Papers by Author: Wen Liang Lai

Abstract: The present study analyzed the tolerance of 10 common woody plants to gaseous nitrogen dioxide (NO₂). Experimental trees species were placed in fumigation chambers and exposed to different concentrations of NO₂ (600, 1000, and 2000 ppb) for 48 hours. Their physiological health was determined by measuring how chlorophyll fluorescence varied, identifying which tree species were more adaptive and resistant to NO₂. The results showed that NO₂-affected plants were harmed to some extent by reduced levels of chlorophyll fluorescence, which decreased more serous with higher concentrations of NO₂. Among the experimental tree species, the tolerance to NO₂ was ranked as Melia azedarach > Decussocarpus nagi > Palaquium formosanum > Pongamia pinnata > Messerschmidia argentea > Diospyros morrisiana > Lagerstroemia speciosa > Semecarpus gigantifolia > Aglaia formosana > Koelreuteria formosana.

Abstract: In this study, we use canonical correlation analysis to interpret the relationship between water quality parameters (T, Alk, Cl, EC, TN, TP, UV-254, pH, HPC, DO) and primary productivity parameters (algae and chlorophyll-a). In these two sets of constructed canonical variables, the water quality parameters can account for 39.25% of the total variance of primary productivity. The majority of the explanatory power is from the first set of canonical variables, which has a correlation coefficient of 0.84. The main factors that control chlorophyll-a are HPC, Alk, T, TN, and pH.

Abstract: After Typhoon Morakot in 2009, the Taiwanese government relocated three indigenous villages to the lowland, leading to changes in traditional lifestyles and customs. Using the Wutai community as a case study, this paper suggests a strategy for sustainable post-disaster indigenous development . The paper focuses on two issues, the traditional land use of Rukai people in Wutai Township and their methods used regarding village relocation, afforestation and mountain patrol after Typhoon Morakot. Our research found that about 73.0% of locals who agree with afforestation in Aboriginal territory, 54.3% would like to sign a contract with the government which lasts more than twenty years, and 84.5% wish to be included in mountain patrol. Therefore, we propose that a mountain patrol foundation be established, to be responsible for the recruitment of mountain patrol members, planning afforestation, and conservation. Moreover, through the foundation, a mountain academy might be established, which could handle dynamic activities and systematize disciplines so as to link traditional environmental knowledge and modern conservation skills. Also, the foundation could help the local communities to develop eco-tourism and other related industries to increase local incomes and conservation funds, as a step towards sustainable development.

Abstract: Canonical discriminant analysis (CDA) was applied in order to distinguish the sediment-quality parameters from neighboring rivers, and to recognize similarities of sediment properties between lagoon and neighboring rivers. Two set of constructed discriminant functions showed a marked contribution to most of the discriminant variables. In sediment, the significantly parameters - porosity, Cd, Cr, Al, and Pb were combined as the heavy metal factor. The recognition capacities of the two discriminant functions were 82.6 and 17.4, respectively. The Dapeng Bay had no significant similarity with the three neighbouring rivers with the sediment properties.

Abstract: Ta-Peng Bay lagoon in southwestern coast of Taiwan belonging to a shallow, productive, coastal lagoon was heavily polluted by the effluent of agriculture from fisheries and domestic sewage. This area provided a plentiful bivalves mollusks for regional market, including Anadara antiquate, Katelysia hiantina, Perna viridis and Anomalocardia squamosa. For understanding correlation between heavy metals existed in aquatic product and variation of heavy metal varied with season, during Dec., 2005- Sep., 2006, six heavy metals, such as Cu, Zn, Pb, Ni, Cr and Cd were analyzed by an air-acetylene flame / Graphite Atomizer atomic absorption spectrophotometer. The variations of different heavy metals existed in aquatic product in season were evaluated using multivariate analysis. Results show that the mean concentration of heavy metal in soft tissues for six aquatic products, Cd species had the lowest value than the others, and Cu and Zn were significantly higher than the other elements. The relationships of all heavy metal species in seasonal variations showed significant dependence. High concentrations of heavy metals were observed in winter. The negative correlation coefficient (p < 0.05) between heavy metals content and season variations statistically revealed decreased with season series for Ni, Pb, and Cr. An interesting finding that Cd bioaccumulation among the species had a significant discrepancy was observed. It means that bivalves mollusks could be develped as a potetial tool for monitoring Cd species.

