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African Journal of Basic & Applied Sciences 5 (1): 01-07, 2013
ISSN 2079-2034
© IDOSI Publications, 2013
DOI: 10.5829/idosi.ajbas.2013.5.1.1115
The Interrelation of Biodiversity Dynamics,
Ecosystem Processes and Abiotic Factors: A Review
1
Olutoyosi Ayeni and 2Learnmore Kambizi
Department of Environmental and Occupational Studies,
2
Department of Horticultural Sciences,
Cape Peninsula University of Technology, Faculty of Applied Sciences, Cape Town 8000, South Africa
1
Abstract: The ecological consequences of wetland loss have aroused global interest in recent years. Major
advances have been made in describing the relationship between species diversity and ecosystem processes,
in identifying functionally important species and in revealing tolerant mechanisms. There is, however,
uncertainty as to how results obtained in recent experiments scale up to landscape and regional levels and
generalize across ecosystem types and processes. Under stress, a plant has minimal mobility and control of its
environment; wetland plants are exposed to environmental conditions outside the range normally exposed due
to natural or anthropogenic changes, such as exposure to environmental pollution. The mechanism of defense
breakdown and the production of activated oxygen exceed the plant’s capacity to detoxify it, leading to
deleterious degenerative occurrences as loss of osmotic responsiveness, wilting and necrosis. A future
challenge is to determine how biodiversity dynamics, ecosystem processes and abiotic factors interact. The
strengths and limitations of the various measures used to assess the successes of the interaction are now being
discussed. This paper reviews the challenges of heavy metals, highlight on challenges of wetland loss and
ecosystem processes in a changing environment.
Key words: Abiotic factors
Biodiversity
Biodiversity dynamics
INTRODUCTION
Ecosystems processes
Wetlands
therefore expected that all ecosystems will undergo
changes in some abiotic and biotic factors or both as the
human population climax impacting on biodiversity
dynamics [3].
The environmental risk associated with recalcitrant
metal contaminants coupled with their recycling to the
food chain through the biogeochemical cycling of
metals is a limiting factor [18]. The degradation of South
African wetlands and their vulnerability to humaninduced changes in catchments and in the sea is a
concern recognized by governments and such requires
attention.
Environment consisting of balanced interaction
between biotic and abiotic factors and often abrupt
perturbations in abiotic factors such as urbanization alters
both biotic and abiotic ecosystem properties within,
surrounding and even at great distances from urban areas
[1-3]. It is globally acknowledged over the last decade that
the introduction of harmful substances into the
environment has generated a colossus magnitude of
detrimental effects on human health, agricultural
productivity and natural ecosystems [4-6]. Heavy metal
contamination ruins biological community; destroy
landscape ecology and environmental functions [7-17].
Changes in the environment can have direct effects on the
ecosystem processes through biotic controls or indirectly
through effects on the physiology, morphology and
behavior of individual organisms, the structure of
populations and the composition of communities. It is
The Impact of Wetland on Biodiversity Dynamics:
Naturally, aquatic ecosystems undergo “natural stress”
both from biotic (living) or abiotic (non-living) origins.
Wetlands are constantly under threat due to a mix of
social, economic and political factor. With the current rate
of increasing anthropogenic impact on both natural and
Corresponding Author: Olutoyosi Ayeni, Department of Environmental and Occupational Studies,
Cape Peninsula University of Technology, Faculty of Applied Sciences, P.O. Box 652,
Cape Town 8000, South Africa.
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African J. Basic & Appl. Sci., 5 (1): 01-07, 2013
semi-natural wetland ecosystems, there is a growing
interest in understanding factors controlling ecosystem
processes. This would enhance our ability
to
manage and protect wetland ecosystems, as well as
obtain the maximum benefits from its values and
functions [19].
A noticeable potential effect of climate change would
be the increased loss of biodiversity and natural habitats.
The assessment of the interrelation of biodiversity
dynamics, ecosystem processes and abiotic factors in a
sustainable way has been and still is a subject of research
and development of various debates among stakeholders.
