Effects of livestock grazing on key vegetation attributes of a remnant forest reserve : the case of Desa'a Forest in northern Ethiopia

The study was conducted in Desa'a Forest with the objective of investigating livestock-forest interaction. This study also evaluated the grazing pressure on Desa'a Forests from livestock, the potential of forests biomass feed production and current livestock density relation to the sustainable stocking rate. Data on socio-economic and community perception about livestock-forest interaction were collected through structured questionnaire on 90 households. To determine the species composition, abundance, density and diversity of woody plants, using stratified random sampling, four transect lines were laid out in east, west, north and south direction. Accordingly, the results are representative of Desa'a Forest. In the study area, 90% of the respondents (81 households) entered their livestock into Desa'a Forest and only 10% of the respondents (9 households) did not use Desa'a Forest. A total of 63 woody plant species were identified in the study area. According to farmers and pastoralists' opinion, 49.15%, 15.25%, 28.81% and 6.79% of woody species were identified as highly palatable, palatable, less palatable and unpalatable respectively. The mean herbaceous biomass production in Desa'a Forest is 1255.86 kg/ha. The predicted mean annual browse biomass production was 3000.72 kg/ha. The potential stocking rates for Desa'a Forest were 68480.39 TLU/year obtained based on the amount of fodder available to the livestock in the forest. The available potential browsing unit per hectare in the centre, North-West direction and south-east direction was 1432.66 BU/ha, 665.83 BU/ha and 203.66 BU/ha, respectively. Only 5.65% of the total surveyed households practice forage development which are the key to overcome feed shortage and decrease the pressure from the forest

Solid Waste Management in Africa: Governance Failure or Development Opportunity?

Waste management is a social, economic, and environmental problem facing all African countries. If the 2030 Agenda for sustainable development is to be achieved, sustainable waste management approaches must be an environmental and public health imperative deserving political priority. Current reasons for the poor management of waste in Africa, include, amongst others, weak organizational structures; lack of appropriate skills; inadequate budgets; weak legislation; lack of enforcement; low public awareness; corruption, conflict; political instability; and lack of political will. At the heart of the problem, is a failure in governance. However, through these gaps, many social and technological innovations have emerged. Innovations that recognize the opportunity that waste provides as a secondary resource. Diverting waste away from dumpsites and landfills towards reuse, recycling and recovery can improve the livelihoods of thousands of informal waste reclaimers, while also creating new jobs and business opportunities for the continent. Reintroducing secondary resources such as polymer, fiber, metals and nutrients back into local value chains has the potential to strengthen manufacturing economies and reduce the economic burden on product imports. Bringing waste under control in Africa and unlocking the opportunities that “waste” provides as “resource” will require immediate intervention by government, business and civil society

Management Interventions to Assist Restoration of Degraded Dry Afromontane Forest N. Ethiopia

