Floristic surveys of some lowlands polluted of a tropical urban area: the case of Yaounde, Cameroon.

NOVELTY AND IMPACTS OF THE SUBMISSION: This study presents original results for field surveys in lowland sites polluted in Yaounde-Cameroon. The screening of 11 polluted lowlands compared to a natural lowland (unpolluted), made it possible to identify species which may exhibit the best capacities to adapt to environmental changes and to develop in contaminated areas, in particular heavy metals. This work can be a preliminary study around the species growing in contaminated lowlands. Thus, this study can be reproduced in other regions, to compare the results obtained and identify potential plants for the lowlands remediation in Cameroon.

DNA barcoding of native Caucasus herbal plants: potentials and limitations in complex groups and implications for phylogeographic patterns.

DNA barcoding has rapidly become a useful complementary tool in floristic investigations particularly for identifying specimens that lack diagnostic characters. Here, we assess the capability of three DNA barcode markers (chloroplast rpoB, accD and nuclear ITS) for correct species assignment in a floristic survey on the Caucasus. We focused on two herbal groups with potential for ornamental applications, namely orchids and asterids. On these two plant groups, we tested whether our selection of barcode markers allows identification of the "barcoding gap" in sequence identity and to distinguish between monophyletic species when employing distance-based methods. All markers successfully amplified most specimens, but we found that the rate of species-level resolution amongst selected markers largely varied in the two plant groups. Overall, for both lineages, plastid markers had a species-level assignment success rate lower than the nuclear ITS marker. The latter confirmed, in orchids, both the existence of a barcoding gap and that all accessions of the same species clustered together in monophyletic groups. Further, it also allowed the detection of a phylogeographic signal.The ITS marker resulted in its being the best performing barcode for asterids; however, none of the three tested markers showed high discriminatory ability. Even if ITS were revealed as the most promising plant barcode marker, we argue that the ability of this barcode for species assignment is strongly dependent on the evolutionary history of the investigated plant lineage.

Distribution and conservation of Cactaceae in Brazilian Seasonally Dry Tropical Forests: insights from floristic and phytosociological surveys / Distribución y conservación de Cactaceae en Bosques Tropicales Estacionalmente Secos: apreciaciones a partir de estudios florísticos y fitosociológicos

Abstract Species lists available from floristic and phytosociological studies contain important information about species distributions that are useful for making biogeographical inferences and even to evaluate conservation status of species and ecosystems. In the case of the Caatinga, this information may contribute to challenging the pre-established idea that it is a homogeneous vegetation unit. The strong relation between the substrate and the plant assemblages of the Caatinga may characterise different types of vegetation. In this way, the objective of the present study is to evaluate whether differences in the distribution of Cactaceae relate to distinctive types of substrate (sedimentary and crystalline) as much in terms of floristic richness as species density. Concomitantly, we evaluated the conservation status of the Caatinga areas studied. To obtain the data, we undertook a bibliographic revision of floristic and phytosociological studies in the Caatinga and constructed a similarity matrix using the selected floristic studies in order to evaluate the relation among different areas of Caatinga. We found that 48 areas included Cactaceae species; 33 species distributed in 14 genera were recorded. Among these taxa, Cereus jamacaru was the species that presented the largest number of occurrences, appearing in 17 areas, followed by Pilosocereus gounellei (=Xiquexique gounellei), found in 11 studies, and Tacinga inamoena in 10. The grouping analysis resulted in the formation of 10 groups, with a remarkable relationship between species and soil type. There were differences in both the diversity and density of species related with the degree of conservation of the Caatinga, noticeable from the direct relationship between conservation and richness and, indirectly, between density and number of species.