Ecosystems under stress usually cause species diversity
to decrease and may result in an increase in numbers of
the species capable of tolerating stress. The more diverse
any population in a community, the more stable the
community becomes and the knowledge of the species
composition of communities can provide insights into
the ecological function of these communities and assist in
the choice of suitable methods for remediation of polluted
system. Wetlands are key ecosystems for mitigating
the effects of fossil fuel emissions on climate.
Internationally and in South Africa context, the future of
biodiversity conservation lies in the great progress that
has been made in assessing the state of biodiversity as
well as the development made so far with the development
of biodiversity plans which set targets for future
conservation needs. Irrespective of the nature of the
ecosystem involved, maximum efficiency of resources is
crucial.
Wetlands management has being associated with the
several functions and values commonly attributed to
wetlands. The functions, classified into three main groups
(hydrology, biogeochemistry and habitat) are linked to the
self-maintenance of the wetlands and their surroundings
[20]. Because wetlands are at the interface of land and
water, they are strongly connected to both terrestrial and
aquatic ecosystems. Therefore, the health of a wetland is
strongly affected by what is happening upstream. This
means that an unhealthy wetland will often be a good
indicator of problems in its catchments.
(ROS) are increasingly appreciated as down-stream
effectors of cellular damage and dysfunction under
natural and anthropogenic stress scenarios in aquatic
systems. Oxygen free radicals induce damage due to
peroxidation to bio-membranes and also to DNA, which
leads to tissue damage. It is well understood that the
generation of ROS beyond the capacity of a biological
system to eliminate them gives rise to oxidative stress.
Plants are vulnerable to various stress factors. e.g.
oxidative stress from deleterious effects of reduced
oxygen species such as superoxide and hydrogen
peroxide. These oxygen species can form hydroxyl
radicals (OH-), the most reactive species known to
chemistry. Hydroxyl radicals cause lipid peroxidation,
protein denaturation, DNA mutation, photosynthesis
inhibition and so forth. In order to survive, aerobic
organisms have evolved a defense mechanism against
oxidative stress. Because hydroxyl radicals are far too
reactive to be controlled easily, the defense mechanism is
based on elimination of superoxide and hydrogen
peroxide. The central role in the plant antioxidative
mechanism is played by superoxide dismutase (SOD), an
enzyme that converts superoxide into hydrogen peroxide,
which is then broken down by either catalase or various
peroxidases [22].
Accumulation and Challenges of Heavy Metals: Both
technological and industrial advances are loading the
environment with heavy metals [23-24]. Main heavy
metal concern is the modification of river flows by
damming, irrigation and pollution from land, marine
and atmospheric sources. Degradation has become
increasingly acute within the last 50 years, creating
further losses of biological resources. Many
researchers have revealed on how contamination might
not only affect the microorganisms and plants in the
environment but invariably, poses a threat to animals and
human health through exposure through the food web
[7-11, 13].
Wetland has been indicated to be very much used
recently in the treatment of the contamination especially
acid mine drainage (AMD), for the new use of water
purification in constructed wetlands [25]. Scientists are
continually expanding the number of plants found to be
highly dynamic ecologically, physically tough and
resilient with good root and rhizosphere structure and
chemistry, for example, Phragmites [26]. However, the
disruptions on the biodiversity dynamics, ecosystem
processes and abiotic factors which these plants relate
after receiving high concentrations of metals remain
unclear.
Oxidation Effects on Metal Uptake by Wetland
Plants: Environmental management of biodiversity
and ecosystem particularly, wetlands; requires an
understanding of the linkage of management actions to
biological response [21]. For instance, plants generally
transform energy from sunlight to chemical energy by
means of photosynthesis. During the process, plants fix
carbon dioxide (CO2) and release oxygen (O2) while coping
with the loss of water (H2O). Reactive oxygen species
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African J. Basic & Appl. Sci., 5 (1): 01-07, 2013
The vulnerability of the wetland environment to
chemical damage depends on several factors, including
the: physical and chemical properties of the chemical
and its transformation products; concentration of the
chemical entering the ecosystem; duration and type of
inputs; properties of the ecosystem that enable it to resist
changes which could result from the presence of the
chemical; and location of the ecosystem in relation to the
release site of the chemical [27, 28].
