Tropical Forests In Africa Research Articles

Phylogenetics of the rust fungi (Pucciniales) of South Africa, with notes on their life histories and possible origins

ABSTRACT South Africa has an indigenous rust (Pucciniales) funga of approximately 460 species. This funga was sampled with species from as many genera as possible. The nuclear ribosomal large subunit (28S) region was amplified from samples representing 110 indigenous species, as well as the small subunit (18S) region and the cytochrome c oxidase subunit 3 (CO3) in some cases, and these were used in phylogenetic analyses. One new species is described, 12 new combinations made, six names reinstated, and two life history connections made. The life histories of this funga were summarized; it is dominated by species with contracted life histories. The majority of species are autoecious, with a small proportion being heteroecious. Of the autoecious species, many will likely be homothallic with no spermagonia. A shortened life history with homothallism allows for a single basidiospore infection to initiate a local population buildup under the prevailing unpredictable climatic conditions. Suggestions are made as to the possible origin of this funga based on the development of the modern South African flora. It is postulated that the rusts of South Africa are of relatively recent origin, consisting of three groups. Firstly, there is an African tropical element with members of the Mikronegerineae (Hemileia), the Sphaerophragmiaceae (Puccorchidium, Sphaerophragmium), and certain Uredinineae (Stomatisora). Their immediate ancestors likely occurred in the tropical forests of Africa during the Paleogene. Secondly, there is a pantropical element including the Raveneliaceae (e.g., Diorchidium, Maravalia, Ravenelia sensu lato, Uropyxis). This likely diversified during the Neogene, when the mimosoids became the dominant trees of the developing savannas. Thirdly, the Pucciniaceae invaded Africa as this continent pushed northward closing the Tethys Sea. They diversified with the development of the savannas as these become the dominant habitat in most of Africa, and are by far the largest component of the South African rust funga.

Estimation of Long-Term Above-Ground Biomass, Carbon Stocks and Carbon Dioxide Equivalent Lost Due to Deforestation in Mapfungautsi Forest, Zimbabwe

Tropical forests play an important role of storing significant quantities of carbon, both, aboveground and belowground. However, deforestation activities for various purposes, among them, agriculture and settlement, have continued to remove unknown quantities of biomass and carbon stocks across tropical forests of Africa. This study was conducted to estimate aboveground tree biomass (AGB), carbon stocks (AGCS) and carbon dioxide equivalent (CO2 e) among three vegetation cover types (wooded land, bushland and grassland) found in Mapfungautsi forest and to quantify the long-term estimated total AGB, AGCS and CO2 e lost due to deforestation activities in the forest (between the year 2000 and 2020). Data collection was conducted using remote sensing imagery, field measurements and an allometric equation. A total of 22 plots, each measuring 50m x50m were established across the three vegetation cover types where tree height, diameter at breast height, number of stems/ha and regeneration were measured. The collected data was analysed using EViews Version 10 software. Wooded land generally had the highest values across all the four tree growth variables followed by bushland and grassland. The average estimated AGB stored were 50.78t/ha, 14.7t/ha and 8.2 t/ha for wooded land, bushland and grassland respectively. From the 10632ha cleared over 20 years, losses amounting to an estimated mean total AGB, AGCS and CO2 e of 387669.53t, 182205.09t and 668692.69t respectively were observed. We conclude that quantifying and raising awareness about the lost AGB, AGCS and CO2 e among stakeholders will lead to the implementation of remedial action to replenish the lost biomass and carbon stocks.

