Effect of bioremediation on the growth of Okro (<Emphasis Type="Italic">Abelmoshus esculetus</Emphasis>) in the Niger Delta soils

This paper communicates the effect of bioremediation on the performance of Okro plant (Abelmoshus esculentus) in a typical Niger Delta soil that has received 5% crude oil pollution level. Biodegrading bacteria such as Pseudomonas fluorescen, Acinetobacteria iwofii, Bacillus subtilus, Arthrobacter globiformis that was isolated from previously polluted soils was introduced into the samples. The treatment combinations are as follows (A) = control without crude oil; B = soil + crude oil, (C) = soil + crude oil + microbes, (D) = soil + crude oil + microbes, (E) = soil + crude oil + microbes + fertilizer (F) soil + microbes and (G) = soil + fertilizer. The treatment (E) gave the highest number of leaves, % crop emergence, plant biomass, microbial population and degradation of petroleum hydrocarbon compared to any of the treatments that had received crude oil. This suggested that fertilizer application does not only stimulate microbial growth but it provides the plant with more available nutrients required for plant growth.     

Livestock excreta management through vermicomposting using an epigeic earthworm Eisenia foetida

In India, millions of tones of livestock excreta are produced. Our study explores the potential of an epigeic earthworm Eisenia foetida to compost different livestock excreta (cow, buffalo, horse, donkey, sheep, goat and camel) into value added product (vermicompost) at the laboratory scale. Vermicomposting resulted in lowering of pH, electrical conductivity, potassium and C:N ratio and increase in nitrogen and phosphorus contents. Total K was lower in the final cast than in the initial feed. C:N ratios of the vermicomposts ranged from 16.2 ± 2.17 to 75.4 ± 6.84. Microbial activity measured as dehydrogenase activity in buffalo, donkey and camel wastes increased with time up to day 90. But in sheep and goat wastes, maximum dehydrogenase activity was recorded on day 60 and decreased thereafter. The cocoons and hatchlings production by Eisenia foetida in different excreta were also investigated. The greatest number and biomass of hatchlings was recorded in horse excreta followed by cow, goat and sheep excreta. Thus, cow, horse, sheep and goat excreta show potential as good substrates in vermicomposting using Eisenia foetida, although further research is required to explore the feasibility of use of buffalo, donkey and camel excreta in combination with cow/sheep/goat excreta.     

Genotypic Variation in the Phytoremediation Potential of Indian Mustard for Chromium

The term “phytoremediation” is used to describe the cleanup of heavy metals from contaminated sites by plants. This study demonstrates phytoremediation potential of Indian mustard (Brasicca juncea (L.) Czern. & Coss.) genotypes for chromium (Cr). Seedlings of 10 genotypes were grown hydroponically in artificially contaminated water over a range of environmentally relevant concentrations of Cr (VI), and the responses of genotypes in the presence of Cr, with reference to Cr accumulation, its phytotoxity and anti-oxidative system were investigated. The Cr accumulation potential varied largely among Indian mustard genotypes. At 100 μM Cr treatment, Pusa Jai Kisan accumulated the maximum amount of Cr (1680 μg Cr g⁻¹ DW) whereas Vardhan accumulated the minimum (107 μg Cr g⁻¹ DW). As the tolerance of metals is a key plant characteristic required for phytoremediation purpose, effects of various levels of Cr on biomass were evaluated as the gross effect. The extent of oxidative stress caused by Cr stress was measured as rate of lipid peroxidation. The level of thiobarbituric acid reactive substances (TBARS) was enhanced at all Cr treatments when compared to the control. Inductions of enzymatic and nonenzymatic antioxidants were monitored as metal-detoxifying responses. All the genotypes responded to Cr-induced oxidative stress by modulating nonenzymatic antioxidants [glutathione (GSH) and ascorbate (Asc)] and enzymatic antioxidants [superoxide dismutase (SOD), ascorbate peroxidase (APX), and glutathione reductase (GR)]. The level of induction, however, differed among the genotypes, being at its maximum in Pusa Jai Kisan and its minimum in Vardhan. Pusa Jai Kisan was grown under natural field conditions with various Cr treatments, and Cr-accumulation capacity was studied. The results confirmed that Pusa Jai Kisan is a hyperaccumulator of Cr and hypertolerant to Cr-induced stress, which makes this genotype a viable candidate for use in the development of phytoremediation technology of Cr-contaminated sites.     

