『Abstract
Streamwater chemistry was measured at 100-m intervals in all
streams of the Hubbard Brook Valley, NH during ‘spring’ (May-July)
and during ‘fall’ (October^December) 2001. Overall, streamwater
chemistry was very similar during these two periods, but fall
median concentrations were consistently higher than spring values,
except for ANC, pH, NO3- and PO4-, which had lower values in fall.
Median concentrations for NH4+
were approximately the same in spring and fall. Stream chemistry
varied throughout the Hubbard Brook Valley by elevation, channel
length, drainage area and type of drainage, but most of the variability
in stream chemistry was subtle and relatively small. Overall,
there were relatively large (two- to 10-fold) changes in chemistry
with longitudinal distance of wetted channel, elevation and/or
size of drainage area in some streams and for some elements (e.g.,
H+, Aln+, DOC), but other chemical concentrations
changed relatively little (e.g., Cl-, dissolved Si).
The main Hubbard Brook, a fifth-order stream at the mouth of the
Valley, was remarkably constant in chemistry throughout its length,
except where human disturbance near the mouth changed the chemistry.
Differences in vegetation, geologic substrates and wetland areas
were related to changes in pattern of streamwater chemistry throughout
the Valley.』
Introduction
Site description
Method
Field
Analytical
Periods of collection
Results
Discussion
Conclusions
Acknowledgements
References