Abstract Ice-free areas of Antarctica represent an important study region that helps us understand how human activity affects plant communities and soil properties. The goal of this study was to determine the changes in plant composition and soil properties around a whale bone skeleton (WB) near Ferraz Station, King George Island, Antarctica from 1972 to 2020 (48 years). The WB was assembled in 1972 by Jacques-Yves Cousteau and his team. It is located in a large moss field and visited by many tourists. We studied the plant composition and development based on historical and recent photographs and phytosociological studies from 1986 to 2020. The soil was sampled in February 2009 to determine general properties. The results showed that human activity surrounding the WB directly affected the plant community composition and soil properties. The Syntrichia cushions were positively affected by the calcium deposits from bone dissolution. The principal component analysis revealed that mineralization of the bones increased soil nutrient assembly. A strong phosphatization process was observed in the WB area, similar to that in ornithogenic soils. The WB on the marine terrace enhanced soil fertility and changed the plant community.

Abstract The Antarctic Peninsula has experienced some of the most accelerated warming worldwide, resulting in the retreat of glaciers and creation of new areas for plant development. Information regarding the plant dispersal processes to these new niches is scarce in Antarctica, despite birds being important vectors elsewhere. Many bird pellets (with feed remains such as bones and feathers) are generated annually in Antarctica, which are light and easily transported by the wind and include vegetation that is accidentally or purposely swallowed. The aim of this study was to analyze the presence of plant fragments within skua (Stercorarius/Catharacta spp.) pellets collected from two sampling areas in the Maritime Antarctic: Stinker Point (Elephant Island, 17 samples) and Byers Peninsula (Livingston Island, 60 samples), in the South Shetland Archipelago, during the austral summers of 2018 and 2020. In both study areas, five species of Bryophyta were found that were associated with the pellets and viable in germination tests in a humid chamber. The ingestion of Bryophyta for the skuas contribute to the dispersion of different moss species, including to areas recently exposed by the ice retreat. This is the first demonstration that skua pellets effectively act in the dispersion of Antarctic mosses.

Abstract Antarctic plant communities show a close relationship with soil types across the landscape, where vegetation cover changes, biological influence, and soil characteristics can affect the dynamic of greenhouse gases emissions. Thus, the objective of this study was to evaluate greenhouse gases emissions in lab conditions of ice-free areas along a topographic gradient (from sea level up to 300 meters). We selected 11 distinct vegetation compositions areas and assessed greenhouse gases production potentials through 20 days of laboratory incubations varying temperatures at -2, 4, 6, and 22 °C. High N2O production potential was associated with the Phanerogamic Community under the strong ornithogenic influence (phosphorus, nitrogen, and organic matter contents). Seven different areas acted as N2O sink at a temperature of -2 °C, demonstrating the impact of low-temperature conditions contributing to store N in soils. Moss Carpets had the highest CH4 emissions and low CO2 production potential. Fruticose Lichens had a CH4 sink effect and the highest values of CO2. The low rate of organic matter provided the CO2 sink effect on the bare soil (up to 6 °C). There is an overall trend of increasing greenhouse gases production potential with increasing temperature along a toposequence.

Abstract High resolution topography (HRT) surveys is an important tool to model landscapes, especially in zones subjected to strong environmental changes, such as Antarctica, where landform is highly influenced by cryoclasty and permafrost melting. The aim of this work was to obtain a high accurate DTM for Keller Peninsula, Maritime Antarctica. The survey study was assessed in the 2014/2015 and 2015/2016 during the austral summer, by using Terrestrial Laser Scanner (TLS). In order to cover 8 km² of the Peninsula, the TLS equipment was installed in 81 different points. Results of the DTM generated by TLS (hereafter, HRT-DTM), and the terrain variables Aspect, Slope and Hillshade obtained were compared with previous models generated by aerophotographic survey (hereafter, APG-DTM). RMSE for the HRT and APG-DTM were 0.726 and 2.397 m, respectively. Spatial resolution of the DTMs was 0.20 m. Morphometric variables obtained from the two methods presented visual differences on the thematic maps, especially related to the Aspect. Generalization was the main process, whereas interpolation occurred for the HRT survey, being the process of choice for the APG method. A large number of points are obtained by the TLS, providing a dense cloud of points, spatially well-distributed, enabling the generalization process to obtain surface models with high performance.