Biochemical responses,growth and reproduction of earthworm in low density polyethylene (LDPE)

There is an unprecedented production of plastic that is accelerating its disposal while affecting the fitness of the terrestrial as well as the aquatic environment. The term microplastics refers to plastic fragments that are less than 5 mm in size and are widely distributed in the environment. Therefore, the present study intends to explore the biological response of earthworms (Eisenia fetida) toward different concentrations of low-density polyethylene. E. fetida treated with low-density polyethylene concentration (Control), 250 mg kg⁻¹, 1000 mg kg⁻¹, 6000 mg kg⁻¹, 12,000 mg kg^−1, and 25,000 mg kg⁻¹. The above ratios were thoroughly mixed with 1kg of artificial soil and tested for growth, reproduction (cocoons and hatchling count), and enzymatic activities namely superoxide dismutase, guaiacol peroxidase, glutathione-S-transferase, and glutathione reductase and molecular docking studies. No mortality was observed during the exposure period at any concentrations. On the 28th day, when compared to the control the highest decrease in body weight of earthworms was observed in 25,000 mg (28.4%) followed by 12,000 mg (12.2%) and 6000 mg (3.4%). The cocoon and hatchlings significantly declined as the dose of microplastics increases. Enzymatic activity such as SOD and POD showed declined trend as the dose increased, while GST and GR increased with an increase in microplastic concentrations on 28th day. Furthermore, molecular docking showed that LDPE can modulate the activity of all four enzymes significantly.     

Investigating efficiency of <Emphasis Type="Italic">Lampito mauritii</Emphasis> (Kinberg) and <Emphasis Type="Italic">Perionyx ceylanensis</Emphasis> Michaelsen for vermicomposting of different types of organic substrates

The vermicomposting ability of Lampito mauritii (Kinberg) and Perionyx ceylanensis Michaelsen was evaluated by using three different types of organic substrates such as leaf litter of Polyalthia longifolia, Pennisetum typhoides cobs (pearl millet) and a weed, Rottboellia exaltata (whole plant except the roots) in combination with cowdung (1:1). Vermicomposting studies (120 days) conducted to optimize the number of worms required for efficient conversion based on the reduction of C/N ratio, percentage decomposition of organic substrates, total number and biomass of earthworms recovered from the vermibed substrates clearly showed that vermibeds with 4 kg of organic materials can hold about 60–80 L. mauritii and about 90–120 P. ceylanensis for efficient decomposition. The percentage decomposition of each organic substrate treated with different numbers of L. mauritii (20, 40, 60, 80 and 100 earthworms) and P. ceylanensis (30, 60, 90, 120 and 150) showed significant difference (P < 0.001) between numbers of worms introduced per vermibed but the difference between substrates was not significant within the treatments. Vermicomposting resulted in significant increase in electrical conductivity (28.54–49.82%), total nitrogen (43.96–90.83%), total phosphorus (27.42–68.10%) and total potassium (27.42–113.18%), whereas decrease in organic carbon (35.05–49.74%), C/N ratio (55.48–73.18%) and C/P ratio (50.46–66.90%) in different vermibeds introduced with L. mauritii and P. ceylanensis. Both the earthworm species can be used for vermicomposting different organic substrates; however, duration of vermicomposting with P. ceylanensis is not as much of L. mauritii. The use of L. mauritii for vermicomposting of other substrates has been well established by other workers also but standardization of P. ceylanensis, a locally available species, for vermicomposting of different organic substrates is a new finding and the species could be useful for vermiconversion of organic substrates under local conditions.     

