The effect of silvicultural management on regeneration, growth and yield of Arundinaria alpina (Highland bamboo) at Choke Mountain, East Gojam, Northwest Ethiopia

With the objective of determining the effects of silvicultural management on regeneration and growth of mismanaged Arundinaria alpina stands, an experiment was conducted in the Choke Mountain, northwest Ethiopia. Eight soil and plant management techniques that comprise soil loosening, selective thinning and removal of old stumps were splited on two levels of organic fertilizer and applied on one hectare communally owned bamboo stand. Effect of the treatments was observed from data collected in 2009 and 2010 rainy seasons. The number of recruited culms of previous years (2007 and 2008) which had intermittent protection from human and livestock interference was also quantified employing culm age determination techniques. Result of combined analysis of 2009 and 2010 indicated that soil loosening combined with selective thinning and removal of old stumps resulted in culm recruitment of 13,750 plants ha-1, i.e. 37% higher than the control plot. This treatment combination decreased shoot mortality by 61% less than the control and increased culm recruitment by 40 % more than the control plot during the 2009 shooting season. Culm diameter and height of individual culms recruited in 2009 and 2010 showed increasing trend across the two years. Comparison of culm recruitment of previous years with recruitments after treatment application indicated that with improved management, including protection from interference, culm yield of communally owned bamboo stands can be maximized by 158-589%.Keywords: soil loosening, selective thinning, highland bamboo, silviculture, Yushania alpin

Propagation Techniques for Highland Bamboo (Arundinaria alpina) in the Choke Mountain, Northwestern Ethiopia

With the aim of identifying improved propagation techniques that can be applied in a larger scale plantation, six types of vegetative propagation materials obtained from three A. alpina landraces (TIFRO, WELELE and WONDE) were evaluated for their performance under field condition in the Choke Mountain, northwestern Ethiopia. The three techniques namely stump, rhizome and whole-culm had fastest shoot emergence (21-22 days) and superior performance during the four Months period After establishment (MAE).Shoot height was 262, 233 and 193 cm for stump, rhizome and whole-culm with respective to diameter at breast height of 1.0, 1.1 and 1.5 cm 4 MAE, respectively. The whole-culm method also produced the maximum number of shoots (10 new shoots per propagule), along its stem length (at the upper, middle and butt positions excluding its lower one-third portion) but branch cuttings and culm cuttings had slow shoot emergence (average 30 days) and very poor performance. In general, TIFRO and WELELE landraces had faster shoot emergence (21-23 days) and significantly higher number of new shoots than WONDE landrace. Shoot emergence of the offset (traditional) method was delayed up to the next shooting season (11 MAE) but its performance, including survival rate of the propagules (85%), was superior at that season. New shoots from stump, rhizome and whole-culm were found to be prone (survival rate 17-26%) primarily to strong wind and storm and most probably moisture fluctuations under field condition after four months period hence further research on silvicultural practices that can maximize their persistence is required.Keywords: cuttings, landraces, offset, rhizome-based propagation, Yushania alpin

Population Structure And Phenology Of The Selected Indigenous Tree Species In Moist Evergreen Afromontane Forests Of South West Ethiopia

Understanding the population structure, regeneration status, and phenology of indigenous tree species in natural forests is a basic requirement for establishing in-situ seed production sites and introduce appropriate management options. The aim of this study was, therefore, to investigate the population structure and regeneration status and reproductive phenology of Prunus africana, Pouteria adolfi- friedericii and Milicia excelsa. This study was conducted in four Afromontane forests such as Yayu, Bonga, Bebeka, and Masha, south west Ethiopia. For this, systematic sampling method was used to collect the data and accordingly, from each site ten transects of 160m long were laid out at 100 m interval along slope gradient and quadrats (size: 20 m x 20 m each) were laid at 50m interval along each transect line. In total 270 quadrats were used for vegetation data collection. To collect data on regeneration, sub sample quadrats (size: 5 m × 5m each) were established at four corners and at the center of each of the main quadrats. From each main quadrat, DBH and total height of the three study tree species were measured using a diameter tape and clinometer respectively. The results of the distribution of the population of P.africana showed broken J-shape and irregular patterns across the forests; Pouteria adolfi‑ friedericii exhibited irregular and broken inverted Jshape across the forest sites; the shape of the structure for Milicia excelsa tree species observed in sampled forests was almost irregular. The regeneration status of P. africana is “good” in Bonga and Masha and “fair” in Yayu sampled natural forest; for P. adolfi‑ friedericii is “good” in Masha and “fair “in Bonga and Yayu, and it is “fair” and “none” in Masha and Yayu sampled natural forests for M. excelsa tree species. The result of the phenology assessment indicated that the times of flowering and fruiting generally ranges between December and June across the forest sites. Overall, the population structure of the studied tree species vary and also similar in some cases across the inventoried forest sites. There is a slight variation in phenology among sites showing the essence of exhaustive description of these parameters prior to the establishment of the seed provenances and domestications for the desired populations of the indigenous tree species

