Effect of Habitat Complexity on Richness, Abundance and Distributional Pattern of Forest Birds

Structurally complex forests provide more diverse conditions in comparison to homogenous forests because of greater variety of microhabitats and trees. This study assesses the association of bird species richness, abundance, and distributional pattern with habitat complexity (HC) in Kheyrud Forest in the north of Iran. Birds were surveyed during spring 2009 by 100 point counts. In each point count six habitat features related to the index of HC were computed and scored from 0 to 3. Then the scores were summed and divided into two groups of low and high complexity, HC ≤ 6 and HC > 6, respectively. To compare bird richness and abundance in different HCs, a two sample t-test was used. Presence and absence of bird species at each plot as a dependent variable were compared with the vegetation characteristics as an independent variable by means of the Canonical Correspondence Analysis. The results revealed bird species richness and abundance were significantly higher in more complex habitats. Bird species can be divided into two groups, the first group including species which associated with late successional stages and the second group, species belonging to early successional stages. Numbers of birds belonging to the first group declined in less complex forests, whereas the numbers of birds belonging to the second group increased. At the stand scale, our results reveal that bird abundance and richness are strongly associated with the complexity of vegetation structure in the study area.     

Organochlorine pesticides in soil under irrigated cotton farming systems in Vertisols of the Namoi Valley, north-western New South Wales, Australia

Organochlorine pesticides (OCPs) such as DDT and DDE have been detected in the surface 0.2 m of Vertisols in the lower Namoi Valley of north western New South Wales, Australia even though they have not been applied to crops since 1982. However, their presence in the deeper soil horizons has not been investigated. The objective of this study was to determine if OCPs were present to a depth of 1.2 m in Vertisols under irrigated cotton farming systems in the lower Namoi Valley of New South Wales. Soil was sampled from the 0-1.2 m depths in three sites, viz. the Australian Cotton Research Institute, ACRI, near Narrabri (149°36′E, 30°12′S), and two cotton farms near Wee Waa (149°27′E, 30°13′S) and Merah North (149°18′E, 30°12′S) in northern New South Wales, Australia. The OCPs detected and their metabolites were α-endosulfan, β-endosulfan, endosulfan sulphate, DDD, DDE, DDT and endrin. The metabolite DDE, a breakdown product of DDT, was the most persistent OCP in all depths analysed. Endosulfan sulphate was the second most persistent followed by endrin > α-endosulfan > β-endosulfan > DDT and DDD. DDT was sprayed extensively in the lower Namoi Valley up to the early 1980s and may explain the persistence of DDE in the majority of soil samples. Dicofol and Dieldrin, two OCPs previously undocumented in Vertisols were also detected. The movement of OCPs into the subsoil of Vertisols may occur when irrigation or rain transports soil colloids and organic matter via preferential flow systems into the deeper layers of a soil profile. Persistence of OCPs was closely correlated to soil organic carbon concentrations. The persistence in soil of OCP’s applied to cotton crops grown more than two decades ago suggests that they could enter the food chain. Their presence at depths of 1.2 m suggests that they could move into groundwater that may eventually be used for domestic and stock consumption.     

Decolouration of azo dyes by <Emphasis Type="Italic">Phanerochaete chrysosporium</Emphasis> immobilised into alginate beads

Background, aim and scope  

Because of high discharged volumes and effluent composition, wastewater from the textile industry can be considered as the most polluting amongst all industrial sectors, thus greatly requiring appropriate treatment technologies. Although some abiotic methods for the reduction of several dyes exist, these require highly expensive catalysts and reagents. Biotechnological approaches were proven to be potentially effective in the treatment of this pollution source in an eco-efficient manner. The white-rot fungi are, so far, the most efficient microorganisms in degrading synthetic dyes. This white-rot fungi’s property is due to the production of extracellular lignin-modifying enzymes, which are able to degrade a wide range of xenobiotic compounds because of their low substrate specificity. In this paper, we studied the ability of the white-rot fungus Phanerochaete chrysosporium immobilised into Ca-alginate beads to decolourise different recalcitrant azo dyes such as Direct Violet 51 (DV), Reactive Black 5 (RB), Ponceau Xylidine (PX) and Bismark Brown R (BB) in successive batch cultures. To the best of our knowledge, this is the first study on the immobilisation of P. chrysosporium into Ca-alginate beads for its application in dye decolouration.     

Performance evaluation of a bipolar electrolysis/electrocoagulation (EL/EC) reactor to enhance the sludge dewaterability

The present study aimed to evaluate the performance of a bipolar electrolysis/electrocoagulation reactor designed to enhance the sludge dewaterability. The reactor was 15 L in volume, with two series of plates used in it; Ti/RuO₂ plates for the electrolysis of the sludge, and also aluminum and iron plates for electrocoagulation process. The dewaterability of the sludge was determined in terms of its capillary suction time (CST) and specific resistance to filtration (SRF), while the degree of sludge disintegration was determined based on the value of degree of sludge disintegration (DD_SCOD). The maximum reduction in CST and SRF was observed at a detention time of 20 min and a voltage of 30 V. However, increasing of both detention time and voltage significantly increased the values of CST and SRF even to an extent that they both exceeded those of the untreated sludge. The optimal degree of sludge disintegration achieved by the present study was 2.5%, which was also achieved at a detention time of 20 min and a voltage of 30 V. As reported previously, increased DD_SCOD values led to increasing CST and SRF values, due primarily to the disruption of the sludge flocs. According to the results from the present study, it can be concluded that simultaneous application of electrocoagulation and electrolysis is effective in enhancing the sludge dewaterability, because electrocoagulation helps to achieve a higher degree of sludge disintegration while maintaining the desired sludge dewaterability.     

