Yohannes Et Al 2011 Manag Biol
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ISSN 1989‐8649 Manag. Biolog. Invasions, 2011, 2 Abstract Survey and documentation of the potential and actual invasive alien plant species and other biological threats to biodiversity in Awash The study was conducted at the Awash National Park, Ethiopia National Park (ANP) Ethiopia, to document Invasive Alien Species (IAS) Tamene YOHANNES , Tesfaye AWAS and Sebsebe DEMISSEW and to assess the spread of Prosopis juliflora (Sw.) DC. A total of 64 sample plots were laid systematically along the Introduction diversity within it. Through the altitudinal gradient of 750 to 1916 m. conservation of biodiversity not only Potential IAS were recorded. IAS which Ethiopia spans a remarkable number the survival of many threatened may threaten biodiversity of the park of the world’s broad ecological species and habitats can be ensured, includes species such as Prosopis regions due to its dramatic but also these valuable resources juliflora, Parthenium hysterophorus L., geological history, broad latitudinal will be secured for future Cryptostegia grandiflora Roxb. ex R. Br. , spread and immense altitudinal generations and also the well being Parkinsonia aculeata L., Senna range. This range from the of eco‐system functions protected. occidentalis (L.) Link, Datura ferox L. and In‐situ is considered the most Xanthium strumarium L. Except P. depressions in the Afar (126 m juliflora and P. hysterophorus, all others below sea level) to the spectacular appropriate way of conserving were not recorded in Ethiopia as IAS. P. mountaintops of Ras Dashen in the biodiversity. Conserving the areas juliflora was recorded in three plots north (4620 m) and the Bale where populations of species exist with cover of 1% to 10%. P. juliflora was Mountains in southeast Ethiopia naturally is an underlying condition also found spread in different parts of (4272 m). This variety of habitats for the conservation of biodiversity. the park particularly following the route also supports a rich variety of That is why protected areas form a of cattle movement. P. hysterophorus different species which contributes central element of any national was recorded in and around nine to the overall biodiversity of the strategy to conserve biodiversity. sample plots. Plot 46, 47 and 48 were country (IBC 2005). highly infested by P. hysterophorus Awash National Park (ANP) is which covered more than 60, 70 and Biodiversity conservation is one of the protected areas in 80% of the ground layer respectively. C. the protection, restoration and Ethiopia. It shelters 81 mammal grandiflora was recorded in 11 plots sustainable management of wildlife species such as Beisa Oryx (Fig. 1), with cover ranging from 1% to 35%. In and natural resources such as Lesser Kudu, Waterbuck, Somme view of all the natural as well as forests and water and the biological ring’s Gazelle, Hamadryas and anthropogenic threats to the biodiversity of the Park, the ANP is at high risk. The rich biodiversity needs immediate management intervention. Keywords Cryptostegia grandiflora, Datura ferox. Fig 1. Beisa Oryx, one Parkinsonia aculeata, Parthenium of the many species hysterophorus, Prosopis juliflora, Senna with high conservation occidentalis, Xanthium strumarium. value of the Awash National Park. 3 DOI: http://dx.doi.org/10.3391/mbi.2011.2.1.01 T. Yohannes et al. Plant Invasions in Awash National Park , Ethiopia Anubis Baboon. There are also more proximity of ANP to Amibara (one of Resumen than 460 bird species and several the Districts bordering it, where El estudio se llevó a cabo en el Parque plant species including the endemic there is a high infestation of P. Nacional de Awash (ANP) en Etiopia, tree species Acacia prasinata juliflora. Together with uncontrolled con el objetivo de documentar Especies Exóticas Invasoras (IAS) y evaluar la pro‐ Schweinf. In Ethiopia as a whole, movement of both wild and pagación de Prosopis juliflora (Sw.) DC. the major threats to protected areas domestic animals to the Park, the Se establecieron sistemáticamente un emanate from settlement within the invasion of the Park by P. juliflora total de 64 parcelas de muestreo a lo National Parks/Sanctuaries or may be inevitable unless largo de un gradiente altitudinal 0de 75 adjacent to them, crop cultivation, precautionary measures are taken a 1916 m, registrando posibles IAS. Las grazing and deforestation (Hillman at an early stage. IAS que pueden amenazar la biodiversi‐ 1993; Jacobs & Schloeder 1993; IBC dad del parque incluye especies como 2005). Therefore, this study was Prosopis juliflora, Parthenium hyste‐ initiated to assess and document rophorus L., Cryptostegia grandiflora Roxb. ex R. Br. , Parkinsonia aculeata L., Most of the National Parks the Invasive Alien plant Species and Senna occidentalis (L.) Link, Datura fe‐ of Ethiopia are found in Acacia‐ the spread of P. juliflora in the Park rox L. y Xanthium strumarium L.. Excep‐ Commiphora Woodland Ecosystems and to identify other threats to the to P. juliflora y P. Hysterophorus, el including the ANP (IBC 2005). This Biodiversity of the Park in order to resto