Primary Productivity and the Impacts of the Exotic Weed <Emphasis Type="Italic">Eupatorium Glandulosum</Emphasis> in a Montane Grassland of Garhwal Himalaya

Summary The biomass and productivity of a montane grassland of Garhwal Himalaya were estimated with the objectives to compare these values of the dominant exotic species, Eupatorium glandulosum HBK. (Asteraceae) with other species, and to compare the sites more dominated by this species with other study sites. The effect of dominance of this species on other species was undertaken because of its continuous spread in the grasslands of the Garhwal Himalaya causing replacement of some native grasses and economically important herbaceous plants. Out of six study sites, SW₁, SW₂, and NE₁ were more dominated by Eupatorium glandulosum. Total net primary productivity (TNP) ranged from 1528.5 to 2163.4 g m⁻² yr⁻¹. Eupatorium glandulosum showed individual highest biomass on all the study sites, and the sites more dominated by this species showed higher values of primary productivity, thereby reducing the biomass and production of other species on these sites.     

Conversion of temperate forests into heaths: Role of ecosystem disturbance and ericaceous plants

Fire and logging in nutrient-poor temperate forests with certain ericaceous understory plants may convert the forests into heaths. The process of disturbance-induced heath formation is documented by using examples ofCalluna in western Europe,Kalmia in Newfoundland, andGaultheria (salal) in coastal British Columbia. In a cool, temperate climate, rapid vegetative growth ofCalluna, Kalmia, and salal following disturbance results in increasing organic accumulation (paludification), nutrient sequestration, soil acidification, and allelochemicals. These are thought to be the main reasons to conifer regeneration failure in disturbed habitats. If continuation in forest is a land-use objective, then temperate forests with an ericaceous understory should not be logged unless effective silvicultural methods are devised to control the ericaceous plants and restore forest regeneration. Preharvest vegetation control may be considered as an option. Failure to control the understory plants may lead to a long-term vegetation shift, from forest to heathland, particularly in nutrient-poor sites. Successful methods of controllingKalmia andGaultheria, however, have yet to be developed. While theKalmia- andGaultheria- dominated heathlands are undesirable in Canada and the Pacific Northwest, a wide range ofCalluna heathlands of western Europe are being conserved as natural and seminatural vegetation.     

Relationships of salt-marsh plant distributions to tidal levels in Connecticut,USA

A three-year study of Connecticut, USA, salt-marsh vegetation was undertaken to determine the relationship of its distribution on the marsh surface to tidal levels, particularly mean high water (MHW) as measured on each of three sites representing different tidal amplitudes. Elevations and species present were measured on 1-m² grids in 10x 70-m belt transects at each site. After the data were subjected to discriminant analysis and other standard statistical procedures, the results showed that 98.4% of all observations ofSpartina alterniflora Loisel. occurred at or below MHW. The data can aid in salt-marsh restoration by offering a reliable indicator of what species should be planted when restored elevations and on-site MHW are known.     

Effect of Agave attenuata extracts on detoxification enzymes of Biomphlaria alexandrina

The toxicity and rising costs of synthetic molluscicides have led to interest in compounds derived from locally growing plants that can be used as molluscicides. The aim of the present work was to study the effect of extracts of some Egyptian plants having lethal effect on snails of medical importance (Biomphlaria alexandrina) as well as on antioxidant and glutathione detoxification enzymes. Ethanolic extracts of locally growing plants Agave attenuata, Agave sislana, Phytolaca dodecandra and Euphorbia spllendens were applied as a contact poison to B. alexandrina, the intermediate host of Schistosoma mansoni. The LC₅₀ of A. attenuata, A. sislana, P. dodecandra and E. spllendens are 82, 101, 98 and 98 mg/L, respectively. Glutathione and the enzymes involved in protection of the snail from reactive oxygen species namely, glutathione peroxidase, glutathione reductase, glutathione S-transferase, catalase, gamma glutamyl transferase increased in the survival snails exposed to high concentrations of A. attenuata. Glucose-6-phosphate dehydrogenase indirectly affecting glutathione reductase and the oxidation, reduction of glutathione significantly decreased in snails exposed to A. attenuata extracts. Superoxide dismutase level tend to decrease in snails exposed to A. attenuata of action. In conclusion A. attenuata is preferable when compared with synthetic molluscicides. The enzymes involved directly or indirectly in protection mechanism of the snail against A. attenuata are mainly responsible for snails survival.     

