Abstract Green areas have important social, biological and aesthetical values. They might provide house and food for fauna, protect biodiversity and can provide several ecosystem services of provision, regulation, support and culture. This research aimed to analyze composition of native and exotic species in urban parks in São Paulo (Brazil), in response to variables considered drivers of diversity adapted to urban environment and to socioeconomic aspects. We expected that socio-economic factors and age and size of parks would be important determinants of species richness All county parks (municipal management) larger than 1 ha were selected, which summed 68 parks throughout São Paulo. Socioeconomic variables for this study were population, growth rate of population, average per capita income, IDH and population density. We also accessed native and exotic species richness of plants and trees from the flora list of each park. In order to determine the effects of park size and age and neighbourhood socio-economic status on richness of plants and trees we used multiple regression analyses. We found a great species richness in urban parks in São Paulo and that richness associated to park age and size, and to some socio-economic factors, especially when combined to age and size of parks. Bigger sites could offer more resources and area for the growth and establishment of native plants, and older parks in São Paulo likely had more management and interventions improving its biodiversity. Lastly, in vulnerable regions and in smaller and newer parks, we recommend improvement in plant species diversity by managers.

Abstract Brazilian biomes have been experiencing an increase in fires during the whole year, but fires increase substantially during drier periods. Several indexes might be good indicators of the severity of the droughts, such as The Rainfall Anomaly Index (RAI), Standardized Precipitation Index (SPI) and the Vegetation Health Index (VHI). This study therefore aimed to understand the dynamics of climate, using some indexes and fires in Paraíba do Sul River Valley, Paulista portion, to verify whether fire is more likely to spread in hotter and drier years. We hypothesized that fire events are more frequent and burned areas are larger in hotter and drier years in the region. By conducting a cross-correlation analysis and separating the monthly data into dry and rainy seasons, it was possible to establish a correlation between climate parameters and fire. A significant correlation was found between RAI and fires in both seasons. Additionally, we observed that high occurrences of fire events and burning areas were more explained by RAI, VHI and SPI-3 in dry and wet seasons than by temperature and SPI-1, SPI-6 and SPI-12. We noticed a complex dynamic between fire events, burned area, the environment, and climatic variables. However, the studied indexes proved to be effective tools for detecting drought conditions in the region and their relationship to fire.

Resumo Os biomas brasileiros têm experimentado um aumento nos eventos de queimadas (focos e área queimada) durante todo o ano, mas as queimadas aumentam substancialmente nos períodos mais secos. Vários índices podem ser bons indicadores para medir a severidade das secas como o Índice de Anomalia de Chuvas (RAI), Índice de Precipitação Padronizada (SPI) e o Índice de Saúde da Vegetação (VHI). Assim, este estudo teve como objetivo compreender a dinâmica entre clima, usando alguns índices, e incêndios no Vale do Rio Paraíba do Sul, porção paulista, e verificar se há maior probabilidade de propagação do fogo em anos mais quentes e secos. Nossa hipótese é que os eventos de incêndio são mais frequentes e as áreas queimadas são maiores em anos mais quentes e secos na região. Ao realizar uma análise de correlação cruzada e separar os dados mensais em estação seca e chuvosa, foi possível estabelecer uma correlação entre os parâmetros climáticos e o fogo. Uma correlação significativa foi encontrada entre RAI e incêndios em ambas as estações. Adicionalmente, observamos que as altas ocorrências de eventos de incêndio e área queimada foram mais explicadas pelo RAI, VHI e SPI-3 nas estações seca e chuvosa do que pela temperatura e SPI-1, SPI-6 e SPI-12. Percebemos uma dinâmica complexa entre eventos de incêndio, área queimada, ambiente e variáveis climáticas. No entanto, os índices estudados se mostraram ferramentas eficazes para detectar as condições de seca na região e sua relação com o fogo.

