Land-Use Effects on Aquatic and Wetland Ecosystems: An Overview of Environmental Impacts and Tools for Ecological Assessment

MISERENDINO, M.L.; BRAND, C.; ASSEF, Y.A.; HORAK, C.N.; MANZO, L.M.; EPELE, L.B.; WILLIAMS-SUBIZA, E.

Freshwaters and Wetlands of Patagonia

Springer Cham

Año: 2022; p. 295 - 323

Unlike in many other territories, the colonization process in Patagonia is relativelyrecent; however, important human-induced changes have occurred since the arrivalof the first settlers. With regard to aquatic resources, there has been frequent irresponsible management driven by the idea that the supply of water is unlimited.Despite their low population density (2.5 inh km−2), some areas in Patagonia areseeing an important increase in population, at a higher rate than many other regionsin Argentina (INDEC 2010). This expansion is promoting an intensification of theland use (Morello et al. 2018; Nanni et al. 2020) and is having significant environmental impacts on the region’s aquatic resources.According to Morello et al. (2018), three different ecoregions can be distinguished in the vast Patagonian territory (Fig. 11.1). A narrow strip of forests overand along the Andes and at the headwaters of all Patagonian basins forms thePatagonian Forest ecoregion. It is extended on the occidental part of Neuquén, RíoNegro, Chubut, Santa Cruz province, and the austral strip of Tierra del Fuego,Antarctic, and South Atlantic Islands. The ecoregion also exhibits a wide proportion of shrubs, rocks, and continental ices. The temperate semi-deciduous rainforestdominates, with species changing with elevation, location (exposure), and latitude.The Patagonian Steppe ecoregion is a vast area that comprises Southwestern ofMendoza, west of Neuquén and Río Negro, most of Chubut and Santa Cruz andnorth of Tierra del Fuego. The main vegetation forms are shrub-grass species mostlyadapted to extreme aridity conditions, low temperature, strong winds, and frequentfrosts. It is composed of short shrubs, with cushion forms, prickly, with reduced leafor even leafless. The herbaceous steppe with xerophytic grasses appears in a lowerproportion. Wetlands are conspicuous in the continental sector and include meadows, marshes, bogs, forests, and shrubs (see Chap. 10). The Plains and PlateausMonte ecoregion spreads from the Andes Cordillera to the Atlantic Ocean andincludes great part of Mendoza, Neuquén, La Pampa, and a little portion of RíoNegro and Chubut provinces. The landscape is dominated by plains and staggeredplateaus wherein aridity is a prevailing feature (see details in Chap. 1).The main land-use practices in Patagonia include extensive livestock breeding,pasture conversion, forestry, pine plantations, mining and oil extraction, and to alesser extent urbanization and industrial development. These practices have led tomajor ecosystem stressors, defined as any physical or chemical change promoted byanthropogenic action that causes significant modifications in biological components, patterns, and relationships in natural systems (Sundermann et al. 2013).According to Dudgeon et al. (2006), five major threats or stressor categories havethe potential to impact on freshwater biodiversity: overexploitation, water pollution,flow modification, habitat degradation, and species invasion. However, new threatsemerged during the last few decades, with some of them disproportionately impacting freshwater systems (Reid et al. 2019). The consequences or impacts of thesestressors are quantifiable through the assessment of the attributes of biological components. Among organisms that respond consistently to different stressors areperiphyton, macrophytes, and macroinvertebrates (Allan et al. 2021).Biodiversity in Patagonia is globally significant due to the region’s pronouncedendemism, habitat heterogeneity, and biogeographic location (Morrone 2006).There is strong concern from a conservation standpoint, since both ongoing andemerging land-use practices are rapidly changing the ecological status of freshwaterresources in the region.