Wondie Mebrat - Academia.edu (original) (raw)
Papers by Wondie Mebrat
Forest provides livelihoods for millions of people worldwide, through provision of different prod... more Forest provides livelihoods for millions of people worldwide, through provision of different products. However, their diversity and area coverage are highly declined through time. Deforestation, invasive species and land degradation are the main threats accelerated plant diversity loss. Like most countries in the Sahelian region Ethiopia is affected by these factors heavily and finally resulted desertification, poverty and natural resource losses. About 75 percent of the countries land mass is estimated to have been affected by the threat of desertification. To overcome these problems efforts has been made to launch afforestation and conservation programs. So, the purpose of this review is to present threats of plant diversity and forest conservation in Ethiopia.
Abstract: The study was conducted to detect vegetation stress changes using GIS techniques in Eas... more Abstract: The study was conducted to detect vegetation stress changes using GIS techniques in East of Lake Tana, Ethiopia. It was conducted using Landsat 5 TM 1985 and Landsat 7 ETM+ 2011 images. Global positioning system and topographical maps of scale 1:50,000 were used for ground verification. Normalized Difference Vegetation Index was calculated from the two images in order to recognize the vegetation stress changes. For this purpose, ERDAS Imagine 9.1 for calculating NDVI values and ArcGIS 9.3 for NDVI mapping was used. The result showed that there has been a reduction of vegetation biomass coverage from 1985 to 2011. Taking the maximum value, it decreases from 0.96 in 1985 to 0.68 in 2011. To this effect, the standard deviation value decreases in 2011 image as compared to 1985. Overall, there was an increase in the size of land cover class classified as severely stressed area.
Journal of Biology Agriculture and Healthcare, 2014
Journal of Biology Agriculture and Healthcare, 2014
Ethiopia is considered as the center of origin with many forests richest in species diversity. Th... more Ethiopia is considered as the center of origin with many forests richest in species diversity. These Forests are one of Ethiopian greatest natural assets. They play an indispensible role in protection of environment, regulating climate, controlling water runoff, maintaining ecological balance and producing valuable materials. However, these forest resources are highly declined due to rapid and continuous deforestation activities; agricultural expansion and settlement. To minimize the risk, there are increasing needs to measure and monitor the extent and condition of Ethiopian forests for management purposes. Monitoring is an essential tool in ecological and biodiversity management. It improves the manager's ability to make proper decisions through a wide range of forest data collection by agencies including Federal and State and Territory governments. These are often collected using different methods and are not always consistent across boundaries making national compilations difficult. Monitoring indicates changing methods of forest mapping over time also poses problems for assessing trends in forest extent and condition.
However, their diversity and area coverage are highly declined through time due to deforestation,... more However, their diversity and area coverage are highly declined through time due to deforestation, invasive species, expansion of agricultural practice and land degradation. In line of these several interventions have been tried to undertake environmental degradation in Ethiopia. One of these intervention mechanisms is area enclosure, a method by which an area is protected from human and livestock interference. This method of environmental improvement appears to be successful, through applying artificial and natural regeneration methods. This method has indispensible role for rehabilitation of degraded lands, animal conservation, soil development and conservation. This paper is therefore helpful to know the success of conservation activities through enclosure and to design management plans for the future.
The study was carried out to evaluate woody species diversity comparatively on enclosed forest an... more The study was carried out to evaluate woody species diversity comparatively on enclosed forest and open site in North Western highlands of Ethiopia. Systematic sampling method was used to collect vegetation data from 36 quadrants. Each quadrant has 20 m x 20 m size with an interval of 100 m which was laid along four transect lines. Within each quadrant, vegetation data such as seedlings, saplings and tree species were directly counted from both open and enclosed sites. The counted and recorded trees, saplings and seedlings of each species were marked with dyes to avoid confusion. Shannon-Wiener and Simpson’s diversity index were applied to quantify species diversity, richness and evenness. The result showed that sapling and seedling diversity was very high from enclosure site. These imply the enclosure was at high rate of regeneration. Keywords: , Woody species, diversity, enclosure, open site
Journal of Biology Agriculture and Healthcare, 2014
The study was carried out to evaluate woody species diversity comparatively on enclosed forest an... more The study was carried out to evaluate woody species diversity comparatively on enclosed forest and open site in North Western highlands of Ethiopia. Systematic sampling method was used to collect vegetation data from 36 quadrants. Each quadrant has 20 m x 20 m size with an interval of 100 m which was laid along four transect lines. Within each quadrant, vegetation data such as seedlings, saplings and tree species were directly counted from both open and enclosed sites. The counted and recorded trees, saplings and seedlings of each species were marked with dyes to avoid confusion. Shannon-Wiener and Simpson's diversity index were applied to quantify species diversity, richness and evenness. The result showed that sapling and seedling diversity was very high from enclosure site. These imply the enclosure was at high rate of regeneration. Keywords:, Woody species, diversity, enclosure, open site 1. Introduction In many countries such as Greenland, Egypt and Pakistan, the natural forest coverage accounts less than 5% of the land. On the other hand, in a few places like Suriname and French Guinea natural forests cover more than 90% of their