The transitional semi-evergreen bushland in Ethiopia: Characterization and mapping its distribution using predictive modelling

TY - JOUR

T1 - The transitional semi-evergreen bushland in Ethiopia

T2 - Characterization and mapping its distribution using predictive modelling

AU - van Breugel, Paulo

AU - Friis, Ib

AU - Sebsebe, Demissew

PY - 2016/4/1

Y1 - 2016/4/1

N2 - Question: Evergreen bushlands in Ethiopia have been inadequately studied and mapped. We address the question whether there is a transitional semi-ever-green bushland on the eastern escarpment of the Ethiopian Highlands, with unique floristic characteristics that distinguish it from the evergreen bushlands in other parts of Ethiopia and eastern Africa. Methods: Based on a review of the recent descriptions of evergreen bushlands in Ethiopia, we hypothesize that there is a distinct zone of natural semi-ever-green bushland, which is restricted to the eastern and southeastern escarpment of the Ethiopian Highlands. In contrast, evergreen bushlands in other parts of Ethiopia are considered to be of a secondary nature. To test this hypothesis, we carried out qualitative vegetation surveys in 354 locations across Ethiopia and classified the vegetation in these locations based on the occurrences of indicator species. Based on this data, we created predictive distribution models of the semi-evergreen bushland in Ethiopia using various environmental distribution models. We furthermore compared the occurrences of characteristic evergreen bushland species in Ethiopia with the occurrence of these species within the evergreen bushlands in Kenya and Uganda. Results: The vegetation surveys confirmed the existence of a distinct type of evergreen bushland vegetation. The transitional semi-evergreen bushland forms a transitional zone between the Acacia–Commiphora woodland and bushland and the Afromontane forest on the eastern and southeastern escarpments of Ethiopia, but is also characterized by a number of species that, within Ethiopia, are unique to this zone. Most of the characteristic species of the transitional semi-evergreen bushland are not found or only in lower densities in western Ethiopia. There is, furthermore, a limited overlap in characteristic species of the evergreen bushlands of Kenya and Uganda. Conclusions: Our results provide important information on the hitherto inadequately studied semi-evergreen bushland of Ethiopia. It highlights the unique character of this part of the evergreen bushlands in Ethiopia, which we argue should be taken into account for future conservation planning.

AB - Question: Evergreen bushlands in Ethiopia have been inadequately studied and mapped. We address the question whether there is a transitional semi-ever-green bushland on the eastern escarpment of the Ethiopian Highlands, with unique floristic characteristics that distinguish it from the evergreen bushlands in other parts of Ethiopia and eastern Africa. Methods: Based on a review of the recent descriptions of evergreen bushlands in Ethiopia, we hypothesize that there is a distinct zone of natural semi-ever-green bushland, which is restricted to the eastern and southeastern escarpment of the Ethiopian Highlands. In contrast, evergreen bushlands in other parts of Ethiopia are considered to be of a secondary nature. To test this hypothesis, we carried out qualitative vegetation surveys in 354 locations across Ethiopia and classified the vegetation in these locations based on the occurrences of indicator species. Based on this data, we created predictive distribution models of the semi-evergreen bushland in Ethiopia using various environmental distribution models. We furthermore compared the occurrences of characteristic evergreen bushland species in Ethiopia with the occurrence of these species within the evergreen bushlands in Kenya and Uganda. Results: The vegetation surveys confirmed the existence of a distinct type of evergreen bushland vegetation. The transitional semi-evergreen bushland forms a transitional zone between the Acacia–Commiphora woodland and bushland and the Afromontane forest on the eastern and southeastern escarpments of Ethiopia, but is also characterized by a number of species that, within Ethiopia, are unique to this zone. Most of the characteristic species of the transitional semi-evergreen bushland are not found or only in lower densities in western Ethiopia. There is, furthermore, a limited overlap in characteristic species of the evergreen bushlands of Kenya and Uganda. Conclusions: Our results provide important information on the hitherto inadequately studied semi-evergreen bushland of Ethiopia. It highlights the unique character of this part of the evergreen bushlands in Ethiopia, which we argue should be taken into account for future conservation planning.

KW - Faculty of Science

KW - botany

KW - biogeography

KW - climate envelope modelling

KW - correlative modelling

KW - East Africa

KW - Ethiopia

KW - endemic species

KW - phytogeography

KW - habitat distribution modelling

KW - vegetation classification

KW - vegetation mapping

U2 - 10.1111/avsc.12220

DO - 10.1111/avsc.12220

M3 - Journal article

SN - 1402-2001

VL - 19

SP - 355

EP - 367

JO - Applied Vegetation Science

JF - Applied Vegetation Science

IS - 2

ER -