Identification of priority areas for plant conservation in Madagascar using Red List criteria: rare and threatened Pandanaceae indicate sites in need of protection

A major problem in establishing effective protocols for conserving Madagascar's biodiversity is the lack of reliable information for the identification of priority sites in need of protection. Analyses of field data and information from herbarium collections for members of the plant family Pandanaceae (85 spp. of Pandanus; 6 spp. of Martellidendron) showed how risk of extinction assessments can inform conservation planning. Application of IUCN Red List categories and criteria showed that 91% of the species are threatened. Mapping occurrence revealed centres of richness and rarity as well as gaps in Madagascar's existing protected area network. Protection of 10 additional sites would be required to encompass the 19 species currently lacking representation in the reserve network, within which east coast littoral forests are particularly under represented and important. The effect of scale on assessments of risk of extinction was explored by applying different grid cell sizes to estimate area of occupancy. Using a grid cell size within the range suggested by IUCN overestimates threatened status if based solely upon specimen data. For poorly inventoried countries such as Madagascar measures of range size based on such data should be complemented with field observations to determine population size, sensitivity to disturbance, and specific threats to habitat and therefore potential population decline. The analysis of such data can make an important contribution to the conservation planning process by identifying threatened species and revealing the highest priority sites for their conservatio

Malagasy Dracaena Vand. ex L. (Ruscaceae): an investigation of discrepancies between morphological features and spatial genetic structure at a small evolutionary scale

Abstract Malagasy Dracaena (Ruscaceae) are divided into four species and 14 varieties, all of them showing a high level of morphological diversity and a putatively artefactual circumscription. In order to reveal relationships between those entangled entities, a span of Malagasy Dracaena were sampled and analyzed using cpDNA sequences and AFLP. The cpDNA analyses resolved three biogeographic clades that are mostly inconsistent with morphology, since similar phenotypes are found across the three clades. Bayesian inference clustering analyses based on the AFLP were not in accordance with the cpDNA analysis. This result might be explained by (1) a recent origin of the Malagasy species of Dracaena with an incomplete sorting of chloroplast lineages; (2) a high amount of hybridizations; (3) a complex migration pattern. Interestingly, when the AFLP are analyzed using the parsimony criterion, a trend towards a directional evolution of inflorescence types and ecological features was observed. This might be considered either as phenotypic plasticity and/or as the result of fast evolution in flower characters according to habitat preferences. Overall, our results point to the difficulty of defining evolutionarily significant units in Malagasy Dracaena, emphasizing the complex speciation processes taking place in tropical regions

Optimal Design of Intervention Studies to Prevent Influenza in Healthy Cohorts

Background: Influenza cohort studies, in which participants are monitored for infection over an epidemic period, are invaluable in assessing the effectiveness of control measures such as vaccination, antiviral prophylaxis and nonpharmaceutical interventions (NPIs). Influenza infections and illnesses can be identified through a number of approaches with different costs and logistical requirements. Methodology and Principal Findings: In the context of a randomized controlled trial of an NPI with a constrained budget, we used a simulation approach to examine which approaches to measuring outcomes could provide greater statistical power to identify an effective intervention against confirmed influenza. We found that for a short epidemic season, the optimal design was to collect respiratory specimens at biweekly intervals, as well as following report of acute respiratory illness (ARI), for virologic testing by reverse transcription polymerase chain reaction (RT-PCR). Collection of respiratory specimens only from individuals reporting ARI was also an efficient design particularly for studies in settings with longer periods of influenza activity. Collection of specimens only from individuals reporting a febrile ARI was less efficient. Collection and testing of sera before and after influenza activity appeared to be inferior to collection of respiratory specimens for RT-PCR confirmation of acute infections. The performance of RT-PCR was robust to uncertainty in the costs and diagnostic performance of RT-PCR and serological tests

Extinction Risk and Diversification Are Linked in a Plant Biodiversity Hotspot

Plant extinction risks in the Cape, South Africa differ from those for vertebrates worldwide, with young and fast-evolving plant lineages marching towards extinction at the fastest rate, but independently of human effects

Transfer of the Malagasy genera Humbertianthus and Macrostelia to Hibiscus (Malvaceae) with description of four new species

© 2020 CONSERVATOIRE ET JARDIN BOTANIQUES DE GENÈVE. Two Malagasy species of the genus Macrostelia Hochr. (Malvaceae) are transferred to Hibiscus L. and two new combinations are proposed: Hibiscus calyculatus (Hochr.) M. Hanes, G.E. Schatz & Callm. and Hibiscus involucratus (Hochr.) M. Hanes & G.E. Schatz & Callm. The monotypic genus Humbertianthus Hochr. with its single species Humbertianthus cardiostegius Hochr. was defined as a taxon in its bud stage and represented unopened flowering collections of Hibiscus laurinus Baill. Several recent herbarium collections from the eastern humid forest of Madagascar represent four new restricted range species: Hibiscus ambanitazensis M. Hanes & G.E. Schatz, Hibiscus analalavensis M. Hanes & G.E. Schatz, Hibiscus ankeranensis M. Hanes & G.E. Schatz, Hibiscus vohipahensis M. Hanes & G.E. Schatz. Each of the new species are documented by field photographs and their geographic distribution is presented. Risk of extinction assessments of the seven species discussed indicate three taxa are threatened as Critically Endangered , and four are Least concern

A new name in Hibiscus (Malvaceae) for Madagascar

Callmander, Martin W., Schatz, George E., Gereau, Roy E., Hanes, Margaret M. (2020): A new name in Hibiscus (Malvaceae) for Madagascar. Candollea 75 (2): 323-324, DOI: 10.15553/c2020v752a1