area, which accounts about 30% of the world total natural vegetation cover (FAO, 2006; Gorta and Sheikh, 2010). These diversified forests are found in different parts of the world and they are used to meet the basic needs of the forest dependent communities (Murthy et al., 2002). They play an indispensible role in the protection of environment, regulating climate, controlling water runoff, maintaining ecological balance and producing valuable materials such as timber for construction and furniture, extraction of chemicals, paper and pulp. Furthermore, they have paramount role in purifying the air, serving as a habitat for wild animals and have aesthetic value (Mesfin, 2004). Apart from ecological values, forests are also significantly important for the economy of many tropical and subtropical countries (Taye, 2006) Despite their economic, social and environmental welfare of the world, the diversity of woody plant species is being threatened because of ever increasing population pressure and its associated effects such as deforestation and expansion of agricultural lands that caused overall environmental degradation. According to FAO (2006), forest resources are declined world wide by 0.22% per year in the period 1990-2000 and by 0.18% per year between 2000 and 2005 due to different natural and anthropogenic factors. These results in a rapid decline of forest ecosystems and increased the extinction of plant and animal species. Especially Ethiopia is a mountainous country characterized by great geographic diversity with rugged mountains, flat topped plateaus and deep gorges (Tewoldeberhan, 1988). These diversified topographic features made the country richest in flora of tropical Africa (Tolera et al., 2008). As a result, Ethiopia is considered as the center of origin and the richest in plant species diversity (Mesfin, 2004). However, these rich forest resources are highly declined due to rapid and continuous deforestation activities. Changes in land use mainly through the conversion of natural vegetation to agricultural lands and settlement are the main causes for this rapid deterioration of forest areas in the country (Eyayu et al., 2009). For instance, some reports in the country indicated that at the beginning of the 20 th century, 40 percent of the country was covered with a natural forest. This larger sized forest declined to 16 percent in 1950s and to less than 3 percent at the end of the century (Mesfin, 2004). Hundreds of years exploitative traditional land use aggravated by high human and livestock population pressure lead to cultivate sloppy lands and over exploit slowly renewable resources in the region (Eyayu et al., 2009). These expansions of agricultural lands to marginal areas at the expense of forest lands have been documented by some studies such as that of Gete and Hurni (2001), Woldeamlak (2002) and Eyayu et al. (2009). The problem is also common in the North Gondar zone, where forests are fragmented into patches and strips of hills (Alemayehu, 2003). Thus, assessment of plant diversity is important to evaluate the success of conservation activities and design management plans for the future. Therefore, the study aims to assess woody species composition and dynamics of plant communities in enclosed and open site of West Belessa District.
Forest provides livelihoods for millions of people worldwide, through provision of different prod... more Forest provides livelihoods for millions of people worldwide, through provision of different products. However, their diversity and area coverage are highly declined through time. Deforestation, invasive species and land degradation are the main threats accelerated plant diversity loss. Like most countries in the Sahelian region Ethiopia is affected by these factors heavily and finally resulted desertification, poverty and natural resource losses. About 75 percent of the countries land mass is estimated to have been affected by the threat of desertification. To overcome these problems efforts has been made to launch afforestation and conservation programs. So, the purpose of this review is to present threats of plant diversity and forest conservation in Ethiopia.
Abstract: The study was conducted to detect vegetation stress changes using GIS techniques in Eas... more Abstract: The study was conducted to detect vegetation stress changes using GIS techniques in East of Lake Tana, Ethiopia. It was conducted using Landsat 5 TM 1985 and Landsat 7 ETM+ 2011 images. Global positioning system and topographical maps of scale 1:50,000 were used for ground verification. Normalized Difference Vegetation Index was calculated from the two images in order to recognize the vegetation stress changes. For this purpose, ERDAS Imagine 9.1 for calculating NDVI values and ArcGIS 9.3 for NDVI mapping was used. The result showed that there has been a reduction of vegetation biomass coverage from 1985 to 2011. Taking the maximum value, it decreases from 0.96 in 1985 to 0.68 in 2011. To this effect, the standard deviation value decreases in 2011 image as compared to 1985. Overall, there was an increase in the size of land cover class classified as severely stressed area.
Journal of Biology Agriculture and Healthcare, 2014
Journal of Biology Agriculture and Healthcare, 2014
Ethiopia is considered as the center of origin with many forests richest in species diversity. Th... more Ethiopia is considered as the center of origin with many forests richest in species diversity. These Forests are one of Ethiopian greatest natural assets. They play an indispensible role in protection of environment, regulating climate, controlling water runoff, maintaining ecological balance and producing valuable materials. However, these forest resources are highly declined due to rapid and continuous deforestation activities; agricultural expansion and settlement. To minimize the risk, there are increasing needs to measure and monitor the extent and condition of Ethiopian forests for management purposes. Monitoring is an essential tool in ecological and biodiversity management. It improves the manager's ability to make proper decisions through a wide range of forest data collection by agencies including Federal and State and Territory governments. These are often collected using different methods and are not always consistent across boundaries making national compilations difficult. Monitoring indicates changing methods of forest mapping over time also poses problems for assessing trends in forest extent and condition.