ABSTRACT Viruá National Park encompasses a vast and complex system of hydromorphic sandy soils covered largely by the white sand vegetation ("Campinarana") ecosystem. The purpose of this study was to investigate a vegetation gradient of "terra-firme"-white sand vegetation at the Viruá National Park. Nine plots representing three physiognomic units were installed for floristic and phytosociological surveys as well as to collect composite soil samples. The data were subjected to assessments of floristic diversity and similarity, phytosociological parameters and to statistical analyses, focused on principal components (PC) and canonical correspondence analysis (CCA). The vegetation of the Campinaranas types and Forest differed in biomass and species density. Ten species, endemic to Brazil, were particularly well-represented. PC and CCA indicated a clear distinction between the studied plots, based on measured soil variables, especially base sum and clay, which were the most differentiating properties between Campinarana and Forest; For the separation of the Campinarana types, the main distinguishing variable was organic matter content and cation exchange capacity. Higher similarity of Campinaranas was associated to a monodominant species and the lower similarity of Forest was related to the high occurrence of locally rare species.

RESUMO O objetivo deste estudo foi conhecer a localização preferencial de espécies da sinúsia arbórea em resposta ao gradiente de umidade no Pantanal Matogrossense, Brasil. Foram estabelecidas parcelas para amostragem da sinúsia arbórea ao longo dos gradiente de umidade do solo e de inundação. Piezômetros foram instalados permitindo medições mensais da profundidade do lençol freático e da altura da lâmina de inundação durante um ano. Análise de Correspondência Destendenciada, Análise Direta de Gradientes, Procedimento de Permutação Multi-resposta e Análise de Espécies Indicadoras foram realizadas para avaliar o efeito do gradiente de umidade sobre a distribuição das plantas. A oscilação do lençol freático é mais superficial e similar na Floresta Sazonalmente Inundada e nos Campos de Murundus, com acréscimo da profundidade no Cerrado no Cerradão e nas Florestas Secas. Cerca de 64% das espécies foram caracterizadas como de localização preferencial em "habitats terrestres normalmente não sujeitos a inundação", enquanto 8% ocorrem preferencialmente em "habitats inundáveis". A baixa riqueza de espécies arbóreas em tipos vegetacionais sujeitos a inundação está relacionada à alta sazonalidade climática atual e aos paleoclimas secos do Pleistoceno Superior no Pantanal. A composição de espécies arbóreas ao longo das diferentes formações no Pantanal apresenta uma relação direta com o gradiente de umidade no solo estudado.

ABSTRACT This study aimed to recognized the preferential location of species of the tree sinusiae in response to a moisture gradient in Pantanal Matogrossense, Brazil. We established sampling plots of arboreal sinusiae along a soil moisture and flood gradient. Piezometers were installed, allowing monthly measurements of water table depth and flood height during one year. Detrended Correspondence Analysis, Gradient Direct Analysis, Multi-response Permutation Procedures and Indicator Species Analysis were performed to evaluate the effect of moisture gradient on tree distribution. The annual variation of water table is shallower and similar in Seasonally Flooded Forest and Termite Savanna, with increasing depths in Open Savanna, Savanna Forest and Dry Forest. Circa 64% of the species were characterized as having a preferential location in "terrestrial habitats normally not subjected to inundation", while 8% preferentially occur in "wet habitats". Lowest tree richness in flood-affected vegetation types is related to both present-day high climatic seasonality and Late Pleistocene dry paleoclimates in the Pantanal wetland. The tree distribution across different formations in the Pantanal shows a direct relationship with soil moisture gradient.

Vegetação e propriedades do solo de uma ilha de canga rica em ferro (laterita) no maior afloramento de formação ferrífera bandada, na Serra de Carajás (Amazônia oriental, Brasil), foram estudados, ao longo de um gradiente topográfico (738-762 m de altitude), e analisados para testar a hipótese de que os atributos químicos e físicos do solo desempenham um papel fundamental na estrutura e composição florística destas comunidades vegetais. Solos e vegetação foram amostrados em oito parcelas replicadas dentro de cada um dos quatro tipos de vegetação. Amostras de solo superficiais (0-10 cm) de cada parcela foram analisadas para cátions básicos, N, P e densidade de espécies de plantas para todas as espécies foram registradas. Análise de ordenação CCA evidenciou uma forte separação entre áreas florestais e não florestais no primeiro eixo, e entre campo rupestre herbáceo e arbustivo no segundo eixo. Os quatro tipos de vegetação compartilham poucas espécies de plantas, o que pode ser atribuído aos seus ambientes de solos distintos e filtragem de suas espécies constituintes por limitações químicas, físicas e hidrológicas. Assim, podemos inferir que fatores edáficos (pedológicos) são cruciais para explicar os tipos e distribuições da vegetação dos campos rupestres associados com platôs ferruginosos (Canga), em Carajás, no leste da Amazônia, sendo, portanto, as propriedades do solo as principais condutoras da composição e estrutura da vegetação nestas ilhas ferríferas.

