Does compliance with the Brazilian Forest Code mitigate the impacts of sugarcane agriculture on instream nutrient concentrations in Brazil? Maíra Ometto Bezerra, Solange Filoso, Margaret Palmer ______________________________________________________________________________ 2016 SFS Meeting

Forests have been used to control nutrient concentrations in agricultural streams for decades Virginia (2002) ‘Best management practices for water quality’ British Columbia (1996) ‘Forest Practices Code of British Columbia Act’ Finland (1996) ‘Forest Act Finland New Zealand (1991) ‘Resource Management Act’ many others (McDermott et al. 2010) Declines in water quality, habitat, and biological assemblages etc. Increased instream N and P concentrations Intensive agriculture Policies and BMPs to recover riparian buffers e.g.

The Forest Code Areas of Permanent Preservation (APP): riparian buffers, hilltops Legal Reserve(LR): native vegetation must be restored on 20% to 80% depending on biome

Forest Code Compliance = high degree of protection to streams (?)

The use of riparian forests to control instream nutrient concentrations may have two problems in Brazil 1. Limited knowledge on the extent of the impacts of intensive agriculture on streams. 2. Lack of understanding of the effectiveness of the Brazilian Forest Code. (Williams and Melack 1997, Neill et al. 2001, Silva et al. 2007, Silva et al. 2007, Silva et al. 2011, Cassati, unplished data) Forest Low intensive ag. Soy Sugarcane Pasture Error bars - min. and max.

Research goals To verify whether the N and P levels in sugarcane streams are high in comparison to more pristine streams and other agricultural streams. To investigate whether compliance with the Forest Code prevented streams from having high concentrations of N and P.

Study area 11 first order catchments Land use: sugarcane & forest Size range: 3 – 18 ha Soil type: ultisol Similar topography Baseflow sampling P1 P5 P6 CF CM CA P4 P3 CC P2 P1

Results Instream nitrate concentrations are high This study Forest Low intensive ag. Soy Sugarcane Pasture Error bars - min. and max. n = # of streams in the study (Williams and Melack 1997, Neill et al. 2001, Silva et al. 2007, Silva et al. 2007, Silva et al. 2011, Cassati, unplished data)

Results Instream orthophosphate concentrations are also high This study Forest Low intensive ag. Soy Sugarcane Pasture Error bars - min. and max. n = # of streams in the study (Williams and Melack 1997, Neill et al. 2001, Silva et al. 2007, Silva et al. 2007, Silva et al. 2011, Cassati, unplished data)

Historical land use patterns to understand the effects of compliance with the Forest Code Average % sugarcane cover Law compliance: agriculture to forest ratio > 4 < 4

P7 P5 P6 CF CM CA P4 P3 CC P2 P1 Compliance even prior to the law Agriculture to forest ratio < 4 in 1962 and < 4 in 2013

P7 P5 P6 CF CM CA P4 P3 CC P2 P1 Compliance with the law Agriculture to forest ratio > 4 in 1962 and < 4 in 2013

P7 P5 P6 CF CM CA P4 P3 CC P2 P1 No compliance with the law Agriculture to forest ratio > 4 in 1962 and > 4 in 2013

Results avg_perc_cane % avg_perc_cane % 0 A B Average % sugarcane cover over the 51-yr period Compliance even prior to the law Compliance with the law No compliance with the law

Results avg_perc_cane % 0 A B Average % sugarcane cover over the 51-yr period 34 – 43% Compliance even prior to the law Compliance with the law No compliance with the law

Results 0 A B Average % sugarcane cover over the 51-yr period 72 – 86% Compliance even prior to the law Compliance with the law No compliance with the law

Results 0 A B Average % sugarcane cover over the 51-yr period 23% 34 – 43% 72 – 86% Compliance even prior to the law Compliance with the law No compliance with the law

Results a B A b 23% 34 – 43%72 – 86% Average % sugarcane cover over the 51-yr period Compliance even prior to the law Compliance with the law No compliance with the law

Potential explanatory factors for the unexpected patterns Soil retentiveness Instream processing N P Hydrological connectivity Gully formation Goodale et al (Ecosystems) Taylor and Townsend 2010 (Science) TSS (mg L -1 ) R 2 = 0.10 p < Number of gullies

Summary N and P concentrations in streams draining intensive agriculture in Brazil can be high. Compliance with the Forest Code is not a good predictor of nutrient concentrations in streams in Brazil. Need to increase studies in Brazil as many other factors might be influencing instream nutrient concentrations. Critical implications for the effectiveness of the Forest Code to protect water resources within farms in Brazil.

Thank you Maíra Ometto Acknowledgments Margaret Palmer (advisor) Solange Filoso (co-advisor) Committee members: Matthew Baker, Tom Fisher, Silvio Ferraz Palmer Lab Laboratory of Forest Hydrology (USP, Brazil) Laboratory of Isotope Ecology (USP, Brazil)

Compliance even prior the law Did not comply with the law Complied with the law Results Catchments were categorized mainly in terms of Forest Code Compliance and average sugarcane cover

% cane cover