Metal accumulated by wetland plants was mostly
distributed in root tissues; suggesting that there is
tolerance strategy. Numerous wetland plants have
constitutive metal tolerance and mechanisms of resistance
that enable most cells in plants experiencing metal toxicity
to continue normal activities while sacrificing a few cells
that accumulate large amounts of the metal [29-31].
Metals, when found in high concentrations, are
potentially toxic inorganic pollutants that destabilize
ecosystems because of their bioaccumulation in
organisms, biomagnifications in food chains and toxic
effects on biota. [23, 7] highlighted the relevance of
knowing the processes of metal accumulation, removal,
uptake and distribution in the wetland. Knowing these,
researchers could understand these systems and ensure
that wetlands do not themselves become sources of metal
contamination. This is necessary due to the
environmental risk associated with remobilization of metal
contaminant and their recycling to the food chain,
particularly by the infiltration into the ground water.
in order to reap its full potential [34]. Biodiversity
dynamic’s major challenges for the future include the
consolidation of reserves in under represented regions,
the improved management of natural plant resources
outside reserves and the need to justify protected areas
within the framework of major and far reaching sociopolitical change. However, the consequences are the
possible loss of species, an altered species complement
and ultimately an altered and less productive ecosystem
[32].
It is a great challenge to measure large-scale
biodiversity dynamics; therefore, biodiversity is generally
evaluated using only one population metric (metric per
species), however, single population metric may not
precisely indicate the changing state of a target
population [35]. The extent to which biodiversity
dynamics particularly plants exert an influence over
ecosystem processes such as nitrogen cycles is largely
unknown, it is also unclear how such processes may be
dependent on abiotic factors. The ability of plant species
to continue to influence ecosystem processes under a
changing climate is unclear [36], which limits the ability to
predict ecosystem responses to future environmental
changes. Thus, the impact of biodiversity dynamics on
some ecosystem processes may be primarily a result of
change.
Benefits of Biodiversity: A deep understanding of
ecosystem processes is the best foundation for
formulating good restoration and protection policies,
which are multi sectoral and at multiple levels. Changes in
biodiversity have the potential to either increase or
reduce the incidence of infectious disease in plants and
animals-including humans, because they involve
interactions among species. At a minimum, this requires
a host and a pathogen; often many more species are
involved, including additional hosts, vectors and other
organisms with which these species interact. [37]
reviewed that reduced biodiversity affects the
transmission of infectious diseases of humans, other
animals and plants with a conclusion that biodiversity
exerts a protective effect on infectious diseases is
sufficiently strong to include biodiversity protection as a
strategy to improve health [33].
Implications on Biodiversity Dynamics: The world is
faced with the challenge of sustainable global food
security. This seems to be more challenging as global
climate is changing unpredictably. Worldwide, the
production of food is being affected largely by myriads of
environmental extremities and the sensitivity of plant due
to pollution is a major limitation for high productivity [32].
The ever increasing population, whose majorities are
children and women, are most vulnerable to dietary
deficiency. Population growth, increased food demand,
climate change, urbanization, rising health and
environmental standards increasingly call for an
integrated approach by all [33]. Many studies have
quantified the contribution that biodiversity makes to
people’s livelihoods in term of income [32].
A noticeable potential effect of climate change would
be the increased loss of biodiversity and natural habitats.
Healthy, functioning ecosystems are global defense
against climate change and storm damage, so it becomes
imperative to ensure conservation of wetland ecosystems
Ecological Consequences of Wetland Loss: Human
activities such as rural development, urbanization and the
creation of hydro power reservoirs have influence plants
and other sessile organisms by the destruction / reduction
of available habitat. Mobile animals (especially birds and
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African J. Basic & Appl. Sci., 5 (1): 01-07, 2013
mammals) retreat into remnant patches of habitat, which
lead to crowding effects and increased competition.
