Community composition and distribution of macroinvertebrates in the Umzimvubu River,South Africa: a pre-impoundment study

This paper presents baseline biological data on aquatic macroinvertebrates and water quality in the Umzimvubu River and selected tributaries, Eastern Cape Province, South Africa, prior to the construction of proposed large-scale water resource developments. Sampling was conducted seasonally at 14 sites between 1996 and 1998. The macroinvertebrate community composition was strikingly similar (±70%) across sites. Faunal diversity was low (104 taxa in total), but many taxa found were sensitive to water quality change (ASPT 5.0 to 9.6), indicating good water quality, which is attributed to the currently undeveloped nature of the catchment. Concentrations of water quality variables fell within a narrow range, except for total suspended solids, which at times was very high (up to 8 532mg l^–1). The highly variable concentration of the total suspended solids and its potential effects on biodiversity need to be investigated further. It is likely that bilharzia will spread and that pest blackflies may become a problem to livestock if the water resources become developed as is proposed. We suggest that more flow gauging weirs are needed to measure flows better for future management and also that the implications of the proposed developments on the estuary need to be investigated.     

The Hepaticae and Anthocerotae of the subantarctic and temperate islands in the eastern Southern Hemisphere (90°E to 0°): an annotated catalogue

Abstract

On the subantarctic and temperate islands of the eastern Southern Hemisphere (90°E to 0°) 66 Hepaticae and two Anthocerotae species are recorded, among them ten are recorded for the first time. The reports of a further 18 are rejected. Fifteen species and five variety names are newly synonymized. Nineteen species and two subspecies are regarded as endemics. Among the recorded species, 75% are only or mainly known from the Subantarctic Zone. Species otherwise known also from southernmost South America predominate, contrary to its geographical distance, whereas those otherwise known only from the closer Africa are weakly represented and those known only from Australasia are almost lacking.     

Notes on Fissidens VII–IX

Abstract

Note VII: Fissidens ah-pengae and F. aristifer spp. nov. are described and figured. The first is known from La Réunion, the second from Madagascar and La Réunion. Both belong to subgenus Aloma.

Note VIII: Fifteen new synonyms are proposed: Fissidens bryoides Hedw. var. glaucus Brid. is subsumed under F. crassipes Wilson ex Bruch & Schimp., F. comorensis Müll.Hal. under F. crispulus Brid., F. sigmocarpoides P.de la Varde under Fissidens erosulus (Müll.Hal.) Paris, F. atroviridis Besch., and F. luridus Renauld & Cardot under F. flaccidus Mitt., Moenkemeyera rarotongae Dixon and Fissidens jonesii Bizot ex Pócs under F. lagenarius Mitt. var. lagenarius, F. onraedtii Bizot nom. nud. under F. madecassus Schimp. ex Müll.Hal., F. bryum var. terrestris P.de la Varde under F. metzgeria (Müll.Hal.) Broth., F. edamensis M. Fleisch. under F. pallidinervis Mitt., F. brunnthaleri var. filipes Dixon & P.de la Varde under F. ramulosus Mitt., F. desertorum (Müll.Hal.) Paris and F. bambariensis Broth. & P.de la Varde under F. reflexus Hampe, F. usambaricus var. acutifolius P.de la Varde under F. usambaricus Broth. and F. glauculus var. circinicaulis (Cardot) P.de la Varde under F. weirii Mitt. Fissidens gedehensis M. Fleisch. is re-instated as a good species.

Note IX: Fifty-five new country and state records including F. anguste-limbatus Mitt. new to Africa. Fissidens pocsii Bizot & Dury ex Pócs is the first record of an epiphyllous species of this genus. The African distributions of F. flaccidus and F. pallidinervis are amended.     

Notes on the genus Dendroceros in West Africa and South Atlantic Islands

Abstract

Following revision of Dendroceros specimens from West Africa and South Atlantic islands, three species are recognized for this geographical area: Dendroceros adglutinatus, D. africanus and finally D. herasii which is described as new. On the other hand, D. crispatus is excluded from Africa while Folioceros fuciformis (Megaceros lacerus, Anthoceros fuciformis) is excluded from Equatorial Guinea. A preliminary key to the five Dendroceros species known to occur in Africa is included.     

New synonymy and typification in African Schlotheimia (Bryopsida: Orthotrichaceae)

Abstract

Schlotheimia grevilleana Mitt., Schlotheimia rigescens Broth., Schlotheimia laetevirens Broth., Schlotheimia bequaertii Thér. & Naveau and Schlotheimia brachypodia Thér. & Naveau are placed in synonymy with Schlotheimia ferruginea (Bruch ex Hook. & Grev.) Brid. The typification of Schlotheimia percuspidata Müll.Hal. is discussed and a neotype is proposed.     