Abundance and Foraging Ecology of the Black and White Colobus Monkey (Colobus guereza ssp. guereza) in Nech Sar National Park, Ethiopia

We estimated the abundance of Colobus guereza ssp. guereza in the moist evergreen riparian forest part of Nech Sar National Park, Ethiopia. The survey was conducted using the distance sampling method. Based on a preliminary study, 17 newly cut line transects were randomly aligned across the study area. The survey data were then collected for three consecutive months. Transects were walked once per month for 14-16 days. Abundance estimates were analyzed using the program 'DISTANCE'. The half-normal key function with cosine adjustment fitted our data sets best. Mean group density and mean animal density were 14 animals km-2 and 102 animals km-2, respectively, resulting in a mean estimated abundance of 2,153 animals distributed over thestudy area. The mean estimated group size was 7.24 with an estimated encounter rate of 1.72. Compared to similar studies from tropical forests in Africa, our population density estimates were intermediate between the mean values (100 to 168 animals km-2). We conclude that such intermediate density estimates reflect the fact that guerezas have suffered from human-induced reductions in habitat availability. We also suggest that the natural forest is still in a reasonable condition that likely provides them with sufficient food supply to compensate for such intermediate densities. However, a replication of this study would lead to a more comprehensive abundance estimate. We also recommend studies that would address the activity-time budget and populationdemographics of these monkeys. Nonetheless, our results provide a reference point for future studies in this area, particularly to assess population trends of C. g. guereza.

The role of fire in global forest loss dynamics.

Fires, among other forms of natural and anthropogenic disturbance, play a central role in regulating the location, composition and biomass of forests. Understanding the role of fire in global forest loss is crucial in constraining land‐use change emissions and the global carbon cycle. We analysed the relationship between forest loss and fire at 500 m resolution based on satellite‐derived data for the 2003–2018 period. Satellite fire data included burned area and active fire detections, to best account for large and small fires, respectively. We found that, on average, 38 ± 9% (± range) of global forest loss was associated with fire, and this fraction remained relatively stable throughout the study period. However, the fraction of fire‐related forest loss varied substantially on a regional basis, and showed statistically significant trends in key tropical forest areas. Decreases in the fraction of fire‐related forest loss were found where deforestation peaked early in our study period, including the Amazon and Indonesia while increases were found for tropical forests in Africa. The inclusion of active fire detections accounted for 41%, on average, of the total fire‐related forest loss, with larger contributions in small clearings in interior tropical forests and human‐dominated landscapes. Comparison to higher‐resolution fire data with resolutions of 375 and 20 m indicated that commission errors due to coarse resolution fire data largely balanced out omission errors due to missed small fire detections for regional to continental‐scale estimates of fire‐related forest loss. Besides an improved understanding of forest dynamics, these findings may help to refine and separate fire‐related and non‐fire‐related land‐use change emissions in forested ecosystems.

Mining increases the prevalence of avian haemosporidian parasites in Northeast Amazonia.

Studies contrasting parasite prevalence and host-parasite community structure between pristine and disturbed environments will improve our understanding of how deforestation affects disease transmission and parasite extinction. To determine how infection rates of a common and diverse group of avian blood parasites (Plasmodium and Haemoproteus) respond to changes in avian host composition after mining, we surveyed 25 bird communities from pristine forests (two forest types: plateau and hillside) and reforested sites in Northeast Amazonia. Infection rates and both parasite and avian host community structure exhibited considerable variation across the deforestation gradient. In opposition to the emerging pattern of lower avian haemosporidian prevalence in disturbed tropical forests in Africa, we show that secondary forests had higher haemosporidian prevalence in one of the largest mining areas of Amazonia. The dissimilarity displayed by bird communities may explain, in part, the higher prevalence of Haemoproteus in reforested areas owing to the tolerance of some bird species to open-canopy forest habitat. On the other hand, deforestation may cause local extinction of Plasmodium parasites due to the loss of their avian hosts that depend on closed-canopy primary forest habitats. Our results demonstrate that forest loss induced by anthropogenic changes can affect a host-parasite system and disturb both parasite transmission and diversity.

