ABSTRACT
In Mediterranean area, Acacia melanoxylon biomass is an abundant waste material from non-native and invasive tree species control actions, requiring suitable disposal. Valorisation of such biomass residues requires its complete characterization to best approach the full potential of each plant material that could suit specific applications. This study compares mature and juvenile A. melanoxylon plant tissues (wood and bark) from two stands in different locations, regarding their chemical characteristics and organic growing media properties, such as mineral content and phytotoxicity effect for Lepidium sativum seeds. Juvenile bark (JB) showed greater total extractives (29%) extracted using solvents of increasing polarity (dichloromethane, ethanol, and water), followed by mature bark (MB) (21%). MB revealed the highest lignin content (>50%) suggesting material resistance to microbial biodegradation in horticultural applications. High barks phenolic content proved to be phytotoxic for cress seeds (null JB root index), although the toxic substances may be removed. After 1 week, ageing effect reduced MB phytototoxicity (root index > 60%) improving seed performance. Bark presented more mineral elements availability than wood. Wood high cellulose (>50%), low extractive (<9%) and moderate total lignin (<30%) contents can be attractive for pulp production, while bark growth medium profile may potentiate its application for horticultural uses. The future research on novel uses of A. melanoxylon plant residues can result in economic benefits that may alleviate management costs.
Subject(s)
Acacia , Biomass , Phenols , Plant Extracts , WoodABSTRACT
The use of industrial Eucalyptus globulus bark residues for organic growing media formulation was studied. Hydrothermal treatments were tested using Response Surface Methodology approach. Model design consisted of twelve combinations of temperature (T: 60-140⯰C) and residential time (t: 20-60') to evaluate the effect on bark properties. Temperature had a significant effect in C mineralization and N immobilization rates, where the lowest responses (111.8â¯mmol CO2 kg-1â¯d-1 and NIRâ¯=â¯4.1â¯mmolâ¯Nâ¯kg-1â¯d-1, respectively) compared to IEB (214.6â¯mmol CO2 kg-1â¯d-1 and 8.9â¯Nâ¯kg-1â¯d-1, respectively) were suggested after modeling at 40⯰C during 70'. Industrial bark was phytotoxic and treatments were effective for phytotoxicity removal. Industrial bark presented high air content but low water availability; treatments had no effect on bark physical properties and the use of demineralized water may have leached nutrient content. Results from pot experiment recommend the use of 25% (v v-1) of treated barks in future growing media formulations.
Subject(s)
Eucalyptus , Cold Temperature , Plant Bark , Temperature , WaterABSTRACT
The concentration of airborne pollen from Cupressaceae was regularly monitored++ in Lisbon during 1997 and 1999, and the phenology of flowering cypress was studied in several species of the genus from 1992 to February 2000. Both methods showed a peak of pollen abundance during the month of February, with the airborne pollen concentration decreasing strongly to March and April. The results obtained are in accordance with the literature for the Mediterranean area, but in Lisbon the peak started and finished earlier than in other Mediterranean towns already studied.
Subject(s)
Air Pollution/analysis , Pollen , Cities , Portugal , Seasons , Species Specificity , TreesABSTRACT
We describe the case of a patient with restrictive cardiomyopathy due to primary amyloidosis associated with aging. The patient had a complex myocardial function. A brief review is made of the etiology, diagnostic procedures and therapy of this clinical entity, which is an important rare cause of cardiac death in elderly patients.