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

Background: The remaining natural forests of Ethiopia are only small patches mostly conned 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 oristic 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 m 2 ) each and established along line transects approximately at 100 m intervals. A general survey consisting of eld 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 m 2 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 The present study was conducted to generate baseline and to: (a) investigate (b) prioritize woody species for their Value Index (IVI) regeneration (c) assess the forest management systems and the role of the churches and in the forest; (d) identify the anthropogenic factors causing loss and the forest. on the biophysical land use extent of deforestation and soil erosion, indigenous resource management traditional agroforestry and soil conservation, and human impacts on the Ten key informants, which have been suggested by the forest guards and representatives of the local communities, were selected and interviewed using the open-ended questionnaire prepared in this For the FGD, a group consisting of the representatives of around the elderly, youth, clergymen, representatives of governmental institutions and coordinator of the Ambo Meda Seedling At the beginning of the the aim of the survey was explained to the participants by the investigator so as to ensure openness in the discussion. The actual FGD was carried out using relevant discussion points or questions, mainly the socio-economic importance of the forest, the forest management systems, challenges/problems/constraints in the conservation and management of the forest, and the human activities affecting the forest. The ideas and suggestions forwarded by the group participants were recorded.

It is believed that about 35% of the total land area of Ethiopia was covered with natural forests in the beginning of the 20th century (EFAP 1994). However, the forest cover has been declining from time to time. The forest cover of the country was 16% in the early 1950s, 3.6% in the early 1980s and 2.7% in 1989 (EFAP 1994). The present forest cover of the country is about 4% (Earth Trends 2007). The remaining natural forests of Ethiopia are only small patches mostly con ned to inaccessible areas (mountaintops, steep slopes, valleys) and sacred places (churches, monasteries, mosques). Furthermore, these remnant forests are dwindling at an alarming rate due to natural and mainly anthropogenic factors.
The major drivers of deforestation and forest degradation are agricultural expansion (farmland expansion, overgrazing by livestock), overexploitation, rural (re)settlements, urbanization, re incidences and invasive alien species, which are all driven by the rapid human population growth, lack of appropriate policies and strategies, and poverty (Bekele 1993;EFAP 1994 Though a few preliminary surveys have been done on Fach forest by other scholars in the past, there has been neither particular nor detailed study on the vegetation ecology and socio-economic aspects of the forest so far. The present study was conducted to generate baseline ecological and socio-economic information, which would be relevant for conservation, management and sustainable utilization of the forest. Therefore, the objectives of the study were to: (a) investigate the oristic composition and diversity, population structure, natural regeneration status and socio-economic importance of the forest; (b) prioritize woody species for conservation based on their Importance Value Index (IVI) values and regeneration status; (c) assess the forest management systems and the role of the churches and monasteries in conserving the forest; (d) identify the anthropogenic factors causing loss and degradation of the forest.
Fach forest forms part of the Lake Tana Sub-Basin, which is the northeastern part of the Blue Nile Basin (Mequanent et al. 2021). It also forms part of the Eastern Afromontane Biodiversity Hotspot (Mittermeier et al. 2004). With a surface area of 3156 km 2 stretching approximately 84 km north-south and 66 km east-west, Lake Tana is the largest lake in Ethiopia and one of the largest in Africa (zur Heide 2012), containing almost 50% of the country's freshwater resources (de Graaf et al. 2004). Lake Tana is the source of the Blue Nile (locally known as Abay River), the only natural out owing river (at the southern tip of the lake) and which ows to the Sudan (where it fuses with the White Nile [originating from Lake Victoria] at Khartoum, the country's capital city) and Egypt, owing for approximately 4750 km and eventually ending up in the Mediterranean Sea. The remnant natural forests including Fach and the wetlands in the Lake Tana Region have a high local and global signi cance as natural and economic resource, and thus high priority should be given to their conservation and sustainable management (zur Heide 2012).