Also, agricultural development leaves small fragments of
habitat which can only support small population of plants
and animals, while small populations are more vulnerable
to extinction. As available area is the primary determinant
of the number of species in a wetland. The size of wetland
will be influenced by number of species which were
present when the wetland was initially created and
influence the ability of these species to persist in the
wetland. Minor fluctuations in climate, resources, or other
factors would be unremarkable and quickly corrected in
large populations can be catastrophic in small, isolated
populations. Thus, fragmentation of habitat is an
important cause of species extinction.
The major influence is the loss, alteration and
fragmentation of habitats, mainly through conversion of
natural land for agricultural, aqua cultural, industrial or
urban use; damming and other changes to river systems
for irrigation or flow regulation. This has led to
overexploitation of wild species’ populations, harvesting
of animals and plants for food materials or medicine at a
rate higher than they can reproduce. Another ecological
consequence of wetland loss is through over-exploitation
of resources which impacts on the livelihood, survival and
food security [38]. Wetlands are sensitive to climate
change, due to rising levels of greenhouse gases in the
atmosphere, caused mainly by the burning of fossil fuels,
forest clearing and industrial processes. Introduction of
invasive species either deliberately or inadvertently to
one part of the world from another can become
competitors, predators or parasites of native species.
Environmental impact assessments have been used
as tools to identify the potential impacts of project
activities on habitats of concern. Therefore, preservation
of specific habitats (usually the remaining natural areas
within the landscape) should be a priority for ecological
functioning or species diversity of the ecosystem. The
best understood examples of habitats critical to
ecosystem functioning are wetlands. Environmental
analyses through various researches’ have indicated that
habitat alteration and destruction are among the greatest
risks to ecological and human welfare.
Ever-growing human demand for resources, however,
is putting tremendous pressure on biodiversity. This
threatens the continued provision of ecosystem
services, which not only further threatens
biodiversity, but also our own future security, health
and well-being.
It is important to harmonize the relationships between
human population growth, regional economic
development, environmental conservation and
ecological restoration [39].
Limited understanding of the ecological regimes
and the interactions between humankind and
nature.
Ecosystem Processes in the Changing Environment:
Effective management of our natural resources depends
on accurate assessment of wetland processes and the
functions they serve. In other words, different classes of
wetlands have different functions with respect to water
quality and these differences need to be recognized in our
management strategies. Assessment of function provides
an estimate of the capacity of a wetland to participate in
a given environmental process. Wetland function often is
divided into three major categories: hydrologic;
biogeochemical; habitat and food web support. Function
should not be confused with value, which is an estimate
of worth to society. The integrity of the native biological
components of a wetland is known to be a reflection of
the condition or health of a wetland. One of the first
indicators of reduced condition or health is a change in
the wetland plant community. For example, plant species
have different ranges of tolerance to a variety of
environmental factors such as inundation, wetness,
salinity, pH, sedimentation, physical alterations, etc.
Healthy, functioning wetlands serve as environmental
filters and protect aquatic systems. However, if the rates
of addition exceed the capacity of the wetland to perform
chemical transformations, toxic concentrations may result.
The consequences may be twofold: deterioration of the
wetland biotic system, causing a reduction in function;
and elevated chemical concentrations in adjacent aquatic
systems due to reduced wetland function.
It is beginning to be evident that nearly all
ecosystems will undergo changes in some biotic and
abiotic or both as the human population climax, impacting
on biodiversity dynamics [3]. Changes in the environment
can have direct effects on the ecosystem processes
directly through biotic factors or indirectly through
effects on the physiology, morphology and behavior of
individual organisms, the structure of populations and the
composition of communities and the question that this
Main Challenges Facing in Wetland Restoration:
South Africa is a developing nation with nearly all its
wetlands loss or degraded and diversified environmental
conditions, strong drive for socioeconomic development.
This explains that environmental quality, resources
usability and ecological security are important concerns
for the success of regional sustainable development?
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African J. Basic & Appl. Sci., 5 (1): 01-07, 2013
paragraph tries to answer is what are the consequences
of a changing environment on the ecosystem functioning
and ecosystem services?
