Note. DOC: dissolved organic carbon.
Regression model significance: absent (non-significant: P>0.05); * (P<0.05); ** (P<0.01); *** (P<0.001).
Figure 1: Location and Digital Terrain Model (DTM - from LiDAR mapping) of the southern hillslope of Archer Hill and sample areas: Summit (SMT); Upper Hillslope (UHS); Lower Hillslope (LHS); Valley Bottom (VBT).
Figure 2: Mean values of annual litterfall (n = 5) and litter stock above ground (n = 6) for each slope position. Significant difference: non-significant (ns); *** (P <0.001). The letters indicate variant groups by the Dunn’s test. Decomposition coefficient (k ’) of Olson (1963). Adapted from Miranda and Avelar (2019).
Figure 3: Instruments for water sampling from different forest compartments.
Figure 4: Average monthly precipitation over 18-years and for 2016-2017 hydrological year (a); and daily precipitation for 2016-2017 hydrological year showing the eight sampled rainfall events (b).
Figure 5: Dissolved organic carbon (DOC) content in above-ground compartments in each rainfall event (n = 20). Bi-factorial ANOVA (temporal variation) for each compartment: ns (non-significant); * (p<0.05); ** (P<0.01); *** (P<0.001). Letters indicate the variant data-groups by the Dunn’s test (P < 0.05): lowercase for the field-values (throughfall and under-litter); uppercase for leaching-values (canopy and litter leachates).
Figure 6: Content of dissolved organic carbon (DOC) in each compartment at different hillslope positions (n = 40, except for UL and LL, which had n = 36). Bi-factorial ANOVA (spatial variation) for each compartment: ns (non-significant); * (p<0.05); ** (P<0.01); *** (P<0.001). Letters indicate the variant data-groups by the Dunn’s test (P < 0.05): lowercase for the field-values (throughfall and under-litter); uppercase for the leaching-values (canopy and litter leachates). DOC: dissolved organic carbon. TF: throughfall. CL: canopy leachate. UL: under-litter. LL: litter leachate.
Figure 7: DOC concentrations (under-litter and litter leachate) in the different hillslope positions in each event analyzed. Kurskal-Wallis variance analysis: ns (non-significant); * (p <0.05); ** (P <0.01); *** (P <0.001). Letters indicate the variant data-groups by the Dunn’s test (P < 0.05): lowercase for the field-values (under-litter); uppercase for the leaching-values (litter leachate).
Figure 8: Scatter plots and second-degree regression of dissolved organic carbon (DOC) under-litter and litter leachate against litter stocks and decomposition coefficients (k’) of each hillslope position.