According to the 2007 Population and Housing Census of Ethiopia, Libo Kemkem District had a total population of 198435, of whom 100987 were males and 97448 females (CSA 2007b). The inhabitants of the study area belong to the Amhara ethnic group, who speak the Amharic language. The majority of the people are Orthodox Christians and few are Muslims. The economy of the local people is predominantly based on subsistence agriculture. The local people are engaged in crop cultivation and livestock rearingthus a mixed farming system. The major crops grown in the area are tef (Eragrostis tef), nger millet (Eleusine coracana), maize (Zea mays), sorghum (Sorghum bicolor), barley (Hordeum vulgare), eld pea (Pisum sativum), faba bean (Vicia faba) and nigerseed (Guizotia abyssinica). The main livestock reared in the area are cattle, goats, sheep, donkeys, horses, mules and poultry. The people are involved in the collection of forest products (particularly fuelwood, construction material, charcoal and timber, as well as non-wood forest products) for domestic consumption and/or income generation through selling in local markets. The local people have limited access to modern health services, and thus partly depend on traditional medicine to ful ll their healthcare needs. They use medicinal plants, most of which are harvested from the wild including Fach forest, to treat various human and livestock diseases.
There are three churches and monasteries within Fach forest, namely Shammo Medhane-Alem Monastic Church (established in 1270) at the northeastern periphery, Ambo Meda Michael Church at the eastern periphery (close to the town of Ambo Meda), and Estifanos Church at the southern periphery. These churches and monasteries own a certain part of the forest and manage it, still under the umbrella of the protected area system. Vegetation sampling and data collection Systematic sampling, in which plots are laid at regular intervals along line transects, was used to collect vegetation data following Mueller-Dombois and Ellenberg (1974) and Sutherland (1996). Three line transects directed northeast-west were established across the forest. Plots, measuring 20 m × 20 m (400 m 2 ) each, were established along the line transects approximately at 100 m intervals. A total of 34 plots were sampled from the forest. Herbaceous species were sampled using a 1 m × 1 m (1 m 2 ) subplot laid within each main plot where the herbaceous vegetation is assumed to be representative, i.e., nested plot design was used. In each plot, all vascular plant species were listed by their local and/or scienti c names, and their identities were recorded. Trees, shrubs and woody climbers were counted. Diameter at Breast Height (DBH) (i.e., 1.3 m above the ground) of trees and shrubs with DBH ≥ 2 cm was measured with a calliper following the methods described by Martin (1995). Individuals of trees and shrubs with DBH 2 cm were counted by species as seedlings, and included in the regeneration assessment. Altitude and geographic position (latitude, longitude) were measured with a Garmin GPS 72H. Human disturbances were also recorded. Plant species that occur outside the sample plots were also recorded to produce a more complete list of the plant species in the area; but only as present (i.e., they were not included in the subsequent data analysis). Data collection was carried out between November 2016 and March 2017.
Plant specimens were collected, pressed, dried and brought to the Department of Biology, Debre Tabor University. Identi cation of most plant species was made in the eld by recognition and with the help of eld assistants (forest guards) as well as local people familiar with the ora, and using available taxonomic literature and databases. Unidenti ed plant specimens were taken to the National Herbarium (ETH), Addis Ababa University for identi cation. Plant nomenclature in this paper follows the Flora of Ethiopia and Eritrea Edwards 1989, 1995;Edwards et al. 1995Edwards et al. , 1997Edwards et al. , 2000Hedberg et al. 2003Hedberg et al. , 2004Hedberg et al. , 2006Hedberg et al. , 2009aHedberg et al. , 2009b).