A morphological revision of the genus Herbertus S.Gray (Herbertaceae,Marchantiophyta) in Africa,including the East African islands

Abstract

The genus Herbertus S.Gray in Africa and the East African islands is revised. The division of the genus into two broad species complexes centred on H. dicranus (Tayl.ex Gottsche et al.) Trev. and H. juniperoideus (Sw.) Grolle is confirmed. H. capensis (Steph.) Sim, H. capillaris (Steph.) H. doggeltianus (Steph.) Demaret, H. lobatus (Steph.) Demaret, H. mascarenicus (Steph.) S.Arn., H. mollis (Steph.) Dusén, H. stuhlmannii (Steph.) Demaret and Schisma kilimandjarense Steph. are synonymous with H. dicranus. H. grossevittatus (Steph.) S.Arn. ex Grolle is synonymous with H. juniperoideus. Three new species are described: H. spicatus N.G.Hodgetts sp. nov., which is related to H. juniperoideus and appears close to the neotropical H. pensilis, with long, narrow leaf lobe apices and a sheathing leaf base; H. mauritianus N.G.Hodgetts sp. nov., also related to H. juniperoideus, has fewer basal slime papillae and the vitta bifurcating lower down; and H. pocsii N.G.Hodgetts sp. nov., which is related to H. dicranus but has setaceous leaf lobe apices composed of long, narrow cells. The relationships of the taxa and patterns of distribution, taking account of recent molecular work, are discussed.     

Phylogeography of the African catfish,Chrysichthys maurus (Valenciennes, 1839)

Polymorphism at 19 allozyme loci was studied in 227 individuals of the catfish, Chrysichthys maurus (Valenciennes, 1839), collected from ten populations representing nine different river basins in west Africa. Eleven of the loci studied were polymorphic. Analysis showed that populations clustered according to their geographical origin: eastern populations close to the root represented by a population of a closely related species (C. auratus); then populations from the centre of the species' range, followed by the more western populations. Networks observed, regression of genetic distances versus geographical distances, results of the Mantel test as well as the apomorphic status of two alleles suggested that the genetic differentiation corresponds to an isolation by distance model. These results strongly suggest that the populations initially occurred in the lagoons and rivers of Ivory Coast and from here spread to the western part of the species' range by progressively colonising basins from east to west.     

Seasonal variability of macroinvertebrate assemblages in two regions of South Africa: implications for aquatic bioassessment

Seasonal variability of macroinvertebrate assemblages was examined in two regions of South Africa: Western Cape and Mpumalanga. Sampling was undertaken at reference sites using the rapid bioassessment method SASS4 (South African Scoring System, Version 4). This study examined the influence of sampling season on the occurrence of taxa, macroinvertebrate assemblages and SASS scores. In the Western Cape a few taxa were more common at certain times of the year, and multivariate analysis of macroinvertebrate assemblages showed that assemblages grouped by season. The number of taxa and the Average Score per Taxon (ASPT) were significantly different among seasons in the Western Cape, with fewer taxa recorded in winter compared to summer, and significantly higher ASPT values recorded in winter and spring than summer and autumn. Whereas more taxa were recorded in autumn than in spring, a higher proportion of sensitive and high-scoring taxa were recorded in spring. In Mpumalanga macroinvertebrate assemblages did not group by season, and differences in SASS scores were not significant, although more taxa were recorded in winter than in spring or autumn, and ASPTs were slightly higher in winter than in spring. Results are discussed in relation to ecological reference conditions and the interpretation of bioassessment data.     

British Bryological Society Expedition to Mulanje Mountain,Malawi. 17 Sematophyllaceae (Bryopsida): Part 1

Abstract

The family Sematophyllaceae is a difficult family to treat in Africa because of the large number of species described without any subsequent revision or monography and, despite the many collections mentioned in this paper, only two species had previously been identified from Malawi. A total of four species in four genera (Gammiella, Mρacrohymenium, Radulina and Wijkia) are recorded in this paper, all but one new to Malawi. The two remaining genera (Sematophyllum and Trichosteleum) present additional difficulties of identification, and will be dealt with separately.     

Liverworts of southwest Ethiopian montane forests: ecological and biogeographical notes

Abstract

Ethiopia has diverse topographic features and climatic conditions with a diverse flora. The liverwort flora of southwest Ethiopia is practically unknown, despite a favourable climate and the occurrence of suitable ecosystems such as montane rainforests. During an ecological study of diversity patterns of bryophytes and vascular plants in relation to land use, we recorded many bryophyte species. In this paper we report the finding of 89 species of liverworts, and give short ecological notes and describe the distribution (locally and in Africa) for each species. Of these, 51 species are newly reported from Ethiopia. It is thus obvious that Ethiopia is considerably richer in liverworts than might be expected from previous checklists.