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.