In aquatic sciences, the agreement between laboratory and field observations remains a challenge. Using kinetic modeling, this research aims to compare the decomposition in laboratory and in situ conditions. In the in situ incubations, the mass decreases of the aquatic macrophytes (Echinodorus tenellus, Hydrocotyle verticillata, Najas microcarpa and Pontederia parviflora) were described using a litter bag technique and in the laboratory their decomposition was maintained under controlled conditions. The plants and water samples were collected from a tropical reservoir (Brazil). To describe the particulate organic carbon (POC) decay we adopted a two stage kinetic model that considered the heterogeneity of resources. The released organic carbon (i.e., losses related to mineralization, dissolution and sedimentation of smaller particles than the litter bag mesh) were used to compare the results derived from the field and laboratory incubations. Despite the methodological differences, the results show equivalence among the POC decay. The decomposition measured by litter bags method was 1.32 faster, owing to the effects of losses by sedimentation of the smaller particles, abrasion, action of decomposer organisms (e.g., fragmentation and enzymatic attack) and synergy among these factors. From a mathematical modeling approach, the results validate the use of decomposition data obtained under controlled conditions providing estimations of energy and matter fluxes within aquatic ecosystems. However, it is necessary to adopt a coefficient to acquire the similarity (e.g., 1.32).

Brazil is the world's richest country in biodiversity, including mammal species. In the Brazilian Cerrado biome, mammalian diversity is vast, with about 251 species, 32 of them are endemic and 22 listed as threatened species. In this work, we investigated species diversity of medium- and large-sized mammals in the private protected area RPPN Pontal do Jaburu (RPPN-PJ) and its surroundings, which is a flooded area located in an important biological corridor in the Cerrado-Amazon ecotone zone, a priority area for biodiversity conservation in Brazil. We used camera-trapping, active search (night and day), and track survey during dry season (Apr – Aug 2016). We recorded 29 mammal species, being the Carnivora order the most representative with 11 species. Regarding threat status, 35.7% of the recorded species were listed as threatened in Brazil and 32.1% worldwide. We highlight the high relative frequency of threatened species records such as Tapirus terrestris, Panthera onca, Blastocerus dichotomus, Pteronura brasiliensis, Priodontes maximus, and other, as well as the presence of the newly described aquatic mammal species Inia araguaiaensis. We stress the importance of RPPN-PJ and its surroundings for mammal conservation, which include complex habitats (wetlands) located in an important ecotone zone.