Toward Consensus-Based Actions that Balance Invasive Plant Management and Conservation of At-Risk Fauna

Limiting the spread of invasive plants has become a high priority among natural resource managers. Yet in some regions, invasive plants are providing important habitat components to native animals that are at risk of local or regional extirpation. In these situations, removing invasive plants may decrease short-term survival of the at-risk taxa. At the same time, there may be a reluctance to expand invaded habitats to benefit at-risk species because such actions may increase the distribution of invasive plants. Such a dilemma can result in “management paralysis,” where no action is taken either to reduce invasive plants or to expand habitats for at-risk species. A pragmatic solution to this dilemma may be to develop an approach that considers site-specific circumstances. We constructed a “discussion tree” as a means of initiating conversations among various stakeholders involved with managing habitats in the northeastern USA to benefit several at-risk taxa, including New England cottontails (Sylvilagus transitionalis). Major components of this approach include recognition that expanding some invaded habitats may be essential to prevent extirpation of at-risk species, and the effective control of invasive plants is dependent on knowledge of the status of invasives on managed lands and within the surrounding landscape. By acknowledging that management of invasive plants is a complex issue without a single solution, we may be successful in limiting their spread while still addressing critical habitat needs.     

Quantitation of hydroxyl radical during fenton oxidation following a single addition of iron and peroxide

Chemical probes were used to study the formation of hydroxyl radical in aqueous iron-hydrogen peroxide reaction. Hydroxyl radical formation rate and time dependent concentration were determined in pure water, in aqueous fulvic acid (FA) and humic acid (HA) solutions, and in natural surface waters. Indirect determinations of hydroxyl radical were made by quantitating hydroxyl radical reactions with probe compounds under controlled conditions. High probe concentrations were used to determine radical formation rates and low probe concentrations were used to determine time dependent radical concentration. Two independent probes were used for intercomparison: benzoic acid and 1-propanol. Good agreement between the two probes was observed. Natural water matrices resulted in lower radical formation rates and lower hydroxyl radical concentrations, with observed formation rate and yield in natural waters up to four times lower than in pure water. HA and FA also reduced hydroxyl radical formation under most conditions, although increased radical formation was observed with FA at certain pH values. Hydroxyl radical formation increased linearly with hydrogen peroxide concentration.     

Copper Emissions from Fuel Combustion Consumption and Industry in Two Urban Areas 1900–1980

The type of energy system andindustrial structure of urban areas is veryimportant for the total amounts of Cu emitted.The total per capita emission for the New Yorkarea is estimated to be approximately 4 timeslarger than Stockholm municipality between 1900–1980. The latter was mainly the result of largedifferences in energy systems and industrialstructure. Hydro-electric power and non fossilfuels were important energy sources for Stockholmwhile coal was a much more significant fuel forthe New York area. Metal processing hascharacterised the industries of Stockholm whilethe New York area was a national centre forcopper and petroleum refining as well as thechemical industry. In both cases the estimated Cuemissions from fuel combustion and industrydecreased from 1900–1980. But in the case ofconsumption related emissions the time trendsdiffer between the two urban areas. In Stockholmend use was the largest category of Cu emissionsduring the whole time period studied. In the NewYork area consumption related emissions becamethe largest source of Cu emission in the 1950s.     

The development of secondary industries through the sustainable utilisation of reeds and forest timber in the Tembe Elephant Park,Maputaland, South Africa

The harvesting of Phragmites australis reeds in the Tembe Elephant Park has to be managed pro-actively. Solutions to potential problems should be sought before they arise. This paper offers a potential solution to the problem of instating a winter-only reed harvest in the Muzi Swamp. The potential for manufacturing finished products such as prefabricated huts from sustainably harvested reeds and forest timber is examined and a cost estimate is presented. A prefabricated reed hut is three-times cheaper than a similarly-sized house made of bricks and cement. The manufacturing of finished products from the harvested material will add secondary value to the resource and also offer an alternative employment to harvesting reeds in the summer. The higher prices obtained for a processed article will also, hopefully, reduce the demand for the resource in its raw form, thereby increasing the perceived value of the resource and reducing wastage from raw materials that are not sold.