ABSTRACT
The amounts and pathways of reactive nitrogen (Nr) losses in Austria into the surface water, soil, and atmosphere were determined under four climate change scenarios for the period 2041-2070. Two nutrient models were used to undertake the analysis at two different scales. Firstly, a semi-empirical, conceptual model (MONERIS) was setup for Austria to calculate the overall annual Nr surpluses, categorise flows of Nr, and identify regional hotspots of Nr losses. Secondly, a physically based eco-hydrological model (SWAT) was setup in three agricultural catchments to determine the hydrological processes related to Nr transport and quantify the amounts transported by various pathways in cropland at a detailed spatial and temporal resolution. The agricultural N surplus calculations for Austria were revised and used as input data for both models. The MONERIS and SWAT simulated inorganic N loads transported into waterbodies are overall similar, with average differences for the subsurface inorganic N loads of ±3 kg ha-1 yr-1 and for surface inorganic N loads of +0.4 to -0.03 kg ha-1 yr-1. Crop level N losses under future climate scenarios was contingent upon the fertilizer type, the crop grown and its accumulated biomass, as well as the type of climate scenario (wet or dry). In the SWAT model, an examination of the sensitivity of the input data (climate data and parameter values) found the dominant contribution to the sensitivity of simulated monthly discharge was from the climate data (69 % to 98 %). For simulating N loads, the climate scenarios contributed 30 % to 89 % of the sensitivity. Simulating Nr flows under climate scenarios is policy relevant to assess critical areas of N losses and identify future N transport pathways. Using a dual-model approach saves on resources required to set up a complex, data intensive model at a large scale, and can focus on critical catchments in detail.
ABSTRACT
Abstract: The development of strategies that conciliate anthropogenic activities with nature conservation is becoming increasingly urgent, particularly in regions facing rapid conversion of native vegetation to agriculture. Conceptual modelling enables assessment of how anthropogenic drivers (e.g. land use/land cover change and climate change) modify natural processes, being a useful tool to support strategic decision-making. The present work describes a conceptual model to evaluate water-related ecosystem service provision under different land use scenarios in the Matopiba region of the Brazilian Cerrado, the world's most biodiverse savanna and an agricultural frontier. Model variables were determined (direct drivers, indirect drivers, focal components and responses) and the Nature Futures Framework was consulted to incorporate socio-ecological components and feedbacks. Future scenarios were developed considering potential trajectories of drivers and governance responses that may impact land use in the region, including the possibility of full compliance with Forest Code and implementation of the Soy Moratorium in the region. The conceptual model and scenarios developed in the present study may be useful to improve understanding of the complex interactions among anthropogenic drivers, water-related ecosystem services and their potential repercussions for natural and social systems of the region. Governance decisions will be critical to maintaining the ecosystems of the region, the services it provides and the culture and tradition of the people historically embedded in the landscape. In acknowledgment of humanity's dependence on nature, the importance of inverting the way scenarios are used is highlighted. Rather than using scenarios to measure the impacts of different policy options on nature, scenarios representing the desired outcomes for biodiversity and ecosystem services can be used to inform how policies can guarantee ecosystem integrity into the future.
Resumo: O desenvolvimento de estratégias que conciliem atividades antropogênicas com a conservação da natureza tem se tornado cada vez mais urgente, principalmente em regiões que enfrentam uma rápida conversão da vegetação nativa em agricultura. Modelos conceituais permitem avaliar como fatores antropogênicos (por exemplo, mudança de uso e cobertura do solo e mudanças climáticas) modificam os processos naturais, sendo uma ferramenta útil para apoiar a tomada de decisões estratégicas. O presente trabalho descreve um modelo conceitual para avaliar a provisão de serviços ecossistêmicos relacionados à água sob diferentes cenários de uso do solo na região de Matopiba, no Cerrado, a savana com maior biodiversidade do mundo e uma fronteira agrícola. Foram determinadas as variáveis do modelo (fatores diretos, fatores indiretos, componentes focais e respostas) e o Nature Futures Framework foi consultado para incorporar componentes socioeconômicos e feedbacks. Cenários futuros foram desenvolvidos considerando possíveis trajetórias de fatores antropogênicos e respostas de governança que podem impactar o uso do solo na região, incluindo a possibilidade de cumprimento total do Código Florestal e a implementação da Moratória da Soja na região. O modelo conceitual e os cenários apresentados no presente trabalho podem ser úteis para melhorar a compreensão das complexas interações entre fatores antropogênicos, serviços ecossistêmicos relacionados à água e suas possíveis implicações para os sistemas naturais e sociais da região. Decisões de governança serão críticas para manter os ecossistemas da região, os serviços fornecidos por eles, a cultura e tradição das pessoas historicamente inseridas na paisagem. Em reconhecimento da dependência da humanidade em relação à natureza, destaca-se a importância de inverter a maneira como os cenários são usualmente usados. Em vez de mensurar os impactos de diferentes políticas na natureza, cenários representando os resultados desejados para biodiversidade e serviços ecossistêmicos podem ser usados para informar como políticas podem garantir a integridade dos ecossistemas no futuro.
