Invasive alien species in Indian ornamental industry

S. Rameshkumar, K. Manivannan, C.T. Sathappan and J. Padmanaban
Annamalai University, India

Quantum jump of increase in the awareness about global warming and environmental pollution made the mind set of industries, institutions, corporate and even common man to think about finding a solution to it. Establishment of ornamental gardens and green belt development in the surroundings and waste lands is becoming the best option to curtail pollution problems and it has almost been considered as mandate in urban areas. Increased green belt development and gardening activities help the industries and corporate to manage their carbon credit and in turn helps in reducing climate change.  In these green belts and corporate landscapes and even in botanical gardens many alien species are used in larger volumes.

In a survey conducted in nursery pockets and landscape industries of south India evinced the status of alien species that more than 60 per cent of the ornamental species are foreign in origin and few species are Invasive in nature. More than 50 per cent of the landscape architects opted for foreign ornamental plants to be incorporated in their present and future projects and opined it is inevitable to avoid the invasive alien ornamentals as they have preference among the clients. Though many of these plants are well accommodative and have ornamental value, there is a chance for certain highly invasive alien species to become threat for the eradication native species in the locale and may become serious weed as evident from Lantana Sp. and water hyacinth which were introduced as ornamental plants and now being a threat as major weeds in Indian sub continent. Hence it becomes necessary to have check measures to evaluate the invasiveness of the alien species when it is introduced as an ornamental plant.

Economics of Utilization of Fly Ash Originating From the Coal Power Plant, Norochcholai

B.R. Jayasekara and U.A.D.P. Gunawardena
Department of Forestry and Environmental Science, University of Sri Jayewardenepura , Sri Lanka

A new type of a solid waste which is known as fly ash will be available in Sri Lanka at the end of year 2010 due to operations of the Coal power plant, Norochcholai. Fly ash is a superfine, powdery byproduct which is carried away from the power plant boiler in the flue gas during coal combustion. It is expected to generate 70,000 tons of fly ash annually from the coal power plant. The objective of the study was to investigate the potential for effective utilization of fly ash originated from the Coal power plant while minimizing the environmental and social impacts.

The methodology of the study involved three surveys; an expert opinion survey to identify environmental impacts of fly ash and potential utilization opportunities of fly ash; an industrial survey to investigate willingness of industries to utilize fly ash and a contingent valuation survey to estimate the potential damage cost to the surrounding communities. In order to find out the best uses of fly ash financial and economic analysis were carried out for each and every industry that have the potential to use fly ash.

The expert opinion survey indicated that only the fine portion of fly ash (20%) is usable for cement production and the rest could be used for industries such as ready mix concrete, asbestos cement sheets, dam and road construction and cement based products such as light weight concrete blocks, clay-fly ash bricks, etc. The main impacts of land filling of fly ash include contamination of soils and water especially due to highly alkaline leachate.

The financial analysis of fly ash utilization indicates that asbestos cement industry receives highest financial benefit while the lowest were received by cement industries. However the highest economic benefit of fly ash utilization is gained by cement production which is Rs 13,330.35 per ton. Total cost of land filling of fly ash (per ton) is estimated as Rs 228,721.72 and therefore the full utilization of fly ash is very important while avoiding land filling.

In conclusion, the best practice to handle fly ash originating from the coal power plant is to utilize the ash in order gain the highest economic benefits to the country. This is very important because the fly ash storage capacities in the power plant are only enough for two days.

A Boolean Network Model to test ecosystem resilience under elevated nitrogen deposition and drought

K.  Naithani and E. A.H. Smithwick
The Pennsylvania State University, University Park, USA

Elevated nitrogen deposition alters soil biogeochemistry and associated ecosystem processes that can lead to plant mortality and decline in stand productivity. Understanding the effects of elevated nitrogen deposition as a result of different land use practices is critical for predictive understanding of ecosystem productivity and resilience. Nitrogen cycling in terrestrial ecosystems is a nonlinear, complex and dynamic process which can be characterized by coupling of physical, chemical and biological processes and their feedback at different spatial and temporal scales. This paper presents a graph theoretic approach to characterize the behavior of nitrogen dynamics in terrestrial ecosystems. Different pools and observations are presented as nodes and their direct and indirect effects are displayed as edges connecting them. The directed network allows the percolation of perturbations among couplings in a desired direction. We used a Boolean Network Model to test the effect of elevated nitrogen deposition on ecosystem productivity by running the model under different initial conditions and analyzing alternate stable states (attractors).

Prior information about the processes involved in nitrogen cycle and its influence on plant growth is used to determine a set of rules that encodes causal relationships and change in one component leads to the change in another component of the network which is used as an input to a Boolean form of the process network.

