Effects of grazing and cultivation on forest plant communities in Mount Elgon National Park, Uganda

Plant communities in the montane forest of Mount Elgon National Park were studied in order to assess the impact of grazing and cultivation on species composition. Present and former land uses, tree, shrub and herb species, soil properties and the percentage cover and height of trees, shrubs and herbs were determined in 40 plots. An indirect ordination of these plots showed that species composition was primarily determined by successional stage and agricultural disturbance. In forest plots (ordinated separately) where the widest range of former and current grazing intensities had occurred, evidence of grazing history, soil phosphorus and vegetation height correlated negatively with the strongest ordination axis. Least grazed forest plots had fewer tree seedlings and saplings than more intensively grazed plots. This may be due to the increase in Mimulopsis alpina (Acanthaceae) in less grazed forest where tree regeneration might otherwise be more advanced. Tree seedlings and saplings were uncommon in the forest, rarely exceeding 30cm in height and there was no tree understorey. Although grazing is important for preserving species diversity in Mount Elgon National Park through the maintenance of species-rich grasslands, long-term effects on montane forest communities must be considered in future park management.     

Ruminants from the Early Miocene of Napak,Uganda

Since the late 1950's, many ruminant specimens have been recovered from the Early Miocene volcano-sedimentary succession at Napak, Uganda. Beginning in 1958 when the first fossils were recognised by J.G. Wilson, and the subsequent surveys of Bishop and colleagues, more than 340 specimens have been found. Preliminary publications in the 1960's identified three species, Dorcatherium songhorensis, Dorcatherium ? chappuisi, and Palaeomeryx africanus. Napak material hitherto identified as Dorcatherium ? chappuisi represents a new species of tragulid smaller than D. chappuisi, and is here identified as Dorcatherium iririensis nov. sp., while material previously assigned to Palaeomeryx is transferred to Walangania. A new finding for the site is the tiny tragulid, Dorcatherium parvum. There are thus four species of ruminants at Napak.     

Palaeoenvironments of Early Miocene hominoid-bearing deposits at Napak,Uganda, based on terrestrial molluscs

Studies of fossil molluscs from Early Miocene deposits at Napak, Uganda, reveal that between 20 and 18.5 Ma, there were various kinds of palaeoenvironments on the flanks of the volcano ranging from forest to open country. The basal Iriri Member contains fluvial deposits from which freshwater gastropods and bivalves have been collected. The younger Napak Member is subaerial in facies, and has yielded a predominantly forest assemblage of gastropods, but with some indications of open country species at one of the sites. Napak has yielded a rich and diverse primate fauna, including the large ape Ugandapithecus major, the small ape Micropithecus clarki, the earliest known cercopithecid in the world (Prohylobates sp.) and several galagids (Mioeuoticus bishopi) among other less well-known taxa.     

Parasitism of Hypothenemus hampei (Coleoptera: Scolytidae) in different farming systems and altitudes of Mount Elgon,Uganda

Altitude and farming system play a vital role in modifying the niche for arthropods, by directly influencing microclimatic conditions, the quality and quantity of vegetative cover, which act variably on the behaviour of the pests, and their natural enemies. The objective of the study was to determine their effect on the abundance and parasitism of the Coffee berry borer (Hypothenemus hampei) in the Mount Elgon region. Altitude was categorized as: low (1,400–1,499 m.a.s.l); mid (1,500‐1,679 m.a.s.l); and high (1,680–2,100 m.a.s.l), and farming system was categorized as: Coffee monocrop; Coffee + annual; Coffee + banana; and Coffee + banana + shade trees. For each altitudinal range, each farming system was represented three times. The study was in two districts of the Mt. Elgon, covering a total of 72 Arabica Coffee study sites. The work involved field pest infestation inventories, followed by laboratory rearing for the abundance and parasitism studies. The results revealed highly significant interactions between altitude and farming system in influencing the abundance of the pest and its four parasitoids: Phymastichus coffea, Cephalonomia stephanoderis, Prorops nasuta and Heterospilus coffeicola. C. stephanoderis was highest in the mid‐altitudes within Coffee + banana+shade tree system; P. nasuta was highest at high altitude within Coffee + banana system; P. coffea was most abundant at mid‐altitude within Coffee + banana system, whereas H. coffeicola was highest at high altitude within the Coffee + annual cropping system. H. hampei counts were highest at low altitudes, especially in the Coffee + annual system. Some of these trends can be explained by the condition of the microclimate in the Coffee fields. There was a negative relationship between temperature and abundance of all the four parasitoids. Only C. stephanoderis had a relationship (+) with semi‐natural vegetation species counts. And only H. coffeicola had a relationship (+) with light intensity. These contrasted with H. hampei, which was positively related to temperature and negatively to light intensity.     

