The total area of study covers an extension of 683,150 ha, equivalent to the amount areas of the Jacaré-Guaçu and Jacaré-Pepira watersheds with areas of 416,800 ha and 266,350 ha, respectively. The study area is located between 21˚37’/22˚31’ south latitude and 47˚43’/49˚02’ west longitude, encompassing around 58% of the Tiete-Jacaré watershed’s area (UGRHI 13). The total study area covers 22 municipalities of the eastern-central region of São Paulo state, of which only sixteen of their urban perimeters can be found on the watershed limits (Figure 1).

Four protected areas are within the Jacaré-Guaçu and Jacaré-Pepira watershed limits: two Integral Protection areas (Itirapina Ecological Station with 2300 ha and Mata do Jacaré Ecological Station with 7 5 ha); and two Sustainable Use areas (Environmental Protection Areas of Corumbataí-Botucatu-Tejupá and of Ibitinga with 214,706.70 and 64,900 ha, respectively) (Figure 1). These protected areas occupy about 280,000 ha of the total area of both watersheds, but only 75,000 ha are related to natural vegetation and water resources [15] .

The Jacaré-Guaçu River, with a 155 km long, begins between the São Carlos and Itirapina municipalities, while the Jacaré-Pepira River, with 174 km long, begins between the Brotas and São Pedro municipalities. The Jacaré-Guaçu and Jacaré-Pepira river mouth areas known as “Pantaninho” and “Varjão”, respectively, comprise a wetland system (Figure 1), with remnants of natural vegetation in an advanced recovery stage, known as “Pantanal Paulista” [15] .

The UGRH1 13 region (Figure 1) presents a Cwa climate, according to the Köppen-Geiger classification [16] , with hot and humid summers and dry winters. In the driest month, rainfall is less than 30 mm and medium temperatures are above 22˚C in the hottest months. Temperatures are lower than 18˚C in the colder months. The annual rainfall average is 1500 to 2000 mm [15] .

Economic activities are related to sugarcane and citrus cultivation, extensive areas for pasture and reforestation of Pinus sp. and Eucalyptus sp. The industrial sector is related to citrus fruits and sugar cane processing, as well as paper, beverages, footwear, and textiles. Some municipalities have natural scenic features that provide ecotourism activities [15] [17] .

Land use/cover dynamic were obtained based on screen digitizing of LandSat imagery, with 30 m spatial resolution, and a multispectral composite of three bands: near infrared, red and green wavelengths, over the 10-year period (2004-2014). The LandSat 5/TM and LandSat 8/OLI images, path 220 and 221, raw 75 and 76, were obtained on August 21 and 30, 2004 and August 1 and September 11, 2014, respectively. Image processing and georeferencing were carried out using ArcMap 10.2 software [18] .

The land use/cover typology was discriminated by tone, texture and context criterias [19] [20] , using on screen digitalizing. Each polygon of land use/cover was related to a previously first hierarchical level according to decreasing naturalness or increasing artificiality [21] [22] . The second hierarchical level described the typologies of land cover for each first level.

The consequences that land use changes have had on landscape naturalness were analyzed based on the Urbanity Index (UI) [23] . For this procedure, land use was considered to be the main driver of change in the ecosystem [3] . This study did not consider indirect drivers related to demographic, economic, socio-political, cultural, religious, scientific or technological conditions [24] [25] .

The UI [23] reflects the landscape naturalness condition and estimates (Equation (1)) the extent to which landscape is dominated by strongly human-altered systems [11] :

UI = log 10 [ A + U F + W ] (1)

where A denotes agricultural area, U urban area, F natural vegetation area, and W aquatic environments and wetland area.

The spatial representation of the Urbanity Index was obtained through the commands Vector, Raster, Area and Image calculator in the IdrisiSelva software [26] , rescheduled (fuzzy logic) for linear function, ranging between a minimum value = 0 (zero) and maximum value = 1 (one). This representation considers the maximum naturalness degree (UI = 0) and the minimum naturalness degree (UI = 1), which corresponds to human altered systems. High naturalness areas were defined by UI ≤ 0.3 values, whereas low naturalness areas were established by UI ≥ 0.7 values.

The permutational multivariate analysis of variance (PERMANOVA) [27] [28] with Euclidian distance was used to test the null hypothesis of equal naturalness conditions between the Jacaré-Guaçu and Jacaré-Pepira watersheds (factors), and 2004 and 2014 (levels) [28] . It was randomly sampled 1000 points of UI spatial distribution for 2004 and 2014 (levels). The sampling was carried out using the “dismo” [29] and “raster” [30] packages for program R [31] and the PERMANOVA test was performed using the “vegan” package [32] .

