Effect of heavy metals on salt march biota

Environmental restoration of disturbed, degraded and potentially contaminated wetland sites aims for the persistent and sustainable re-establishment of biological communities and important wetland functions. An ecologically informed restoration strategy presupposes some understanding of these system processes, but also of potential impacts on contaminants in the environment for risk assessment, long-term management, and potential cost-effective mitigative measures. In this study, potential effects of moderate heavy metal contamination in sediments of the urban salt marsh Harrier Meadow, NJ, were evaluated on growth performance of the common salt marsh plant S. patens and associated arbuscular mycorrhizal fungi (AMF) colonizing its roots. Growth performance as well as uptake of heavy metals into roots and translocation from below- into above-ground parts was studied as a function of basic environmental conditions such as pH and redox potential, absence or presence of AMF, as well as additional contamination with nickel (Ni) at selected times during the first growing season, and after the third growing season. The experimental setup in the greenhouse with soil cores containing S. patens from Harrier Meadow resulted in consistent environmental conditions in cores within and between treatments, with values for most physicochemical parameters being not significantly different at comparable depths. Concentrations and spectra of total hydrolysable amino acids (THAA) in the organic material analyzed after the third growing season as measure for organic matter quality and thus metabolic processes were similar in cores of all treatments and thus indicated no significant biotic environmental differences that might have developed in time as a function of treatments. Measures for AMF were similar on plants from all treatments even though small, statistically significant differences were obtained for percent root length colonized, and arbuscular or vesicular colonization. Since none of the treatments eliminated AMF, these differences could not be related to treatment effects, but were suggested to be the result of potential shifts in AMF community structure, that, however, were not analyzed within the scope of the thesis. Plant growth performance assessment based on leaf nitrogen (N) content, stable isotope ratios (δC), carboxylation efficiency (CE), CO2 saturated photosynthetic capacity (Amax), estimations of optimal transfer efficiency of open photosynthesis II (PSII) reaction centers (Fv/Fm), sprout numbers, and shoot and root biomass generally showed seasonal variation in these characteristics only. However, additional variation was displayed for parameters such as Amax, Fv/Fm, and shoot and root biomass where significant effects of Ni amendment were found during reproduction . These effects were no longer significant at the end of the growing season, and were not obtained when Ni amendment was combined with AMF suppression. Sediment of Harrier Meadow was found to be moderately contaminated with heavy metals (Cd, Cr, Cu, Ni, Zn). Calculations using MineQL+, a data driven, chemical equilibrium modeling program suggested that, under suboxic and anoxic conditions found in all cores, only Cd, and under anoxic conditions, Ni would not form precipitates, while Cd, Cr, Cu, Pb and Zn would mainly form precipitates. 70-95% of the total concentration of the dissolved forms of all heavy metals could also be adsorbed to organic compounds. None of the heavy metals nor the additional Ni application resulted in uptake or translocation values typical for hyperaccumulating plants, but rather values in the typical range found for many agricultural plants. Since all values in plant tissues were above the critical deficiency contents and below the critical toxicity contents, effects on plant growth performance should not be expected. Ni amendment did not increase uptake and translocation in most cases although effects of Ni amendment were displayed for root uptake of certain heavy metals (i.e., Cu, Pb, Zn and Fe) at the depth of 7.5 cm. These results demonstrate that moderate heavy metal contamination found in sediments of Harrier Meadow did not affect growth performance of the common salt marsh plant S. patens and associated arbuscular mycorrhizal fungi (AMF) colonizing its roots during key points of the growing season. Although considerable uptake of all heavy metals into or adsorption to roots was encountered, translocation from below- into aboveground parts of S. patens was not significant, and always below regulatory action limits (maximum limit levels for vegetative leaves of Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn are 0.2, 2.30, 73.3, 425.50, 500, 67.90, 0.3 and 99.40 mg.kg-1). Thus, the risks associated with the restoration of moderately contaminated salt marshes with S. patens, i.e., the potential of S. patens to act as a conduit for the movement of toxic metals into the food web, are minimal and thus of low public health concern