RESUMO A adoção de sistemas de plantios mistos (espécies exóticas e nativas) é viável e representa uma importante alternativa no contexto da restauração florestal e paisagística. Este estudo avaliou se o cultivo de Eucalyptus está associado a mudanças na cobertura florestal nativa e conectividade de fragmentos na região de 1987 a 2017. A região de estudo (Mata Atlântica do Sudeste) vem passando por um processo de transição florestal. Com base em imagens de satélite, mapas de uso e cobertura da terra e uma comparação pareada, verificamos que a dinâmica em uma cobertura da terra não estava necessariamente associada à outra. A partir de 2007 verificamos um aumento da cobertura de Eucalyptus, possivelmente relacionado às regras do Novo Código Florestal, que permite o uso de plantios de espécies exóticas para recomposição da vegetação, não ultrapassando 50% da área total, e aumento da cobertura vegetal nativa, destacando o importante papel de várias ações de restauração que ocorrem na região e algumas regulamentações nacionais. Além disso, remanescentes florestais foram maiores e menos complexos com a presença de Eucalyptus, indicando que essa cobertura do solo é potencialmente benéfica para a conectividade dessa paisagem.

ABSTRACT The adoption of mixed plantation systems (exotic and native species) is viable and represents an important alternative in the context of forest and landscape restoration. This study evaluated whether Eucalyptus cultivation is associated with changes in native forest cover and fragment connectivity in the region from 1987 to 2017. The study region (Southeast Atlantic Forest) has been undergoing a forest transition process. Based on land use/land cover maps obtained from satellite images and a pair-wise comparison, it was detected that the dynamics in one land cover were not necessarily associated with the other one. It was verified an increase in Eucalyptus cover since 2007, possibly related to the New Forest Code that allows the use of exotic species in reforestation, provided it does not exceed 50% of the total area. An increase in the native vegetation cover was also observed, highlighting the importance of restoration actions and national regulations. In addition, forest patches were larger and less complex with Eucalyptus presence, indicating that this land cover is potentially beneficial for the landscape connectivity.

ABSTRACT Cerrado tree species can survive fire by resprouting. Generally, large and less damaged plants produce new branches and leaves from stem buds (aerial), whereas small and highly injured individuals would resprout from the stem base or from underground organs (basal). We compared the three most common Cerrado woody plant species in a savanna area of the IBGE Ecological Reserve, Brasília, Brazil, aiming to verify if the resprouting strategy (aerial or basal) differed between species and if that was related to plant size. Guapira noxia had small-sized plants, a higher percentage of trunk charred and more individuals with basal resprouting, while Eriotheca pubescens had large-sized plants with a greater intensity of aerial resprouting, Basal resprouting was associated with disturbance severity for Dalbergia miscolobium, while plant size was associated with aerial resprouting for E. pubescens. None of variables explained the variation in resprouting of G. noxia. The results showed that the post-fire regeneration strategy varied according to the species, confirming other studies of post-fire resprouting.

Mesmo adaptadas à baixa fertilidade dos solos, acredita-se que as espécies de plantas do Cerrado seriam capazes de responder a uma maior disponibilidade de nutrientes e alterar sua produtividade. Este estudo teve por objetivo comparar a produção de frutos, massa de frutos e sementes, germinação e comprimento e biomassa das plântulas da espécie arbórea Dalbergia miscolobium entre áreas fertilizadas e não fertilizadas de Cerrado sensu stricto na Reserva Ecológica do IBGE, Distrito Federal, Brasil. Não houve aumento na produção de frutos, na massa de sementes e na biomassa das plântulas de D. miscolobium em resposta ao aumento da disponibilidade de nutrientes minerais no solo. A massa dos frutos e a porcentagem de germinação foram menores em resposta à fertilização, enquanto o comprimento radicular foi maior em plântulas de sementes fertilizadas. Plantas adaptadas aos solos oligotróficos do Cerrado são menos exigentes em nutrientes e possuem estratégias, como a retranslocação de elementos minerais e orgânicos de órgãos senescentes que podem suprir a demanda por nitrogênio, fósforo e potássio necessários para as atividades reprodutivas.

ABSTRACT Even adapted to poor soil conditions, Cerrado plants may respond to higher nutrient availability and change their crop production. The aim of this study was to compare the fruit-production, fruit and seed mass, germination, seedlings length and biomass of Dalbergia miscolobium trees growing in fertilized and non-fertilized Cerrado sensu strict plots in Reserva Ecológica do IBGE, Distrito Federal, Brazil. Nutrient addition did not increase fruit-production, seed mass and seedling biomass of D. miscolobium. Fruit mass and seed germination were lower in fertilized plants; root length was higher in seedlings from fertilized seeds. Thus, plants adapted to the oligotrophic soils of Cerrado are less demanding in nutrients and have strategies such as retranslocation of mineral and organic elements of senescent organs that can meet the demand for nitrogen, phosphorus and potassium needed for reproductive activities.