RESUMO Embora as espécies estejam continuamente expostas a variações do clima ao longo do tempo, há uma preocupação crescente em relação ao ritmo acelerado de mudança climática a que estão expostas atualmente, pois o clima é determinante na distribuição geográfica de animais e plantas. O presente trabalho avaliou o nicho climático e o impacto da mudança climática para o período de 2061-2080 sobre as áreas de ocorrência geográfica das espécies indicadoras dos agrupamentos de florestas aluviais da porção centro-sul da Mata Atlântica e do Pampa brasileiro. Foram consideradas 19 variáveis climáticas para o clima contemporâneo e futuro. Os nichos climáticos das espécies foram modelados por meio do algoritmo Maxent. A adequabilidade das espécies do grupo Paraná-Uruguai foi influenciada fortemente por variáveis relacionadas à temperatura, enquanto a adequabilidade das espécies do grupo Atlântico relacionou-se com precipitação e temperatura. Estima-se redução na área de adequabilidade climática para a maioria das espécies consideradas, com comportamento semelhante para os dois grupos abordados. As espécies tenderão a ocupar uma posição mais austral, utilizando as áreas de maior altitude, latitude e próximas ao litoral do Brasil como refúgios climáticos, destacando essas áreas como estratégicas para a conservação.

ABSTRACT Although species are continually exposed to variations in climate over time, there is growing concern about the accelerated pace of climate change to which they are currently exposed, as climate is determinant in the geographic distribution of animals and plants. This study evaluated the climatic niche and impact of climate change in the 2061-2080 period on areas of occurrence of indicator tree species of alluvial forests in the south-central portion of the Atlantic Forest and Brazilian Pampa. Nineteen climatic variables were considered for the contemporary and future climates. The species’ climatic niches were modeled using the Maxent algorithm. Climatic adequacy for species in the Parana-Uruguay group was strongly influenced by variables related to temperature, while adequacy for species in the Atlantic group was related to rainfall and temperature. A decrease in the area of climatic adequacy is estimated for most species considered, with similar behavior in the two groups assessed. The species tend to occupy a more southern position, using areas of higher altitude, latitude and proximity to the Brazilian coast as climate refuges, highlighting these areas as strategic for environmental conservation.

Resumo Este estudo buscou investigar se a composição florístico-estrutural de uma floresta aluvial é influenciada pelas variações pedológicas e se há baixa diversidade e similaridade florística nesses ambientes. Ainda, objetivou avaliar se, independentemente do tipo de solo, essas florestas apresentam monodominância. O estudo foi realizado às margens do rio Iguaçu, no município de Araucária, Paraná, onde foram mapeadas e demarcadas a área de ocorrência de duas classes de solo: Gleissolo Háplico Ta Distrófico típico e Neossolo Flúvico Psamítico típico. Para a análise da estrutura fitossociológica, foram instaladas em cada compartimento 10 parcelas de 10 m x 10 m e monitorada a profundidade média do lençol freático. Foram amostradas 39 espécies, distribuídas em 21 famílias botânicas. Destas, somente seis espécies foram similares nos compartimentos analisados. A flutuação do lençol freático diferiu entre os compartimentos, sendo mais próximo da superfície no Gleissolo. Gymnanthes klotzschiana apresentou os maiores valores de densidade, dominância e importância em ambos os compartimentos. A segunda espécie de maior importância na área de Gleissolo foi Myrciaria tenella, e na área de Neossolo destacase Araucaria angustifolia, devido à maior profundidade do lençol freático e ao caráter não hidromórfico do solo. Os ambientes ripários apresentaram distinções florístico-estruturais, evidenciando a necessidade de compartimentação baseada em parâmetros pedológicos, obtendo-se assim um melhor entendimento da comunidade vegetal.

Abstract This study aimed to investigate if the floristic-structural composition of an alluvial forest is influenced by pedological variations and if there is low floristic diversity and similarity in these environments. Furthermore, it aimed to assess whether, independently of the type of soil, these forests have monodominance. The study was carried out in the Iguaçu River, in the municipality of Araucária, Paraná state, where two soil classes were mapped and demarcated: Gleysol and Fluvisol. To analyze the phytosociological structure, we installed 10 plots of 10 m x 10 m in each compartment and monitor the average depth of the water table. We sampled thirty-nine species, distributed in 21 botanical families. Of these, only six ones were similar to both compartments. The fluctuation of the water table differed between the compartments, being closer to the surface in the Gleysol. Gymnanthes klotzschiana showed the highest values of density, dominance, and importance in both compartments. The second most important species in Gleysol was Myrciaria tenella and in the Fluvisol Araucaria angustifolia stands out, due to the greater depth of the water table and the non-hydromorphic character of the soil. The riparian environments presented floristic-structural distinctions, highlighting the need for compartmentalization based on pedological parameters, thus obtaining a more detailed understanding of the plant community.