Vegetation and soil properties of an iron-rich canga (laterite) island on the largest outcrop of banded-iron formation in Serra de Carajás (eastern Amazonia, Brazil) were studied along a topographic gradient (738-762 m asl), and analyzed to test the hypothesis that soil chemical and physical attributes play a key role in the structure and floristic composition of these plant communities. Soil and vegetation were sampled in eight replicate plots within each of the four vegetation types. Surface (0-10 cm) soil samples from each plot were analyzed for basic cations, N, P and plant species density for all species was recorded. CCA ordination analysis showed a strong separation between forest and non-forest sites on the first axis, and between herbaceous and shrubby campo rupestre on the second axis. The four vegetation types shared few plant species, which was attributed to their distinctive soil environments and filtering of their constituent species by chemical, physical and hydrological constraints. Thus, we can infer that Edaphic (pedological) factors are crucial in explaining the types and distributions of campo rupestre vegetation associated with ferruginous ironstone uplands (Canga) in Carajás, eastern Amazonia, therefore the soil properties are the main drivers of vegetation composition and structure on these ironstone islands.

Solos associados aos Complexos Rupestres de Altitude no Brasil destacam-se pela baixa fertilidade química, baixa saturação de bases e elevados teores de alumínio trocável. Esta condição estressante impõe pressões evolutivas que determinam o sucesso ecológico de espécies capazes de tolerar ou acumular grandes quantidades de alumínio. Vários métodos analíticos são utilizados para mapeamento de elementos químicos em estruturas biológicas, como microfluorescência de raios-X (μ-EDX) e testes histoquímicos. O objetivo do presente trabalho foi combinar a μ-EDX e testes histoquímicos para quantificar o teor de Al em espécies vegetais de Complexos Rupestres de Altitude, e identificar os principais sítios de bioacumulação de Al. Cinco das espécies investigadas apresentaram concentração total de Al maior que 1000 mg kg−1. As principais hiperacumuladoras de Al,Lavoisiera pectinata, Lycopodium clavatume Trembleya parviflora, apresentaram reação positiva nos testes histoquímicos com Chrome Azurol e Aluminon. Alta correlação positiva foi observada entre as concentrações totais de Al e as magnitudes de sinal obtidas por μ-EDX. A análise com o uso da μ-EDX mostrou-se uma ferramenta promissora para mapear e quantificar Al em espécies hiperacumuladoras, constituindo uma importante técnica não destrutiva. Testes histoquímicos podem ser úteis na identificação de padrões de acumulação de Al em amostras vegetais antes de serem submetidas a uma minuciosa análise com a μ-EDX.

The soils developed under High Altitude Rocky Complexes in Brazil are generally of very low chemical fertility, with low base saturation and high exchangeable aluminium concentration. This stressful condition imposes evolutionary pressures that lead to ecological success of plant species that are able to tolerate or accumulate high amounts of aluminium. Several analytical methods are currently available for elemental mapping of biological structures, such as micro-X-ray fluorescence (μ-EDX) and histochemical tests. The aim of this study was to combine μ-EDX analysis and histochemical tests to quantify aluminium in plants from High Altitude Rocky Complexes, identifying the main sites for Al-accumulation. Among the studied species, five showed total Al concentration higher than 1000 mg kg−1. The main Al-hyperaccumulator plants,Lavoisiera pectinata, Lycopodium clavatumand Trembleya parviflora presented positive reactions in the histochemical tests using Chrome Azurol and Aluminon. Strong positive correlations were observed between the total Al concentrations and data obtained by μ-EDX analysis. The μ-EDX analysis is a potential tool to map and quantify Al in hyperaccumulator species, and a valuable technique due to its non-destructive capacity. Histochemical tests can be helpful to indicate the accumulation pattern of samples before they are submitted for further μ-EDX scrutiny.