Evolution of the African slippery frogs (Anura: Conraua), including the world’s largest living frog

AbstractAlthough Conraua goliath is well known as the largest living frog species, the diversity and evolution of the genus Conraua across sub‐Saharan Africa remain poorly understood. We present multilocus phylogenetic analyses of the six currently recognized species that provide insights into divergence times, biogeography, body size evolution and undescribed species. An analysis of divergence times demonstrates that crown‐group Conraua arose some time during the latest Oligocene to mid‐Miocene followed by divergence into major lineages in the mid‐Miocene that may reflect the fragmentation of widespread tropical forests in Africa that began at this time. We find three pairs of sister species, C. crassipes + C. beccarii, C. alleni + C. derooi and C. goliath + C. robusta, each of which diverged during the Miocene. These relationships reject phylogenetic hypotheses based solely on biogeography as the geographically peripheral C. beccarii from north‐eastern Africa is nested within western African species and the Central African species do not form a clade. Our species delimitation analyses provide support for undescribed species in C. alleni, C. beccarii and C. derooi, and possibly C. crassipes, suggesting that the current taxonomy substantially underestimates species diversity. There is no clear directional trend of either increasing or decreasing body size in Conraua and the three largest species do not form a clade. With a robust phylogenetic hypothesis in hand, further field‐based studies are needed to understand the evolution of morphology and life history in this charismatic African anuran clade.

Monitoring tropical forests under a functional perspective with satellite‐based vegetation optical depth

Monitoring ecosystem functions in forests is a priority in a climate change scenario, as climate-induced events may initially alter the functions more than slow-changing attributes, such as biomass. The ecosystem functional properties (EFPs) are quantities that characterize key ecosystem processes. They can be derived by point observations of gas and energy exchanges between the ecosystems and the atmosphere that are collected globally at FLUXNET flux tower sites and upscaled at ecosystem level. The properties here considered describe the ability of ecosystems to optimize the use of resources for carbon uptake. They represent functional forest information, are dependent on environmental drivers, linked to leaf traits and forest structure, and influenced by climate change effects. The ability of vegetation optical depth (VOD) to provide forest functional information is investigated using 2011-2014 satellite data collected by the Soil Moisture and Ocean Salinity mission and using the EFPs as reference dataset. Tropical forests in Africa and South America were analyzed, also according to ecological homogeneous units. VOD jointly with water deficit information explained 93% and 87% of the yearly variability in both flux upscaled maximum gross primary productivity and light use efficiency functional properties, in Africa and South America forests respectively. Maps of the retrieved properties evidenced changes in forest functional responses linked to anomalous climate-induced events during the study period. The findings indicate that VOD can support the flux upscaling process in the tropical range, affected by high uncertainty, and the detection of forest anomalous functional responses. Preliminary temporal analysis of VOD and EFP signals showed fine-grained variability in periodicity, in signal dephasing, and in the strength of the relationships. In selected drier forest types, these satellite data could also support the monitoring of functional dynamics.

Liver Transplantation for Acute Liver Failure due to Yellow Fever: A Case Report

Yellow fever is a noncontagious disease caused by an arbovirus in the Flaviviridae family. It is an endemic disease in the tropical forests of Africa and South America, with the mosquito as a vector. Approximately half of those infected will be asymptomatic, while 15% will develop the severe/malignant form of the disease that includes renal and hepatic failure, bleeding, and neurological impairment as the principal symptoms. The lethality of the severe form reaches up to 70%. The objective of this study was to report on the case of a patient who was transferred to the hepatobiliary unit of our service due to acute liver failure due to yellow fever. He was treated with liver transplantation. The patient progressed satisfactorily, being discharged from the intensive care unit in 10 days and discharged from the hospital within 19 days after transplantation. Despite the encouraging result of our team, this has not been applied to other centers that have also performed this modality of treatment; therefore, the question remains as to whether and when to recommend liver transplantation for treatment of severe yellow fever.

