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Abstract: The development of systemic environmental monitoring and indicators for sustainability requires one to tackle the complexity of human–environmental systems. To this end the ecosystem approach is proposed here as a framework and the ecological network analysis as a tool for investigation while an urban system, represented as a water flow network, is discussed as a case study. Flow distribution is used to calculate total system throughput, development capacity, average mutual information, ascendency and overhead. These indices condense the complexity of the flow structure (representing system''s metabolism) into a few measures that provide information on how systems grow and develop; because of this they are consistent with the sustainability context. Two alternative scenarios are presented to discuss the effects of management actions (policies) on sustainability as they change the flow structure and system level indices. While it is shown that increasing system activity (intensity of processes) augments potential for development but not realized development, actions that improve the organization of flows, thus increasing average mutual information, may reduce total system throughput and drive the system toward more sustainable conditions. System level indices are holistic measures that unveil the relation between internal processes and whole system performance. Understanding this relation is crucial because the former are the target of environmental policies but sustainability, the objective of such policies, is an overall system trait. Because of these features system level indices can be examples of a new quality of indicators for sustainability assessment. [Copyright &y& Elsevier]

Abstract: In this study, we review the current available information on the social–ecological context of Brazilian tropical dry forests (TDFs), a vegetation type that covers approximately 3% of the country territory. For this purpose, we conducted a comparative analysis of two case studies, one study in the north of Minas Gerais state and the other in Paranã River Basin, situated in southeastern and central Brazil, respectively. We compiled published bibliographical and census-based data for the two regions, concerning the historical human occupation and land use and the environmental and development policies affecting TDF management and sustainable use. Brazilian TDFs usually occur in semi-arid climates, and have been intensely converted mainly to extensive pasturelands in large farms, thus leading to high income concentration in those areas. Our case studies involve less-developed regions that support populations with very low human development indices, which is the norm for Brazilian TDFs. Many of these are traditional populations, such as indigenous and slave descendents, with peculiar cultural practices only recently considered in government policies proposed for the forest management. Though the two regions have similar land use histories, current social–ecological scenarios are very different. In the north of Minas Gerais, TDF conversion policies were debated intensely for the last 15 years, recently resulting in a state law specifically generated to regulate TDF use. Also, this region has 20 conservation units (CUs), some of them delimited inside the territories of the several traditional populations that inhabit TDF areas. This process caused enduring conflicts that can affect both CUs’ effectiveness and the sustenance of these populations. In the Paranã River Basin, there is no specific policy towards TDFs, whose use is regulated by the 43-year-old Brazilian Federal Forest Code. There are only four CUs in this region, and most traditional populations were expelled from their original territories and consequently lost their cultural identity. Government sustainability strategies are limited to the establishment of CUs, a response that may disregard social demands and cultural practices, depending on the local context. Given the uniqueness and threat level to TDFs, specific and more diversified policies towards land use should be established for these ecosystems in order to stimulate low-impact activities that maintain ecosystem services and improve the livelihoods of TDF inhabitants. [Copyright &y& Elsevier]