Abstract During a period of 5 years, we monthly monitor the phenology and the stem diameter increment of 12 of Schinus terebinthifolius trees. Dendrometer bands were used for it. This study was aimed to answer the following questions: (i) Are there conflicting demands for resource allocation in different phenophases? (ii) In which period does the stem diameter increment occur? (iii) Which phenophases are more likely related to stem radial growth? The phenological observations were carried out using the Activity Index. In order to identify patterns in phenology and diameter increment over the assessment period (2010-2015), we performed an analysis of seasonal decomposition, followed by Pearson’s correlation analysis. Apparently, there is no conflicting demand for resources, but an optimized distribution of them, regulated mainly by the allocation of nutrients derived from leaf senescence, as well as, temperature rise and photoperiod. Higher diameter growth rates occurred from December to March which coincided with the flowering period.

Abstract The aims of this study were to identify floristic assemblages for alluvial forests in the Atlantic Forest and Pampa regions in Brazil, assess the level of floristic similarity between assemblages, and determine environmental gradients and indicator species for these assemblages. Surveys carried out in alluvial forests in the Atlantic Forest and Pampa regions were selected, based on which a presence/absence matrix was built for tree species. A cluster analysis was performed to verify the existence of species assemblages. Floristic similarity was determined by means of the Sorensen Distance measure, from which a dendrogram was developed. The floristic matrix was ordinated by means of NMDS. A PCA was performed with climatic data from areas to determine environmental gradients. An assessment of indicator species was carried out afterwards. Two groups of areas not related to the separation of the regions became visible from the dendrogram and were corroborated by NMDS. Temperature, rainfall and altitude gradients were synthesized by the PCA. Gymnanthes klotzschiana and Andira fraxinifolia were the most relevant species, respectively, in the Paraná-Uruguay and Atlantic assemblages. Alluvial forests were gradually separated in two floristic assemblages associated with river basins and migration routes, while especially influenced by tropicality and altitude gradients.

Resumo Em um remanescente de Floresta Ombrófila Mista Aluvial, foram abatidas 56 árvores adultas de Gymnanthes klotzschiana, árvore típica e representativa desta formação e popularmente conhecida como branquilho, às margens do rio Barigui, em Araucária - PR, o qual teve o curso de seu leito retificado na década de 1960. Considerando-se as técnicas e premissas básicas para estudos dendrocronológicos, os discos foram secos, polidos e os anéis de crescimento identificados e demarcados, para a construção de séries cronológicas e sua correlação com variáveis climáticas/ambientais. O presente trabalho tem por objetivo verificar se: (i) Gymnanthes klotzschiana apresenta características potenciais para estudos dendroecológicos; (ii) a espécie responde a estímulos ambientais e intervenções antrópicas; (iii) a estrutura etária das árvores estudadas é compatível com a ocorrência de distúrbios antrópicos na região. A análise dos resultados reforça a potencialidade da espécie em estudos dendroecológicos, considerando a sincronia dos dados e a sensibilidade às variáveis climáticas. Além disso, a idade máxima constatada das árvores analisadas é próxima ao final do ciclo de extração da madeira utilizada pelas embarcações a vapor nesta região, que preponderaram até meados da década de 1950.

Abstract In a remnant area of Alluvial Ombrophylous Forest, 56 adult trees of Gymnanthes klotzschiana, a typical and representative tree of this formation and popularly known as “branquilhos”, were slaughtered on the banks of the Barigui River, in Araucária, PR state, which the watercourse was rectified in the 1960s. Following the techniques for dendrochronological studies, the discs were dried, polished and the growth rings identified and marked, for the construction of chronological series and their correlation with climatic/environmental variables. This study aims to verify, if (i) Gymnanthes klotzschiana presents potential characteristics for dendroecological studies; (ii) the species responds to environmental stimuli and anthropogenic disturbances (iii) the age structure of the studied trees is compatible with environmental disturbances, documented for the region. The analysis of the results reinforces the potentiality of the species in dendroecological studies, considering the synchrony of the data and the sensitivity to the climatic variables. In addition, the maximum tree age corresponds to the end of the harvest intervention in this region, which prevailed until the middle of 1950s.

