This thesis investigates the effects of genetic modification of the starch quality in potato on the structure and function of the soil fungal community via changes in root-exudates and litter... Show moreThis thesis investigates the effects of genetic modification of the starch quality in potato on the structure and function of the soil fungal community via changes in root-exudates and litter composition, and compares the observed differences between the GM- and its parental variety in the context of the __normal__ variation effected by conventionally produced cultivars. In order to study the fungal community composition and functionality, an integrated approach of molecular fingerprinting methods and measurements of fungal enzymes involved in degradation of organic matter in the soil was employed. In field experiments the effect of soil type, season and plant growth stage on rhizosphere fungi were evaluated and in the greenhouse experiments stable isotopes were employed to monitor carbon flow from the plant to rhizosphere microbes and a decomposer experiment was designed to investigate the faith of the potatoes and leaves possibly left into the soil. The detailed greenhouse studies revealed differences between GM- and its parental variety. The field studies, however, confirmed that these differences are transient in field conditions and that fungi in the potato rhizosphere are affected more by soil type, sampling year, plant growth stage and cultivar type than the genetic modification. Show less
The focus of this thesis is on the dynamics and functions of saprotrophic soil fungi during conversion from an arable land into a natural ecosystem (heathland) and to asses their effects on soil... Show moreThe focus of this thesis is on the dynamics and functions of saprotrophic soil fungi during conversion from an arable land into a natural ecosystem (heathland) and to asses their effects on soil ecosystem processes. Chapter 2 describes that fungal biomass in abandoned arable land is not increasing for at least 3 decades to the level of a natural ecosystem. Opportunistic fungi showed to be responsible for the decomposition processes, and these fungi are stimulated by large sizes of nitrogen-rich substrate buried in soil (Chapter 4& 5). Chapter 3 presents that no large amounts of phosphorus seem to leach into deeper soil layers after land abandonment. In Chapter 6 it is shown that the establishment of Calluna vulgaris in a recently abandoned arable land can be due to a fast colonization of Calluna immediately after abandonment and the reduction of microbial nitrogen mineralization, in combination with the colonization of Calluna roots by ericoid mycorrhizal fungi. In Chapter 7 it is concluded that an increase in fungal biomass in ex-arable soils can be of interest for soil ecosystem restoration and this may be triggered by the introduction of large particles of recalcitrant organic matter together with sufficient fungal biomass. Show less
The main topic of the book is the nature of inner aspect of the Verb Phrase, and the relation between the decompositional and the quantificational approaches to this problem. Decompositional... Show moreThe main topic of the book is the nature of inner aspect of the Verb Phrase, and the relation between the decompositional and the quantificational approaches to this problem. Decompositional approaches analyze eventualities into simpler components, organized by some kind of structure. In this view, an eventuality is telic if, in decomposition, it can be shown to involve a result component (also referred to as the culmination or termination component, or as the telos). Quantificational approaches see telicity as a property of the predicate of an eventuality, usually described as boundedness, lack of the subinterval property, or a specified quantity. The major advantage of the decompositional approaches is that they directly match the syntax-semantics interface of the VP with the conceptual image of an eventuality. Quantificational approaches blur the picture in this respect, because they involve effects like distributive readings, which are not a typical interpretational component of the VP domain. On the other hand, the major advantage of the quantificational approaches is that they assign similar or identical properties to (the predicates of) eventualities and nominal expressions. This enables them to capture the phenomenon of incremental themes (participants that appear to measure out the eventuality in which they take part), by relating the predicates of eventualities and those of their arguments. The dissertation presents a new approach, which not only combines the two approaches above, but also shows how they are directly mutually related, and how some quantificational properties can be derived from the domain of decomposition. Show less