We found that network is robust against simulated perturbations via introduction of drought and elevated nitrogen deposition alone, but showed great vulnerability under combined influence of drought and elevated nitrogen deposition. Simulation of ecosystem behavior from our model indicates the potential vulnerability of key nitrogen cycling process and provides basis for future experimental and field research to test the outcome of our model.

Relative importance of salinity regimes and neighbor competition on vegetation dynamics in Sundarbans mangrove forest, Bangladesh: An individual-based model approach

M. N. I. Khan and U. Berger
Department of Forest Biometry and Systems Analysis, Institute of Forest Growth and Computer Sciences, Technical University Dresden, Germany

Along with the global depletion of mangrove ecosystems due to over-exploitation and other anthropogenic activities, sea level rise due to climate change may exert a potential impact to the salinity regimes in mangrove ecosystems. Sundarbans mangrove forest in Bangladesh shows distinctive vegetation composition in three salinity zones, e.g., fresh water, oligohaline and polyhaline zones, as the forest partially receives upland fresh water flow by the Ganges. Information on mangrove succession and the ecological processes behind it is still little known because of absence of long term monitoring data in this regard. Nevertheless, such information is important in understanding ecosystem processes and in analyzing forest planning and management options.

In this study, we evaluated the impact of different salinity regimes and inter-and-intra- specific competition on vegetation composition in Sundarbans and analysed the results in the light of succession, based mainly on simulated data and empirical data as well. For the purpose of simulation experiments, the KiWi mangrove model was parameterized in this study to a South Asian as well as tropical mangrove forest (Sundarbans) for the first time and it was found suitable to extract information on vegetation dynamics. The most dominant four mangrove species (Heritiera fomes Buch.-Ham.; Excoecaria agallocha L.; Ceriops decandra (Griff.) Ding Hou; Sonneratia apetala Buch.-Ham) were taken into account for this study. We used the simulation model to understand how species-dependent growth rate, salt tolerance and shade tolerance lead to the observed patterns in horizontal and vertical forest structure in Sundarbans. Our study will enrich scientific knowledge on mangrove structure and dynamics, which in turn will help building the adaptation measures to mitigate the adverse impacts posed by sea level rise to Sundarbans.

Key words: KiWi model, mangrove succession, simulation experiment, slat tolerance, shade tolerance

Restoration of sand dune vegetations after the Tsunami in Cuddalore, SouthEast coast of India

M. S. Muthukumarasamy and K.D. Kaliyaperumal
Faculty of Marine Science, Annamalai University, India

Sand dune plants or psammophytes include creepers like beach morning glory (Ipomea pescaprae) and sand spinifex (Spinifex littoreus). These vegetations serve as binding agents to form sand dunes which in turn act as a shelter for some marine animals during the breeding season. The sea turtles lay eggs in such sand dunes.  Moreover, the sand dunes also protect the coast from the waves by lessening the force of the oncoming waves.

These plants are threatened due to the construction of roads, formations of groynes and conversion of the coast into a tourist destination.  This occurs at Cuddalore, Silver Beach also.  A preliminary restoration work was under taken during the post-tsunami period and sand dune vegetation has been successfully restored in a few places on the Silver Beach of Cuddalore.  Propagation of I. pescaprae was done by plucking a portion of the creeper and planting it in pits dug at a depth of 30 to 40 cm. Three places were selected for restoration with 6m x 6m.  The planting of creepers were performed at an interval of 2m distance each in 6 pits.  The growth rate of the creepers was found to be 60 cm in length within two months.  The overall survival was 80%.  The plants were nurtured without any fertilizers except watering once in a week.  Fencing was made to protect the study area. Ideal season for the culture of Ipomea pescarprae in the sand dune area is the northeast monsoon period.

Key words: sand dune vegetation, Tsunami, coastal ecosystem

Utilization of treated tannery waste water using HRTS (High Rate Transpiration System)

S. Krishnamoorthi and G. Kandasamy

The major objective of this paper is given to soil and ground water quality improvement by utilizing the high transpiration pull property of specific plants. It acts as a catalyst to improve the water management and also effluent is getting treated in a eco friendly manner. We utilized the tannery effluent for the High Rate Transpiration System (HRTS). The treated tannery effluent is distributed in the designed plants of ridges and Furrows. And three design layouts were developed in the research activity for the plantation to get Maximum benefits depends upon the load and the nature of effluent.

Moreover, implemented system results were collected and analyzed for the impact of system on the environment. The effluent loading capacity to the designed plants were calculated and summarized.

The advantages of the HRTS are 1) No separate processing is required for effluent 2) Effluent Solids will be taken as nutrient for the plants growth 3) Water in the effluent will be penetrated under the beneath of earth and improve the ground water quality as well as quantity 4) HRTS process is ecofriendly.