Abstract Considering the importance of the Iguaçu National Park for the conservation of the Atlantic Forest and the absence of scientific or technical studies characterizing the ecology of forest species after seven and a half decades of its existence, a phytosociological survey of the arboreal vegetation was conducted to identify the various existing species and their successional stages. A total of 54 families, 135 genera, and 218 species were found in this survey. Euterpe edulis Mart. was the most frequently occurring species, which together with Aspidosperma polyneuron Müll. Arg., characterize the seasonal forests in the central and south regions of the park. In the north region, located 700 m asl, Araucaria angustifolia (Bertol.) Kuntze and Ilex paraguariensis A. St.-Hil. were observed along with some seasonal species, characterizing a transitional environment between seasonal and ombrophillous forests. In general, forests in the park were classified in advanced stages of ecological succession.

ABSTRACT We examined the climatic response of Cedrela fissilis radial growth based on precipitation, air relative humidity, temperature and monthly thermal amplitude. It was intended to assess how the secondary growth of C. fissilis is influenced by the climatic variables and which one are the best growth predictors in Ombrophilous Mixed Forest, southern Brazil. Wood cores were processed using classical dendrochronology methodology. Principal Components Analysis, Generalized Linear Models and correlation were used to explore the relationship between radial growth and climate. Our results indicated that the best radial growth predictor is the temperature: the seasonal behavior, under well-watered conditions, seems to have a dominant effect on growth responses. Changes in tree growth corresponding to an increase in temperatures suggest a sensitivity of the species to climate changes. These results are important to help understand how the global warming may influence long-lived pioneer tree growth.

ABSTRACT The Atlantic Subtropical Rainforest covers a huge area of Santa Catarina state, starting on the coast and going through the Serra Geral. Along its distribution, the vegetation changes according to altitude, geomorphology, and soil. In the attempt to evaluate vegetation variations related to different soil types in an Atlantic Forest remnant, 43 plots of 200 m2 were sampled. All the individuals with DBH ≥ 5.0 cm were measured. We have found consistent floristic and structural variations, which separated sample plots with Litholic Neosol and Rogosol situated in slopes from those with Yellow-Red Ultisol and Haplic Cambisol, as well as plots with Fluvic Neosol from Haplic Gleisol in plateaus. Species richness increased according to water availability and soil depth, with the plateaus’ soils being the richest. Each area was characterized by a range of indicator species and the results indicated that soil attributes are important drivers of vegetation variation.

Abstract The present study aimed at sampling the biomass of vascular epiphytes within a protected area in South Brazilian Atlantic Forest. All tree specimens with diameter at breast height equal or greater than 4.8 cm were measured and divided into classes. In each class, 10% of tree specimens were randomly selected for epiphytic biomass measuring. Furthermore, we divided the phorophytes into five tree parts to analyze epiphytic biomass. We generated mathematical models to estimate epiphytic biomass in similar forest areas. We analyzed 55 phorophytes and found an estimated epiphytic biomass of 5.3 Mg/ha. Epiphytic biomass ranged from 0.02 to 135 kg and the lower values were found on small-sized phorophytes. Higher values of epiphytic biomass were found on phorophytes with diameter at breast height between 30 and 36.5 cm. The tree part with higher epiphytic biomass was the outer crown. The epiphytic biomass showed a high correlation with phorophyte diameter, according to the mathematical models. We selected two equations which presented the most similar values to the ones we measured. Our results corroborate that epiphytes play a very important role as to the biomass level within tropical forests.

