The montane moist forest ecosystem comprises high forests of the country mainly the southwest forests, which are the wettest, and also the humid forest on the southeastern plateau known as the Harenna forest. Several authors in the past (for example, Mooney, 1963; Chaffey, 1979; Mesfin Tadesse, 1986; Friis, 1986 and 1992; Lisanework Nigatu and Mesfin Tadesse, 1989; Uhlig, 1988; Zerihun Woldu et al., 1989; Kumlachew Yeshitila, 1997) studied the composition and structure of this forest vegetation and described them on floristic basis. The forest vegetation was stratified into four different layers, namely, upper canopy, sub-canopy, shrub layer and the ground layer. The upper canopy is occupied the spectacular emmergent trees of Pouteria adolfi–friederici. Afrocarpus falcatus become important in the mixed broad-leaved forests of the Bale Mountains, although conifers are generally less important in moist forests of Ethiopia. Other characteristic species in the canopy include Olea capensis subsp. welweitschii and subsp hochestetteri, Prunus africana, Albizia schimperiana, Milletia ferruginea and Celtis africana. Others such as Polyscias fulva, Schefflera volkensii, Trilepisium madagascariense, Schefflera abyssinica, Bersama abyssinica, Mimusops kummel are also associated to it. Sub-canopy species include Croton macrostachyus, Cordia africana, Dracena steudenri, Syzygium giuneense sub-sp. afromontanum, Sapium ellipticum, Ilex mitis, Erythrina brucei and Rothmannia urcelliformis. The shrub layer consists species of Coffee arabica, Galiniera saxifraga, Teclea nobilis, Ocotea kenyensis, Clausena anisata, Measa lnceolata and Maytenus spp.
The Woody climbers are Ureara hypselodendron, Landolphia owarensis, Embelia schimperi and Jasminum spp. The ground vegetation are mainly herbaceous plants including Acanthus, Justicia, Piperoma, Galinsoga, Impatiens, Urtica and several grass species. In the attempt of classification of the vegetation types in montane moist forests of Ethiopia, Lisanework Nigatu and Mesfin Tadesse (1989) and Kumlacew Yeshitila (1997) recognised five and nine association groups at Harenna and Southwest forests, respectively. Plant community types recognised at Harenna forest have shown distinct variation in thier composition and structure of the vegetation across altitudinal changes, while those community types from Southwest forests were described mainly by their dominant species.
The montane moist forest ecosystem is distiguished also by supporting luxuriant growing epiphytes Canarina, Orchids, Scadoxus and fern plants such as Platycerium and Drynaria. Mosses also occur in the wettest porton of forests associated to major branches and barks of trees.
Generally in southwest plateau of Ethiopia, tertiary lava lie directly on the crystslline basement. The soils are predominantly developed on Trap series volcanics and metamorphic Precambrian basement materials. The color is red and red brown to silty loam (FAO, 1984). According to FAO/ UNESCO (1974) the soil in southwestern part of the country was clasified as Dystric Nitisols. Soil acidity tends to become an environmental problem due to leaching as a result of heavy rain that occur in the region.
The montane moist forest ecosystem of Ethiopia is found mostly in the southwestern plateau, with altitudinal range between 800 m-2500 m a.s. l. and the southeastern plateau, on the southern portion of the Bale Mountains at an altitude between 1450 m-2700 m a. s. l. In general, the southwestern recieves the highest amount of rainfall in the country. Some of the good examples of the moist forests are, Tiro-Boter-Bacho, Belete-Gera, Yayu, Sigmo-Gatira, Harenna-Kokosa in Oromia Region (Jimma Illubabor, East and West Wollega Zones) and the Masha-Anderacha, Bonga, Godere forests in Southern Regions (Yem, Gurage, Keffa-Sheka Zones). These forests are recognised as high forests with closed continuos canopy cover. Most of the forests in the southwestern plateau which seem to be intact from above canopy are Coffee managed forests highly encroached by humans.The trees have been selectively felled for timber, construction, expansion of agriculture as well as Coffee and Tea plantations.