S. Krishnamoorthi and G. Kandasamy

Environmental Research Center, Sri Ramanathan Engineering College, Erode, India

Efficient removal of nitrogen/phosphorus by Bio-Geo Filter ditches consisting of laterite

G.S.M Fonseka1, N.P.M Rajaguru2, K.C.J Jayasekara2, B.C Liyanage2 and S.S. Iqbal2

In order to develop low-cost energy saving ways to treat wastewater in combination with resource recycling, a plant bed filter ditch in which terrestrial and aquatic plants are used to remove nitrogen (N) and phosphorus (P) from domestic wastewater specially from the septic tank effluents. Discharging waste water into inland surface waters leads to contamination of water bodies is becoming a serious problem in Sri Lanka. Though there are several treatment methodologies adopted to treat wastewater, a low cost system with less maintenance is very much needed that suits small waste capacities and for domestic installation, so as to prevent release of nutrients to the natural ecosystem. Therefore this study focuses on introducing an ideal treatment system using a combination of bio and geo materials namely Geo Filter (BGF) ditches.

 A pilot scale Bio-Geo Filter ditches has been established at the Open University premises to demonstrate the potential for treatment of domestic wastewater using geo materials and plants. Selected bed filter materials and useful terrestrial plant species such as African merigold, canas, papyrus and reeds were employed for nutrient removal. This pilot-scale BGF containing laterite (kabook) stones with its rich composition of iron and aluminium, has been achieved nearly 100% removal of phosphorus.

The BGF shows the excellent pollutant removal efficiencies for NH4 +, NO3-, and NO2 –. Though the removal efficiency of NH4 + is 90%, while the removal of NO3 – and NO2- is around 100%. Ditches with papyrus and reed help to control pH before discharge. Reduction of turbidity and COD is also more than 90%. The BGF significantly removes TDS, conductivity and salinity. The plant species, which provides economic and aesthetically appealing aspects, will engage to produce renewable energy in further step of this study.

[This project was funded by the Asian Development Bank, Distance Education Modernization Project]

G.S.M Fonseka1, N.P.M Rajaguru2, K.C.J Jayasekara2, B.C Liyanage2 and S.S. Iqbal2

1Department of Chemistry, University of Colombo, Sri Lanka 2Department of Civil Engineering, Open University of Sri Lanka.

A Multi agent system for environmental friendly agriculture

R. Rupasinghe, A. Ranatunga, S. Rathnayake, A. Sajagahan and A. Karunananda

Environmental sustainability has become an important topic nowadays due to various adverse effects of natural systems which has caused the mankind to suffer in multi faceted difficulties. Achieving the environmental sustainability is not an individual effort but a collective effort of all the stake holders of a natural system. Therefore mankind should be able to work in harmony with natural processes in utilizing the environment without harming the sustainability.

Agriculture is a direct encounter of humans with the natural environment. Here, the challenge is to reap the maximum possible harvest in the most efficient manner while keeping up with the environmental sustainability. In addressing this issue we propose to incorporate modern agent technology for controlling an agricultural environment. Since we need a controlled environment we decided to select hydroponics, the technology of growing plants on a nutrient solution that supply all nutrient elements needed for optimum plant growth, in a greenhouse environment. We have built an adaptable hydroponics system with high level of autonomy with the help of a multi agent system. In doing so, we have combined embedded computer technology with the state of the art artificial intelligence. The system has a higher capacity of autonomous decision making in a dynamic environment. Decisions about activities to be performed by the actuators (dosing system, water control system etc.) were generated as an emergent property of interacting autonomous software components. Each of these software components represent a particular environmental parameter (nutrient level, pH level, temperature etc.) that is subjected to change dynamically. Each of these autonomous software components contains limited logical capabilities for interacting with nearby components in case of a change of the interested parameter. Therefore the decision will be emerge as a result of the interactions among individual software components with limited rationality. The advantage of this approach is that it enables the hydroponics system to become proactive to the environmental changes rather than being just a reactive entity.

The system has been evaluated using a domestic hydroponics environment. Firstly, we changed key parameters of the nutrient solution in an artificial manner to test how the system would react to those changes. For example, in the first scenario we reduce the water level and switch on the system. System  was able to identify that and pumped the water up to the required level. Similar tests were conducted to ensure component testing. So we reduce the light, change EC / pH, change nutrient level. Also the system was evaluated through a comparative approach with the traditional agriculture. Five farmerswere utilized to obtain data about 6 six parameters for a period of 3 months. The test results showed a considerable improvement over the traditional agricultural practices. Therefore this research has shown that we could achieve a better harmony and sustainability with the natural environment by using the multi agent technology for controlling an agricultural environment.

R. Rupasinghe, A. Ranatunga, S. Rathnayake, A. Sajagahan and A. Karunananda

Faculty of Information Technology, University of Moratuwa, Sri Lanka.