Abstract Studies about dispersal syndromes and spatial distribution can provide information about species ecology. However, few studies analyze these ecological patterns in different vegetation layers. In this work, we verified the relationship between the dispersion syndromes and the spatial distribution in different layers in Araucaria Forest. We sampled 180 plots with size and inclusion criteria that changed according to the vegetative layer. We sampled 15,545 individuals in 103 tree species. We found significant differences between the number of species in the dispersion syndromes (χ2 = 11.52; P ≤ 0.05) and spatial distribution patterns (χ2 = 10.94; P ≤ 0.05), being zoochoric and tends to clustering the most predominant. We also found a significant interaction between the dispersion syndromes and spatial distribution patterns in the analyzed layers (F = 1,044; P < 0.0001), with anemochoric species characterized by random distribution, autochoric in the cluster distribution and zoochoric in the tends to clustering. The results demonstrate that the tree species of the different layers are related to the type of dispersion and the aggregation pattern.

Resumo O campo de Teyú Cuaré no departamento de San Ignacio, na província de Misiones, Argentina, tem se destacado pela sua flora e fisionomia, o que levou a pesquisadores a indicar que poderia ser um relicto do bioma Cerrado. Analisou-se a florística e a fitossociologia do componente arbóreo-arbustivo de uma comunidade savânica, discutindo-se os processos que a originaram e contribuem para a permanência desta fitofisionomia. Em 12 parcelas quadradas de 400 m2 foram mensurados o perímetro e a altura de todos os indivíduos lenhosos com perímetro ≥ 10 cm ao nível do solo. Avaliamos a similaridade florística entre a área estudada e outras áreas de Cerrado do Brasil e do Paraguai. No total foram detectadas 15 famílias e 17 espécies, onde Leptolobium elegans foi a de maior importância estrutural. A flora lenhosa da área é mais fortemente associada com as áreas de Cerrado do Paraná e Canindeyú e Amambay no Paraguai. A vegetação do local possivelmente é um reflexo da expansão das fisionomias abertas do Pleistoceno tardio e Holoceno médio, dominantes em parte da província e do Sul do Brasil. A permanência desta unidade campestre provavelmente está relacionada à atuação de mecanismos de natureza geológica, pedológica, antrópica e por perturbações pelo fogo.

Abstract The Teyú Cuaré field, in Misiones province, Argentina, has been renowned for its flora and physiognomy, which led researchers to indicate that it could be a relict of Cerrado biome. We analyzed the floristic structure of the woody component of a savanna community in this site, and discussed the processes that could contribute to the permanence of this vegetation type over time. Perimeter and height of all woody individuals ≥ 10 cm of perimeter at soil height were collected in 12 square plots (400 m2 each one). We found 15 families and 17 species in our site and compared the woody flora surveyed at this site with the flora of other Cerrado áreas from Brazil and Paraguay. Leptolobium elegans had the highest importance value. The woody flora of the área is closely related to the Cerrado areas from Paraná state in Brazil and Canindeyú and Amambay in Paraguay. This site probably reflects old open physiognomies which were predominant in Misiones and Southern of Brazil in the late Pleistocene and middle Holocene. We inferred that the permanence of open physiognomies at Teyú Cuaré is probably related to mechanisms that act at different levels, such as geological, edaphic, anthropic, and fire disturbance.

RESUMO Em uma área da Floresta Ombrófila Mista Aluvial impactada por vazamento de óleo bruto no município de Araucária - PR, Brasil, conduziu-se o estudo dendroecológico de Sebastiania commersoniana (Baill.) L.B.Sm. & Downs (Euphorbiaceae) e da espécie exótica Hovenia dulcis Thunb. (Rhamnaceae). Os objetivos do estudo foram avaliar o efeito do alagamento da área a partir da construção de diques como medida de descontaminação de petróleo e de fatores meteorológicos no crescimento em diâmetro do tronco de ambas as espécies. Foram coletadas três séries temporais radiais do lenho de cada indivíduo adulto selecionado com uso de sondas de incremento, em duas condições, ambas com solo hidromórfico (Gleissolo Háplico), tendo como diferença a altura do lençol freático: SHT - saturação hídrica temporária (Sebastiania commersoniana n=12; Hovenia dulcis n= 10) e SHP - saturação hídrica permanente (Sebastiania commersoniana n=6; Hovenia dulcis n= 0). Séries cronológicas foram desenvolvidas, correlacionando-as com dados meteorológicos da região. Os resultados demonstraram que os indivíduos da espécie nativa em ambas as condições apresentaram padrão semelhante de crescimento, com tendência de diminuição ao longo dos anos; diferentemente dos indivíduos da espécie exótica, com tendência de aumento do incremento ao longo dos anos. Os indivíduos da condição SHP tiveram taxas menores de incremento após o ano do derramamento, o que mostra que o alagamento da área a partir da construção de diques como tentativa de descontaminação afetou o crescimento dos indivíduos. O crescimento das espécies correlacionou-se com a precipitação apenas na condição SHT. A temperatura mínima representou ser fator limitante ao crescimento de Sebastiania commersoniana, mostrando que temperaturas mais elevadas são importantes para o crescimento, principalmente no início do período deste. Entretanto, a ocorrência de temperaturas muito altas nos meses mais quentes pode ser limitante ao crescimento. Para Hovenia dulcis, nenhuma correlação significativa foi observada com a temperatura, porém, a precipitação mostrou-se fundamental nos meses em que a espécie mais cresce, sendo, no entanto, prejudicial em meses subsequentes às fortes chuvas devido ao efeito de saturação hídrica do solo.