Diversity, Seasonality, and Context of Mammalian Roadkills in the Southern Great Plains

Thousands of mammals are killed annually from vehicle collisions, making the issue an important one for conservation biologists and environmental managers. We recorded all readily identifiable kills on or immediately adjacent to roads in the southern Great Plains from March 2004–March 2007. We also recorded distance traveled, whether a road was paved or divided, the number of lanes, and prevailing habitat. Surveys were opportunistic and were conducted by car during conditions of good visibility. Over our 239 surveys and >16,500 km traveled, we recorded 1412 roadkills from 18 different mammal species (size ranged from Sciurus squirrels to the white-tailed deer, Odocolieus virginianus). The overall kill rate was 8.50 / 100 km. Four species were prone to collisions: the Virginia opossum (Didelphis virginiana), nine-banded armadillo (Dasypus novemcinctus), striped skunk (Mephitis mephitis), and northern raccoon (Procyon lotor). Together they accounted for approximately 85% (1198) of all roadkills. Mortality rate differed significantly between 2- and 4-lane roads (8.39 versus 7.79 / 100 km). Kill rates were significantly higher on paved versus unpaved roads (8.60 versus 3.65 / 100 km), but did not depend on whether a road was divided. Roadkills were higher in spring than in fall (1.5×), winter (1.4×), or summer (1.3×). The spring peak (in kills / 100 km) was driven chiefly by the armadillo (2.76 in spring/summer versus 0.73 in autumn/winter) and opossum (2.65 versus 1.47). By contrast, seasonality was dampened by a late winter/early spring peak in skunk mortalities, for which 41% occurred in the 6-week period of mid-February through March. The raccoon did not exhibit a strong seasonal pattern. Our data are consistent with dispersal patterns of these species. Our results underscore the high rate of highway mortality in the southern plains, as well as differences in seasonality and road type that contribute to mortality. Conservation and management efforts should focus on creating underpasses or using other means to reduce roadkill rates.     

Stand density index applied to timber and goshawk habitat objectives in Douglas-fir

Silvicultural guidelines are presented for the management of intermountain Douglas-fir (Pseudotsuga menziesii) stands for sawtimber production and goshawk (Accipiter gentilis) nesting habitat in the northern Rocky Mountains. Data from 14 goshawk nest stands in Douglas-fir forests on the Targhee National Forest in Idaho (Patla 1991) were used to characterize the range of stand conditions considered suitable for goshawk nesting. A density management regime is presented using Reineke's stand density index that includes a technical rotation designed to produce sawlogs with a single commercial thinning. On average timber-growing sites, stands reach goshawk habitat suitability when site height is 25 m at age 75 and provide 65 years of goshawk nesting habitat until the final harvest at age 140. Approximately 1320 m³/ha are harvested over the rotation. On higher-quality sites, rotation length declines from 140 to 85 years, of which roughly 35 years are suitable for goshawk nesting.     