Efficiency of some local plants as eco-friendly pest control agents in reducing infestation

T.V.N.M. Gunarathna and M.M.S.C. Karunaratne

Repellent effects of powdered leaf mixtures of four plant species, Piper nigrum (black pepper), Ocimum gratissimum (maha maduruthala), Cinnamomum verum (cinnamon) and Mentha viridis (mint) were evaluated against the adult rice weevil, Sitophilus oryzae under laboratory conditions (29 ±200 C and 84±2 % relative humidity). The evaluation was made with the view of finding plant materials that effectively protect stored produce and are less poisonous and less detrimental to the environment. A modified cup-bioassay was used for repellency tests. Leaf powders of the plants were tested separately and in different mixtures against S. oryzae. Four combinations of leaf powders were made using two plants at a time (15g altogether) at 1:1 ratio, and added to hundred grams of clean and un-infested rice grains separately. Similarly, another bioassay was set by mixing powdered leaves of all four plants together at a ratio of 1:1. Twenty rice weevils each were introduced into bioassay chambers. When compared with the control, all combinations of plant leaves caused significantly higher repellency (p < 0.05) in adult weevils. Repellent effect of the mixture of M. viridis and O. gratissimum was the most striking as it elicited an extremely high repellency (95.0%) in the weevils just after 2 hours of exposure. Conversely, the weevils demonstrated considerably high rates of repellency to the combinations of, P. nigrum + M. viridis, and P. nigrum + O. gratissimum which were 88.0% and 87.0% respectively. In contrast, a significantly low rate of weevil repellency (46.0%) was observed with the combination of C. verum and P. nigrum after 2 hours. Moreover, a very much high repellent activity (85.0%) was also obtained when weevils were exposed to the combination of leaf powders of all four plants mixed together. Furthermore, when tested separately, only M. viridis elicited a high repellent activity (90.0%) in the weevils. Also, the highest rate of repellency with single plants was observed only after 6 hours of exposure where as all the plant combinations showed their highest repellent effects shortly after 2 hours of exposure. These observations clearly indicate a rapid and great increase in weevil repellency when different mixtures of plant powders were used. The results of the present investigation highly signify the potential of using mixtures of the four plant materials, especially the combination of M. viridis and O. gratissimum as eco-friendly pest control agents in reducing infestation of rice caused by S. oryzae.

T.V.N.M. Gunarathna and M.M.S.C. Karunaratne

Department of Zoology, University of Sri Jayewardenepura, Sri Lanka.

Investigation of ergonometric parameters of university lecture hall furniture

U.L. Palamakumbura and H.S. Amarasekara

Sitting comfort is considered important particularly in working environments with regards to health  and performances of day to day work. Sitting on a comfortable seat helps to relax the body and reduce energy consumption but on the other hand prolong sitting slackens abdominal muscles and may cause backache. Application of ergonomic approach to furniture designing helps to increase the comfort of furniture.

There has been an inherent in Sri Lanka on ergonomics of furniture designing (Abeysekara, 1982 and Silva 2006). No considerable attention has been given on ergonomics of universities or school furniture. It is important to concentrate on furniture in lecture halls and class rooms because children are spending a long period of their lives in schools and university working environments. The present study aimed at investigating of ergonomic parameters of lecture hall furniture of USJP (University of Sri Jayewardenepura). Though, the investigation has been done for Faculty of Applied science (FAS), the results can be applied to the whole university. The FAS of USJP has eighteen lecture halls and these eighteen lecture halls consist of four major types of furniture designs. A distinct variability was observed in the all ergonomic parameters of furniture in eighteen lecture hall. Most variability was observed in height of the back rest.

Furniture in each lecture hall of FAS was compared with the developed ergonomic standard values. Many mismatches were observed between standard ergonomic parameters based on anthropometric data with the ergonomic parameters of present lecture hall furniture in FAS. This may cause many health problems like back pain, neck pain and fatigue of university students. Seat height of the university lecture hall furniture of FAS does not match with the popliteal height of the students.

Furthermore, the user survey shows several problems regarding comfort of university lecture hall furniture. Students do not like fiber glass chairs with desktop arm rest at the right side and the ergonomic parameters (seat height, seat width) do not comply with the student’s body dimensions. None of the seating units in FAS fulfilled all the ergonomic parameters.

Positive remarks were given by the students for lecture hall P1 and M1. Based on anthropometric data of university students in FAS ergonomic parameters were proposed. Recommended ergonomic parameters are 42.5-43.5cm for seat height, 45-46cm for seat depth to back support, 16-17cm for height lowest point back support, 37-38cm for height highest point back support, 37-38cm for seat width, 54-55cm for vertical span below the table and 63-64cm for horizontal clearance below the table.

U.L. Palamakumbura and H.S. Amarasekara

Department of Forestry and Environmental Science, University of Sri Jayewardenepura, Sri Lanka.