Brazilian and German researchers are jointly attempting to understand the processes that regulate soil respiration in different land use models in Amazonian Basin areas. Based on such information, the researchers intend to offer support information for decision making on which models more are more suitable for the environmental rehabilitation of agricultural areas in the region. Soil respiration is a set of biochemical phenomena that involves natural factors such as temperatures, humidity, nutrients and oxygen levels, and which are influenced by human action such as, for instance, soil and environmental management. The process involves emissions of carbon dioxide (CO2) and other gases such as methane (CH4) and nitrous oxide (N2O), which are some of those known as greenhouse gases (GHG). The Embrapa Western Amazon researcher Roberval Lima considers that the research project has excellent and unprecedented results available to quantify CO2, CH4 and N2O emissions in the Amazon Basin. “With this measurement, it is going to be possible to reflect and have an understanding from a pedogeochemical point of view of the different land use changes in Central and South Amazon regions”, he asserts. The initiative involves two complementary projects: one of them is Eco Respira Amazon, led by the German university Techinische Universität Bergakademie Freiberg (Tubaf), in partnership with Embrapa Western Amazon, which intends to understand respiration in the ecosystem and emissions from soils in the Amazonian Basin, and how they comparativily vary from one environment to the other and land uses in the Amazon biome. The project “Ecologically sustainable models for compliance with the Brazilian Forest Code by rural properties in Amazonas state (ModelCF Amazon)”, led by Embrapa Western Amazon, has the aim of using data related to respiration in ecosystems to propose and implement models to restablish Permanent Preservation Areas, Legal Reserve Areas and Restricted Use Areas, which can make rural properties' environmental compliance possible in Amazonas state. “We want to gather this knowledge and turn it into a technological solution for use in the processes of forest recovery to comply with the Forest Code”, asserts one of the coordinators of the Model CFAmazon project, the Embrapa Western Amazon researcher Roberval Lima. The projects are implemented in partnership with the Interdisciplinary Environment Research Center of the German University Techinische Universität Bergakademie Freiberg (Tubaf) and Embrapa Western Amazon, in Amazonas, Brazil. Other participating institutions are the Amazonas Institute of Environmental Protection (Ipaam) and the Federal University of Amazonas (Ufam), and the National Institute of Meteorology (Inmet) and National Amazon Research Institute (Inpa) are also collaborators. Advanced measurement technology According to Jörg Matschullat, a researcher from the German university Tubaf and Eco Respira Amazon project coordinator, this study's differential lies in the methodology used to measure soil and ecosystem respiration. Matschullat explains that the equipment used in the measurements quantifies gas emissions through a high-precision spectrometer that can measure both carbon dioxide and other gases. But learning about emissions is not the only issue at stake. “Emissions are just an indicator, nothing more. We study much more than this: soil chemistry, soil physics, and all of this information are combined to obtain a complex vision on how system operates”, he says. The team uses a portable chamber system that contains a closed tube and is planted in the soil. The equipment's portability allowed the team of researchers more mobility to perform the measurements, as they went to 13 different locations in Central and South Amazonas state, comprising forest soils, areas with several agricultural models, and pasture areas. The field work started in 2016 and lasted until early 2017. The measurements were repeated in the dry and rainy seasons. “And now we have representative data on the Amazonian Basin, which, at least in my eyes, are also valid for other areas with the same kind of biome like central Africa and parts of Asia”, Matschullat celebrates. “The data collected in the Amazon region are going to bridge an important gap in the apprehension of tropical climates and contribute to a broader understanding of ecosystems in the Amazonian Basin”, states the researcher. “There is a lack of data on biomes in the Southern Hemisphere, which play a role of major relevance in the way our planet works”, ponders the German researcher, who works with environmental geochemistry, climatology and ecosystem chemical reactions. The project team also relies on other biogeochemistry, geoecology, agronomy and forest science professionals . The next challenge is the data analysis for the elaboration of technical-scientific publications. At that stage, the Embrapa researcher Roberval Lima will be in Germany until the end of 2017, working with researchers at Tubaf. According to the Embrapa researcher, the data interpretation will analyze the best agricultural models from an environmental point of view, and how they can be adjusted to sustainably generate income. Up to the moment, the measurements took place following different models, such as: Agroforestry systems (AFS) Brazil nuts, Brazil nut monoculture for fruit and timber production, açaí berry production system, pastures, orande monoculture in different kinds of soils, among others. The basic model of comparison is the little disturbed native forest. Lima explains that the intention is to expand the models' representation, which will be proposed at a future stage of the project. The study results will be used to identify the extent to which each land use model contributes to soil carbon stocks, and be the foundation to validate which models are more suitable and efficient for environmental recovery. “This work in partnership will bring forth high level scientific contributions and practical answers to governments and farmers,” hopes Matschullat, the researcher. The scientist believes that the results could offer alternatives to support soil management in the Amazon and humid tropical regions. About the projects Both projects are part of international Brazil-Germany cooperation, through the New Partnerships program (Nopa II). On the Brazilian side, the partnership is funded by the Brazilian Federal Agency for Support and Evaluation of Graduate Education (Capes), and European country has funds from the agencies Deutscher Akademischer Austausch Dienst (DAAD) and Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ). Forest recovery models for the Amazon According to the agricultural control manager of the Amazon Environmental Protection Institute (Ipaam), the state's environmental inspection agency, Alexandra Bianchini, there is an expectation in the environmental agency that the project results can help the implementation of the Environmental Compliance Policy for rural properties by indicating technical parameters regarding which models are more effective for the rehabilitation of degraded areas. “The project results are long-awaited and will be important so that the responsible agency can assess environmental recovery plans with confidence that they are approving proposals that actually can provide an ecological response to the environment that is being recovered”, Alexandra assesses. She adds that it is important that the environmental recovery models also promote economic gains for farmers. Translation: Mariana Medeiros