Relationship between instream and riparian processes H3 & H4.
Leaf stocks were higher, and C/N, shredder abundances, CK and FK lower,
in the riparian than in the instream habitat, respectively (Table S5).
Invertebrate richness did not differ between the instream and riparian
habitats, except at mainstem, where instream richness was higher than
riparian richness (Table S5).
The relationships between riparian and instream responses were
relatively weak but selected for most of the response variables, apart
from C/N (Table 2 & 3). Although invertebrate community responses were
weak, instream invertebrate taxa richness tended to decrease and
increase with riparian richness at low and high DS, respectively (Table
2; Fig S6). Contrastingly, instream leaf-shredder abundances increased
with increasing riparian abundance, and more so as FP increased (Table
2; Fig S6). Instream CK increased with riparian CK but only among sites
with higher DS, i.e. the mainstem (Table 3, Fig. 3a). Instream FK was
positively related to riparian FK, particularly in spring and this
relationship increased as flow permanence decreased, i.e. among
intermittent sites (Table 3, Fig. 3b).
Leaf stock characteristics differed between network locations and
habitats (Table 4) and instream vs. riparian leaf stock characteristics
tended to be more similar in the mainstem (pairwise PERMANOVA: F =
3.096; p = 0.034) than in headwaters (F= 10.788, p = 0.001; Fig. 4a).
Invertebrate communities differed among habitats, locations and flow
regimes (Table 4); significant interactions indicated that communities
differed more among locations and flow regimes instream than in the
riparian area (Fig 4b, c). Decomposition differed among flow regimes and
habitats (Table 4) with greater differences among flow regimes instream
(F = 12.127; p < 0.001) than in the riparian zone (F = 0.078;
p = 0.760; Fig 4d).