The watershed’s landscape pattern, over a 10-year period (2004-2014), is determined by the presence of four land use classes (Figure 2), later categorized into 13 land cover types, in both watersheds total area: 1) Natural (Mixed Semi-de- ciduous Forests and Cerrado vegetation); 2) Anthropogenic agricultural (temporary cropping , continuous cropping, forestry, pasture, bare soil and rural infrastructure); 3) Anthropogenic non-agricultural (urban area, industry, mining and road networks); and 4) Aquatic environment (rivers, lakes, reservoirs, and wetland).

The territorial limit of watersheds represents a human space occupation resulting from developmental actions in the natural landscape. Agricultural and

forestry sectors act as main drivers of change concerning watersheds [17] .

Natural land use in Jacaré-Guaçu and Jacaré-Pepira watersheds’ total area, over the 10-year period (2004-2014), showed a minimal increase in change, equivalent to 173,075 and 91,654 ha, respectively, mainly due to the reduction of agricultural activities (Figure 2). Quantitatively, 30% of natural vegetation has been proposed as a minimal limit to ensure sustainability in human-altered landscape [33] . Since natural areas occupy around 20% of the total area in each watershed (Figure 2), its continuous commitment is evidenced due to progressive anthropogenic agricultural and non-agricultural land use over the 10-year period (2004-2014).

Farming practices act as the main drivers of change as anthropogenic agricultural land use comprises over 70% of both watersheds total area. Anthropogenic agricultural land use was reduced around 1% compared to the Jacaré-Guaçu and Jacaré-Pepira watersheds (Figure 2), over the 10-year period (2004-2014).

Continuous cropping and forestry land cover reduced from 10.03% to 5.72% and 6.91% to 6.62%, respectively, while bare soil increased by 22.96% to 31.80%. The increase in the total area of bare soil, equivalent to 60,388.76 ha, could be associated with the sugarcane harvest, which occurs between April and October in the state of São Paulo, as well as sugar cane expansion to produce ethanol [34] [35] [36] .

The rate of land use change is increasing supporting biofuel feedstock production. In Brazil, sugarcane expansion is displacing degraded pastures, besides to impact soil physical quality due intensive mechanization [34] . In this case, human activities deplete natural capital stocks that support ecosystem services in society resulting in social problems, such as reducing the quality and availability of water in cities and biodiversity loss [5] . Sugar cane crops have also replaced citrus production areas, as a consequence of reduced production profitability [34] . This trend was also observed in the west of the state of São Paulo, where the soil fertility, climate and topography are favorable for citrus development [35] .

Non-agricultural anthropogenic land use increased by 3,357.13 and 669.57 ha in the Jacaré-Guaçu and Jacaré-Pepira watersheds’ total area, respectively (Figure 2), over the 10-year period (2004-2014). Increased urbanization area follows the number of inhabitants in 22 municipalities located at watershed boundaries, which increased from about 766,757 to 892,487 over the 10-year period (2000-2010), representing an average of 5700 inhabitants per municipality [37] [38] .

The aquatic environment showed an increase of 0.22%, equivalent to 886.13 ha, of Jacaré-Guaçu watershed total area, and a decrease of 0.15%, equivalent to 378.93 ha, of Jacaré-Pepira watershed total area (Figure 2), over the 10-year period (2004-2014). The reduction of the aquatic environment area may be associated with an atypical drought which occurred in 2014. In the normal dry season, from April to September, the water stored in groundwater supplies the springs keeping a perennial flow of the reservoirs, as well as the wetland continuity.

High temperatures, even in autumn 2014 and a shortage of rainfall induced rapid evaporation of soil moisture. During the dry season, a lack of rainfall and the water demand for public supply, together with high water transpiration in the soil and absorption of minimum reserves by the vegetation, caused a reduction in the water sources level. However, in the study area, the natural vegetation and the extent of flooded area did not change, showing a dependence of water that supplies the availability reservoir. The natural vegetation surrounding the Jacaré-Guaçu and Jacaré-Pepira wetland areas, known as “Pantanal Paulista”, can use part of the stored water in the dry season, preventing water evaporation. However, when there are extreme cases of a lack of water, the vegetation competes with reservoirs in the water reserve.