Socio-economic survey
A general survey consisting of eld observations, key-informant interviews and Focus Group Discussion (FGD) was carried out following Martin (1995). Field observations were made on the biophysical features of the study area, land use types, extent of deforestation and soil erosion, indigenous resource management systems such as traditional agroforestry and soil conservation, and human impacts on the forest. Ten key informants, which have been suggested by the forest guards and representatives of the local communities, were selected and interviewed using the open-ended questionnaire prepared in advance for this purpose. For undertaking the FGD, a group consisting of the representatives of communities around the forests, elderly, youth, clergymen, representatives of governmental institutions (Libo Kemkem District Administrative O ce, Libo Kemkem District Agricultural Development O ce), forest guards, and coordinator of the Ambo Meda Seedling Nursery was established. At the beginning of the discussion, the aim of the survey was explained to the participants by the investigator so as to ensure openness in the discussion. The actual FGD was carried out using relevant discussion points or questions, mainly the socio-economic importance of the forest, the forest management systems, challenges/problems/constraints in the conservation and management of the forest, and the human activities affecting the forest. The ideas and suggestions forwarded by the group participants were recorded.

Data analysis
The diversity and evenness of woody species were determined using the Shannon-Wiener Diversity Index (H') and Evenness or Equitability Index (E) (Krebs 1989). The density, percentage frequency and dominance / basal area of woody species were calculated. The Importance Value Index (IVI) for each woody species was computed following Cain and Castro (1959) and Lamprecht (1989), as follows: Relative density = (Density of a species / Total density) × 100; Relative frequency = (Frequency of a species / Total frequency) × 100; Relative basal area = (Basal area of a species / Total basal area) × 100; IVI = Relative density + Relative frequency + Relative basal area.

Results And Discussion
Species richness and composition Diversity and evenness of woody species The diversity (H') and evenness (E) values of woody species were 3.53 and 0.72, respectively. The high diversity is attributed to habitat diversity and low human disturbances (as slopy terrain limits human exploitation and livestock grazing/browsing). The high evenness showed that there is more or less balanced distribution of individuals among the different species. The diversity value implies the need to conserve the forest from oristic diversity perspective.
The diversity and evenness of woody species in Fach forest were higher than or comparable to that of most other DAFs, for example, Tara  Density and frequency of woody species The total density (inclusive of seedlings) of woody species was 4938.24 individuals ha −1 ( is attributed to suitable environmental conditions for regeneration, high reproductive capacity of the species, and the relatively better protection of the forest from human exploitation and livestock grazing/browsing as it is a protected area and the presence of sacred places within the forest area. Ten species had the lowest density (0.74 individuals.ha −1 each), and thus were poorly represented in the forest. Table 1 Density (D, number of individuals ha -1 ), relative density (RD, %), frequency (F, %), relative frequency (RF, %), basal area (BA, m 2 ha -1 ), relative basal area (RBA, %) and IVI (%) of woody species (arranged alphabetically by scienti c name) The total density of woody species in Fach forest was higher than that of most other DAFs, for example, Tara   angustifolia, Maytenus serrata, Calpurnia aurea, Euclea racemosa subsp. schimperi, Acokanthera schimperi, Carissa spinarum and Vernonia myriantha had high densities but their basal areas were less than that of the aforementioned species due to their smaller diameters. It indicated that the total basal area of woody species was low since most species having high densities were shrubs and small-sized trees, and big-sized trees were absent or represented by very few numbers of individuals (this is due to slopy terrain, rocky land and shallow soil, as well as human exploitation). The presence of high numbers of small-sized trees and inadequate numbers of big-sized trees indicates that Fach forest is at the stage
The IVI is an important parameter that reveals the ecological importance and/or dominance of species in a given ecosystem (Cain and Castro 1959;Lamprecht 1989). Species with high IVI values are considered more important than those with low IVI values. According to Curtis and McIntosh (1951), a given species is said to be dominant if it had the highest IVI value compared to other plant species within an area. In a very general sense, the higher the IVI value of a species, the more successful it is in that pariticular habitat (Peters 1996). Accordingly, Combretum molle, Olea europaea subsp. cuspidata, Dodonaea angustifolia, Calpurnia aurea, Maytenus serrata, Ficus vasta, Rhus vulgaris, Euclea racemosa subsp. schimperi, Acokanthera schimperi, Carissa spinarum and Acacia pilispina were ecologically the most important species in Fach forest. In other words, these species were more abundant, frequent and dominant in the forest.
The IVI values can also be used to prioritize species for conservation: species with high IVI values need less conservation efforts whereas those with low IVI values need high conservation efforts (Shibru and Balcha 2004). The results suggest that species with low IVI values such as Rhus retinorrhea, Ficus sycomorus, Maytenus undata, Gardenia ternifolia, Abutilon longicuspe, Flueggea virosa, Maesa lanceolata, Albizia schimperiana, Pavetta abyssinica and Ficus thonningii should be given high priority for conservation.

