1. Introduction
Fast-growing forest plantations represent an important part of the economy of countries located in the tropical region (Payn et al., 2015), expanding in the last decade mainly to meet the demand for cellulose for industry (Costa & Oliveira, 2019). The expansion of forest plantations to regions with greater human presence and occupying areas previously used by agriculture is responsible for the existence of some conflicts, among which those related to water use stand out (Cao & Zhang, 2015; Ferraz, Rodrigues, Garcia, Alvares, & Lima, 2019; Gerber, Veuthey, & Martínez-Alier, 2009; Van Wilgen & Richardson, 2012).
The concern about water use by fast-growing plantations is old in these regions and mainly results from the early period of the introduction of plantations, when environmental regulation was lower, forest management technology was developing, and the socio-environmental commitments of the companies were not yet so clear (Lima, Ferraz, Rodrigues, Zakia, & Salemi, 2017).
As a result of this period, the debate on the hydrological effects of plantations lasted for years and still persists (Scott, 2005), although several studies on forest hydrology have begun (Sahin & Hall, 1996; Scott, 2005) and already have results that can clarify the initial doubts (Farley, Jobbagy, & Jackson, 2005; Van Dijk & Keenan, 2007) and guide forest management and public policies (Ferraz et al., 2013; Little et al., 2014). Among the studies conducted, we highlight the hydrological monitoring of catchments in production areas which evaluates the effects of forest management on the quantity and quality of water (Ferraz et al., 2019; Neary, 2016; Scott & Prinsloo, 2008).
Brazil occupies a prominent position in this debate, not only because of the high productivity of plantations (Stape et al., 2010) and expansion of the sector (FAO, 2020), but also because of the location of plantations in regions with lower water availability, where some conflicts for water use begin to emerge (Ferraz et al., 2019). And following the development of the sector, research in forest hydrology in planted forests began in the late 1980s with hydrological monitoring in catchments (Arcova & Lima, 1985; Lima, 1988; Lima, 1987). Among them, the experimental area of the University of São Paulo located in Itatinga-SP stands out with one of the first experimental catchments to evaluate the effects of forest management in Brazil (Lima, Ferraz, Rodriguez, & Voigtlaender, 2012).
Currently, the debate on the hydrological effects of plantations has been changing from water use by forest plantations (Calder, Hall, & Adlard, 1992), or their comparison with native forests (Hou, Duan, Tang, & Fu, 2010; Klinge, Schmidt, & Fölster, 2001; Salemi et al., 2013), to which changes in forest management can reduce effects on water use and regulation in production areas (Dai, Wang, Zhu, & Xi, 2017; Vanclay, 2009). Despite the potential for reduction of effects from changes in the landscape scale, such as reduction in the occupation of the catchments by the plantations (Lima et al., 2012; Little, Cuevas, Lara, Pino, & Schoenholtz, 2014), or use of the mosaic of ages (Ferraz, Lima, & Rodrigues, 2013) and even advance in soil and water conservation techniques by forest management (Aust & Blinn, 2004; Silva, Silva, Curi, Avanzi, & Leite, 2011), there are still gaps in knowledge about forest management strategies related to the rotation cycle (Scott & Prinsloo, 2008; Vertessy, Watson, & O’Sullivan, 2001), conduction of regrowth (Neary, 2016), strategies for locating plantations in the landscape (Kalantari et al., 2014), in addition to the climatic influence of past years (David, Henriques, David, Tomé, & Ledger, 1994).
As these situations are not commonly used in commercial management of plantations, the monitoring of different forest management strategies is more difficult to implement and is restricted to experimental areas (Tetzlaff, Malcolm, & Soulsby, 2007). In this study we analyzed the hydrological regime of 3 paired catchments under different types of forest management including cutting, regrowth, ages and forest types, which allows us to understand the effects of forest management on the quantity and quality of water.