Sustainable Floating Vegetation Linking Cultural Identity of the Intha Farmers Responding to Deforestation on Upland Catchment

Erosion loads and soil sediment characteristics from the deforestation of the Kalaw catchment causes shallow water level and reduced plant nutrients in the Inle Lake aquatic ecosystems. This research aimed to address the effect of soil sediment changes both loads and quality on the practices of floating vegetation which is part of the cultural identity of Intha community. Soil sediment quality data and GIS maps were gathered from government departments and they were used to estimate the topsoil loss and household questionnaire survey were conducted in six Intha communities to evaluate the adverse impacts on Intha livelihoods. The soil sediment loads to the Lake’s littoral zone due to the forest cover depletion was 80,584 tons per year and their characteristics and large quantity were found affected to process of floating vegetation by using chemical fertilizers and pesticides. All respondents (n = 282) agreed that they were concerned with the adverse effects and impacts from changes in soil sediment that it had a negative impact and it was an impediment to achieving sustainable livelihoods. An Integrated Lake Ecoregion Management Plan including a livelihood development plan are required for implementation by central government so that conservation measures proposed in this research can address environmental, social and economic issues affecting the Inle lake ecoregion. Buffer zone management should be implemented by local government in order to control high sediment loads in the lake and its flood plain area. The results provided evidence that support the improvement of ecoregion including the Intha livelihoods as a criterion for the Inle aquatic ecoregion for the sustainable management

Post occupancy evaluation for sustainable neighborhood development

This paper present the preliminary study of a post occupancy evaluation (POE) model on neighborhood assessment criteria towards sustainable urban development. The aim of the study is to develop a POE model based on sustainable pillar dimensions. The objective is to identify and formulate POE model towards sustainable neighborhood development and to implement the model in assessing & evaluate GBI certified neighborhood towards sustainable urban development for Malaysia. The consensus-based approached is used in this study in order to gather experts’ opinion regarding the proposed POE model for sustainable neighborhood development for the certified GBI neighborhood project. The significant contribution of the research is the POE model for future sustainable neighborhood development for Malaysia and similar development phenomenon in the region of ASEAN nations and country throughout the world

Sustainable dimension pillars adaptation in neighborhood assessment criteria of community planning & design

This paper presents the study of sustainable dimension pillars (SDP) on neighborhood assessment sub-criteria of community planning & design. The problem of the study is to find out whether the townships assessment tools fully address sustainability or it might be ‘green but not sufficient’ to be sustainable. The aim of the study is to evaluate the adaptation and balance of SPD in Community, Planning, and Design (CPD), which is one of the core-criteria of GBI Township/Neighborhood Assessment Criteria. The objective is to identify and evaluate the adaptation of SPD indicators balance towards sustainable urban development in Malaysia. The expert interview and questionnaires survey approach is used in this study in order to gather experts’ opinion regarding the SPD indicators in the CPD sub-criteria. The significant contribution of the research is the findings will be used as references/guides for future review and refinement GBI Township/Neighborhood Assessment Criteria

Solubilization and transformation of insoluble zinc compounds by fungi isolated from a zinc mine

Fungi were isolated from zinc-containing rocks and mining soil. They were screened for the ability to solubilize and transform three insoluble zinc compounds: ZnO, Zn3(PO)4, and ZnCO3. Fungi were plated on potato dextrose agar (PDA) medium which was supplemented with 0.5% (w/v) of insoluble zinc compounds. Of the strains tested, four fungal isolates showed the highest efficiency for solubilizing all the insoluble zinc compounds, producing clearing zone diameters > 40 mm. These were identified as a Phomopsis spp., Aspergillus sp.1, Aspergillus sp.2, and Aspergillus niger. Zinc oxide was the most easily solubilized compound and it was found that 87%, 52%, and 61% of the tested fungi (23 isolates) were able to solubilize zinc oxide, zinc phosphate, and zinc carbonate, respectively. Precipitation of zinc-containing crystals was observed in zinc oxide-containing agar medium underneath colonies of Aspergillus sp.1, and these were identified as zinc oxalate. It is suggested that these kinds of fungi have the potential application in bioremediation practices for heavy metal contaminated soils