Ekologi tumbuhan air dalam reka bentuk lanskap lembut
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Date
2010
Authors
Gaik Im, Cheah (Carmen)
Journal Title
Journal ISSN
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Abstract
Aquatic landscaping is a method used to design or redesign, and create or recreate an
aquatic system that mayor may not pre-exist in an area
This study attempts to highlight the usefulness of a man-made aquatic system, that can
be built and. mantained in a built environment, just as it can exist in the natural
environment as shown in the hypothesis "Aquatic lanscaping can be used to design and
create an aquatic system that may not pre-exist in an area and such areas can reflect the
natural system". Such systems can be designed and used in a water garden or it can also
be used as a filtration system for urban run-offs.
The ecosystem of the man-made pond was observed by planting selected easily available
aquatic plants like Hydrilla verticillata, Cabomba caroliniana and Blyxa malayana. A
few other aquatic plants (Hanguana malayana, Nymphoides indica, Pistia stratiotes,
Trapa biconis, Cryptocorne minima and Typha angustifolia) were also planted but did
not survive because there was not enough of sunlight and nutrient for these species. The
result showed that only 3 species of the aquatic plants survived and thrived satisfactorily
in this man-made pond.
Almost at the same time three species of fishes (L. reticulates, X helleri and S. discus)
were introduced into this pond. one of the spesies (s. discus) was more sensitive
comaparatively and it could not survive and thrive in this environment. Its inability to
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survive and thrive in this environment could also be due to the incompatible presence of
the other two species that is L. reticulatus and X helleri and this shows what is known
as interspesies competition. (Odum, 1983; Townsend, Begon, and Harper, 2008).
Besides studying the survival of the plants and the fishes, water quality of the pond water
was monitored every month for one year (December 1997 till December 1998). The
physico-chemical parameters under observation were alkalinity, ammoniun-nitrogen,
soluble reactive phosphate and others. These parameters were monitored and analysed
using suitable chemical methods. The pH values of the water in the pond were collected
and recorded. Data collected showed that there were no extreme fluctuations in the pH
values and the highest and lowest recorded values were pH 8.58 ± 0.45 and pH 6.48 ±
0.15, respectively.
Monitoring and observing the biomass and energy flow of the plants and fish in the pond
were also carried out by measuring the weight increase (kg) of the species present and
the light intensities in the pond area in Lux. Prior to determining the energy flow, the
number of spesies and number if individual spesies were recorded on a monthly basis.
Although the recorded data showed that even though the biomass of the fish was higher
than that of the plants, it was found that the energy flow from the plants were higher
compared to the fishes Therefore an inverted Pyramid of Biomass was obtained
compared to the normal upright Pyramid of Energy.
Data recorded from the propagation of Pistia seedlings that was carried out in the
laboratory using simulated situation showed that the method used was satisfactory But
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the growth of Pistia stratiotes in the man made pond was not as satisfactory because. all
of the samples planted died after a short period of time. The different condition that exist
in both the two situations is in the intensitiy of light that was given to it whereby the
intensity at the simulated condition or the laboratory was rather high and continuous
compared to the intensity at the pond that was periodically low and not continuous. Thus
the results showed that this aquatic plant needs high light intensity and nutrient level.
The number'of algae and types of algae present were recorded in this pond. The results
showed that succession in the pond occurred in the short period of observation time that
is 15 weeks.
This study shows that the built environment needs to have such a system so that areas
that have been destroyed by man in the chase of development can be rebuilt agam.
Although such a man made thing cannot be the exact replica as the natural one, it can
still be a very useful and functional system in order to prevent or avoid any further
destruction of nature which in due time can aggravate further any future destruction of the aquatic system.