4.3 Species Diversity
The montane moist forest ecosytem is the most diverse ecosystem in composition, structure and habitat types.This ecosystem lies on mountaineous area which allows the existence of wide ecological gradients along the altitudes. As a result, large complexes of mountain forest exist forming several distinct vegetation units.The various vegetation types, therefore, support different flora and fauna that can be distinguished as forming unique associations. The structural diversity in the forest also allows both animals and plants to occupy different ecological niche. The moist forests are interspersed also by patches of various grasslands and wetland which have their own unique faunistic as well as floristic associations. The high forests are not only diverse in their composition but hold also important genetic components and populations of wild Coffee and several associated economic plant species. Previous study of the montane moist forests in southwest and Harenna by Kumlachew Yeshitila (1997) and Lisanework Nigatu and Mesfin Tadesse (1989) had shown that more than 160 and 200 vascular plant species were recorded from these forests, respectively.
Several animal species are known to inhabit the montane forest ecosystem although intesive scientific investigations are lacking in the past. Larger mammals living in this ecosystem includes, among others, Lion, Leopard, Black Leopard, Serval Cat, Black
Common Jackal, Wild Dog, Wild Cat, Bush Pig, Giant Forest Hog, Warthog, Bush Bug, Colobus Monkey, Olive Babbon, Grey Duicker and Bush Babby. Although complete inventory is lacking some of the montane moist forest ecosystem is recognized to be important bird areas of Ethiopia (EWNHS, 1996). For example, Bonga forest consists of morethan 15 highland species of birds, Metu-Gore-Tepi forest consists of morethan 16 of which at least two are endemic, and Tiro-Boter-Becho forest have also morethan 32 highland biome species of Birds (EWNHS, 1996).
4.4 Uses and values
The montane moist forests are important surces of timber, non timber forest products, agricultural and pasture land, coffee and tea production, and source of raw material supply for various developement works including construction.The non timber forest products include medicinal plants, fuelwood, natural gums, edible fruits, honey, spices and household materials.The southwest forests of Ethiopia have been serving as a major sources of timber for saw log, plywoods, chipwood and paper industries during the last century. For example, over 57,987 m3 of logs, 6273 m3 7701m3 of logs have been removed between 1982 and 1993 from Gera forest, Belete forest and Bonga forests in Oromia and Southern Regions, respectively. Similarly, morethan 30,000 m3 of timber was extracted from Harenna forest between 1982 and 2000 (Getachew Tesfaye, 2001).
The moist montane forests in the country with their many timber-producing tree species have attracted the eyes of several investors in recent years. Forests are being cleared in the pretext of of using the land for Coffee and Tea plantation. Belete forest in Jimma Zone was cleared for coffee plantation while Wushwush was replaced by Tea plantation during the past few decades. Multitudinal benefits have been extracted from the high forests both at local and national level, although information is lacking on the location, amount and type of the different forest products (value) extracted.
Not only plantation Coffee is produced from the montane moist forest ecosystem, but also wild (forest) Coffee are also harvested by the local people in many places of the ecosystem. In addition, as mentioned earlier the montane moist forests of the country are also important bird habitats including some of the notable endemic species such as Rouget’s Rail and Abyssinian Longclaw. Moreover, forest resources of the country ingeneral and the montane moist forests in particular are important components of the planet to sequester the CO2 gases in the Atmosphere and, therefore, a major ‘Carbon sink’ reducing the Green House Gases (GHG). Current estimates has shown that our forests sequester nearly 27,579 Gg of CO2 per annum from the atmoshpere (Million Bekele, 2001) and at present Ethiopia is a net sinker of GHG owing to her natural forest resources. The net GHG emission of the country is only 2,596 Gg per annum (NMSA, 2001).
