Zur Histopathologie der Granulose vonChoristoneura murinana (HBN.) (Lepidopt., Tortricidae)

The Science of Nature -     

The Ythan Project: A Case Study on Improving Catchment Management through Community Involvement

Increased participation in resource management decisions by a wide range of stakeholders has been widely advocated, and has recently been formally incorporated into the European Water Framework Directive. However, achieving such participation has generally proved to be problematical. In response to locally perceived needs, a project was set up in the Ythan catchment in northeast Scotland, to undertake catchment management actions with increased public involvement. This paper outlines the methods used to increase public participation in such actions, and some preliminary assessments of the effectiveness of these. The experience of the project and the lessons learnt, including some of the difficulties of ensuring fully representative stakeholder involvement, are discussed in relation to published criteria for public participation in resource management.     

Reciprocal effects of platinum and lead on the water household of poplar cuttings

In order to study the accumulation rates and effects of platinum as influenced by lead, experiments were performed with poplar cuttings in a growth chamber. The heavy metals were added at a final concentration of 34.8 ppb each to nutrient solutions as PtCl₄ and Pb(NO₃)₂. The variants were 1) control; 2) permanent Pt treatment for 6 weeks; 3) pretreatment with Pt plus subsequent treatment with Pb (three weeks each), and 4) heavy metal application in inverse order to variant 3. The experiments revealed that platinum accumulates in the roots of poplar cuttings to a higher degree than lead. It is translocated from the roots to other plant parts to an extremely low degree. Lead is displaced from the roots by subsequent Pt treatment. Insoluble platinum was found to be associated especially on the cell walls of the rhizodermis and exodermis of the root tips. Accumulation of platinum in the roots leads to a gradual depletion of the plants’ water supply. The disturbance of the water household causes a reduction of the transpirational surface, lowered transpiration rates and enhanced root growth. All these alterations are induced as a means of coping water stress. From the results of this experiment, the conclusion can be drawn that, under the chosen experimental conditions, platinum manifests a higher toxicity than lead in plant roots because of its higher accumulation rates.