Sero-prevalence of yellow fever and related Flavi viruses in Ethiopia: a public health perspective

BackgroundYellow fever (YF) is a viral hemorrhagic fever, endemic in the tropical forests of Africa and Central and South America. The disease is transmitted by mosquitoes infected with the yellow fever virus (YFV). Ethiopia was affected by the largest YF outbreak since the vaccination era during 1960–1962. The recent YF outbreak occurred in 2013 in Southern part of the country. The current survey of was carried out to determine the YF seroprevalence so as to make recommendations from YF prevention and control in Ethiopia.MethodologyA multistage cluster design was utilized. Consequently, the country was divided into 5 ecological zones and two sampling towns were picked per zone randomly. A total of 1643 serum samples were collected from human participants. The serum samples were tested for IgG antibody against YFV using ELISA. Any serum sample testing positive by ELISA was confirmed by plaque reduction neutralization test (PRNT). In addition, differential testing was performed for other flaviviruses, namely dengue, Zika and West Nile viruses.ResultOf the total samples tested, 10 (0.61%) were confirmed to be IgG positive against YFV and confirmed with PRNT. Nine (0.5%) samples were antibody positive for dengue virus, 15(0.9%) forWest Nile virus and 7 (0.4%) for Zika virus by PRNT. Three out of the five ecological zones namely zones 1, 3 and 5 showed low levels (< 2%) of IgG positivity against YFV. A total of 41(2.5%) cases were confirmed to be positive for one of flaviviruses tested.ConclusionBased on the seroprevalence data, the level of YFV activity and the risk of a YF epidemic in Ethiopia are low. However additional factors that could impact the likelihood of such an epidemic occurring should be considered before making final recommendations for YF prevention and control in Ethiopia. Based on the results of the serosurvey and other YF epidemic risk factors considered, a preventive mass vaccination campaign is not recommended, however the introduction of YF vaccine in routine EPI is proposed nationwide, along with strong laboratory based YF surveillance.

Relative contribution of neutral and deterministic processes in shaping fruit-feeding butterfly assemblages in Afrotropical forests.

The unified neutral theory of biodiversity and biogeography has gained the status of a quantitative null model for explaining patterns in ecological (meta)communities. The theory assumes that individuals of trophically similar species are functionally equivalent. We empirically evaluate the relative contribution of neutral and deterministic processes in shaping fruit‐feeding butterfly assemblages in three tropical forests in Africa, using both direct (confronting the neutral model with species abundance data) and indirect approaches (testing the predictions of neutral theory using data other than species abundance distributions). Abundance data were obtained by sampling butterflies using banana baited traps set at the forest canopy and understorey strata. Our results indicate a clear consistency in the kind of species or species groups observed at either the canopy or understorey in the three studied communities. Furthermore, we found significant correlation between some flight‐related morphological traits and species abundance at the forest canopy, but not at the understorey. Neutral theory's contribution to explaining our data lies largely in identifying dispersal limitation as a key process regulating fruit‐feeding butterfly community structure. Our study illustrates that using species abundance data alone in evaluating neutral theory can be informative, but is insufficient. Species‐level information such as habitat preference, host plants, geographical distribution, and phylogeny is essential in elucidating the processes that regulate biodiversity community structures and patterns.

Redescription and diagnosis of the African genus Gemeneta Karsch, 1892 (Orthoptera: Acrididae: Catantopinae)

The subfamily Catantopinae is a poorly defined subfamily of the Acrididae, having many genera that require taxonomic clarification. The genus Gemeneta from this subfamily is found in African forests and has only two described species, Gemeneta terrea and Gemeneta opilionoides. However, the original descriptions of the genus relied heavily on external female morphology, and a description of male G. opilionoides was completely lacking. The present work provides the first description of the male of G. opilionoides, a morphological description of both species, including internal genitalia, and clarifies the generic diagnosis. This study is a contribution to a better understanding of the taxonomy of Catantopinae in the tropical forests of Africa.