An Evaluation of Techniques to Control Problem Bird Species on Landfill Sites

Birds feeding on landfill sites cause problems in terms of nuisance to neighbors, flight safety, a threat to public health, and affecting the day to day site operation. A number of control measures exist to deter problem species; however, research into their effectiveness across sites and for multiple species has been limited. We use a modeling approach in order to assess the effectiveness of nine techniques — pyrotechnics, hand-held distress calls, static distress calls, blank ammunition, a combination of blank and lethal use of ammunition, the use of falcons, the use of hawks, wailers and helium-filled bird-scaring kites — at deterring three commonly recorded species — the Black-headed Gull (Larus ridibundus), the Herring Gull (Larus argentatus) and the Lesser Black-backed Gull (Larus fuscus) — from six landfill sites across the United Kingdom. The use of distress calls, falconry, and combinations of lethal and nonlethal use of ammunition were the most effective techniques for initially deterring birds from these sites. However, when habituation is considered, there is a clear difference between techniques such as falconry, which have a lethal aspect and may act to reinforce the deterrence, and the use of techniques such as distress calls, which do not. However there are problems related to legislation and public perception when lethal techniques are used.     

The influence of the precursor and synthesis method on the CO2 capture capacity of carpet waste-based sorbents

Adsorption is one of the most promising technologies for reducing CO₂ emissions and at present several different types of sorbents are being investigated. The use of sorbents obtained from low-cost and abundant precursors (i.e. solid wastes) appears an attractive strategy to adopt because it will contribute to a reduction not only in operational costs but also in the amount of waste that is dumped and burned in landfills every year. Following on from previous studies by the authors, in this work several carbon-based adsorbents were developed from different carpet wastes (pre-consumer and post-consumer wastes) by chemical activation with KOH at various activation temperatures (600–900 °C) and KOH:char impregnation ratios (0.5:1 to 4:1). The prepared materials were characterised by chemical analysis and gas adsorption (N₂, −196 °C; CO₂, 0 °C), and tested for CO₂ adsorption at temperatures of 25 and 100 °C. It was found that both the type of precursor and the conditions of activation (i.e. impregnation ratios, and activation temperatures), had a huge influence on the microporosity of the resultant samples and their CO₂ capture capacities. The carbon-based adsorbent that presented the maximum CO₂ capture capacities at 25 and 100 °C (13.8 wt.% and 3.1 wt.%, respectively), was prepared from a pre-consumer carpet waste and was activated at 700 °C using a KOH:char impregnation ratio of 1:1. This sample showed the highest narrow microporosity volume (0.47 cm³ g⁻¹), thus confirming that only pores of less than 1 nm are effective for CO₂ adsorption at atmospheric pressure.     

Possible Input of Nitrogen of Visitors’ Origin on a Protected Peatland

The Ozegahara peatland, in the Nikko-Oze National Park in Japan, is ecologically significant because of its oligotrophic environment; it is one of the most strictly preserved areas in the country. The isotope ratio of nitrogen (¹⁵N/¹⁴N) and carbon (¹³C/¹²C) and C/N ratio of peat moss (Sphagnum spp.) and sundew (Drosera rotundifolia) in the peatland were analyzed. The correlation of the isotope ratio with some parameters (sundew population density, number of trapped insects, water level, bog myrtle coverage, and visitor density) was investigated. The nitrogen isotope ratio of sundew showed the most significant covariation with visitor density, where sundew from lunch areas or along busy walkways showed a higher nitrogen isotope ratio. The nitrogen isotope ratio of peat moss covaried, not only with route traffic frequency but also with water level, bog myrtle coverage, and number of trapped insects by sundew, indicating that factors other than the visitor level influence the local nitrogen cycle. This study suggests that the nitrogen imported into the peatland by visitors is a principal factor to be monitored for the maintenance of the natural environment.     

