Annual changes in summer patterns of mesohabitat distribution and associated macroinvertebrate assemblages

Measuring submerged macrophyte standing crop in shallow rivers: A test of methodology

“…Our estimated values of macrophyte standing crop over a cycle of growth and recession were within the seasonal ranges reported in other studies of the chalk river macrophyte community (Dawson, 1976;Ham et al, 1981;Armitage and Cannan, 2000;Flynn et al, 2002). Percentage cover, percentage volume, and dry weight 8 biomass co-varied in accordance with our first hypothesis, concordant with previous studies which had reported positive relationships (O'Hare et al, 2010b;Yin et al, 2011).…”

Measuring submerged macrophyte standing crop in shallow rivers: A test of methodology

“…Our estimated values of macrophyte standing crop over a cycle of growth and recession were within the seasonal ranges reported in other studies of the chalk river macrophyte community (Dawson, 1976;Ham et al, 1981;Armitage and Cannan, 2000;Flynn et al, 2002). Percentage cover, percentage volume, and dry weight 8 biomass co-varied in accordance with our first hypothesis, concordant with previous studies which had reported positive relationships (O'Hare et al, 2010b;Yin et al, 2011).…”

Surface flow types, near-bed hydraulics and the distribution of stream macroinvertebrates

“…The results presented here support other studies that have highlighted the importance of inferred near-bed hydraulic conditions, independent of the influence of riverbed substratum alone (Quinn and Hickey, 1994;Armitage and Cannan, 2000;Rempel et al, 2000). That these relationships are found, despite the strong interactions between river-bed substratum and hydraulic conditions, may reflect the fact that the substratum at any one location on the stream bed reflects the longer-term history of hydraulic conditions experienced at a location, in particular, the recent history of high discharge events, rather than the ambient hydraulic conditions (Beisel et al, 1998;Armitage and Cannan, 2000). Moreover, other variables independent of hydraulic character, such as catchment geology, also have the potential to influence river-bed substratum character.…”

“…This present study shows that, although there are clear interactions between near-bed hydraulic conditions and river-bed substratum character, each subset of physical variables appears to be independently important, as shown by the fact that the strongest relationships between macroinvertebrates and explanatory variables were obtained when both near-bed hydraulic conditions and other physical variables were considered (Tables 3 and 4). The results presented here support other studies that have highlighted the importance of inferred near-bed hydraulic conditions, independent of the influence of riverbed substratum alone (Quinn and Hickey, 1994;Armitage and Cannan, 2000;Rempel et al, 2000). That these relationships are found, despite the strong interactions between river-bed substratum and hydraulic conditions, may reflect the fact that the substratum at any one location on the stream bed reflects the longer-term history of hydraulic conditions experienced at a location, in particular, the recent history of high discharge events, rather than the ambient hydraulic conditions (Beisel et al, 1998;Armitage and Cannan, 2000).…”

Do hydraulic units define macroinvertebrate assemblages in mountain streams of central Argentina?

“…In several studies, the lowest values of richness and diversity were found in habitats with fine substrate (Armitage & Cannan, 1999;Baptista et al, 2001;Brunke, Hoffmann & Pusch, 2001;Tickner et al, 2000;Vela´squez & Miserendino, 2003); these results agree with those we have found in this study. On the other hand, habitats with abundant aquatic vegetation allocate the highest diversity (Armitage & Cannan, 1999;Buffagni et al, 2000;Principe & Corigliano, 2006;Tickner et al, 2000) since these habitat units are highly complex.…”

Measuring submerged macrophyte standing crop in shallow rivers: A test of methodology

“…Our estimated values of macrophyte standing crop over a cycle of growth and recession were within the seasonal ranges reported in other studies of the chalk river macrophyte community (Dawson, 1976;Ham et al, 1981;Armitage and Cannan, 2000;Flynn et al, 2002). Percentage cover, percentage volume, and dry weight 8 biomass co-varied in accordance with our first hypothesis, concordant with previous studies which had reported positive relationships (O'Hare et al, 2010b;Yin et al, 2011).…”

Surface flow types, near-bed hydraulics and the distribution of stream macroinvertebrates

“…The results presented here support other studies that have highlighted the importance of inferred near-bed hydraulic conditions, independent of the influence of riverbed substratum alone (Quinn and Hickey, 1994;Armitage and Cannan, 2000;Rempel et al, 2000). That these relationships are found, despite the strong interactions between river-bed substratum and hydraulic conditions, may reflect the fact that the substratum at any one location on the stream bed reflects the longer-term history of hydraulic conditions experienced at a location, in particular, the recent history of high discharge events, rather than the ambient hydraulic conditions (Beisel et al, 1998;Armitage and Cannan, 2000). Moreover, other variables independent of hydraulic character, such as catchment geology, also have the potential to influence river-bed substratum character.…”

