Mapping and evaluating sugarcane expansion in Brazil’s savanna using MODIS and intensity analysis: a case-study from the state of Tocantins

In Brazil, the main biofuel crop is sugarcane, and with its rapid expansion, there is much debate about what land uses and land covers it is replacing, and what are the associated environmental and social impacts. Some argue sugarcane is mainly replacing cattle pasture, thus having minimal impacts on native vegetation and small-scale family farming. In contrast, others claim sugarcane is replacing cropland traditionally under soybeans, rice, beans, and corn. Thus, food security is negatively affected and small-scale family farming livelihoods and culture are threatened. This is a proof-of-concept paper illustrating methods contributing toward the resolution of such debates. First we map land use and cover change in areas undergoing sugarcane expansion using satellite data from MODIS (Moderate Resolution Imaging Spectroradiometer); second, we test the hypothesis that sugarcane is replacing traditional annual crops using intensity analysis, via a case study of land change in the municipality of Pedro Afonso, Tocantins in northern Brazil between the 2008–2013 crop years. Maps matched reference data with overall agreements between 87–91%. Intensity analysis confirmed sugarcane is replacing annual crops much more than cattle pasture and other land uses and covers, pointing to particular economic and social processes driving land change.     

Removal of Hg2+ ions by adsorption using (TiO2@MnO2)-NPs nanocomposite

Journal of Material Cycles and Waste Management - Waste water contaminated with inorganic mercury is considered a serious environmental problem, mainly due to the hazardous effects this contaminant...     

Effect of unfavorable trophic scenarios on amylase and protease activity of <Emphasis Type="Italic">Nephrops norvegicus</Emphasis> (L.) larvae during their first vertical migration: a laboratory approach

In Portuguese waters, Nephrops norvegicus larvae hatch at 400–800 m depth and need to perform a vertical migration to food-rich shallower waters to find suitable prey. The effect of suboptimal feeding on digestive enzymes activity of N. norvegicus larvae during this early period of their larval life remains unknown. Protease and amylase activities were investigated ex situ using flurometry in laboratory-hatched larvae exposed to different feeding and/or starving scenarios in the 24 h following hatching, the period during which they typically accomplish their upward vertical migration. Amylase activity was very low in comparison with protease activity, indicating that carbohydrates are not a primary energy reserve. Larvae starved for 12 h and subsequently fed displayed no increase in amylase activity, which suggests that feeding may be required before 12 h post-hatch to trigger amylase activity. Protease activity was high under all feeding conditions, and the increase in protease activity under sustained starvation indicated the catabolism of protein reserves. The ability of first-stage N. norvegicus larvae to metabolize protein reserves may play a decisive role for their survival during their first vertical migration, as it enables them to overcome the deleterious effects of short-term starvation and/or suboptimal feeding.     

Invasion by <Emphasis Type="Italic">Artocarpus heterophyllus</Emphasis> (Moraceae) in an island in the Atlantic Forest Biome,Brazil: distribution at the landscape level,density and need for control

Invasion by alien species is one of the most critical factors affecting global biodiversity, leading to homogenization and species loss worldwide. Jackfruit (Artocarpus heterophyllus Lam., Moraceae) is one of the most conspicuous invasive plants in Brazil. We studied jackfruit invasion in the Atlantic Forest in Ilha Grande State Park, located on an island (Ilha Grande), by assessing jackfruit distribution and density along 23 trails (90 km). Presence or absence was verified in a total of 857 plots. Data showed that jackfruit is spread all over Ilha Grande, and that plant density varied significantly along and between trails. Jackfruit was registered as the dominant tree species on some of the trails. Control by park managers is an urgent need in order to ensure the conservation of local biodiversity. A decision key for jackfruit management according to jackfruit density, age class and slope is provided.     

Exploring community assembly through an individual-based model for trophic interactions

Traditionally, the dynamics of community assembly has been analyzed by means of deterministic models of differential equations. Despite the theoretical advances provided by such models, they are restricted to questions about community-wide features. The individual-based modeling offers an opportunity to link bionomic features to patterns at the community scale, allowing us to understand how trait-based assembly rules can arise by dynamical processes. The present paper introduces an individual-based model of community assembly, and discusses some of the major advantages and drawbacks of this approach. The model was framed to deal with predation among size-structured populations, incorporating allometric constraints to energetic requirements, movement, life-history features and interaction relationships among individuals. A protocol of assembly procedure is proposed, in which a period of intense species introductions is followed by a period without introductions. The resultant communities did not present any pattern of trait over-dispersion, meaning that the multivariate distances of bionomic features among co-occurring species were neither larger nor more regular than expected in a random collection of species. It suggests a weak influence of interspecific interactions in the model environment and individualistic rules of coexistence, driven mainly by the spatial structure. This highlights that trait over-dispersion and resource partitioning should not be considered a necessary condition for coexistence, even in communities entirely structured by internal processes like predation and competition.