Influence of Landfill Gas on the Microdistribution of Grass Establishment Through Natural Colonization

Many revegetated landfills have poor cover including bare areas where plants do not grow. This study, on the Bisasar Road Landfill site in South Africa, assessed grass species preferences to microhabitat conditions in a mosaic of patches of well-established grassed areas and bare, nonvegetated areas. Factors, including soil CO₂, CH₄, O₂, nutrients, and other general soil conditions, were measured in relation to species distribution and grass biomass in the field. Cynodon dactylon was the dominant grass in the established grass areas but was less abundant in the areas bordering the bare areas where Paspalum paspalodes and Sporobolus africanus were common. A number of soil factors measured were significantly correlated with grass biomass and these included Mg, Ca, Zn, Mn, K, temperature, moisture, and CO₂. However, a laboratory bioassay using the growth of C. dactylon with soils removed from the landfill indicated that there were no differences in the soils from the bare areas and those that supported high plant biomass. Thus, no nutrient deficiency or chemical toxicity was inherent in the soil in the laboratory. The results of the field investigation and bioassay indicated that soil CO₂ as a result of landfill gas infiltration into the root zone was probably the main factor causing bare areas on the landfill where no grass species could colonize and grow and that C. dactylon was more sensitive to elevated soil CO₂ than other grass species such as P. paspalodes and S. africanus.     

Assessment of the Microbiological Quality of Clarias gariepinus Exposed to an Industrial Effluent in Nigeria

The microbiological impact of a detergent and soap industries effluent on Clarias gariepinus was assessed under laboratory conditions. The heterotrophic bacterial count obtained from fish surfaces ranged from 1.2 × 10²−2.0 × 10²cfu/ml amongst the control, while values of 4.8× 10⁶−8.6 × 10⁶ cfu/ml were obtained for the experimental fish exposed to the industrial effluent (0.025 ppm). The fungal count for the controls ranged from 1.2× 10²−1.2 × 10³ cfu/ml; while a range of 1.0 × 10⁶−2.0 × 10⁶ was obtained for the fish exposed to the industrial effluent. While twelve bacterial species were isolated from the fish exposed to the industrial effluent, only two were isolated from the parts of the control fish used in the study. The bacterial species are those in the genera Staphylococcus, Proteus, Streptococcus, Micrococcus, Bacillus, Pseudomonas, Serratia, Enterobacter, and Escherichia. The fungal isolates include Saccharomyces, Aspergillus, Rhodosporium, Candida, Alternaria, and Fusarium. The resistance of the bacterial isolates to the commonly used antibiotics showed that 100% were resistant to Augmentin, Amoxycillin and Cloxacillin, 85.71% to Tetracycline, 80.95% to Cotrimoxazole, 71.43% to Erythromycin, 33.33% to Chloramphenicol, and 28.57% to Gentamicin. Among the eight antibiotics tested, five patterns of multiple drug resistance were obtained, with the number of the antibiotics ranging from 4–8. The public health implications of these observations are discussed.     

Effect of spent engine oil on the growth parameters and chlorophyll content of <Emphasis Type="Italic">Corchorus olitorius</Emphasis> Linn

The effect of spent engine oil on the height, leaf number, leaf area, stem girth, chlorophyll, and moisture contents of Corchorus olitorius grown on 0, 0.2%, 0.4%, 0.6%, 0.8%, 1.0%, 2.0%, and 3.0% (v/w oil/soil) oil-contaminated soil was investigated. The engine oil at all concentrations delayed the germination of C. olitorius by 2 days (compared to control) and there was a general significant reduction in all the growth parameters in plants grown on contaminated soil compared to control plants. The highest leaf area of 26.8 cm² was found in the control plant and least was found in the 0.6% soil (0.11 cm²) after 3 weeks while no values were recorded on the 0.8–3.0% engine-oil-contaminated soil after 5 weeks of experiment. The highest chlorophyll content was also found in the control plant (11.5 mg/l). This showed that spent engine oil has an adverse effect on the growth of C. olitorius plant.     