“…This present study shows that, although there are clear interactions between near-bed hydraulic conditions and river-bed substratum character, each subset of physical variables appears to be independently important, as shown by the fact that the strongest relationships between macroinvertebrates and explanatory variables were obtained when both near-bed hydraulic conditions and other physical variables were considered (Tables 3 and 4). The results presented here support other studies that have highlighted the importance of inferred near-bed hydraulic conditions, independent of the influence of riverbed substratum alone (Quinn and Hickey, 1994;Armitage and Cannan, 2000;Rempel et al, 2000). That these relationships are found, despite the strong interactions between river-bed substratum and hydraulic conditions, may reflect the fact that the substratum at any one location on the stream bed reflects the longer-term history of hydraulic conditions experienced at a location, in particular, the recent history of high discharge events, rather than the ambient hydraulic conditions (Beisel et al, 1998;Armitage and Cannan, 2000).…”

Do hydraulic units define macroinvertebrate assemblages in mountain streams of central Argentina?

“…In several studies, the lowest values of richness and diversity were found in habitats with fine substrate (Armitage & Cannan, 1999;Baptista et al, 2001;Brunke, Hoffmann & Pusch, 2001;Tickner et al, 2000;Vela´squez & Miserendino, 2003); these results agree with those we have found in this study. On the other hand, habitats with abundant aquatic vegetation allocate the highest diversity (Armitage & Cannan, 1999;Buffagni et al, 2000;Principe & Corigliano, 2006;Tickner et al, 2000) since these habitat units are highly complex.…”

Measuring submerged macrophyte standing crop in shallow rivers: A test of methodology

“…Our estimated values of macrophyte standing crop over a cycle of growth and recession were within the seasonal ranges reported in other studies of the chalk river macrophyte community (Dawson, 1976;Ham et al, 1981;Armitage and Cannan, 2000;Flynn et al, 2002). Percentage cover, percentage volume, and dry weight 8 biomass co-varied in accordance with our first hypothesis, concordant with previous studies which had reported positive relationships (O'Hare et al, 2010b;Yin et al, 2011).…”

Surface flow types, near-bed hydraulics and the distribution of stream macroinvertebrates

“…The results presented here support other studies that have highlighted the importance of inferred near-bed hydraulic conditions, independent of the influence of riverbed substratum alone (Quinn and Hickey, 1994;Armitage and Cannan, 2000;Rempel et al, 2000). That these relationships are found, despite the strong interactions between river-bed substratum and hydraulic conditions, may reflect the fact that the substratum at any one location on the stream bed reflects the longer-term history of hydraulic conditions experienced at a location, in particular, the recent history of high discharge events, rather than the ambient hydraulic conditions (Beisel et al, 1998;Armitage and Cannan, 2000). Moreover, other variables independent of hydraulic character, such as catchment geology, also have the potential to influence river-bed substratum character.…”

“…This present study shows that, although there are clear interactions between near-bed hydraulic conditions and river-bed substratum character, each subset of physical variables appears to be independently important, as shown by the fact that the strongest relationships between macroinvertebrates and explanatory variables were obtained when both near-bed hydraulic conditions and other physical variables were considered (Tables 3 and 4). The results presented here support other studies that have highlighted the importance of inferred near-bed hydraulic conditions, independent of the influence of riverbed substratum alone (Quinn and Hickey, 1994;Armitage and Cannan, 2000;Rempel et al, 2000). That these relationships are found, despite the strong interactions between river-bed substratum and hydraulic conditions, may reflect the fact that the substratum at any one location on the stream bed reflects the longer-term history of hydraulic conditions experienced at a location, in particular, the recent history of high discharge events, rather than the ambient hydraulic conditions (Beisel et al, 1998;Armitage and Cannan, 2000).…”

Do hydraulic units define macroinvertebrate assemblages in mountain streams of central Argentina?

“…In several studies, the lowest values of richness and diversity were found in habitats with fine substrate (Armitage & Cannan, 1999;Baptista et al, 2001;Brunke, Hoffmann & Pusch, 2001;Tickner et al, 2000;Vela´squez & Miserendino, 2003); these results agree with those we have found in this study. On the other hand, habitats with abundant aquatic vegetation allocate the highest diversity (Armitage & Cannan, 1999;Buffagni et al, 2000;Principe & Corigliano, 2006;Tickner et al, 2000) since these habitat units are highly complex.…”