Yonas Yohannes

Ethiopian Environment and Forest Research Institute

Tree species differ in litter quality and belowground biomass, thereby exerting species-specific impact on soil properties and microbial biomass. A study was conducted to find out the comparative effects of Podocarpus falcatus and Croton macrostachys on basic soil characteristics and microbial biomass, in the Munessa forest, Ethiopia. Four experime...

Tree species differ in litter quality and belowground biomass, thereby exerting species-specific impact on soil properties and microbial biomass. A study was conducted to find out the comparative effects of Podocarpus falcatus and Croton macrostachys on basic soil characteristics and microbial biomass, in the Munessa forest, Ethiopia. Four experime...

The effect of plantation forests on the global carbon balance is controversially discussed in recent times. As soil respiration is a decisive component in the carbon exchange between terrestrial ecosystems and atmosphere, effects of forest management measures (e.g. thinning) in the context of driving parameters of soil CO2 efflux is a key issue in...

Anthropogenic disturbance of old-growth tropical forests increases the abundance of early successional tree species at the cost of late successional ones. Quantifying differences in terms of carbon allocation and the proportion of recently fixed carbon in soil CO(2) efflux is crucial for addressing the carbon footprint of creeping degradation. We c...

Variability of soil CO2 efflux strongly depends on soil temperature, soil moisture and plant phenology. Separating the effects of these factors is critical to understand the belowground carbon dynamics of forest ecosystem. In Ethiopia with its unreliable seasonal rainfall, variability of soil CO2 efflux may be particularly associated with seasonal...

The kinetic, mutual and parallel resolution of a series of structurally related active esters derived from 2-phenylpropanoic acid using a combination of quasi-enantiomeric oxazolidin-2-ones is discussed.

The resolution of 2-phenylpropanoyl chloride using an equimolar combination of quasi-enantiomeric oxazolidinones is discussed. The levels of diastereoselectivity were found to be dependent upon the structural nature of the metallated oxazolidinone, temperature and metal counter-ion.

In the title compound, C19H19NO3, formed from enanti­omerically pure (+)-(4R,5S)-4-methyl-5-phenyl-2-oxazolidinone and racemic 2-phenyl­propanoyl chloride, the two carbonyl groups are oriented anti to each other, and the two methyl groups are oriented anti to each other.

In the title compound, C19H19NO3, formed from enanti­omerically pure (+)-(4R,5S)-4-methyl-5-phenyl-2-oxazolidinone and racemic 2-phenyl­propanoyl chloride, the two carbonyl groups are oriented anti to each other, and the two methyl groups are oriented anti to each other.

Racemic Evans' oxazolidinones were efficiently resolved using a combination of quasi-enantiomeric profens. The levels of stereocontrol were high, giving products with predictable configurations.

The parallel kinetic resolution of 2-phenylpropanoyl chloride using quasi-enantiomeric oxazolidinones is discussed. The levels of diastereoselectivity were found to be dependent on the presence of an additional (quasi)-enantiomeric oxazolidinone and its structural nature. The origin of this stereocontrol was believed to be due to hetero-aggregation...

Forest management practices such as thinning can dramatically change the microenvironment and thereby affect the physicochemical and soil microbiological properties. The aim of this research was to determine the effect of thinning on soil physicochemical properties and microbial biomass under Cupressus lusitanica plantation at Munessa forest. The e...