ABSTRACT In a forest remnant of the Alluvial Mixed Rain Forest impacted by crude oil spill in the district of Araucaria in Paraná, Brazil, we conducted a dendroecological study of Sebastiania commersoniana (Baill.) L.B.Sm. & Downs (Euphorbiaceae) and the exotic species Hovenia dulcis Thunb. (Rhamnaceae). The study objectives were to evaluate the effect of the flooding area by dyke construction as way to decontamination petroleum and the meteorological factors in the tree diameter growth of both species. Wood samples were collected using increment borer, from two conditions, both on hydromorphic soils (Haplic Gleisol), but at two sites differing in the depth of the water table: SHT - temporary water saturation (Sebastiania commersoniana n=12; Hovenia dulcis n= 10) and SHP - Permanent water saturation (Sebastiania commersoniana n=6; Hovenia dulcis n= 0). Radial time series were developed and correlated with the meteorological data from the region. Results show that individuals of native species at both soil conditions experienced similar inter-annual growth patterns with decreasing trend over the years; differently individuals of exotic species, with increase of increment over the years. Individuals of SHP condition had lower rates of growth after the year of the spill, which shows that the flooding of the area by construction of dykes as attempt to decontaminate, affected the growth of individuals. The construction of dykes as attempt to decontaminate the area affected de individual growth. Precipitation showed a direct link with tree growth, only at sites with temporary water saturation. Moreover, minimum air temperature is a factor limiting the growth of Sebastiania commersoniana, showing that high temperatures stimulate growth, particularly at the early stages of the growth period while warmer months may depress the growth. Hovenia dulcis showed no significant correlation with temperature, but precipitation arises as crucial factor for growth, but the effect of soil saturation in the subsequent months may limit tree growth.

RESUMO Fitossociologia da Vegetação Arbórea do Parque Nacional do Iguaçu - O Parque Nacional do Iguaçu está inserido no Bioma Mata Atlântica, sendo considerado o maior Parque extra-amazônico brasileiro. Apesar de sua importância e expressiva área de superfície florestal, poucos são os estudos científicos relacionados à sua vegetação. Com o objetivo de atender esta demanda foi realizado inventário fitossociológico da vegetação arbórea por meio de parcelas instaladas em diferentes condições ambientais, buscando a máxima representatividade ambiental possível. Na classificação da vegetação por meio da TWINSPAN as florestas foram separadas inicialmente em ambientes montanos e submontanos. Uma região de transição entre as florestas estacionais e ombrófilas foi observada no ambiente montano, com altitude acima de 700m. A Floresta Estacional Montana foi observada em altitudes entre 600 a 700 m e a Floresta Estacional Submontana, imediatamente abaixo, foi separada em duas subformações devido às variações fisionômicas regidas pela geomorfologia e variabilidade hídrica existente. A vegetação arbórea do Parque Nacional do Iguaçu é, de acordo com os resultados encontrados, um remanescente de grande relevância para a preservação das espécies florestais no sul do Brasil, entre as quais, se destacam Aspidosperma polyneuron Müll. Arg., Araucaria angustifolia (Bertol.) Kuntze, Euterpe edulis Mart. e Ilex paraguariensis A. St.-Hil.