Este trabalho foi conduzido na Floresta Nacional de Paraopeba. O objetivo desse estudo foi classificar e avaliar o solo, assim como verificar a influência dos atributos do mesmo na vegetação. Para isso, foram também testadas as seguintes hipóteses: 1) nas áreas de Cerradão a fertilidade é mais alta e os teores de alumínio são mais baixos; 2) os cerrados stricto sensu ocorrem nas áreas com altos teores de Al3+. Para isso, os solos da FLONA foram mapeados e identificados, além da análise química e física dos solos de cinco perfis. O gradiente ambiental foi facilmente observado pela análise de componentes principais (PCA), onde as diferenças entres as áreas foram evidenciadas. A correlação de Spearman foi usada para verificar as hipóteses. A relação entre vegetação (área basal, densidade e riqueza) e solo (K, Ca2+, e Al3+) foi estatisticamente significante. As hipóteses foram aceitas, porém a hipótese 1 apenas parcialmente. As características do solo parecem ter uma influência nas fitofisionomias do Cerrado e também em sua estrutura. O fósforo disponível foi um importante fator para a manutenção da fisionomia de Cerradão, assim como o Al3+ que parece ter um papel importante no estabelecimento de diferentes fisionomias de Cerrado.

This study was carried out in Paraopeba National Reserve. It aims to classify and evaluate the soil of the studied area and to verify the influence of soil attributes on vegetation by testing the following hypotheses: 1) under woodland physiognomies (Cerradão) the soil fertility is higher and the Al content lower; 2) open savanna occurs only in areas with high Al contents. For this purpose, representative soils in the Paraopeba National Reserve were mapped, identified, and samples from five profiles were analyzed. The environmental gradient was easily observed by principal components analyses, where the differences between the sites were highlighted. The Spearman correlation was used to verify the hypothesis. The correlation between vegetation (basal area, density, and richness) and soil (K, Ca2+, and Al3+) was statistically significant. The hypotheses were accepted, but hypothesis 1 only partially. Soil features seem to have an influence on the Cerrado phytophysiognomies and structure. Available phosphorous was an important factor for the maintenance of woodland Cerrado. Also, exchangeable Al3+ plays a major role in the establishment of different Cerrado physiognomies in Paraopeba National Reserve.

O objetivo deste estudo foi o de determinar as mudanças na composição, abundância e riqueza de espécies ao longo de um gradiente de floresta com variações de solo e inundações. As florestas localizam-se na margem esquerda do Rio Jucu, no Parque Natural Municipal de Jacarenema, Espírito Santo. O levantamento das espécies arbustivo/arbóreas foi realizado em 80 parcelas de 5x25m, distribuídas equitativamente entre as florestas estudadas. Foram incluídos na amostragem todos os indivíduos com >3,2 cm diâmetro à altura do solo (1,30 m). Foram coletadas amostras de solo superficial (0-10 cm) em cada parcela para análise química e física. Os resultados mostraram a existência de gradiente pedológico significativo, que é influenciado pelas variações sazonais do lençol freático. As formações florestais da Restinga apresentaram diferenças significativas na riqueza de espécies, com exceção da Floresta Não Inundável em relação a Floresta Não Inundável de Transição. A Análise de Correlação Canônica (CCA) mostrou que algumas espécies apresentam sua distribuição ao longo do gradiente sob influência da drenagem, das concentrações de nutrientes e das características físicas dos solos. Entre as variáveis testadas, a inundação parece ser o fator mais limitante para o estabelecimento de espécies vegetais nas florestas de Restinga do que os atributos básicos de fertilidade do solo.

The aim of this study was to determine changes in composition, abundance and richness of species along a forest gradient with varying soils and flood regimes. The forests are located on the left bank of the lower Jucu River, in Jacarenema Natural Municipal Park, Espírito Santo. A survey of shrub/tree species was done in 80 plots, 5x25 m, equally distributed among the forests studied. We included in the sampling all individuals with >3.2 cm diameter at breast height (1.30 m). Soil samples were collected from the surface layer (0-10 cm) in each plot for chemical and physical analysis. The results indicate that a significant pedological gradient occurs, which is influenced by varying seasonal groundwater levels. Restinga forest formations showed significant differences in species richness, except for Non-flooded Forest and Non-flooded Forest Transition. The Canonical Correlation Analysis (CCA) showed that some species are distributed along the gradient under the combined influence of drainage, nutrient concentration and physical characteristics of the soil. Regarding the variables tested, flooding seems to be a more limiting factor for the establishment of plant species in Restinga forests than basic soil fertility attributes.