Road Expansion and the Fate of Africa's Tropical Forests

The tropical forests of Africa are experiencing unprecedented changes as a result of a rapid proliferation of roads and other infrastructure. These projects are dramatically increasing access to relatively unexploited regions, particularly in the greater Congo Basin. We highlight some of the most important new projects and describe in detail an ongoing debate about a particular proposed development, the Cross River Superhighway in Nigeria. The scale and pace of new transportation projects, and the profound environmental changes they could bring, underscore a dire need for proactive land-use planning, capacity building, and environmental assessment in the nations of Equatorial Africa. It is no exaggeration to suggest that, unless carefully managed to ensure sustainability, the spate of planned and ongoing projects could irreparably diminish the forests and wildlife populations of Africa’s most biologically diverse regions.

Nitrogen flux patterns through Oxisols and Ultisols in tropical forests of Cameroon, Central Africa

ABSTRACTWe lack an understanding of nitrogen (N) cycles in tropical forests of Africa, although the environmental conditions in this region, such as soil type, vegetation, and climate, are distinct when compared with other tropical forests. Herein, we simultaneously quantified N fluxes through precipitation, throughfall, and 0-, 15-, and 30-cm soil solutions, as well as litterfall, in two forests with different soil acidity (Ultisols at the MV village (exchangeable Al3+ in 0–30 cm, 126 kmolc ha–1) and Oxisols at the AD village (exchangeable Al3+ in 0–30 cm, 59.8 kmolc ha–1)) over 2 years in Cameroon. The N fluxes to the O horizon via litterfall plus throughfall were similar for both sites (MV and AD, 243 and 273 kg N ha–1 yr–1, respectively). Those values were remarkably large relative to other tropical forests, reflecting the dominance of legumes in this region. The total dissolved N flux from the O horizon at the MV was 28 kg N ha–1 yr–1, while it was 127 kg N ha–1 yr–1 mainly as NO3–-N (~80%) at the AD. The distinctly different pattern of N cycles could be caused by stronger soil acidity at the MV, which was considered to promote a superficial root mat formation in the O horizon despite the marked dry season (fine root biomass in the O horizon and its proportion to the 1-m-soil profile: 1.5 Mg ha–1 and 31% at the MV; 0.3 Mg ha–1 and 9% at the AD). Combined with the published data for N fluxes in tropical forests, we have shown that Oxisols, in combination with N-fixing species, have large N fluxes from the O horizon; meanwhile, Ultisols do not have large fluxes because of plant uptake through the root mat in the O horizon. Consequently, our results suggest that soil type can be a major factor influencing the pattern of N fluxes from the O horizon via the effects of soil acidity, thereby determining the contrasting plant–soil N cycles in the tropical forests of Africa.

Simulating carbon stocks and fluxes of an African tropical montane forest with an individual-based forest model.

Tropical forests are carbon-dense and highly productive ecosystems. Consequently, they play an important role in the global carbon cycle. In the present study we used an individual-based forest model (FORMIND) to analyze the carbon balances of a tropical forest. The main processes of this model are tree growth, mortality, regeneration, and competition. Model parameters were calibrated using forest inventory data from a tropical forest at Mt. Kilimanjaro. The simulation results showed that the model successfully reproduces important characteristics of tropical forests (aboveground biomass, stem size distribution and leaf area index). The estimated aboveground biomass (385 t/ha) is comparable to biomass values in the Amazon and other tropical forests in Africa. The simulated forest reveals a gross primary production of 24 tcha-1yr-1. Modeling above- and belowground carbon stocks, we analyzed the carbon balance of the investigated tropical forest. The simulated carbon balance of this old-growth forest is zero on average. This study provides an example of how forest models can be used in combination with forest inventory data to investigate forest structure and local carbon balances.

Genomic sequencing and microsatellite marker development for Boswellia papyrifera, an economically important but threatened tree native to dry tropical forests.