New Catarrhine fossils from Moroto II, Early Middle Miocene (ca 17.5 Ma) Uganda

During the 1998–2003 field seasons of the Uganda Palaeontology Expedition, dental remains of three catarrhine species were recovered from Moroto II, Uganda. Micromammals from the locality indicate a late Early Miocene to basal Middle Miocene (ca 17.5–17 Ma) age, younger than Rusinga (17.8 Ma), but similar in age to Buluk (17.2 Ma) and Kalodirr (17.2 Ma). This paper describes and interprets new catarrhines from the site, one of which is a victoriapithecid monkey, the second a new genus and species of small-bodied ape, and the third a large hominoid. A fourth species collected in the 1960's is attibuted to Afropithecus turkanensis. To cite this article: M. Pickford et al., C. R. Palevol 2 (2003).     

Habitat occurrence and feeding ecology of Crocidura montis and Lophuromys flavopunctatus on Mt. Elgon, Uganda

The distribution, habitat occurrence and feeding ecology of Crocidura montis and Lophuromys flavopunctatus coexisting in the afro‐alpine zone on Mt. Elgon, Uganda, are described. Crocidura montis was the only shrew species occupying the afro‐alpine zone, but was not found in forested habitats below 3200 m. While there was considerable overlap in habitat occurrence between the two species, C. montis was most abundant in the montane grassland and in drier sites while L. flavopunctatus occupied a wider range of habitats and wetter sites. C. montis ate a diversity of invertebrates, the most important being Coleoptera, Araneae and Lumbricidae. Invertebrates, mostly Diptera larvae, Lumbricidae and Coleoptera, formed a major component of the L. flavopunctatus diets, plus plant material (particularly Hepaticae and monocots). The arthropod components of the diets reflected their abundance in pitfall samples.     

Micropithecus clarki, a small ape from the Miocene of Uganda.

Micropithecus clarki, from Miocene sediments of Napak, Uganda, is the smallest known hominoid primate, living or fossil. In facial morphology it is very similar to extant gibbons. Dentally, it is most similar to the small apes from the Miocene of Kenya, Dendropithecus and Limnopithecus. All of the apes from the early Miocene of East Africa seem to represent a single phyletic group that could be easily derived from the Oligocene apes known from the Fayum of Egypt. Pliopithecus from the Miocene of Europe is more closely allied with the Oligocene radiation than with the later East African radiation.     

A study of altitudinal zonation in the montane forest belt of Mt. Elgon,Kenya/Uganda

Altitudinal changes in the vegetation of the Montane Forest Belt of Mt. Elgon, East Africa, were investigated by analysis of aerial photographs and by sample plots along two transects, one on a relatively wet, and the other on a relatively dry aspect.Classifications for both tree and herb/shrub plots show that the forests along the two transects become increasingly similar floristically with altitude. The total number of tree species recorded is greater for the transect on the moister aspect. The mean altitudinal range for tree species increases on both transects with altitude, while that for herb/shrub species remains constant. It is suggested that the upper altitudinal limits of many species are determined principally by temperature-related factors, while the degree to which species extend their ranges downwards is much influenced by competition.Structural heterogeneity is particularly well marked at altitudes corresponding to the bamboo zone on the wetter slopes and, even in the absence of bamboo, tree density here is much reduced. it is suggested that thicket-forming species, including bamboo, have enhanced competitive ability in intermediate altitude montane forests.Previously advanced classificatory schemes for montane forest vegetation in eastern Africa are examined in the light of the findings.Nomenclature follows Agnew (1974) and Dale & Greenway (1961) with minor modifications after Chapman & White (1970), Mabberley (1973) and Pennington & Styles (1975).The work was funded by a grant from the Natural Environment Research Council (U.K.). We are grateful to the Government of Kenya and to the Forest Department, Kenya, for permission to work on Mt. Elgon. Dr. A. D. Q. Agnew and Miss C. Kabuye very kindly identified some of the plant specimens. The illustrations were drawn by Mr. J. Shaw and the manuseript was critically read by Dr. D. Riley.     