A critical step in that challenge is to understand how
changing environmental conditions influence processes
across levels of ecological organization. Many ecosystem
processes are affected by environmental changes such as
changing climate, increasing CO2 and increasing nitrogen
deposition. Water is essential as sustenance for
organisms and as a driving force for physical changes to
the environment. It also serves to transport energy,
nutrients and biota themselves. To understand the
biodiversity, production and sustainability of ecosystems,
it is necessary to appreciate the central role of
dynamically varying physical environments. Hydrologic
patterns in aquatic ecosystems and their surrounding
landscapes play a key role in these dynamics.
The following major activities may cause the loss of
habitats critical to ecological processes: Land conversion
to industrial and residential land use, Land conversion to
agriculture, Land conversion to transportation, Timber
harvesting practices, grazing practices and mining
practices, water management practices, military,
recreational and other activities. Critical habitats such as
wetlands are well known for their nutrient cycling and
purification services. Habitats obviously support the
species with characteristic genetic diversity, population
dynamics and biotic interactions. The abundance and
distribution of critical habitats affect the pattern and
connectivity in ecological process, natural disturbance
regimes and hydrologic patterns, effective maintenance of
these habitats and their structural complexity regardless
of the intellectual approach, integration of knowledge
across disciplines will be vital because no single
individual or discipline holds the key to understand
regional- and global-scale behaviour.
The fragmentation of habitat has been implicated in
the decline of biological diversity and the ability of
ecosystems to recover from disturbances such as habitat
loss, habitat fragmentation, connectivity and soil erosion
[40]. An understanding of how ecological thresholds
might be best utilized to conserve biodiversity and
sustainably manage natural resources requires further
research.
the geochemical cycle, hence, the protection and
conservation of ecosystem is of paramount importance.
A poor understanding of the value of wetland will
continue to encourage resource overuse and degradation,
thus further compounding threats to development.
Wetland restoration will contribute to the stabilization and
improvement of metal uptake. Strategies that balance use
and development of wetland and protection of the
catchments ecological function should be designed to
limit ecosystem extraction. Trade-offs is inevitable
between protecting wetlands (achieving ecological
integrity) and achieving economic developments. The
future of biodiversity conservation in South Africa rests
on the progress that has been made in assessing the state
of biodiversity and the setting of developmental targets
for future conservation needs. Plant biodiversity in
wetlands should be enhanced to benefit both purification
efficiency and ecology. It can be concluded that there is
a link between critical habitat and ecological processes.
Therefore, understanding the interactions between
biodiversity, ecosystem services and mankind is
fundamental to reversing the trends in ecosystem
dysfunctions and so safeguarding the future security,
health and well-being of human societies.
REFERENCES
1.
2.
3.
4.
CONCLUSIONS
5.
This review presented has demonstrated the
mechanisms by which biodiversity dynamics can impact
ecosystem processes and abiotic factors in their
interconnectivity. Human activities in particular, dominate
5
Malik, A., 2004. Metal bioremediation through
growing cells. Chemosphere, 30: 261-278.
Watson, J.E.M., M. Rao, K. Ai-Li and X. Yan, 2012.
Climate change adaptation Planning for Biodiversity
Conservation - A Review. Adv in Climate Change
Res., 3(1): 1-11.
Suding, K.N., S. Lavorel, F.S. Chapin,
J.H.C. Cornelisses, S. Diaz, E. Garnier, D. Goldberg,
D.U. Hooper, S.T. Jackson and L. Navassm, 2008.
Scaling
environmental
change
through
community- level: a trait-based response- and-effect
framework for plants, Global Change Biol.,
10: 1125-1140.
Petrovic, M.E., M.J. Eljarrat, De Alda. Lopez and
D. Barcelo, 2004. Endocrine disrupting compounds
and other emerging contaminants in the environment:
A survey on new monitoring strategies and
occurrence data. Anal. and Bioanal. Chem.,
378: 549-562.
Shaheen, M.Z., K. Sardar, S. Ayyaz, H.G. Murtaza,
M. Nadeem and U. Iftikhar, 2010. Prevalence of
respiratory symptoms among employees and
residents in the vicinity of a fertilizer factory. Pak. J.
Chest Med., pp: 1-8. [03 June 2011].
