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Vegetation Establishment
The establishment of a healthy plant community is one of the primary
ways to evaluate whether reclamation efforts have been successful.
Plant cover reduces windblown dust and storm water runoff. Plant
transpiration of water during photosynthesis can reduce water infiltration
into hazardous material covered by an emplaced soil cap. Root exudates
contribute to the success of microbial communities in the rooting
zone, also called the rhizosphere. Additionally, plant growth eventually
contributes to the creation of soil
structure and habitat for insects, birds, and other wild land
creatures. All of the benefits brought about by the plants on reclaimed
areas often make revegetation one of the primary objectives of monitoring
programs for reclaimed or restored sites.
Both vegetative cover and production will vary with climatic and
edaphic factors such as temperature, amount of rainfall, soil organic
matter, nutrient content, water holding capacity, pH, and microbial
populations present. The time of the season when sites are assessed
also influences measurements of cover and biomass production; both
are generally higher at the end of a growing season. Year to year
variability occurs due to variability in climate. For example, in
drought years, vegetative cover is often less than in years during
which a site receives well-timed and abundant precipitation. In
order to control for climatic variability, an offsite control or
'bio-equivalent' site might be chosen. The results of yearly monitoring
might then be expressed as a percentage of measured cover or production
values measured on the control.
During a project monitoring phase, one might assess vegetative
cover, production, species diversity, or structural diversity. Sometimes
permanent vegetation monitoring plots or line transects can be installed
during site reclamation, and vegetation can be monitored in the
same location year after year. Trend analyses on yearly monitoring
data can then determine whether the reclamation becomes more or
less successful over time.
In summary, vegetative monitoring is used to detect changes at
a site over time, whereas vegetative sampling results in a measurement
of a specific attribute at some point in time. When monitoring a
site, it is important to return to the same location at the same
time of year and to use the same sampling method used previously
to collect vegetative information. This will ensure that the investigator
is able to compare data collected from different sampling events
to determine a trend. Click
here for information on the different sampling methods used
for vegetative sampling and monitoring.
For more information on vegetation monitoring, see the following
websites:
Problem | Compliance
| Health & Safety | Sampling
| Analytical | Data
Quality
Site Assessment | Prediction
| Construction | GIS
| Monitoring & Assessment
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