Floristic Diversity, Population Structure, Regeneration Status and Socio-Economic Importance of Fach Forest, South Gondar, Northwestern Ethiopia

Mapping Intimacies ◽

10.21203/rs.3.rs-957637/v1 ◽

2021 ◽

Author(s):

Haileab Zegeye

Keyword(s):

Population Structure ◽

Protected Area ◽

Woody Species ◽

Local Communities ◽

Economic Importance ◽

Livestock Grazing ◽

Anthropogenic Factors ◽

Sacred Places ◽

Regeneration Status ◽

Management Interventions

Abstract Background: The remaining natural forests of Ethiopia are only small patches mostly confined to inaccessible areas and sacred places. Fach forest is one of the remnant dry evergreen Afromontane forests (DAFs) in northwestern Ethiopia. There is lack of information on the vegetation ecology of the forest. Thus, the present study was conducted to investigate the floristic composition and diversity, population structure, regeneration status and socio-economic importance of Fach forest, and the anthropogenic factors affecting it.Methods: Vegetation data were collected from a total of 34 plots, measuring 20 m × 20 m (400 m2) each and established along line transects approximately at 100 m intervals. A general survey consisting of field observations, key-informant interviews and Focus Group Discussion (FGD) was used to collect socio-economic data. Results: A total of 230 vascular plant species belonging to 183 genera and 76 families were recorded from the study area, of which 45 (19.57%) were trees, 62 (26.97%) trees/shrubs, 37 (16.09%) shrubs, 13 (5.65%) woody climbers, 10 (4.35%) herbaceous climbers, and 63 (27.39%) herbs. The family with the highest number of species was Fabaceae (28 species, 12.17% of all species), followed by Asteraceae (18 species, 7.83%), Poaceae (13 species, 5.65%), and Acanthaceae and Euphorbiaceae (9 species each). The Shannon-Wiener diversity and evenness values of woody species were 3.53 and 0.72, and the total density and basal area 4938.24 individuals ha-1 and 19.17 m2 ha-1, respectively. The species with the highest Importance Value Index (IVI) value was Combretum molle (25.26%), followed by Olea europaea subsp. cuspidata (21.19%), Dodonaea angustifolia (17.80%), and Calpurnia aurea (15.05%). The local communities were highly dependent on the forest for fuelwood, construction material, charcoal, timber and farm implements, as well as food (edible fruits), medicines, fodder, and bee forage. Fach forest is a protected area and contains sacred places, but at present it is dwindling mainly due to livestock grazing/browsing, tree cutting for various purposes, farmland expansion, rural settlements expansion, urbanization, fire incidences, and exotic species plantations at the expense of the natural forest, as well as soil erosion and climate change.Conclusions: Fach forest possesses high plant diversity and endemism. Woody species having low IVI values and poor regeneration status (as indicated by the Diameter at Breast Height [DBH] class distributions) need high priority for conservation. Fach forest has been maintained to the present-day through the combined indigenous (sacred grove) and modern (protected area system) conservation methods, but is now under increasing human pressure. Therefore, effective conservation and management interventions are urgently needed to ensure the long-term maintenance of the forest ecosystem, and benefit the local communities through sustainable utilization of the forest.

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COMPARISON ON VEGETATION COMPOSITION AND STRUCTURE OF EXCLOSURES VS. OPEN GRAZING LANDS IN NORTHERN ETHIOPIA

International Journal of Research -GRANTHAALAYAH ◽

10.29121/granthaalayah.v9.i8.2021.4154 ◽

2021 ◽

Vol 9 (8) ◽

pp. 70-99

Author(s):

Samson Shimelse Jemaneh

Keyword(s):

