Land Degradation and Resilience in the North Ethiopian Highlands as evidenced by Historical Photographs

none13noneNYSSEN J.; CRUMMEY D.; MUNRO N.; MITIKU HAILE; POESEN J.; FRANKL; A.; HURNI; H.; DESCHEEMAEKER; K.; RITLER; A.; NIEVERGELT B.; MOEYERSONS J.; DECKERS J.; BILLI P.Nyssen, J.; Crummey, D.; Munro, N.; Mitiku, Haile; Poesen, J.; Frankl, A.; Hurni, H.; Descheemaeker, K.; Ritler, A.; Nievergelt, B.; Moeyersons, J.; Deckers, J.; Billi, Paol

Dual, Site-Specific Modification of Antibodies by Using Solid-Phase Immobilized Microbial Transglutaminase

ISSN:1439-4227ISSN:1439-763

Environmental conditions and human drivers for changes to North Ethiopian mountain landscapes over 145 years

As quantitative or spatially distributed studies of environmental change over truly long-term periods of more than 100 years are extremely rare, we re-photographed 361 landscapes that appear on historical photographs (1868–1994) within a 40,000 km2 study area in northern Ethiopia. Visible evidence of environmental changes apparent from the paired photographs was analyzed using an expert rating system. The conditions of the woody vegetation, soil and water conservation structures and land management were worse in the earlier periods compared to their present conditions. The cover by indigenous trees is a notable exception: it peaked in the 1930s, declined afterwards and then achieved a second peak in the early 21st century. Particularly in areas with greater population densities, there has been a significant increase in woody vegetation and soil and water conservation structures over the course of the study period. We conclude that except for an apparent upward movement of the upper tree limit, the direct human impacts on the environment are overriding the effects of climate change in the north Ethiopian highlands and that the northern Ethiopian highlands are currently greener than at any other time in the last 145 years

Are changes in north Ethiopian mountain landscapes over the last 140 years caused by changing climate, or by human-induced degradation and rehabilitation?

Studies on recent environmental change in tropical areas are generally conducted over limited time scales. This study makes a multi-temporal and multi-locational assessment over a period of 140 years, in one of the world’s most degraded areas: the Highlands of Northern Ethiopia. 300 landscapes, recorded on historical photographs, taken from 1868 onwards, were rephotographed in 2006-9 and environmental changes apparent on the paired photographs were analysed through expert rating. General tendencies in landscape changes include an improved vegetation cover, in spite of a general, poorly scientifically supported belief of an opposite trend, as well as better soil and water conservation nowadays as compared to any period of the last 140 years, with a second optimum in the early 20th century. In the Simen Mountains (above 3500 m a.s.l.), upslope shifts of the upper tree line (Erica arborea) and of the upper cultivation limits of barley and potatoes are observed both inside and outside the National Park. These upslope shifts are observed since the 1970s and are probably related to global warming. In other mountain ranges, grazing pressure is greater and no change to the tree line could be observed though an upslope shift of crop species (wheat) was noted. At lower elevations, increased vegetation cover is the result of farmer initiatives as of the 1930s and intense rehabilitation activities since the 1980s. The implementation of physical soil and water conservation (stone and soil bunds, check dams) follows the same trend. Regional variations occurring in these trends are observed and discussed. The findings are substantiated by field investigations. The positive changes that result from these conservation activities in the Northern Ethiopian Highlands are an issue of global concern as they show that (1) in this study area direct human impact on the environment has so far been more important than potential effects of climate change and (2) severe land degradation should not always be irreversible

Impacts of direct human activity and climate change on north Ethiopian mountain landscapes over 140 years

none14noneNYSSEN J.; FRANKL A.; MITIKU HAILE; HURNI H.; DESCHEEMAEKER K.; RITLER A.; CRUMMEY D.; NIEVERGELT B.; MOEYERSONS J.; MUNRO R.N.; PORTNER B.; DECKERS J.; BILLI P.; POESEN J.;Nyssen, J.; Frankl, A.; Mitiku, Haile; Hurni, H.; Descheemaeker, K.; Ritler, A.; Crummey, D.; Nievergelt, B.; Moeyersons, J.; Munro, R. N.; Portner, B.; Deckers, J.; Billi, Paolo; Poesen, J