (N= 206, dp= 5,17) foi calculada utilizando os índices mais indicados pela literatura, relacionando a riqueza observada à variação elevacional e à espessura da serapilheira através de modelos regressivos. O padrão de riqueza observado apresentou um pico na faixa intermediária do gradiente (cota de 400 metros), com 103 espécies, sendo testada a hipótese do domínio médio para explicar sua distribuição. Através deste teste pude constatar que a distribuição é influenciada por processos estocásticos e fatores bióticos e/ou abióticos. Para verificar se houve variação da fauna ao longo do gradiente apliquei índices de dissimilaridade adequados para o tipo de dados, correlacionando os resultados obtidos com a variação elevacional através do teste de Mantel. Além disso, utilizei a análise de correspondência destendenciada (DCA) para entender como a comunidade mirmecológica em questão está estruturada. As análises de dissimilaridade e o teste de Mantel mostraram que a fauna variou significativamente ao longo do gradiente. Por sua vez, a análise de DCA indicou que a substituição acontece de forma gradual ao longo do gradiente elevacional com a distinção de duas assembléias, uma nas áreas baixas e a outra nas áreas altas, ligadas por um continuum entre elas. Além disso, verifiquei o comportamento da riqueza de espécies exclusivas de cada faixa elevacional para entender a dinâmica da comunidade, utilizando um modelo de regressão. A riqueza dessas espécies foi maior nas extremidades do gradiente, principalmente, na cota de 1000 metros, onde a área é menor, e menor nas faixas intermediárias (200 e 400 metros), onde as estimativas de riqueza foram maiores. Considerando os resultados obtidos, sugiro que os fatores bióticos têm papel preponderante na distribuição das espécies e na definição do padrão de riqueza. Entretanto, a influência de tais fatores só poderá ser avaliada com o estudo da estrutura de guildas de formigas ao longo do gradiente elevacional. / Aiming to investigate the influence of the elevation in topography on the myrmecological leaf litter fauna and to verify if there is a richness pattern for the investigated gradient, I studied the distribution of these ants along an elevational gradient in the Núcleo Picinguaba of the Serra do Mar State Park, Ubatuba, SP. For this, I adopted six elevational bands (50, 200, 400, 600, 800 and 1000 meters) at the Eastern coast of the Corisco and Cuzcuzeiro mountains, where I collected 20 1 m2 leaf litter samples at each band along two transect of 225 m each and measured the leaf litter depth of each sample. The 120 samples were submitted to mini-Winkler extractors to remove of the ants. The observed richness in the whole gradient was 176 species and the estimated richness (N = 206; sd = 5,17) was calculated with the best index according the literature, relating observed richness to the elevational variation and to the leaf litter depth using regressive models. The observed richness pattern revealed a peak at the mid-elevational band of the gradient (400 meters quota) with 103 species; the mid-domain effect theory being tested to explain the species distribution. The results indicate that the distribution is influenced by stochastic processes and/or biotic or abiotic factors. To verify if there is variation on the ant fauna along the gradient, I applied the appropriate dissimilarity index for the data types, correlating the obtained results with the elevational variation using the Mantel test. Moreover, I used a detrended correspondence analysis (DCA) to understand how the myrmecological community in question is structured. The dissimilarity analysis and the Mantel test showed that the fauna changed significantly along the gradient. However, the DCA indicated a gradual substitution along the elevational gradient with two distinct assemblages, one in the lower zone and other in the upper zone, with a continuum between them. Furthermore, I verified the presence of exclusive species at each elevational band to understand the dynamics of the community, using a regressive model. The richness of these exclusive species was greatest at the extremities of the gradient, mainly at the 1000 meters quota, where the area is smaller; and it was smallest at the mid-elevations (200 and 400 meters), where the richness estimatives were greater. Considering the obtained results, I suggest that the biotic factors have a preponderant role in the species distribution and in the definition of the richness pattern. However, the influence of these factors may be only evaluated with the study of the ant guilds structure along the elevational gradient.