The Effectiveness of Management Interventions Used to Control Ragwort Species

Ragwort (Senecio jacobaea and S. aquaticus) causes major losses to agricultural revenue and induces livestock morbidity throughout parts of Europe, North America, and Australasia. The introduction of legislation in the U.K. and Australia has meant that landowners can be prosecuted if the plant spreads to adjacent land, which has led to an increase in activities attempting to control these species. Commonly used interventions include natural enemies, herbicide applications, manual and mechanical removal. Through the use of explicit systematic methodology involving comprehensive searches and detailed inclusion criteria, data from primary research are collated for each type of intervention. Meta-analyses show that 2,4-D, Asulam, Clopyralid, and MCPA are effective at reducing ragwort densities. However, when the datasets were analysed for their effectiveness against individual species, 2,4-D and MCPA were only effective against S. jacobaea, while Asulam was only effective against S. aquaticus. Natural enemies Longitarsus jacobaeae and a combination of L. jacobaeae and Tyria jacobaeae appear to have the potential to reduce S. jacobaea densities. Only applying T. jacobaeae does not appear to significantly reduce S. jacobaea densities, but does reduce the number of capitula per plant, seeds per capitula, viability of seeds, and dry weight of the plants. There is insufficient experimental evidence available to assess other interventions such as manual or mechanical removal. Further research into these types of interventions is recommended, as well as more detailed reporting of site characteristics and experimental design to allow full investigation of each intervention to explain possible reasons for variations in their effectiveness.     

Model-Based Assessment of Aspen Responses to Elk Herbivory in Rocky Mountain National Park,USA

In Rocky Mountain National Park (RMNP), aspen (Populus tremuloides Michx.) has been observed to be declining on elk (Cervus elaphus nelsoni) winter range for many decades. To support elk management decisions, the SAVANNA ecosystem model was adapted to explore interactions between elk herbivory and aspen dynamics. The simulated probability of successful vegetative regeneration for senescent aspen stands declines sharply when elk densities reach levels of 3–5 elk/km², depending on model assumptions for the seasonal duration of elk foraging activities. For aspen stands with a substantial component of younger trees, the simulated regeneration probability declines more continuously with increasing elk density, dropping below 50% from densities at 8–14 elk/km².At the landscape scale, simulated aspen regeneration probability under a scenario of extensive seasonal use was little affected by elk population level, when this level was above 300–600 elk (25%–50% current population) over the ca. 107 km² winter range. This was because elk distribution was highly aggregated, so that a high density of elk occupied certain areas, even at low population levels overall. At approximately current elk population levels (1000–1200 elk), only 35%–45% of senescent aspen stands are simulated as having at least a 90% probability of regeneration, nearly all of them located on the periphery of the winter range. Successful management for aspen persistence on core winter range will likely require some combination of elk population reduction, management of elk distribution, and fencing to protect aspen suckers from elk browsing.     

Riverbanks and the law: The arbitrary nature of river boundaries in New South Wales,Australia

Key aspects of environmental management exist within a legislative framework. The Rivers and Foreshores Improvement Act 1948 (NSW) and several Regional Environmental Plans created under the Environmental Planning and Assessment Act 1979 (NSW) make reference to ‘the top of the bank’ for defining areas of protected land adjacent to rivers, within which development consent may be required. It is an arbitrary term and its use within the Rivers and Foreshores Improvement Act 1948 (NSW) leads to confusion. This paper examines the range of definitions of ‘the top of the bank’ in respect of natural watercourses and aims to provide a more lucid and effective definition that will clarify existing ambiguities in legal interpretation. The paper examines the historical origins of the phrase ‘top of the bank’, finding that stereotyped Eurocentric views of what a river ‘should look like’ have impaired the legal definition for Australian rivers, thereby influencing common law and the development of statutory definitions. Judicial applications of the phrase ‘top of the bank’ are examined from a geomorphological perspective, demonstrating the misconceptions of the term in a legal context. The paper identifies the existence of widespread support for the need to protect land adjacent to rivers in the interests of environmental, economic and social sustainability. It concludes by calling for legislative reform that is both tailored to the individual site and consistent with overarching goals at the catchment scale.