However, their diversity and area coverage are highly declined through time due to deforestation,... more However, their diversity and area coverage are highly declined through time due to deforestation, invasive species, expansion of agricultural practice and land degradation. In line of these several interventions have been tried to undertake environmental degradation in Ethiopia. One of these intervention mechanisms is area enclosure, a method by which an area is protected from human and livestock interference. This method of environmental improvement appears to be successful, through applying artificial and natural regeneration methods. This method has indispensible role for rehabilitation of degraded lands, animal conservation, soil development and conservation. This paper is therefore helpful to know the success of conservation activities through enclosure and to design management plans for the future.
The study was carried out to evaluate woody species diversity comparatively on enclosed forest an... more The study was carried out to evaluate woody species diversity comparatively on enclosed forest and open site in North Western highlands of Ethiopia. Systematic sampling method was used to collect vegetation data from 36 quadrants. Each quadrant has 20 m x 20 m size with an interval of 100 m which was laid along four transect lines. Within each quadrant, vegetation data such as seedlings, saplings and tree species were directly counted from both open and enclosed sites. The counted and recorded trees, saplings and seedlings of each species were marked with dyes to avoid confusion. Shannon-Wiener and Simpson’s diversity index were applied to quantify species diversity, richness and evenness. The result showed that sapling and seedling diversity was very high from enclosure site. These imply the enclosure was at high rate of regeneration. Keywords: , Woody species, diversity, enclosure, open site
Journal of Biology Agriculture and Healthcare, 2014
The study was carried out to evaluate woody species diversity comparatively on enclosed forest an... more The study was carried out to evaluate woody species diversity comparatively on enclosed forest and open site in North Western highlands of Ethiopia. Systematic sampling method was used to collect vegetation data from 36 quadrants. Each quadrant has 20 m x 20 m size with an interval of 100 m which was laid along four transect lines. Within each quadrant, vegetation data such as seedlings, saplings and tree species were directly counted from both open and enclosed sites. The counted and recorded trees, saplings and seedlings of each species were marked with dyes to avoid confusion. Shannon-Wiener and Simpson's diversity index were applied to quantify species diversity, richness and evenness. The result showed that sapling and seedling diversity was very high from enclosure site. These imply the enclosure was at high rate of regeneration. Keywords:, Woody species, diversity, enclosure, open site 1. Introduction In many countries such as Greenland, Egypt and Pakistan, the natural forest coverage accounts less than 5% of the land. On the other hand, in a few places like Suriname and French Guinea natural forests cover more than 90% of their area, which accounts about 30% of the world total natural vegetation cover (FAO, 2006; Gorta and Sheikh, 2010). These diversified forests are found in different parts of the world and they are used to meet the basic needs of the forest dependent communities (Murthy et al., 2002). They play an indispensible role in the protection of environment, regulating climate, controlling water runoff, maintaining ecological balance and producing valuable materials such as timber for construction and furniture, extraction of chemicals, paper and pulp. Furthermore, they have paramount role in purifying the air, serving as a habitat for wild animals and have aesthetic value (Mesfin, 2004). Apart from ecological values, forests are also significantly important for the economy of many tropical and subtropical countries (Taye, 2006) Despite their economic, social and environmental welfare of the world, the diversity of woody plant species is being threatened because of ever increasing population pressure and its associated effects such as deforestation and expansion of agricultural lands that caused overall environmental degradation. According to FAO (2006), forest resources are declined world wide by 0.22% per year in the period 1990-2000 and by 0.18% per year between 2000 and 2005 due to different natural and anthropogenic factors. These results in a rapid decline of forest ecosystems and increased the extinction of plant and animal species. Especially Ethiopia is a mountainous country characterized by great geographic diversity with rugged mountains, flat topped plateaus and deep gorges (Tewoldeberhan, 1988). These diversified topographic features made the country richest in flora of tropical Africa (Tolera et al., 2008). As a result, Ethiopia is considered as the center of origin and the richest in plant species diversity (Mesfin, 2004). However, these rich forest resources are highly declined due to rapid and continuous deforestation activities. Changes in land use mainly through the conversion of natural vegetation to agricultural lands and settlement are the main causes for this rapid deterioration of forest areas in the country (Eyayu et al., 2009). For instance, some reports in the country indicated that at the beginning of the 20 th century, 40 percent of the country was covered with a natural forest. This larger sized forest declined to 16 percent in 1950s and to less than 3 percent at the end of the century (Mesfin, 2004). Hundreds of years exploitative traditional land use aggravated by high human and livestock population pressure lead to cultivate sloppy lands and over exploit slowly renewable resources in the region (Eyayu et al., 2009). These expansions of agricultural lands to marginal areas at the expense of forest lands have been documented by some studies such as that of Gete and Hurni (2001), Woldeamlak (2002) and Eyayu et al. (2009). The problem is also common in the North Gondar zone, where forests are fragmented into patches and strips of hills (Alemayehu, 2003). Thus, assessment of plant diversity is important to evaluate the success of conservation activities and design management plans for the future. Therefore, the study aims to assess woody species composition and dynamics of plant communities in enclosed and open site of West Belessa District.