Canola straw as a bio-waste resource for medium density fiberboard (MDF) manufacture

Canola straw as an agricultural residue has been investigated for MDF production. The variables were steaming time (2, 5 and 8 min), the resin content (9% and 11%), and press time (4 and 6 min). Common physical and mechanical properties of experimental boards including modulus of rupture (MOR), modulus of elasticity (MOE), internal bond strength (IB) and thickness swelling (TS) were measured. Fiber properties of canola straw including length, diameter and cell wall thickness were determined. The results showed that all the tested mechanical properties improved with the increase of steaming time level. The results were close to the minimum requirements of MDF specified in the ANSI A208.2 standard. Dimensional stability of the MDFs improved as adhesive content increased. The IB values are positively affected by the increase of press time. MDF properties made from canola straw possess acceptable qualities as compared to those made from other non-wood plants. Furthermore, the fiber dimensions of canola straw were also in the range of reported values in hardwoods.     

MODELS FOR WATER AND POWER SCHEDULING FOR THE CALIFORNIA STATE WATER PROJECT1

ABSTRACT: A large-scale simulation/optimization model provides schedules for operation of water and power for the California State Water Project (SWP). The SWP consists of a series of reservoirs linked by rivers, pumping plants, canals, tunnels, and generating plants and is operated by the California Department of Water Resources. The Department provides water to municipal and agricultural users, and manages its electrical loads and resources. The model, therefore, performs hydraulic and electrical computations leading to optimal operation of the entire system. It consists of hydraulic network programming components to meet the storage objectives at all the reservoirs, a linear programming component to determine the schedules at pumping and generating plants, an electrical network programming component to balance electrical loads and resources, and a number of other simulation components. It operates on yearly, weekly, and daily bases. It is primarily used for real-time operation of the SWP and can provide hourly detail schedules which are implemented by the SWP staff via a computerized system.     

A multiple criteria evaluation of sustainable agricultural development models using AHP

Selection of the appropriate agricultural development model has become an important issue in Iran. Using data from Fars province of Iran, the purpose of this paper is to use analytic hierarchy process (AHP) for selecting between the two competing sustainable agricultural development models, which have been developed based on the general tenets of Ecological Modernization (EM) and De-Modernization (DM) theories. Farmers, environmentalists, board members of rural cooperative, rural women and experts from Fars Agricultural (Jehad-e-Keshavarzi) Organization participated in application of AHP to this study. They applied AHP to determine the priority of DM and EM based sustainable agricultural development models. Each group determined the priority of the two models for sustainable agricultural development. The findings indicated that ecological criteria i.e. wise use of resources, environmental protection and product quality are the most important criteria for sustainable agriculture of Iran, followed by economic criterion employment and social criterion participation. A sensitivity analysis was carried out to determine the critical factors that affected the priority of alternatives. The results indicated that EM-based sustainable agricultural development model has a higher priority as the theoretical base of agricultural development of Iran. Readers should send their comments on this paper to BhaskarNath@aol.com within 3 months of publication of this issue     

Feasibility Assessment of Basin Solar Stills

The present study assesses the feasibility of exploiting single- and double-basin solar stills in our daily lives. An investigation is carried out to determine the thermal performance and economic viability of making use of solar stills in water desalination. The climatic conditions of Tehran (35°44?N, 51°30?E) are considered to assess the feasibility of the basins. Transient energy and mass balance equations are utilized for modeling the thermal performance. The equations are solved by using fourth-order Runge–Kutta method in FORTRAN. The daily productivities of single- and double-basin solar stills are found to be 5.22 kg/m² and 7.73 kg/m², respectively, while the effect of different water masses (20–100 kg) on the productivity of each system was found to be optimum at 20 kg/m². The results are compared with experimental work performed under different climatic conditions to examine the validity of the feasibility of basins in general. A life cycle cost analysis performed for Tehran, yields that single- and double-basin solar stills have savings-to-investment ratios of 4.2 and 4.8, respectively, indicating that they are economically feasible.     

Ploidy-, gender-, and dose-dependent alteration of selected biomarkers in Clarias gariepinus treated with benzo[a]pyrene

Naturally-occurring and artificially-induced polyploids have been documented in various fish species but to date no comparison has been reported of the impacts of ploidy on fish biomarker responses to organic pollutants. This study describes effects of ploidy, gender, and dose on biliary fluorescent aromatic compound (FAC) concentrations, hepatic ethoxyresorufin-O-deethylase (EROD) and glutathione S-transferase (GST) activities in one of the most commonly cultured warm-water species, the African catfish Clarias gariepinus. Recently matured male and female diploid and triploid fish were intraperitoneally (i.p.) injected with 0, 5 or 25 mg/kg benzo[a]pyrene (BaP) and liver and gallbladder were sampled 48 hr later. No significant differences were found between ploidies in bile concentrations of 7,8 dihydrodiolbenzo[a]pyrene (7,8D BaP), 1-hydroxybenzo[a]pyrene (1-OH BaP) or 3-hydroxybenzo[a]pyrene (3-OH BaP). However, concentrations of the biliary FACs did differ between males and females at different dose of injection with generally higher concentrations in females at the low dose of BaP and higher concentrations in males at the higher BaP concentration. Hepatic EROD activity did not exhibit gender-dependent difference, whereas it was significantly higher in triploids than diploids. GST activities were not significantly influenced by any of the tested factors. This work advanced our understanding of the role of ploidy, gender, and dose in biotransformation of pollutants in fish.