Eva November

Effects of pioneer shrubs on the recruitment of the fleshy-fruited tree Olea europaea ssp. cuspidata in Afromontane savanna

Abstract Question: Is seedling recruitment of a fleshy-fruited tree in degraded Afromontane savanna dependent on shelter from pioneer shrubs, and is shelter availability related to shrub traits? Location: Degraded montane savanna in northern Ethiopia (13°36′ N, 39°21′ E). Method: Nurse plants of Olea europaea ssp. cuspidata seedlings were recorded using T-square plotless sampling and clustered according to shrub traits, using Wards method after Principal Components Analysis. Facilitation was further examined through experimental planting and Kaplan-Meier survival analysis. Results: Both in grazed and protected areas, Olea recruits were found exclusively under shrubs, primarily under Euclea racemosa although Acacia etbaica was more abundant. Olea recruitment is distributed randomly at landscape scale, but depends on shelter at patch scale. Shelter ability is related to shrub shape and species identity. Dense multi-stemmed shrubs with a wide base and crown on a mulch-rich mound are key recruitment foci. Euclea shrubs have these favoured traits and probably act as preferential perching sites for avian seed dispersers. Soil and organic matter accumulation under Euclea shrubs may also create favourable conditions for Olea germination and survival. Experimentally planted seedlings had a better chance for survival under Euclea. Conclusions: Olea regeneration is probably subject to both passive (disperser-mediated) and active facilitation. Small changes of shrub traits can alter the suitability of a patch for Olea recruitment. Protection of shrubs can increase facilitation for seedlings, while pruning may reduce competition for saplings and thus enhance forest succession. Planting of raised Olea seedlings under Euclea shrubs in years with a good rainy season may further assist forest restoration. Abbreviation: TSB = Byth robust T-square estimator. Nomenclature: Hedberg & Edwards (1989); Hedberg et al. (2003); Klopper et al. (2005).

Improvised Hand Injury Treatment Using Traditional Veterinary Medicine in Ethiopia

In remote wilderness environments, local people with traditional knowledge of medicinal plants are potentially important first-line health care providers. We present a case of a 31-year-old man who fell off a horse while trekking through a remote mountain landscape in Ethiopia and sustained blunt force trauma to the hand. A local mountain hut keeper examined the patients hand and used heated leaves of the succulent plant Kalanchoe petitiana to treat a suspected metacarpal fracture. As first responder in a low-resource setting, the hut keeper relied on his traditional knowledge of ethnoveterinary medicine to improvise a treatment for a human injury in a remote mountain environment. Although in this case the outcome of the traditional intervention was positive, our analysis shows that the massage component of the intervention could have led to complications. Conversely, reports from the use of related Kalanchoe species suggest that heated Kalanchoe leaves could be useful in the compression component of traditional care for hand injuries. Validation of traditional remedies and their therapeutic potential are needed if they are to complement wilderness wound care safely and reliably. The documentation and validation of these remedies are urgently needed, as many medicinal plants and indigenous knowledge of how to use these valuable natural resources are being lost.

On-line calibration of viable biomass measurements during time-varying agitation conditions

Abstract For optimal process control and quality management of fermentations as well as waste water treament processes, adequate on-line measurements of important process variables are indispensable. The viable biomass, typically present in biological processes, can be detected on-line by the Biomass Monitor as a capacitance measurement. From an economical point of view, the oxygen input in biological processes is to be optimized. Since high costs are involved, it is common practice to implement a controller using the agitation or the air flow rate as manipulatedvariables in order to maintain an ideal oxygenation rate. In this article, the influence of varying agitation and air flow rate on the output signal of the Biomass Monitor is considered. In addition, the observed relation of agitation versus viable biomass measurement is applied on-line in order to generate a smooth curve of the biomass concentration throughout conditions with variable agitation. It is illustrated that for differences in media or other experimental conditions the mathematical relation between agitation and capacitance has to be adapted.