Com o objetivo de investigar a influência da elevação topográfica na distribuição da fauna mirmecológica da serapilheira e de verificar se há um padrão de riqueza para o gradiente investigado, estudei a distribuição das formigas ao longo de um gradiente elevacional no Núcleo Picinguaba do Parque Estadual da Serra do Mar, Ubatuba, SP. Para isso, adotei seis faixas elevacionais (50, 200, 400, 600, 800 e 1000 metros) na costa leste dos Morros do Corisco e do Cuscuzeiro, coletando 20 amostras de 1 m2 de serapilheira em cada uma delas ao longo de dois transectos de 225 m cada e medindo a espessura de cada amostra. As 120 amostras foram submetidas ao extrator mini-Winkler para retirada das formigas. A riqueza observada em todo o gradiente foi de 176 espécies e a estimada (N= 206, dp= 5,17) foi calculada utilizando os índices mais indicados pela literatura, relacionando a riqueza observada à variação elevacional e à espessura da serapilheira através de modelos regressivos. O padrão de riqueza observado apresentou um pico na faixa intermediária do gradiente (cota de 400 metros), com 103 espécies, sendo testada a hipótese do domínio médio para explicar sua distribuição. Através deste teste pude constatar que a distribuição é influenciada por processos estocásticos e fatores bióticos e/ou abióticos. Para verificar se houve variação da fauna ao longo do gradiente apliquei índices de dissimilaridade adequados para o tipo de dados, correlacionando os resultados obtidos com a variação elevacional através do teste de Mantel. Além disso, utilizei a análise de correspondência destendenciada (DCA) para entender como a comunidade mirmecológica em questão está estruturada. As análises de dissimilaridade e o teste de Mantel mostraram que a fauna variou significativamente ao longo do gradiente. Por sua vez, a análise de DCA indicou que a substituição acontece de forma gradual ao longo do gradiente elevacional com a distinção de duas assembléias, uma nas áreas baixas e a outra nas áreas altas, ligadas por um continuum entre elas. Além disso, verifiquei o comportamento da riqueza de espécies exclusivas de cada faixa elevacional para entender a dinâmica da comunidade, utilizando um modelo de regressão. A riqueza dessas espécies foi maior nas extremidades do gradiente, principalmente, na cota de 1000 metros, onde a área é menor, e menor nas faixas intermediárias (200 e 400 metros), onde as estimativas de riqueza foram maiores. Considerando os resultados obtidos, sugiro que os fatores bióticos têm papel preponderante na distribuição das espécies e na definição do padrão de riqueza. Entretanto, a influência de tais fatores só poderá ser avaliada com o estudo da estrutura de guildas de formigas ao longo do gradiente elevacional. / Aiming to investigate the influence of the elevation in topography on the myrmecological leaf litter fauna and to verify if there is a richness pattern for the investigated gradient, I studied the distribution of these ants along an elevational gradient in the Núcleo Picinguaba of the Serra do Mar State Park, Ubatuba, SP. For this, I adopted six elevational bands (50, 200, 400, 600, 800 and 1000 meters) at the Eastern coast of the Corisco and Cuzcuzeiro mountains, where I collected 20 1 m2 leaf litter samples at each band along two transect of 225 m each and measured the leaf litter depth of each sample. The 120 samples were submitted to mini-Winkler extractors to remove of the ants. The observed richness in the whole gradient was 176 species and the estimated richness (N = 206; sd = 5,17) was calculated with the best index according the literature, relating observed richness to the elevational variation and to the leaf litter depth using regressive models. The observed richness pattern revealed a peak at the mid-elevational band of the gradient (400 meters quota) with 103 species; the mid-domain effect theory being tested to explain the species distribution. The results indicate that the distribution is influenced by stochastic processes and/or biotic or abiotic factors. To verify if there is variation on the ant fauna along the gradient, I applied the appropriate dissimilarity index for the data types, correlating the obtained results with the elevational variation using the Mantel test. Moreover, I used a detrended correspondence analysis (DCA) to understand how the myrmecological community in question is structured. The dissimilarity analysis and the Mantel test showed that the fauna changed significantly along the gradient. However, the DCA indicated a gradual substitution along the elevational gradient with two distinct assemblages, one in the lower zone and other in the upper zone, with a continuum between them. Furthermore, I verified the presence of exclusive species at each elevational band to understand the dynamics of the community, using a regressive model. The richness of these exclusive species was greatest at the extremities of the gradient, mainly at the 1000 meters quota, where the area is smaller; and it was smallest at the mid-elevations (200 and 400 meters), where the richness estimatives were greater. Considering the obtained results, I suggest that the biotic factors have a preponderant role in the species distribution and in the definition of the richness pattern. However, the influence of these factors may be only evaluated with the study of the ant guilds structure along the elevational gradient.

Andean montane forests are one of the most diverse ecosystems on Earth, but are also highly vulnerable to climate change. Therefore, the link between plant distribution and ecosystem productivity is a critical point to investigate in these ecosystems. Are the patterns in productivity observed in montane forest due to species turnover along the elevational gradients? Methodological constraints keep this question unanswered. Also, despite their importance, belowground biomass remains poorly quantified and understood. I measured two plant functional traits in seedlings, root:shoot ratio and specific leaf area, to identify different strategies in growth and biomass allocation across elevations. A tradeoff in specific leaf area with elevation was found in only one species, and no generalized directional change was detected with elevations for root:shoot ratio. Lack of information for the ontogeny of the measured plant traits could confounding the analysis.

No description available.

Moderate livestock grazing is often identified as a useful management tool for sustaining biodiverse grassland communities and has long been practiced in Scandinavian mountains. Despite of a growing number of studies focusing on grazing effects along elevational gradients worldwide, there is still limited knowledge of how grazing intensity varies over time and how it affects plant communities on species and functional group level. Moreover, the majority of existing studies are conducted in enclosures with controlled stocking rate, while free-range grazing with a highly varied livestock number is the common practise in Scandinavia. Therefore, the aim of this study was to quantify free-range grazing intensity over the growing season along an elevational gradient and to evaluate how grazing affects plant communities on species, functional group and community level. In order to quantify grazing intensity, we conducted a grazer exclusion experiment along an elevational gradient in Norway in the growing season of 2019. We quantified grazing intensity as the difference in dry above-ground biomass between grazed and caged plots and analyzed plant composition on community and functional group level as well as recorded species-specific grazing damage and potentially influential abiotic factors. To capture the effects of temporal variation in grazing we also relocated caged and grazed plots in four-week intervals during the growing season. We demonstrated that grazing intensity gradually decreased with elevation and elevation explained 77% of the variation in grazing among sites. Lower grazing intensity at high elevation is likely related to decreasing plant productivity and differences in plant community composition along the gradient. Grazers reduced the biomass of graminoids and forbs in the intensively grazed lower sites. Grazing damage varied among sites for five of the eight most commonly grazed plant species, which was mainly driven by a higher grazing damage in the intermediate site (900m a.s.l.). Selective grazing was observed in three sheep-dominated study sites. Grazing intensity did not significantly vary during the growing season at any site, possibly due to weak temporal effects of an overall short growing season. In accordance with other studies, we demonstrated that grazing homogenized plant community composition in actively grazed sites that were relatively species rich. To conclude, livestock grazing can help maintain biodiverse semi-natural grasslands, yet when grazing is applied as a management tool in the mountainous landscapes, we suggest considering that grazing intensity, and therefore its effects, will vary with elevation.