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 SUMMARY Tropical deforestationcontinues to threaten biodiversity and forest-based livelihoods. In thiscontext, management of the remaining forests is becoming an increasinglyimportant component of sustainable land management options. This isparticularly evident in the dry afromontane regions of Ethiopia where there isnear to complete biomass dependence of the population against a background ofcontinuous expansion of agriculture. Moreover, the remaining forests arechallenged by resource limitation due to continuous degradation and drought,and associated loss of biodiversity. The challenge is to identify managementinterventions able to sustain their existence and ability to provide ecosystemservices.A common goal forrestoration of any natural ecosystem is to recover autogenic processes to thepoint where assistance from restorationists is no longer needed. Therefore, themajor challenge to sustainably manage degraded afromontane forests is torestore the forest habitat and microclimate by facilitating naturalregeneration or performing enrichment planting of the existing forests species.In addition, silvicultural treatments to improve resource allocation, growthand productivity, have seldom been integrated in the management of Ethiopianforests, particularly in natural afromontane forests. This research aims atcontributing with observational and experimental work to the conservation andrestoration of dry afromontane forests. The study was conducted in Desa aForest, the emblematic last large natural dry afromontane forest of northernEthiopia. The observational work focussed on assessing the soil, vegetation,and traditional use of the forest by local communities and the experimentalwork evaluated the effects of fencing and silvicultural treatments on survivaland growth of natural regenerated seedlings, planted saplings, and the remainingtree population in an ambitious long-term experimental site. The work included a large variety ofmonitoring techniques ranging from ethnobotanical household interviews todendrometer measurements in permanent plots. Desa a Forest, as most ofthe forests in the semi-arid tropics has a large potential of providingprovisioning, regulating and cultural services to local communities.Integrating local communities needs in forest management is an essentialelement in striving towards sustainability of the forest. One option of doingthis is by providing economic alternatives. An ethnobotanical study wasconducted to investigate the variety of medicinal plants occurring in theforest, their uses and conservation by people living in and around the forest. Information was collected usingsemi-structured interviews and focus group discussions in seven villageslocated close to and inside the forest. In the area, local communities useforest based plants (74.4 % trees and shrubs) as remedies for human and livestocktreatments. Thirty-four medicinal wild plants used as cure for 35 human andlivestock ailments were documented. It was observed that the practice ofcultivating medicinal plants is very poor in the study area, which may be dueto sufficient wild availability of medicinal plants thus far. Focus should be given to domestication and insitu conservation of the existing medicinal plants and the associatedindigenous knowledge, which are both at risk. This may offer the people analternative income-generating activity and contribute to the creation of aforest friendly community in Desa a Forest. Anthropogenic pressuresstrongly hamper natural regeneration of the tropical dry forests, which bringsthe continuity of the forests at stake. The experiment in Desa a Forest allowedstudying the growth establishment, survival and growth response of naturalregeneration in response to four silvicultural treatments, Pruning (P),Thinning (T), Pruning and Thinning (P&T), and No treatment (C), combinedwith two levels of fencing, with and without fencing, using a split plotarrangement. Periodic measurement (Dec. 2009 Jan. 2013) of seedlingregeneration, survival and growth (root collar diameter and height) wereundertaken in 5 x 5 m plots established inside every 40 x 40 m treatmentplot. Fencing improved survival ofnatural regeneration by 21 %. The response could have been stronger had it notbeen for Olea europaea whichmaintains its root stock even under grazing pressure. Olea europaea dominates the regeneration profile with 46.8 %,other 19 species covering 0.2 to 9 %.Juniperus procera was found to have a serious problem with naturalregeneration though performs well in enrichment plantings. Fencing has broughta significant contribution to height growth of regenerating seedlings with meangrowth of 0.065 ±0.011 cm cm-1 yr-1 for fenced and -0.002±0.015 cm cm-1 yr-1 for unfenced plots. Though it isclearly seen that fencing has a strong impact on relative height growth ofseedlings, it is much amplified when combined with silvicultural treatments.The P & T treatment has brought a negative growth in relative height ofseedlings without fencing (-0.005 ± 0.23 cm cm-1 yr-1). In general, from the overall trend, withfencing, silvicultural treatments have the potential to bring an increase inmean height growth. Fencing did not bring any significant change in diametergrowth of seedlings whereas treatments had a marginal effect on their diametergrowth. Performanceof planted seedlings in a forest restoration process may vary widely betweendifferent establishment techniques, with important impact on the success offorest restoration. Enrichment planting is one promising technique of forestrestoration where natural regeneration is assumed insufficient. In our experiment,we tested planted Olea europaea L.subsp. cuspidata, Juniperus procera, and Dodonaea angustifolia seedlings fortheir survival and growth under three levels of natural forest cover and withor without artificial shelters. A total of 72 one-year-old seedlings of eachspecies were monitored over 30 months (July 2010 February 2013). All plantedspecies showed good survival rates averaging 68 %, with a slightly higher valuefor Juniperus procera (72 %).Artificial sheltering improved overall survival significantly by 18 %, in caseof Olea even by 31 %. Better diameter growth was registered withlow natural canopy cover (0.233 ± 0.014 cm cm-1 yr-1),with Juniperus achieving thestrongest growth, followed by Olea andDodonaea. Olea and Juniperus were significantlydifferent from Dodonaea concerningtheir relative height growth, with Olea attainingthe strongest growth (0.2 ± 0.02), followed by Juniperus (0.15 ± 0.023) and Dodonaeathe weakest (0.057 ± 0.026 cm cm-1 yr-1). Artificialsheltering offered a significantly stronger relative height growth (0.2 ±0.023) than without artificial shelter (0.075 ± 0.023). Olea achieved significantly higher relative height growth withartificial shelter (0.31 ± 0.03) followed by Juniperus (0.17 ± 0.033) and Dodonaea(0.12 ± 0.037). From this comparative study of planted seedlings, we can seethe variation in survival and growth among habitats differing in canopyopenness and artificial shelter with interesting implications for futureenrichment planting schemes. In addition toanthropogenic factors, tropical dry forests are challenged by high potentialevapotranspiration combined with limited water resources, for which specificmanagement interventions could be needed to sustain their existence. In thiscontext common management practices like pruning and thinning may not onlyincrease the commercial quality of the standing timber resource, but are alsoimportant means to regulate access to light and water as to improve resourcedistribution, microclimate, growth and productivity of the ecosystem. Wecompared the effect of four silvicultural treatments, Pruning, Thinning,Pruning and Thinning, and No treatment, combined with two levels of fencing,with and without fencing on the growth of individual trees and stands. Periodicmeasurement (Dec. 2009 Jan. 2013) of height and diameter growth of trees wasundertaken using calipers and dendrometers over a period of three years. Onaverage 12.3% of monitored stems disappeared from the forest, mainly because ofillegal logging, especially (46 %), in the unfenced plot with dense vegetation.Both height (H) and diameter at breatsheight (DBH) growth were significantlyaffected by fencing treatment where there is a net decrease in height and anincreased DBH growth in unfenced plots and an increase in height growth infenced plots. Silvicultural treatments did not bring significant difference inboth height (H) and diameter at breats height (DBH) growth though in both casesthere is an indication that the combined application of pruning and thinninghave a trend towards a positive response with time. In general, fencing with some level of pruning and thinningprovides relatively safe sites for seedlings to establish and grow stronger. Atleast temporary exclosure of areas in regeneration during a period of 5-10years has to be considered as part of a future management plan, creatingprotected restoration areas inside the forest. This would temporary decreasethe available forest area for some ecosystem service provision to communitieswith a few percent of the total area, but would guarantee continued provisionof forest ecosystem services over the longer term. The problematic regenerationof J. procera still needs furtherresearch on site specific seed, germination characterstics, and large scaleenrichment scheme. In dry areas where seedling establishment is constrainedmainy due to moisture stress, the possibility of manipulating the forest canopyand use of artificial shelters would help in successful establishments of plantedseedlings. Medium levels of silvicultural treatments have showes a positiveeffect on growth of seedlings and trees though it will need time to see itseffect very clearly. These will also have a potential to improve the foresthealth and productivity there by positively influencingflowering, seed production and regeneration. We concluded that, in the courseof our four year experiment, 1) trees persisted but hardly grew; 2) fencingbrought positive effect on survival and growth of both seedlings and trees; 3)natural regeneration was poor especially for J. procera; 4) plantedseedlings were able to survive and grow given adequate protection (fencing andshelter); 5) the overall slowness of ecological processes in these dry forestscalls for much longer scientific attention to monitor the effect ofsilvicultural treatments. It is highly recommended to maintain the establishedexperimental site in Desa a Forest as a permanent observatory to investigateslow-acting ecological processes and changes, and for evaluating theconsequences of rare events, because this kind of basic ecological informationis commonly missing for the dry afromontane forests of the tropics.Finally, it is recommended to increase the national and internationalprotection status of Desa a forest, like that of UNESCO biosphere reserve forwhich an application is being processed, to implement this conservation statuswith a participatory management plan where the ideas and recommendations fromthis work could be part of. <w:LsdException Locked="false" Priority="60" SemiHidden="false" UnhideWhenUsed="false" Name="Light Shading Accent 5