Abstract: Use of microalgae to remove inorganic nutrients from wastewater and their great potential for low-cost biomass production is gaining attraction. The effect of piggery wastewater content, aeration rate, cultivation temperature, and light intensity on nitrogen and phosphorus removal and biomass production were studied by using a Box-Behnken experimental design under full factorial methodology. Under experimental conditions considered cultures with aeration increased the ammonium and orthophosphate removal efficiency up to an average of 65.3±17 % and 51±7.2 %, respectively and an increase of biomass productivity ranging from 20.8±11 mg/L.d to 52.3±5.5 mg/L.d. The aeration rate was the most important factor influencing the nutrients removal and biomass production.

Abstract: In this work, the excitation-emission fluorescent matrix (EEFM) was used to compare the divergence of fluorescent organic properties of the effluents produced from the operation of the bio-stabilizing filter. Four bio-stabilizing filters were simultaneously operated in the combination of both filtered CCL and FS source waters with ozonation (O₃/NPDOC=1) and two different indigenous bacteria taken from CCL and FS source water. It found that, two peak locations, 220-230/330nm, 320-330/410-420nm, existed in the effluent of the four bio-stabilizing filters, and one another peak of 280-290/340 nm was appeared in bio-stabilizing filter using FS source water as a substrate. The fluorescent organic matter, with an excitation wavelength of 220-230 nm and 280-290 nm may be attributed as protein-like, while that of 320-330/410-420nm had the possibility of humic-like. The humic-like matter was accumulated in the effluent from the bio-stabilizing filter during the operational process. Bio-stabilizing filter operated with consistent source water and indigenous bacteria could release higher humic-like fluorescent intensity than that with inconsistent source water and indigenous bacteria.

Abstract: This study is using Factor Analysis method to analyze the hydrographs of groundwater table for classification of recharge zone. The water table data are taken from 37 wells which located on unconfined aquifer in Pingtung plain. The result shows that 93% of total variance can be explained by three components. The 1th component is related to rainfall; the 2th and 3th are related to recharge from TungKang Basin and Kaoping basin, respectively.

Abstract: Italic textThis research utilized a custom-made air fumigation equipment to evaluate the tolerance of 10 species of side-walk trees with 600, 1000 and 2000 ppb Sulfur Dioxide (SO₂) for 48 hours. The tolerance of tested trees toward SO₂ pollution was analyzed. Results showed that these plants influenced by high concentration SO₂ gas with physiology properties changes and the decrease of photosynthetic rates and the stomata conductance than before fumigation. The net photosynthetic rate and stomata conductance of tested trees was linearly correlated to each tested tree species. Among tested tree, the Quercus glauca had the highest tolerance in exposure with high concentration of SO₂ pollutant. While the Camellia axillaries was the least.

Abstract: Abstract. The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) and surface sediment properties were analyzed from 31 locations in Dapeng Bay and neighboring rivers (Kaoping River, Tungkang River and Lingbeng River), southern Taiwan. Principal component factor analysis (PCFA) was performed to explain the latent factors and spatial variations of sediment quality. And canonical discriminant analysis (CDA) was applied to identify the source of pollution of Dapeng Bay from neighboring rivers. The results show that the most important latent factors in Dapeng Bay and neighboring rivers on wet seasons are the soil texture caused factor, the PAHs caused factor, and the nutrient caused factor. Contour maps incorporating the factor scores showed phenanthrene (Phn) and pyrene (Pyr) of PAHs had the highest content at the entrance of the northern side of the lagoon. Benzo(a)pyrene (BaP) had the highest content located in mid-section of the Kaoping River and in Dapeng Bay. Total nitrogen (TN) and total phosphate (TP) had the highest content located in the last-section of Tungkang River. And CDA shows that sediment quality in Dapeng Bay was not similar to the other three rivers.