Resumen Las listas de especies presentadas en trabajos florísticos o fitosociológicos proporcionan importante información sobre distribución, útil para realizar inferencias biogeográficas y evaluar el estado de conservación de especies o incluso de ecosistemas. En el caso de los bosques secos del nordeste de Brasil, conocidos como Caatinga, el análisis de esas listas puede contribuir para confrontar ideas previamente establecidas sobre la homogeneidad de esa unidad de vegetación. La fuerte relación entre el sustrato y los ensambles de plantas de la Caatinga pueden caracterizar distintos tipos de vegetación. Es así como, el objetivo de este trabajo es evaluar sí la distribución de Cactaceae está relacionada con los tipos de sustrato (sedimentar y cristalino), sea con la riqueza florística o la densidad de las especies. Al mismo tiempo, evaluamos el estado de conservación de las áreas estudiadas de la Caatinga. Los datos fueron obtenidos a partir de revisiones bibliográficas, de estudios de florística y fitosociología en la Caatinga. Para evaluar las distintas áreas, con los estudios florísticos seleccionados se preparó una matriz de similaridad. Se encontró que, 48 áreas tenían especies de Cactaceae; 33 especies distribuidas en 14 géneros fueron listadas. Cereus jamacaru fue la especie con el mayor número de puntos en 17 áreas, seguido por Pilosocereus gounellei (=Xiquexique gounellei), encontrado en 11 estudios y Tacinga inamoena, en 10. El análisis resultó en la formación de 10 grupos con fuertes relaciones entre especies y tipos de sustratos. También, encontramos diferencias en diversidad de especies en relación con el estado de conservación de la Caatinga, notable por las relaciones directas entre conservación y riqueza de especies, e indirectas entre densidad y número de especies.

An annotated checklist of the vascular plants of Aberdare Ranges Forest, a part of Eastern Afromontane Biodiversity Hotspot.

The Aberdare Ranges Forest, located in the Central highlands of Kenya, is an isolated volcanic mountain in the East African Rift Valley with unique flora. Despite its refugial importance to rare and endemic plant species, the diversity of plants in the Aberdare Ranges Forest remains poorly understood. The checklist presented here is a collation of data obtained from multiple floristic surveys and from herbarium specimen collections from the forest. A total of 1260 vascular plants taxa representing 136 families, 613 genera, 67 subspecies and 63 varieties are documented. The ferns comprised 84 species, lycophytes seven, gymnosperms six and angiosperms were 1163 taxa. This represents 17.9% of the Kenyan taxa, 1.7% of the African taxa and 0.3% of all the vascular plants known in the world. A total of 18 taxa were endemic and 14 taxa were found to be threatened globally. The life form, voucher specimen(s), habitat and distribution range of each taxon and a brief analysis of taxa diversity is presented in this checklist. This is the first comprehensive inventory of vascular plants in the entire Aberdare Ranges, providing a solid basis for more sustainable management and improved conservation of this montane forest. The checklist is also an important contribution to the world checklist of plants required by the Global Strategy for Plant Conservation.

Floristic surveys of hydrocarbon-polluted sites in some Cameroonian cities (Central Africa).

Soils pollution with hydrocarbons is on the increase, especially in developing countries like Cameroon. Identifying plant species capable of growing on hydrocarbon-polluted soils remains an essential step in phytoremediation, a low cost, solar energy driven clean up technique in which living green plants are used. Here, we report floristic surveys conducted in 4 cities of Cameroon to identify plants with phytoremediation capacities. A total of 13 hydrocarbon-polluted sites were surveyed in each city using the quadrat method. Unpolluted sites served as the control. 106 species belonging to 76 genera and 30 families were identified on hydrocarbon-polluted sites. Plant diversity was shown to be higher (166 species contained in 125 genera and 50 families) in the control sites. Poaceae, Cyperaceae, Asteraceae and Amaranthaceae families have a higher taxonomic richness on polluted sites (16, 15, 10 and 8 taxa respectively). Shannon diversity index of the hydrocarbon-polluted sites (1.6 to 2.7 bits/ind.) were significantly lower than the control sites (2.7 to 3.2 bit/ind.). Based on a relative frequency > 10% and abundance > 7%, our results show that more than 15 plant species could be tested in preliminary trials to determine their phytoremediation/cleaning-up capacities on hydrocarbon-polluted soils in the tropics.