no estaban registradas en Etiopia ecosystem is currently under strong provide information for appropriate como IAS. P. juliflora se registró en tres environmental stress. Over forty decision making on the biodiversity parcelas con coberturas del 1% al 10%, taxa in this ecosystem are conservation of ANP. encontrándose dispersa en diferentes threatened (Ensermu Kelbessa et al. partes del parque siguiendo la ruta de movimiento del ganado. P. hysteropho‐ 1992). The failure to manage the Material and Methods rus se registró en el interior y alrededor expansion of Invasive Alien Species de nueve parcelas de muestreo; las par‐ (IAS), such as Prosopis juliflora (Sw.) Description of the study area celas 46, 47 y 48 fueron intensamente DC. to the ANP and the ecosystem infectadas por P. hysterophorus abar‐ in which it is included is threatening The study was conducted in ANP, cando más del 60, 70 y 80% de la su‐ the biodiversity (IBC 2005). In order located between 8°45′ to 9°15′ N perficie, respectivamente. C. grandiflora to obtain information for the and 39°45′ to 40°5′ E in the se registró en 11 parcelas con una co‐ management of IAS such as Middle Awash Basin at the southern bertura del 1% al 35%. En vista de todas las amenazas naturales y antropogeni‐ prevention, control, eradication and tip of Afar Regional State and cas de la biodiversidad del parque, el designing mitigation measures for northeastern part of Oromia ANP presenta un riesgo elevado, preci‐ the impacts. It is important to Regional State. The Park is located in sando de medidas de gestión inmedia‐ incorporate proactive assessment of the geographical boundaries of tas.. IAS in vegetation studies in addition Awash‐Fantale and Kereyu‐Fantale to other ecological parameters. Districts of Afar and Oromia Palabras clave Regional States respectively. Cryptostegia grandiflora, Datura ferox. Currently compiled Parkinsonia aculeata, Parthenium hys‐ information on the current status of The ANP was established in terophorus, Prosopis juliflora, Senna occidentalis, Xanthium strumarium. plant diversity of ANP as well as the 1966. It is located 225 kilometers spread of invasive plant species is east of Addis Ababa with its not available. Due to the close southern boundary along the Awash 4 ISSN 1989‐8649 Manag. Biolog. Invasions, 2011, 2 River, and covers 756 km2. The encountered in each sample plot abundance of Parthenium vegetation of the study area is were recorded and their cover was hysterophorus L., Cryptostegia described as open grassland, recorded by visual estimation of the grandiflora Roxb. ex R. Br. and bushland/shrubland and riverine percentage foliage cover of each Prosopis juliflora (Sw.) DC. vegetations (Jacobs & Schloeder species in the sampling plot and 1993), woodland and grassland with recorded as percentage. Sampling Even though, not all alien altitudinal range between 750 and sites in ANP. Park areas where species will become invasive or 1916 m.a.s.l. (Gamachu 1977). distributed among grasslands such threaten the environment, this is an as the Illala Sala area. Other area in which an early investigation The main rainy season is inaccessible areas and areas with should be made to reduce the from July to September, with a short security problems were excluded potentially wide‐ranging impacts rainy season from February to April. from sampling. when they do become invasive, and The nature of rainfall in the study because of the difficulties, including area is irregularly distributed and Data Collection financial costs and in reversing the the mean annual rainfall is 550.9 impacts. Invasive Alien Species are mm (Ebro et al. 2004). The following environmental species which are an introduced parameters were measured for each species which invades natural Sampling Design and data collection sampling plot: habitats, non‐native (or alien) to the ecosystem and whose introduction During the reconnaissance survey, ‐Altitude, by using pocket causes or is likely to cause economic based on visual observation and by altimeter and Garmin GPS; or environmental harm or harm to consideration of the vegetation and ‐Slope, by using clinometer human health. other environmental gradients, the and ANP was grouped into seven ‐Geographical coordinates, by The study showed that, in vegetation stands. Data collection using Garmin GPS. the ANP there are plant species was conducted during October to which are known to be invaders, November 2008 and March 2009. The average cover abundance of noxious weeds and escape from The assessment was conducted plant species from 64 sampling plots cultivation that became semi along altitudinal gradient ranging recorded by visual estimation of the naturalized. Plant species which from 750 to 1916 m by using percentage foliage cover of each were observed in different parts of systematic sampling design. Nine species in the sample plot and the Park and which are alien to the transect lines were established recorded as percentage. ecosystem in general and to the systematically at different places ANP in particular; with actual and based on identified vegetation Results and Discussion future invasive potential and which stands.