Climate change in Brazil: perspective on the biogeochemistry of inland waters

Abstract

Although only a small amount of the Earth's water exists as continental surface water bodies, this compartment plays an important role in the biogeochemical cycles connecting the land to the atmosphere. The territory of Brazil encompasses a dense river net and enormous number of shallow lakes. Human actions have been heavily influenced by the inland waters across the country. Both biodiversity and processes in the water are strongly driven by seasonal fluvial forces and/or precipitation. These macro drivers are sensitive to climate changes. In addition to their crucial importance to humans, inland waters are extremely rich ecosystems, harboring high biodiversity, promoting landscape equilibrium (connecting ecosystems, maintaining animal and plant flows in the landscape, and transferring mass, nutrients and inocula), and controlling regional climates through hydrological-cycle feedback. In this contribution, we describe the aquatic ecological responses to climate change in a conceptual perspective, and we then analyze the possible climate-change scenarios in different regions in Brazil. We also indentify some potential biogeochemical signals in running waters, natural lakes and man-made impoundments. The possible future changes in climate and aquatic ecosystems in Brazil are highly uncertain. Inland waters are pressured by local environmental changes because of land uses, landscape fragmentation, damming and diversion of water bodies, urbanization, wastewater load, and level of pollutants can alter biogeochemical patterns in inland waters over a shorter term than can climate changes. In fact, many intense environmental changes may enhance the effects of changes in climate. Therefore, the maintenance of key elements within the landscape and avoiding extreme perturbation in the systems are urgent to maintain the sustainability of Brazilian inland waters, in order to prevent more catastrophic future events.

Aquatic Insect Biodiversity and Water Quality Parameters of Streams in Northern Thailand

“…In the present study the parameters like dissolved oxygen, sulfate and nutrient have direct impact on the growth of biotic communities. However the other physicochemical variables have a direct as well as an indirect effect on the biological diversity (Roland et al 2012). The physicochemical parameters are useful in detecting the effect of pollution on the water quality, but changes in trophic conditions of water are reflected in the biological community structure including species pattern, distribution and diversity (Ishas & Khan 2013).…”

Addressing key ecological questions to support policy-making in Brazil

“…Recently, several small to large reservoirs have been installed and the number of impoundments is expected to keep increasing in the future. In addition, both local environmental changes and global climatic changes have been changing the ecology and biogeochemistry of Brazilian inland waters (Roland et al, 2012).…”

Effects of global climate change on chlorophyll-a concentrations in a tropical aquatic system during a cyanobacterial bloom: a microcosm study

“…In aquatic environments, the major factors impacted by increased air temperatures are changes in precipitation and wind (Nickus et al, 2010;Roland et al, 2012). These factors can cause physical changes to the environment through stratification (Jeznach and Tobiason, 2015) or turbidity (Meerhoff et al, 2007), and chemical changes such as oxygen concentration (Gordon et al, 2004;Jeppesen et al, 2013) or nutrient cycling (Lecerf et al, 2007), and biological changes in the phenology of species (Daufresne et al, 2009).…”

“…Experimental approaches have been used to evaluate the effect of climate change in aquatic environments. These experiments typically focus on the effects of the increased temperature expected in future scenarios (Jeppesen et al, 2010;Yvon-Durocher et al, 2010;Roland et al, 2012). However, recent studies have investigated other elements affecting aquatic ecosystems as well as their combined effects, such as the interaction between warming, drying, and acidification on consumers and planktonic producers (Christensen et al, 2006), the effects of climate change on water levels compounded with stratification (Berger et al, 2010), the effect of light and CO2 enrichment on nutrient concentrations (Andersen et al, 2005), and the effect of temperature and predation on phytoplankton community (He et al 2015).…”