Population structure and regeneration status of woody species
The DBH class distributions of woody species exhibited different patterns (Fig. 3), and showed that there are species with high number of individuals in the lower classes and some species in the middle classes.
The patterns of DBH class distributions indicated the general trends of population dynamics and recruitment processes of the species. From the DBH class distributions of the species, two broad types of regeneration status were determined: good and poor regeneration. Some species possessed high number of individuals in the lower DBH classes, particularly the rst class (DBH 2 cm, i.e., seedlings), and this suggests that they have good regeneration potential. This implies that dying adult individuals will be replaced by the growth of individuals from the smaller size classes and seems to be a self-sustaining plant population. The species with good regeneration potential were Olea europaea subsp. cuspidata, Combretum molle, Calpurnia aurea, Euclea racemosa subsp. schimperi, Acokanthera schimperi, and Acacia pilispina. Here it is important to note that Acacia pilispina had high number of individuals in the rst DBH class (though less than the second class), indicating that the species has a relatively good regeneration potential. Most of the species, however, possessed low number of individuals in the lower DBH classes, particularly the rst class, and this suggests that the species are in poor regeneration status (demonstrated hampered natural regeneration). The species with poor regeneration status were Rhus glutinosa, Premna schimperi, Albizia gummifera, and Shrebera alata. Hampered or poor regeneration is due to human disturbances, particularly livestock grazing/browsing and tree cutting for various purposes, The DBH class distributions of Olea europaea subsp. cuspidata, Calpurnia aurea, Combretum molle, Euclea racemosa subsp. schimperi and Acokanthera schimperi showed a reverse "J" distribution. The DBH class distributions of all woody species showed a reverse "J" distribution, in which there is high number of individuals in the rst class with decrease towards the middle and higher classes. It is interesting to see that Olea europaea subsp. cuspidata has shown good regeneration potential, unlike the poor regeneration status of the species in many other forests, for instance, Tara Gedam (Zegeye et al.

2011).
A reverse "J" distribution is considered as an indication of stable population structure or good regeneration status ( Forest management has created employment opportunities for the forest guards (currently a total of 9) and workers of the seedling nursery. Moreover, the forest has a potential value for tourism/ecotourism.

Conservation and management of the forest
The conservation and management of Fach forest is a tripartite venture: the conservation efforts of local communities, religious institutions (churches and monasteries), and governmental institutions. Moreover, indigenous (sacred grove) and modern (protected area system) conservation methods have been merged to conserve and manage the forest -a vital synergy. The integration of the conservation methods and the integration of the relevant stakeholders are crucial for conserving the biodiversity.

Role of local communities
The local people have environmentally friendly resource management systems and practices. Terracing and traditional agroforestry are widely practiced in the area. The major reason for constructing terraces is to control soil erosion and improve soil fertility and thereby increase crop production. In addition, the farmers construct terraces on farm boundaries to serve as demarcation lines between adjacent farmlands of different farmers. The local people retain and/or plant indigenous trees (e.g., Acacia abyssinica, Cordia africana, Combretum molle, Croton macrostachyus, Sapium ellipticum, Ficus thonningii, F. sur, F. vasta) in and around the farmlands, and plant Euphorbia tirucalli as a hedge along the edges of crop elds, yards, and roads. They also plant exotic species (e.g., Eucalyptus globulus, Jacaranda mimosifolia, Melia azedarach, Spathodea campanulata subsp. nilotica) in the homesteads, farm woodlots, and roadsides. Besides control of soil erosion and improvement of soil fertility, trees retained and/or planted in the agroforestry systems provide various forest products (fuelwood, construction material, timber, farm implements, food, medicines, fodder, bee forage), and serve as shade and live fence. Thus, the agroforestry systems reduce the pressure on the natural forest, showing the indirect contribution of local communities in conserving the forest.
The maintenance of the sacred groves in the study area is attributed to the strong religious belief and respect of the followers to the church, which is considered the house of God. Cutting trees from the sacred groves is taboo. If a person cuts trees from the sacred sites, the followers of the church inform the case to the religious fathers, and the doer is condemned. The followers of the church actively participate in the religious, conservation (e.g., tree planting in church/monastery yards) and development activities of the churches and monasteries. The majority of the Ethiopian people have respect and trust for the Ethiopian Orthodox Tewahedo Church (EOTC) and it is this spirit that supported the church to maintain forest resources till this generation (Wassie 2002).
The communities in the study area were involved in the conservation activities of the government like construction of terraces and tree plantation programs. The local communities were also instrumental in controlling the forest re incidences that have occurred in Fach forest at different times.

Role of religious institutions (churches and monasteries)
Although the main role of the churches and monasteries is to give religious service to the followers of the church, they are also involved in protecting the sacred groves, planting trees in church/monastery yards, and giving advice to the followers about the importance of conserving the sacred groves. The EOTC has a long history of conserving sacred groves, i.e. patches of natural vegetation conserved on sacred sites. The EOTC has over 30 million followers, 400,000 clergies and 35,000 churches in Ethiopia (Wassie 2002).