Population Structure ◽

Species Richness ◽

Plant Species ◽

Woody Species ◽

Soil Parameters ◽

Northern Ethiopia ◽

Indigenous Species ◽

Regeneration Status ◽

Composition And Structure ◽

Grazing Lands

This study was conducted with the objectives of study investigates, compare, and try to describe the floristic composition and structure of the vegetation of exclosures and open grazing lands. A stratified preferential sampling design technique with flexible systematic model was used for data collection. Data on vegetation and environmental parameters were gathered from 120 quadrants (90 from restorations or exclosures of different ages and 30 from adjacent open grazing lands), of 20 m x 20 m (400 m2) size. Species richness and the presence or absence of herbaceous plants were recorded like soil samples in a 2 m x 2 m (4 m2) subplot inside each main quadrant from five points, one at each corner and one at the center. A total of 142 plant species belonging to 118 genera and 52 families were identified. All exclosures displayed higher plant species richness, diversity, and aboveground standing biomass compared to the adjacent open grazing lands. Consideration of edaphic (e.g. soil total nitrogen, available phosphorus, CEC, exchangeable bases, soil pH and soil texture) and site (e.g. Stoniness, Grazing) variables will help to optimize the selection of areas for the establishment of future exclosures. Moreover, our study suggests that with time exclosures may increasingly obtain an important role as refugees and species pool similar to church forests and should be protected and managed in a sustainable manner. However, economic and social impacts of exclosures should be included in feasibility studies before establishing exclosures in the future. Altitude, Grazing and some soil parameters like Mg were the major environmental factors in the division of the vegetation into plant community types. The result of the frequency distribution of woody species showed a high proportion of small-sized individuals in the lower diameter classes indicating good recruitment potential of the forest patches and the rare occurrence of large individuals. Such trend was probably caused by past disturbance of the original vegetation resulting in a succession of secondary vegetation. In addition, the analysis of species population structure indicated that some tree species had abnormal population structure with no or few individuals at lower size classes. Moreover, assessment of regeneration status on the basis of age classes indicated that significant proportion of woody species were represented by few or no seedlings, entailing that they were under threat. Substantial numbers of forest species were found to have irregular population structure and are in reduced regeneration status. To prevent local extinction of these species, present efforts of nursery establishment and plantation of indigenous species in the exclosures should be strengthened and extended.

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Population structure and regeneration of Himalayan endemic Larix species in three high-altitude valleys in Nepal Himalaya

Journal of Ecology and Environment ◽

10.1186/s41610-020-00166-7 ◽

2020 ◽

Vol 44 (1) ◽

Author(s):

Man Kumar Dhamala ◽

Prakash Chandra Aryal ◽

Madan Krishna Suwal ◽

Sijar Bhatta ◽

Dinesh Raj Bhuju

Keyword(s):

Population Structure ◽

High Altitude ◽

Graphical Representation ◽

Anthropogenic Activities ◽

Tree Height ◽

Diameter Distribution ◽

Conservation Area ◽

Nepal Himalaya ◽

Regeneration Status ◽

Management Interventions

Abstract Background The Himalayan forests are of great importance to sustain the nature and community resource demands. These forests are facing pressures both from anthropogenic activities and ongoing global climatic changes. Poor natural regeneration has been considered a major problem in mountainous forests. To understand the population structure and regeneration status of Larix (Larix griffithiana and Larix himalaica), we conducted systematic vegetation surveys in three high-altitude valleys namely Ghunsa (Kanchenjunga Conservation Area, KCA), Langtang (Langtang National Park, LNP), and Tsum (Manaslu Conservation Area, MCA) in Nepal Himalaya. The average values of diameter at breast height (DBH), height, and sapling height were compared for three sites and two species using Kruskal-Wallis test. Population structure was assessed in terms of proportion of seedlings, saplings, and trees. Regeneration was analyzed using graphical representation of frequencies of seedlings, saplings, and trees in histograms. Results The results showed that the population structure of Larix in terms of the proportion of seedling, sapling, and tree varied greatly in the three study areas. KCA had the highest record of seedling, sapling, and tree compared to other two sites. Seedlings were the least among three forms and many plots were without seedlings. We found no seedling in MCA study plots. The plot level average DBH variation among sites was significant (Kruskal-Wallis χ2 = 7.813, df = 2, p = 0.02) as was between species (Kruskal-Wallis χ2 = 5.9829, df = 1, p = 0.014). Similarly, the variation in average tree height was significant (Kruskal-Wallis χ2 = 134.23, df = 2, p < 0.001) among sites as well as between species (Kruskal-Wallis χ2 = 128.01, df = 1, p < 0.001). All the sites showed reverse J-shaped curve but more pronounced for KCA and MCA. In comparing the two species, Larix griffithiana has clear reverse J-shaped diameter distribution but not Larix himalaica. Conclusion The varied responses of Larix manifested through regeneration status from spatially distinct areas show that regeneration limitations might be more pronounced in the future. In all the three studied valleys, regeneration of Larix is found to be problematic and specifically for Larix griffithiana in MCA and Larix himalaica in LNP. To address the issues of disturbances, especially serious in LNP, management interventions are recommended to sustain the unique Himalayan endemic conifer.

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