4.5 Threats and rates of change
As has already been mentioned, the most stiking changes in the montane moist forest ecosystem is caused by human activities in the form of timber extraction, Coffee and Tea plantations, agricultural expansion, human settellement and fire hazards. As a result of selective felling of trees for timber, few species are targeted and those that are of low commercial value are remaining with few over-matured individualsof quality timber species. At present, Maiz and Teff cultivation is infringing upon parts of the southwestern Ethiopia, which together with high leached acidic soils and rugged topography intensify the degradation processes. Forest grazing by livestock in many places reduced natural regeneration of forest tree species from understorey seedlings. A recent study from Harenna forest has shown that more than 40% of the understorey seedlings are consumed by herbivors or livestock in particular only during the dry season of the year (Getachew Tesfaye, 2001). Unpredictable wild fire is becoming also a major threat to forest ecosystems of the country. In year 2000 alone more than 90,000 hectares of mature forest were completely damaged by fire of which the Harenna forest accounted to one third (30,00 ha) of the damage. The country has neither an appropriate policy nor sound strategy to avoid both forest fire and other unpredictable calamities that would help to minimize the impact.
The presence of huge potential for timber, coffee and tea production in the high forest areas have become very much attractive to various investement endeauvers. In many places investors have made huge profits by selling timber only from the forest and left the areas without any tax payement or implementation of their proposed projctes. The Bebeka Coffee Plantation Developmnent, whcih was there since 1970´s has become know less profitable than the traditionally managed forest coffee.
Over-exploitation, ruthless destuction of natural forests as well as degradation of the various habitat types in montane moist forests made the area to be the most vulnerable and threatened ecosystem. The direct effect of deforstation result in an increase of soil erosion, siltation and other associated hydrological process as well. Poverty and population growth are the roots for habitat destuction. The increasing need to produce more food, fuel wood, shelter and clothings accelerates the rate of deforstation and thereof, environmental degradation. In general, the loss of forest biological resources as a result of human interferance has double-fold interms of national economy, social well being, cultural heritage and environmental health. Babya-Fola forest, Belete-Gera forest and Bonga forest had lost about 77.4, 82.8 and 90 percent of thier closed high forest areas from 1976 to 1990 only and there is no more any closed high forest remaining (Reusing, 1998). The above figure would give a clue how our natural forests are depleted as well as the picture about the rates of change in forest cover of the country.
4.6 Conservation status
The existing knowledge on the extent of the montane moist forest ecosytem, distribution, diversity of their constituent species (flora and fauna) as well as ecological requirments is very limited. The State Forest Conservation and Development Department of the 1980’s designated 58 important forest areas as Natural Forest Priority Areas (NFPA’s). The aim of designating NFPA’s is for their production, protection and biological conservation services (EFAP, 1994). These areas comprise natural forest, plantation and non-forested land. Among the National Forest Priority Areas designated for protection the montane moist forest ecosystem include Harenna-Kokossa, Godare, Gebre Dima, Setema, Sigmo-Geba, Yayu, Babya-Folla, Belete-Gera, Tiro-Botor-Becho, Masha-Anderacha, bonga and Sheko forests. In some of the NFAPA no natural high forests remaining at all, in most of them the forest stands have been partly deforested or severly degraded in quality and quantity as well (Reuising, 1998) and ther is an urgent need to coserve, protect, manage and replenish the montane moist forest ecosystem in general and the biological resources in particular. In addition a detail ecological investigation, structure, compositon and diversity of the flora and fauna of this ecosystem is highly reqiured.
The National policy on forest resources of Ethiopia clearly indicated that the high forest should be kept primarly for protection and conservation purposes. Commercial utilization, according to the policy, is secondary objective. However, the present mamagement of the high forest fails to achive its major primary objective. Actually the forests are declining both in quality and quantity at a faster rate in the last decaded than ever before, and the existing forest polices do not work at all. None of the NFPAs have legal protection and moreover, the lack of accountability and committment both from civil and plitical parties aggravated the situation. Therefore, considerable efforts should be made to promulgate appropriate and effective laws that would safeguard the protection and sustainable utilization of the remaining forest resources. Accurate inventory is required also to assess the extent, distribution and biological diversity of the forest resources. Otherwise the few remaining natural forest cover will go away before our eyes and the Nation would suffer serious environmental degradation while the globe is lossing one of its major ‘Carbon Sink’