Role of governmental institutions
As Fach forest is a protected area, it is managed by governmental institutions, particularly Libo Kemkem District Agricultural Development O ce. Governmental institutions enforce legal protection of the forest.
As such, a total of 9 forest guards have been employed on contractual basis to protect the forest from human and livestock interferences. The forest guards are trying their best to control tree felling and livestock grazing/browsing and enforce the existing forest law. Indeed, the existence of the forest is largely attributed to the remarkable efforts of the forest guards. Though it is very limited, enrichment tree planting has been carried out in the forest (exotic as well as indigenous tree species). Four rebreaks ( re control gaps) have been established in the forest by removing woody vegetation so as to control the spread of re incidence and thus reduce its impacts. Moreover, there is a minor seedling nursery near Ambo Meda. The nursery produces seedlings of exotic and indigenous trees and distributes to users (model farmers, shcools, youth associations, churches and monasteries, institutions). Governmental institutions are promoting tree planting (reforestation, afforestation, agroforestry) in the study area, and this reduces the pressure on the natural forest. In fact, a rigorous tree planting is needed in the study area and beyond.
Threats to the forest Fach forest is a protected state forest and contains sacred places, but it has been dwindling from time to time due to livestock grazing/browsing, tree cutting for various purposes (fuelwood, construction material, charcoal, timber, farm tools), farmland expansion to the peripheral areas of the forest, rural settlements expansion, urbanization (expansion of Ambo Meda town), re incidences (seven major re incidences have occurred since the establishment of the protected forest; also a minor re incidence has occurred during the data collection of this study), exotic species plantations (mainly Cupressus lusitanica and Eucalyptus globulus) at the expense of the natural forest, and road construction across the forest (Addis Zemen-Ebenat main road; minor gravel roads built during the Derg regime for transport of wood harvested from the forest), as well as soil erosion and climate change. The forest will diminish in the near future unless appropriate and immediate measures are taken. The loss of the forest will lead to loss of biodiversity, particularly the endemic plant species. This calls for strengthening the conservation and management of the forest, as it harbours high number of plant species including endemics, and is a refuge for different plants and animals that have disappeared from most parts of northwestern Ethiopia.
A proper forest management plan should be developed and implemented to reverse or at least stabilize the present trend in the forest.

Conclusions And Recommendations
Fach forest possesses high plant diversity and endemism, which is attributed to habitat heterogeneity as well as conservation efforts. As revealed by their IVI values, Combretum molle, Olea europaea subsp. cuspidata, Dodonaea angustifolia, Calpurnia aurea, Maytenus serrata, Ficus vasta and Rhus vulgaris were ecologically the most important species in the forest. The DBH class distributions indicated that most woody species have good regeneration potential, but some are in poor regeneration status. Woody species having low IVI values (such as Rhus retinorrhea and Ficus sycomorus) and poor regeneration status (such as Rhus glutinosa and Premna schimperi) need high priority for conservation.
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. The forest has been maintained to the present-day through the combined indigenous (sacred grove) and modern (protected area system) conservation methods. At present, however, the forest is dwindling due to livestock grazing/browsing, tree cutting for various purposes, farmland expansion, rural settlements expansion, urbanization, re incidences, and exotic species plantations at the expense of the natural forest, as well as soil erosion and climate change. Therefore, effective conservation and management interventions are urgently needed to ensure the long-term maintenance of the forest ecosystem, and bene t the local communities through sustainable utilization of the forest.
Therefore, in order to ensure the long-term maintenance of the forest, the following recommendations are forwarded: Employ in situ and ex situ conservation methods for the conservation of woody species having low IVI values and poor regeneration status; Develop appropriate forest management plan to enhance the conservation, development and sustainable utilization of the forest; Promote tree planting (reforestation, afforestation, agroforestry) in the area with emphasis on multipurpose indigenous and suitable exotic tree species to reduce the pressure on the natural forest; Establish re prevention and control system with the necessary facilities; Provide the local communities with alternative sources of energy (hydroelectric, solar, biogas) and locally-made energy-saving stoves (mirt, gonzie, tikikil, lakech) to reduce the dependency on the forest for fuelwood and charcoal; Promote agricultural and forestry extension services in the area; Carry out further research on the forest, particularly ethnobotany, reproductive biology of the endemic plant species, soil seed banks, forest pathology, and carbon stock potentials, as well as wildlife. Partial views of Fach forest (photos by Haileab Zegeye)