Role of Acacia seyal on Selected Soil Properties and Sorghum Growth and Yield: A Case Study of Guba Lafto District, North Wollo, Ethiopia

Acacia seyal is one of the multipurpose parkland agroforestry tree species in eastern and southern Africa. It is a common on-farm tree in the Rift Valley of Ethiopia, but information is limited on its effect on soil properties and sorghum growth and yield. The study was conducted to evaluate its effect on selected soil properties and sorghum growth and yield in Guba Lafto district of northern Ethiopia. Six isolated and closely comparable Acacia seyal trees growing on sorghum farms were purposely selected, and plots were marked under the canopy of trees with three radial distances (0–2 m, 2–4 m, and 4–6 m) and one outside of the tree canopy (10 m away from any tree). Soil samples from each distance zone were taken between 0–20 cm and 20–40 cm soil depths for soil property analysis. Four quadrates with 1 m2 at each distance zone in four directions were laid for sorghum growth and yield attribute valuation. The results showed that only total nitrogen (TN) was significantly higher (P<0.05) at the subsoil layer under the canopy compared to an open area, while other selected soil parameters were not affected by the tree species. Sorghum biomass yield (P=0.006) and grain yield (P=0.025) were significantly lower under the canopy of the trees than in the open area. Generally, Acacia seyal had little effect in improving soil properties and showed a negative effect on sorghum yield and growth. Further research on its effect under wide area coverage of parkland system should be performed to bring a radical shift on the intercropping farming system

Top-soil salinity mapping using geostatistical approach in the agricultural landscape of Timuga irrigation scheme, South Tigray, Ethiopia

