ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Biodegradation  (1)
  • Herbivory tolerance  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of polymers and the environment 3 (1995), S. 121-131 
    ISSN: 1572-8900
    Keywords: Biodegradation ; poly(β-hydroxybutyrate) ; testing ; carbon balance ; carbon dioxide evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Establishing carbon balances has been proven to be an applicable and powerful tool in testing biodegradability of polymers. In controlled degradation tests at a 4-L scale with the model polymer poly(β-hydroxybutyrate) (PHB), it was shown that the degree of degradation could not be determined with satisfactory accuracy from CO2 release alone. Instead, the course of degradation was characterized by means of establishing carbon balances for the degradation of PHB withAcidovorax facilis and a mixed culture derived from compost. Different analytical methods for determining the different carbon fractions were adapted to the particular test conditions and compared. Quantitative determination of biomass and residual polymer were the main problems in establishing carbon balances. Amounts of biomass derived from protein measurements depend strongly on assumptions of the protein content of the biomass. Selective oxidation of biomass with hypochlorite was used as alternative, but here problems arose from insoluble metabolic products. Determination of soluble components with the method of chemical oxygen demand (COD) also includes empirical assumptions but seems acceptable if the dissolved carbon fraction is in the range of some 10% total carbon. Results confirm both analytical assays and theoretical approaches, in ending up at values very close to 100%, within an acceptable standard deviation range under test conditions comparable to standard test practice.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-1939
    Keywords: Browsing tolerance ; Clipping ; Compensatory growth capacity ; Herbivory tolerance ; Meristematic potential
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Inherent relative growth rate has been suggested as a major determinant of plant species' capacity to regrow and compensate for tissues lost to herbivores. We investigated: 1) the relationship between compensatory growth capacity and relative growth rate (RGR) in six semiarid-land shrubs following removal in winter or spring of 90% of the previous year's growth, 2) the influence of loss of buds on production of new growth and 3) the relationship between meristematic potential and the capacity to produce new growth in four of the six semiarid-land shrub species. Four-year-old plants growing under field conditions were used in the study. The species with the highest inherent growth rate, sagebrush [Artemisia tridentata ssp. vaseyana (Rydb.) Beetle], died following the severe clipping treatments. The other five species exactly compensated for lost tissues. Inherent growth rates and compensatory growth capacity of the shrubs were not correlated. Loss of 90% of the buds on the previous year's growth did not limit production of new growth. Instead, shrubs that lost buds produced more new growth biomass than the controls. The shrub species had significantly different meristematic potential. Curlleaf mountain mahogany (Cercocarpus ledifolius Nutt.) and serviceberry (Amelanchier alnifolia Nutt.) had the greatest and least number of buds and long shoots per plant, respectively. The number of long shoots produced following bud removal was positively correlated with new growth biomass, while the percentage of long shoots produced at the basal position on twigs was negatively correlated with new growth biomass. Our results suggest that inherent growth rate is not likely to influence production of new growth following browsing when resources for growth are not limiting. In contrast, the ability of a shrub to initiate long shoot growth is likely to influence production of new growth even when resources for growth are abundant.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...