Physical and Chemical Monitoring of Wetland Water - Wetland Techniques - page 324

Table 6.1 Overview of common water quality parameters measured in wetland monitoring studies

Potential sources of variability to consider when monitoring
wetlands Parameter General notes/reasons for measuring the parameter

Temperature Temperature has a major influence on chemical and biological

processes including reaction rates, saturation constants of
dissolved gases, water density, and the metabolic rates of
animals

Hydrology :
Water input from overland flow, precipitation or groundwater can
increase or decrease temperature
Internal and other processes :
Diurnal and seasonal variation in water temperature occurs due to
changing incident thermal radiation
Differences in thermal regimes can exist between wetlands due to
position on the landscape (e.g., shading effects, exposure to
prevailing winds)
Spatial variability within the wetland can occur due to differences in
water depth, presence of macrophytes, and shading from
shoreline vegetation
Vertical stratification is possible in open water zones

Dissolved oxygen As the terminal electron acceptor in aerobic respiration, the

concentration of dissolved oxygen in water can influence the
breakdown of organic matter in wetlands and the presence and
distribution of many aquatic organisms that inhabit these
systems

Hydrology :

Water input from overland flow, precipitation or groundwater can
influence dissolved oxygen levels either directly or indirectly by
influencing temperature or introducing nutrients (overland flow
and groundwater) into the system that stimulate biological pro-
ductivity and ultimately biological oxygen demand

Oxygen has a major affinity for electrons and determines the status
of oxidation/reduction reactions that influence the chemical
form of elements in biogeochemical and other chemical
processes in wetland soils and water

Internal and other processes :
Diurnal and seasonal variation in water temperature due to changing
thermal regimes influences oxygen solubility
Diurnal fluctuations in dissolved oxygen levels can result from the
combined effects of photosynthesis and respiration
Spatial variability in oxygen levels may result from differences in
biological activity between stands of macrophytes and open
water
Vertical stratification of dissolved oxygen levels may also occur in
open water zones

When coupled with other chemical indicators such as levels of
nutrients, reduced oxygen levels in wetlands can be indicative of
eutrophication