Changes in the composition of the European snake fauna during the Early Miocene and at the Early / Middle Miocene transition

The members of the ‘modern’ snake families Colubridae, Viperidae and Elapidae (representatives of the family Colubridae appeared in Europe as the first) might have penetrated into the areas of Central Europe probably across the Mazury -Mazowsze continental bridge. The ‘modern’ families penetrated into West Europe across the Rhine Graben by several immigration waves. Based on the known marine incursions into the Rhine Graben and adjacent areas, a total of four distinct waves of dispersal of both the Asiatic and North American immigrants can be discerned within the Early Oligocene — Middle Miocene time span. The Early Miocene (MN 1–MN 2a) and the Early / Middle Miocene (MN 3–MN 4/5) dispersals of snakes are responsible for the final displacement of representatives of the ‘ancient’ family Boidae out of West and Central Europe. The Early and the Middle Miocene migrations have likewise initiated the evolution of the modern European snake fauna.     

Early Miocene vertebrates from Montagna della Maiella,Italy

Vertebrate remains from the lower Burdigalian (early Miocene) carbonates of Montagna della Maiella, central Italy, are described. These remains mostly consist of teeth belonging to 11 elasmobranch taxa (Carcharias acutissima, Carcharias cuspidata, Carcharodon subauriculatus, Isurushastalis, Isurus oxyrinchus, Isurus sp., Parotodus benedeni, Hemipristis serra, Galeocerdo aduncus, Galeocerdo contortus, Negaprion cf. eurybathrodon), eight teleost taxa (Diplodus sp. and two indeterminate sparids, Labrodon sp., Trigonodon jugleri, Sphyraena sp., Chilomycterus sp., Diodon sp.), an indeterminate crocodile, and two odontocete cetaceans (Squalodon sp. and an indeterminate kentriodontid). Paleoenvironmental and paleogeographical implications are discussed.     

Early primary succession on a barren volcanic plain at Mount St. Helens,Washington

The invasion pattern on a barren plain on the eastern flank of Mount St. Helens, Washington, devastated by the 1980 volcanic eruption was monitored between 1988 and 1992. All vascular plants on a grid consisting of 400 contiguous 100-square-meter quadrats were recorded with a cover score. The substrate was initially homogeneous, but significant heterogeneity had developed by 1988. Vascular plant species richness increased from 24 in 1988 to 41 in 1992. Mean species richness per quadrat increased from 0.44 to 5.71, mean cover increased from 0.04% to 0.51%, and mean diversity index (H') increased from 0.08 to 1.56. A variance/mean test of species richness pattern showed that invasion occurred sporadically since plots tended to have either several or no species. By 1992, mean species richness was more evenly distributed. Most seedlings continue to result from long-distance dispersal, but reproductive colonies of species are developing. Seedling distributions are controlled by microsites. Eleven common species strongly and similarly preferred safe-sites created by small rocks, undulations, or rills. However, many apparent safe-sites are empty, suggesting that seeds are scarce and that even the most favorable microsites are marginal. The niches of these species seem to overlap broadly. The Plains of Abraham is in the earliest stage of primary succession. The detailed invasion pattern permitted us to distinguish species still dependent on immigration from those now locally established. Pronounced microsite preferences emphasize that physical amelioration (e.g., nutrient input and erosion) must occur before further succession can commence. We have observed the early stages of succession where an inhospitable site is gradually and heterogeneously changed into a habitat where safe-sites do not limit succession, but where stochastic factors remain important.     

A new pliopithecoid genus from the early Miocene of Uganda

A partial face and mandible from the early Miocene site of Napak IX in Uganda are described here as a new genus and species of catarrhine primate, Lomorupithecus harrisoni gen. et sp. nov. The face is among the most complete specimens known for a Miocene small-bodied catarrhine. Several aspects of its anatomy indicate that the new species is a stem catarrhine, and as such, it may provide valuable information pertaining to the primitive catarrhine cranial morphotype. Lomorupithecus is most similar in its facial anatomy to members of the Pliopithecoidea, and these similarities could be interpreted in three ways. They could be symplesiomorphies, which would support the traditional view of the primitive catarrhine cranial morphotype; they could be synapomorphies reflecting a phylogenetic position of Lomorupithecus within Pliopithecoidea; or they could represent convergence. Phylogenetic analysis of Lomorupithecus along with 35 other primates indicates that it is a pliopithecoid. As such, it would be the oldest and only Afro-Arabian member of this otherwise Eurasian clade.     