ABSTRACT Phytosociology of tree vegetation in Iguaçu National Park is inserted within Atlantic Forest biome and is considered the largest Brazilian non-Amazon Park. Despite its importance and its significant forest area, there are few scientific studies related to its vegetation. In order to meet this demand, we conducted a phytosociological inventory of the tree vegetation by means of plots installed in different environments, striving to achieve optimum environmental representation. In the classification of vegetation by TWINSPAN the forests were initially separated intoambientmontaneand submontane.An ecotone region between seasonal and araucaria forests was observed in the montane site, at an altitude above 700 m. The semideciduous forest montane was observed at altitudes of 600-700 meters. The Forest Seasonal Submontane in the lowlands was separated into two subformations, Typical and Humid, due to physiognomic variations regulated by geomorphology and humidity. According to the results, the tree vegetation of Iguaçu National Park is a remnant of great importance for the conservation of forest species in southern Brazil, among which stand out Aspidosperma polyneuron Müll. Arg., Araucaria angustifolia (Bertol.) Kuntze, Euterpe edulis Mart. and Ilex paraguariensis A. St.-Hil.

RESUMO Objetiva-se com este estudo avaliar a periodicidade do incremento em diâmetro do tronco de Sebastiania commersoniana e das espécies arbóreas exóticas invasoras Hovenia dulcis e Ligustrum lucidum em remanescente de Floresta Ombrófila Mista Aluvial em Araucária, Paraná. Foram selecionados indivíduos presentes no dossel e sub-bosque. Cintas dendrométricas foram instaladas em todos os indivíduos selecionados, que foram monitorados mensalmente, de julho de 2009 a junho de 2012. Os incrementos correntes mensais e anuais foram correlacionados com precipitação e temperatura. As espécies exóticas e os indivíduos do dossel apresentaram incremento superior à espécie nativa, que teve pouca variação ao longo do ano, e aos indivíduos de sub-bosque. Correlações significativas do incremento foram obtidas com temperatura e precipitação, mostrando que o crescimento em diâmetro está, em grande parte, relacionado às condições meteorológicas.

ABSTRACT This study aims to evaluate the periodicity of trunk diameter increment of Sebastiania commersoniana and the two invasive exotic tree species, Hovenia dulcis and Ligustrum lucidum, in a remnant area of Alluvial Mixed Rain Forest at Araucaria, Paraná. We selected individuals of the different species present from canopy and understory. Dendrometric bands were installed in all individuals, which were monitored monthly, from July 2009 to June 2012. The monthly and annual current increments were correlated with precipitation and temperature. Exotic species and canopy individuals presented increment higher than native species, which had low variation in the year, and understory individuals. Significant correlations were obtained between the increment diameter and temperature and precipitation, showing diameter growth of the species is mostly conditioned by the meteorological conditions.

RESUMO A fenologia, o incremento em circunferência do tronco e a atividade cambial de indivíduos de Cedrela fissilis (Meliaceae) foram observados mensalmente em duas tipologias de Floresta Ombrófila (Densa e Mista) na Floresta Atlântica, Estado do Paraná, Brasil. As observações se deram por meio do método de índice de atividade, leitura de incremento em circunferência do tronco com o uso de dendrômetros permanentes e amostragens periódicas de tecido cambial de 24 árvores da espécie. O ritmo de incremento observado é sazonal, iniciando-se após a expansão total do limbo e interrompendo-se quando as folhas maduras estão em senescência adiantada e/ou em sua ausência. Análises estatísticas mostraram relações significativas entre incremento, variáveis climáticas e fenologia. A espécie apresenta formação de anéis anuais de crescimento, sendo observadas flutuações anatômicas intra-anuais. Os resultados indicam que a fenologia vegetativa dos indivíduos parece ser influenciada mais fortemente pelo fotoperíodo e temperatura do que pela precipitação.

ABSTRACT Phenology, girth trunk increment and cambial activity of Cedrela fissilis (Meliaceae) individuals were monthly evaluated in two distinct units of the Atlantic Forest (Ombrophilous Dense and Mixed forests), in the state of Paraná, Brazil. Readings of 24 individuals were assessed by activity index, permanent band dendrometers, and periodic samplings of cambial tissue. The girth increment rhythm is seasonal, it begins after total leaf blade expansion and is suspended when mature leaves are in advanced senescence and/or absent. Statistical analysis shows significant relationships between girth increment, climatic variables and phenology. The species presents annual growth rings and intra-annual anatomical fluctuations. Its vegetative phenology seems to be more strongly driven by day length and temperature than by precipitation.