Long-term irrigation activities in arid and semi-arid areas causes soil salinity problem. Thus, knowing soil salinity status is a prerequisite for designing appropriate irrigation management strategies. This study was therefore conducted to predict top-soil salinity of Timuga irrigation scheme and to map its spatial distribution using geostatistical techniques. An area of 33.5 km2 was delineated, and regularly spaced grid (cell size: 500 m) of sampling points were generated using fishnet of the ArcGIS 10.2. A total of 106 composite soil samples were collected from each sampling points at a depth of 20 cm and geo-referenced using global positioning system. Soil samples were analyzed for pH, electrical conductivity (ECe), cation exchange capacity, and exchangeable bases (Ca++, Mg++, K+, and Na+) following the standard laboratory procedure. Both descriptive statistics and ordinary kriging interpolation techniques were used to analyze the data. The result showed that electrical conductivity ranged from 0.125 to 12.89 mScm−1 and the exchangeable sodium percentage ranged from 0.094% to 27.514%. This indicated that soils of the irrigation scheme are characterized by saline and sodic soils with different degree of spatial variability. The total area of 75.3% and 24.7% has classified as low and medium salinity hazards, respectively. However, 3.11%, 76%, and 20.89% of the total area have classified as high, medium, and low sodicity levels, respectively. Therefore, it was concluded that soil salinity hazard is existed and is building up of gradually in parallel with irrigation expansion. Hence, prevention and recovery measures are needed considering a variety of options such as leaching, fertilization, and planting salinity-resistant crop varieties to sustain irrigation productivity

The effect of shade levels on the survival and growth of planted trees in dry afromontane forest: Implications for restoration success

status: publishe

Detection of Olea europaea subsp. cupsidata and Juniperus procera in the dry Afromontane Forest of northern Ethiopia using subpixel analysis of Landsat imagery

Comprehensive and less costly forest inventory approaches are required to monitor the spatiotemporal dynamics of key species in forest ecosystems. Subpixel analysis using the earth resources data analysis system imagine subpixel classification procedure was tested to extract Olea europaea subsp. cuspidata and Juniperus procera canopies from Landsat 7 enhanced thematic mapper plus imagery. Control points with various canopy area fractions of the target species were collected to develop signatures for each of the species. With these signatures, the imagine subpixel classification procedure was run for each species independently. The subpixel process enabled the detection of O. europaea subsp. cuspidata and J. procera trees in pure and mixed pixels. Total of 100 pixels each were field verified for both species. An overall accuracy of 85% was achieved for O. europaea subsp. cuspidata and 89% for J. procera. A high overall accuracy level of detecting species at a natural forest was achieved, which encourages using the algorithm for future species monitoring activities. We recommend that the algorithm has to be validated in similar environment to enrich the knowledge on its capability to ensure its wider usage.status: publishe

A combination of climate, tree diversity and local human disturbance determine the stability of dry Afromontane forests

Background: Anthropogenic disturbances are increasingly affecting the vitality of tropical dry forests. The future condition of this important biome will depend on its capability to resist and recover from these disturbances. So far, the temporal stability of dryland forests is rarely studied, even though identifying the important factors associated with the stability of the dryland forests could serve as a basis for forest management and restoration. Methodology: In a degraded dry Afromontane forest in northern Ethiopia, we explored remote sensing derived indicators of forest stability, using MODIS satellite derived NDVI time series from 2001 to 2018. Resilience and resistance were measured using the anomalies (remainders) after time series decomposition into seasonality, trend and remainder components. Growth stability was calculated using the integral of the undecomposed NDVI data. These NDVI derived stability indicators were then related to environmental factors of climate, topography, soil, tree species diversity, and local human disturbance, obtained from a systematic grid of field inventory plots, using boosted regression trees in R. Results: Resilience and resistance were adequately predicted by these factors with an R2 of 0.67 and 0.48, respectively, but the model for growth stability was weaker. Precipitation of the wettest month, distance from settlements and slope were the most important factors associated with resilience, explaining 51% of the effect. Altitude, temperature seasonality and humus accumulation were the significant factors associated with the resistance of the forest, explaining 61% of the overall effect. A positive effect of tree diversity on resilience was also important, except that the impact of species evenness declined above a threshold value of 0.70, indicating that perfect evenness reduced the resilience of the forest. Precipitation of the wettest month was the most important factor explaining 43.52% of the growth stability variation. Conclusion: A combination of climate, topographic factors and local human disturbance controlled the stability of the dry forest. Also tree diversity is an important stability component that should be considered in the management and restoration programs of such degraded forests. If local disturbances are alleviated the recovery time of dryland forests could be shortened, which is vital to maintain the ecosystem services these forests provide to local communities and global climate change.</p