African J. Basic & Appl. Sci., 5 (1): 01-07, 2013
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
Shabala, S., 2011. Physiological and cellular aspects
of phytotoxicity tolerance in plants: the role of
membrane transporters for crop breeding for water
logging tolerance. New Phytol., 190(2): 289-298.
Weis, J.S. and P. Weis, 2004, Metal uptake, transport
and release by wetland plants: Implication for
phytoremediation and restoration, Environ. Int.,
30: 685-700.
Sinha, S. and R. Saxena, 2006. Effect of Iron on lipid
peroxidation and enzymatic and non-enzymatic
antioxidants and bacoside- content in medicinal plant
Bacopa monneieri (L), Chemosphere, 62: 1340-350.
Liphadzi, M.S. and M.B. Kirkham, 2006. Heavy-metal
displacement in chelate-treated soil with sludge
during phytoremediation, J. Plant Nutr. and Soil Sci.,
169(6): 737-744.
Sarfraz, M., S.M. Mehdi, G. Hassan and S.T. Abbas,
2007. Metal contamination in Nullah Dek water and
accumulation in rice, Pedosphere, 17(1): 130-136.
Munns, R. and M. Tester, 2008. Mechanism of
salinity tolerance. Ann. Rev. Plant Biol., 59: 651-681.
Achakzai, A.K.K., Z.A. Bazai, T. Ahmad, M.A. Battur
and M.O. Liasu. 2010a. Response of spinach growth
and development under the influence of domestic
sewage and industrial wastewater of Quetta
city-Pakistan. Caderno de Pesquisa Serie Biologia,
22(2): 38-45.
Achakzai, A.K.K., S.A.R. Taran, S.H. Shah,
M. Rahman and M.O. Liasu, 2010b. Effect of air
pollution on the morphological characteristics of few
plants grown in Quetta Distric – Pakistan. Caderno de
Pesquisa, Serie Biologia, 22(3): 90-98.
Miller, G., N. Suzuki, S. Ciftci-Yilmaz and R. Mittler,
2010. Reactive oxygen species homoeostasis and
signaling during drought and salinity stresses. Plant
Cell Environ. 33(3): 453-467.
Achakzai, A.K.K., Z.A. Bazai and S.A. Kayani,
2011. Accumulation of heavy metals by lettuce
(Lactuca sativa L.) irrigated with different levels of
wastewater of Quetta city. Pak. J.
Bot.,
43(6): 2953-2960.
Achakzai, A.K.K., M.O. Liasu and O.J. Popoola, 2012.
Effect of mycorrhizal inoculation on the growth and
phytoextraction of heavy metals by maize grown in
oil contaminated soil.
Yan, H., S. Luo, Y. Wang, Y. He and Y. Xiao, 2012.
Study on the characteristics of heavy metal
accumulation in seven dominant plants in Shilu Iron
Mines areas of Hainan. Adv. Material Res.,
518 -523: 2016-2021.
18. Odum, H.T., W. Woucik and L. Pritchard, 2000.
Heavy metals in the environment: using wetlands for
their removal. Boca Raton, Lewis Publishers, pp: 326.
ISBN 1-56-670401-4.
19. Richardson, C.J., P. Reiss, N.A. Hussain, A.J. Alwash
and D.J. Pool, 2005. The restoration potential of
the Mesopotamian marshes of Iraq. Science,
307: 1307-1310.
20. Mitsch, W.J. and J.G. Gosselink, 2000. Wetlands 3rd
ed. John Wiley and Sons, Inc. New York.
21. Anderies, J.M., M. A. Janssen and E. Ostrom, 2004.
A framework to analyze the robustness of
social-ecological systems from an institutional
perspective. Ecol. and Soc., 9(1):18.
22. Bornette, G. and S. Puijalon, 2011. Response of
aquatic plants to abiotic factors: A review. Aquatic
Sci., 73:1-14.
23. Chapman, P.M., F. Wang, C.R. Janssen, C.R. Goulet
and C.N.
Kamunde,
2003.
“Conduction
ecological risk assessments of inorganic metals and
metalloids. Current status” Hum. Ecol. Assessm.,
9: 641-697.