Intraspecific Morphological Variations among the Populations of Milicia excelsa, Pouteria adolfi-friedericii, and Prunus africana in Different Natural Forests of Southwest Ethiopia

Plants have the ability to change their morphological and physiological traits in response to environmental variations. The objective of this study was to determine the intraspecific morphological variations among the populations of M. excelsa, P. adolfi-friedericii, and P. africana in southwest Ethiopia. Representative forests were systematically selected, and a total of ten transects of 160 m length were randomly laid at 100 m intervals, and 30 quadrats (20 m by 20 m) were laid along each transect line at 50 m intervals. Stem height, DBH, and bole length of trees for each species were measured in each quadrat. The intraspecific morphological variations among populations of each species were computed using hierarchical clustering and principal component analysis (PCA) with R.4.1.3. A total of 55 trees for M. excelsa in four forests, 232 trees for P. adolfi-friedericii in eight forests, and 184 trees for P. africana in five forests were measured. Accordingly, three, five, and three population clusters were identified for M. excelsa, P. adolfi-friedericii, and P. africana, respectively. The analysis of similarity (ANOSIM) indicated the presence of considerable dissimilarity among population clusters for M. excelsa and P. africana but was not significant at p ≤ 0.05 (R = 0.9, p = 0.17 ). However, ANOSIM indicated the presence of considerable dissimilarity among population clusters of P. adolfi-freidericii, which was significant at p ≤ 0.05 (R = 0.9, p = 0.03 ). Overall, there was a visible morphological variability among the populations of M. excelsa, P. adolfi-friedericii, and P. africana each at the different sites. Therefore, it is important to look for conservation strategies, such as domestication, to maintain and improve the variability and genetic quality among the populations in a wider scale of the ecological and social environment.</jats:p

Provenance Variation on Early Survival Rate and Growth Performance of Oxytenanthera abyssinica (A. Rich.) Munro Seedlings at Green House: An Indigenous Lowland Bamboo Species in Ethiopia

Background. Lowland Bamboo (O. abyssinica) is an indigenous multipurpose species in Ethiopia and endemic to Africa. Aims. The present study was aimed at investigating provenance variation on early survival rate and growth performance of O. abyssinica seedlings so as to obtain suitable provenance for production of high quality seedlings. Methods. Seeds were collected from Pawe and Sherkole districts. Following raise of seedlings data on survival count, culm height, root collar diameter (RCD), number of leaves, and biomass were recorded. Results. Pawe provenance had slightly higher survival rate (91%). Except seedlings RCD, rhizomes length, and roots fresh and dry weights, higher mean values of other morphological parameters were recorded in Sherkole provenance. Biomass of leaves and culms was higher in Shekole provenance, while root biomass was exceeded by the Pawe provenance. However, significant variations (P<0.05) between provenances were observed in RCD, rhizomes length, weight of fresh culms, and fresh and dry root system. Seedlings growth parameters (height and RCD) were positively and significantly correlated with Biomass variables and hence could be considered as better evaluation criteria for seedling quality at green house. Conclusion. Sherkole provenance should be considered for raising O. abyssinica seedlings at green house

Intraspecific Morphological Variations among the Populations of Milicia excelsa, Pouteria adolfi-friedericii, and Prunus africana in Different Natural Forests of Southwest Ethiopia

Plants have the ability to change their morphological and physiological traits in response to environmental variations. The objective of this study was to determine the intraspecific morphological variations among the populations of M. excelsa, P. adolfi-friedericii, and P. africana in southwest Ethiopia. Representative forests were systematically selected, and a total of ten transects of 160 m length were randomly laid at 100 m intervals, and 30 quadrats (20 m by 20 m) were laid along each transect line at 50 m intervals. Stem height, DBH, and bole length of trees for each species were measured in each quadrat. The intraspecific morphological variations among populations of each species were computed using hierarchical clustering and principal component analysis (PCA) with R.4.1.3. A total of 55 trees for M. excelsa in four forests, 232 trees for P. adolfi-friedericii in eight forests, and 184 trees for P. africana in five forests were measured. Accordingly, three, five, and three population clusters were identified for M. excelsa, P. adolfi-friedericii, and P. africana, respectively. The analysis of similarity (ANOSIM) indicated the presence of considerable dissimilarity among population clusters for M. excelsa and P. africana but was not significant at p≤0.05 (R = 0.9, p=0.17). However, ANOSIM indicated the presence of considerable dissimilarity among population clusters of P. adolfi-freidericii, which was significant at p≤0.05 (R = 0.9, p=0.03). Overall, there was a visible morphological variability among the populations of M. excelsa, P. adolfi-friedericii, and P. africana each at the different sites. Therefore, it is important to look for conservation strategies, such as domestication, to maintain and improve the variability and genetic quality among the populations in a wider scale of the ecological and social environment