A survey of the fauna of streams on Mount Elgon, East Africa, with special reference to the Simuliidae (Diptera)

The stream fauna of Mt Elgon is described from collections taken during a 6-week visit. Collections were mainly made on the cultivated slopes below the belt of montane forest, and although stations were concentrated on the western sides of the mountain sufficient were worked elsewhere to show that there was little or no geographical variation of the fauna. The streams are physically diverse but faunistically rather uniform, with a few genera dominating the fauna throughout the entire range of altitude investigated. Most of the other taxa showed evidence of altitudinal limitation which may be attri-buted to the pronounced temperature gradients of the mountain's streams. As the species of Simuliidae and adult Elminthidae could be reliably distinguished their distributions were studied in greater detail. The Simuliidae showed a pronounced zonation of species, the majority being confined to narrow ranges of altitude below the forest margin. Factors considered to influence their distribution were principally altitude (temperature), current speed and, to a lesser extent, stream size. The influence of these factors on the distribution of adult Elminthids was less marked, although all species showed at least an upper or a lower limit of altitude, and more than half the commoner species a preference for a particular stream type. Taxonomic knowledge of African freshwater faunas allows few groups to be identified beyond the genus, and with this limitation the Elgon stream fauna is found to differ in only minor respects from the faunas of other highland areas in Central Africa.     

Early Miocene Carnivora of Aktau Mountains, South Eastern Kazakhstan

New material is described ofAktaucyon brachifacialis n. gen., n. sp. (Amphicyonidae, Daphoeninae),Phoberocyon (Cinctocyon n. subgen.)akhmetievi n. sp. (Ursidae, Hemicyoninae), and Mustelidae indet. from the lower Miocene deposits of the middle Member of the Chul’adyr Formation in the Aktau Mountains, Ili Basin, SE Kazakhstan. Daphoenine remnants are reported from Asia for the first time. They are assigned to the new tribe Aktaucyonini, which are middle to large-sized amphicyonids with a shortened facial region; a reduced P/1; enlarged upper canines; an enlarged P4/ with a welldeveloped protocone, paracone and parastyle blade; enlarged M1/ and M2/, which have conical protocones, symmetrical talons, and reduced hypoconules; and an M2/ that is transversely widened with a greatly reduced metacone. The phoberocyonine described here is the first reported from Kazakhstan and for the whole western part of Central Asia. The composition of the carnivore fauna resembles that from Shanwang, eastern China (MN 4–5).     

中国北方草地生态系统服务评估

北方草地是我国天然草地主体部分,其生态功能对提升生态系统稳定性、保障国家生态安全具有重要的作用。在北方草地生态功能分区基础上,开展2011-2015年不同功能区内防风固沙、土壤保持、水源涵养等生态功能评估,探明其现状和空间格局,为北方草地生态功能分区研究提供评估数据,也为推进草地生态系统保护与修复工作提供科技支撑。结果表明：（1）北方草地防风固沙能力为32.44 t hm^-2 a^-1,防风固沙量为89.22亿t/a。半干旱草原区防风固沙能力和固沙量最大,分别为68.76 t hm^-2 a^-1和29.16亿t/a,其固沙量占北方草地固沙总量的32.68%。（2）北方草地土壤保持能力为124.5 t hm^-2 a^-1,土壤保持量为243.59亿t/a。土壤保持功能的空间异质性较大,暖性灌草丛区土壤保持能力最大,为431.52 t hm^-2 a^-1;高寒草甸区土壤保持量最多,为105.36亿t/a,占北方草地土壤保持总量的43.19%。（3）北方草地水源涵养能力为93.03 m³ hm^-2 a^-1,水源涵养量为288.98亿m³/a。高寒草甸区和高寒草原区水源涵养能力较大,分别为211.09 m³ hm^-2 a^-1和118.04 m³ hm^-2 a^-1。两个区域的水源涵养量也较多,分别为125.36亿m³/a和72.13亿m³/a,合占北方草地水源涵养总量的68.34%。整体上,北方半干旱草原区、暖性灌草丛区、高寒草甸区和高寒草原区对发挥我国草地防风固沙、土壤保持、水源涵养等生态多功能效益、提升生态系统服务和稳定性具有极其重要的作用。