24. Agunbiade, F.O. and A.T. Fawale, 2009. Use of Siam
weed biomarker in assessing heavy metal
contamination in traffic and solid waste polluted
areas. Int.
Environ.
Sci.
and Technol.,
6(2): 267- 278.
25. Dunbabin, J.S. and K.H. Bowmer, 1992. Potential use
of constructed wetlands for treatment of industrial
wastewater containing metals. The Science of the
Total Environ. 111: 151-168.
26. Schwitzgu bel, J.P., E. Nehnevajova, G. Federer and
R. Herzig, 2005. Metal
accumulation and
metabolism in higher plants: potential for
phytoremediation. In “soil
and
sediment
remediation, mechanisms, technologies and
applications” Lend P Grotenhuis T, Malina G and
Tabak H (Eds). IWA Publishing London England
Chapter. 15: 289-309.
27. Allen, A., 2002. “Bioavailability of metals in terrestrial
ecosystem’ Importance
of portioning for
bioavailability to invertebrates, microbes and plants”
Society for Environmental Toxicology and Chemistry
(SETAC) Pensacola, Florida, pp: 176.
28. Marchand, L., M. Mench, D.L. Jacob and M.L. Otte,
2010. Metal and metalloid
removal in
constructed wetlands, with emphasis on the
importance
of plants and
standardized
measurement- A Review. Environ.
Pollut.,
158: 3447-3461.
6
African J. Basic & Appl. Sci., 5 (1): 01-07, 2013
29. Matthews, D.J., B.M. Moran and M.L. Otte, 2005.
Screening the wetland plant species
Alisma
plantago-aquatica, Carex rostrata and Phalaris
arundinacea for innate tolerance to zinc and
comparison with Eriophorum angustifolium and
Festuca rubra Merlin, Environmental Pollution,
36. Tylianakis, J.M., R.K. Didham, J. Boscompte,
D.A. Wardle, 2008. Global change and species
interactions in terrestrial ecosystem. Ecol. Lett.,
1: 1351-1363.
37. Keesin, F., L.K. Belden, P. Daszak, C. Dobson,
D. Harvell, R.D. Holt, P. Hudson, A. Jolles,
K.E.Jones, C.E. Mitchell, S.S. Myers, T. Bogich and
R.S. Ostfeld, 2010. Impacts of biodiversity on the
emergence and transmission of infectious diseases.
Nature, 468: 647-652.
38. Lokhande, V.H. and P. Suprasanna, 2012.
Environmental adaptations and stress tolerance of
plants in the era of climate change, Ahmad P and
Prasad M N V (eds.) Springer, Chapter 2.
39. Fu, B.J. and Y.H. Lu, 2006. The progress and
perspectives of landscape ecology in china. Progress
in Physical Geog., 30(2): 232-244.
40. Huggett, A.J., 2005. The concept and utility of
ecological thresholds in Biodiversity conservation.
Biol. Conserv., 124: 301-310.
134: 343-351.
30. Deng, H., Z. Ye and M. Wong, 2006. Lead and zinc
accumulation and tolerance in populations of six
wetland plants. Environ. Pollut., 141: 69-80.
31. Deng, H., Z. Ye and M. Wong, 2009. Lead, zinc and
iron (Fe (II)) tolerances in wetland plants and relation
to root anatomy and spatial pattern of ROL. Environ.
and Expt. Bot., 65: 353-362.
32. DWAF, 2008. Department of Water Affairs and
Forestry, Updated manual for the identification and
delineation of wetlands and riparian areas.
33. WWF, 2012. World wildlife Fund: Living Planet
Report 2012.
34. MEA, Millennium Ecosystem Assessment, 2005.
Ecosystem and human well being: Biodiversity
synthesis: World resources Institute.
35. Yamaura, Y., T. Amano, T. Koizumi, Y. Mitsuda,
H. Taki and K. Okabe, 2009. Does land-use change
affect biodiversity dynamics at a macroecological
scale? A case study of birds over the past 20 years in
Japan. Animal Conservation, 12: 110-119.
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