Naturalness landscape refers to the natural capital stock which provides ecosystem services [8] [39] . The naturalness changes in the Jacaré-Guaçu and Jacaré- Pepira watershed areas, over the 10-year period (2004-2014), are shown in Figure 3. High naturalness areas correspond to UI values ≤ 0.3, whereas low naturalness areas correspond to UI values ≥ 0.7.

The UI values for the total area of both watersheds (Figure 4(a) and Figure 4(b)) showed a significantly higher anthropogenic interference with the commitment of the natural vegetation to ensure scenarios for biodiversity conservation and ecological sustainability for 2014 compared to 2004 (F = 4.6117, ρ = 0.026).

Lower UI values (UI ≤ 0.3) showed that around 15% of the total area of watersheds are related to higher naturalness, while higher UI values (UI ≥ 0.7) showed that around 10% of the total area of watersheds are related to lower naturalness over the 10-year period (2004-2014) (Figure 3 and Figure 4(a) and Figure 4(b)).

The naturalness condition between both watersheds showed a significant difference in 2004 (F = 13.462, ρ = 0.002), but were not statistically different in 2014 (F = 0.2587, ρ = 0.624) (Figures 4(c)-(f)). The Jacaré-Guaçu watershed showed greater impairment of naturalness with a higher extent of critical naturalness area (UI ≥ 0.7), and a lower extent of high naturalness area (UI ≤ 0.3), 8.57% and 11.92%, respectively, when compared to the Jacaré-Pepira watershed (6.25% and 15.43%, respectively) in 2004 (Figure 3).

The Jacaré-Guaçu watershed showed no significant difference in the UI values (F = 2.8266, ρ = 0.106) from 2004 to 2014 (Figure 4(c) and Figure 4(d)). However, high naturalness areas corresponding to UI ≤ 0.3 decreased 0.08%, whereas critical areas of naturalness (UI ≥ 0.7) increased 2.90% (Figure 3) over the 10-year period (2004-2014).

The Jacaré-Pepira watershed showed a significant difference in the UI values (F = 6.9579, ρ = 0.012) from 2004 to 2014 with a higher naturalness commitment in 2014 due to the increase in the occupied area for classes of UI values higher than 0.3 and lower than 0.7 (Figure 4(e) and Figure 4(f)). High naturalness areas corresponding to UI ≤ 0.3 increased 0.52% around 17,600 ha, whereas the critical areas of naturalness (UI ≥ 0.7) increased 0.65% over the 10-year period (2004-2014) (Figure 3).

The Urbanity Index values for the total area of the watersheds, which corroborate with the spatial distribution of biodiversity conservation scenarios, showed a significant increase in natural vegetation areas over the 10-year period (2004-2014). This could be associated to a recovery of natural land use/cover and a reduction in the fragmentation of the natural vegetation process. This is particularly for municipalities that have land use/cover rules in their territorial limits to ensure the preservation of natural vegetation areas.

Despite the increase in natural vegetation areas, the sustainability conditions are not ensured for both watersheds due to the historical process of regional land use/cover by adopting non-sustainable practices. The result is a natural capital deficit framework currently below the minimum of carrying capacity necessary to ensure the stock of natural capital and ecosystem services for human welfare and economic development, mainly for the Jacaré-Guaçu watershed which shows a more critical situation due to natural capital loss.

This scenario makes it essential to know the amount of the remaining natural capital in both watersheds area, as well as the implementation of strategies to control or minimize the loss of habitat and local biodiversity. The question is what amount of natural capital should be remain under current trends and policies given trade-offs with economic development and agriculture. According a review carried out by [39] and [40] based on species of temperate areas, this amount can be considered a threshold of around 30% of remaining habitat, above which the effects of biodiversity loss would be due to habitat loss. Below this threshold, there may be a drastic effect on the spatial distribution of the habitat. This threshold has no empirical support, as shown by results obtained in tropical regions reporting fragmentation effects on the habitat loss process [41] . However, landscapes with less than 30% of natural habitat has evidenced only small and unconnected fragments, thus supporting impoverished communities and different taxonomic groups [42] [43] .

Thus, the threshold of 30% could be considered as the lower natural capital limit for a landscape managed by man to balance economic use and biodiversity conservation [33] . However, even considering the area values of Legal Reserve and Permanent Protection Areas, the Jacaré-Guaçu and Jacaré-Pepira watersheds do not have a natural cover area above this threshold. Governmental initiatives are aligning to assist conservation efforts in expanding legally protected areas in the municipal territories inserted in both watersheds area. These regional strategies can support the complete set of ecosystem services and improve managed watershed sustainability.