Microsatellite (or simple sequence repeat, SSR) markers are highly informative DNA markers often used in conservation genetic research. Next-generation sequencing enables efficient development of large numbers of SSR markers at lower costs. Boswellia papyrifera is an economically important tree species used for frankincense production, an aromatic resinous gum exudate from bark. It grows in dry tropical forests in Africa and is threatened by a lack of rejuvenation. To help guide conservation efforts for this endangered species, we conducted an analysis of its genomic DNA sequences using Illumina paired-end sequencing. The genome size was estimated at 705 Mb per haploid genome. The reads contained one microsatellite repeat per 5.7 kb. Based on a subset of these repeats, we developed 46 polymorphic SSR markers that amplified 2-12 alleles in 10 genotypes. This set included 30 trinucleotide repeat markers, four tetranucleotide repeat markers, six pentanucleotide markers and six hexanucleotide repeat markers. Several markers were cross-transferable to Boswellia pirrotae and B. popoviana. In addition, retrotransposons were identified, the reads were assembled and several contigs were identified with similarity to genes of the terpene and terpenoid backbone synthesis pathways, which form the major constituents of the bark resin.

Effects of logging on bats in tropical forests

Logging is one of the main causes of biodiversity loss in tropical forests. In the past decades there was an increase in the number of studies on the effects of logging on biodiversity, but there has been little advancement for bats, despite their ecological importance. We present a review of studies on the effects of logging on bats in tropical forests worldwide carried out in the past three decades. We aimed at answering the following questions: What is known about the effects of logging on the bat fauna of tropical forests? What are the gaps of knowledge that can be filled? We conducted a literature search of studies on the effect of logging on the bat fauna in tropical forests in the past decades. We surveyed the databases Web of Science, Google Scholar, and Scopus with different keyword combinations: “Bats OR Chiroptera”, “Logging”, “Selective logging”, “Timber extraction”, “Tropic”, “Forest”, and “Tropical Forest”. We found 22 studies focused on Latin America and Southeast Asia. Most studies (81.8%) only compared bat richness and abundance between logged and unlogged areas, where frugivorous bats responded positively to logging, whereas gleaning animalivores bats responded negatively. Few studies (18%) tried to understand how environmental variables, such as changes in vegetation structure, affect bat diversity. We emphasize that future studies aimed at checking the effects of logging on bats should use more than one sampling method in order to obtain more representative samples. Planning should be done with more caution, in order to avoid pseudoreplication and obtain more solid results. Poorly studied regions that have intensive logging, such as the Amazon and the tropical forests of Africa, should receive more attention.

Response of African humid tropical forests to recent rainfall anomalies

During the last decade, strong negative rainfall anomalies resulting from increased sea surface temperature in the tropical Atlantic have caused extensive droughts in rainforests of western Amazonia, exerting persistent effects on the forest canopy. In contrast, there have been no significant impacts on rainforests of West and Central Africa during the same period, despite large-scale droughts and rainfall anomalies during the same period. Using a combination of rainfall observations from meteorological stations from the Climate Research Unit (CRU; 1950-2009) and satellite observations of the Tropical Rainfall Measuring Mission (TRMM; 1998-2010), we show that West and Central Africa experienced strong negative water deficit (WD) anomalies over the last decade, particularly in 2005, 2006 and 2007. These anomalies were a continuation of an increasing drying trend in the region that started in the 1970s. We monitored the response of forests to extreme rainfall anomalies of the past decade by analysing the microwave scatterometer data from QuickSCAT (1999-2009) sensitive to variations in canopy water content and structure. Unlike in Amazonia, we found no significant impacts of extreme WD events on forests of Central Africa, suggesting potential adaptability of these forests to short-term severe droughts. Only forests near the savanna boundary in West Africa and in fragmented landscapes of the northern Congo Basin responded to extreme droughts with widespread canopy disturbance that lasted only during the period of WD. Time-series analyses of CRU and TRMM data show most regions in Central and West Africa experience seasonal or decadal extreme WDs (less than -600 mm). We hypothesize that the long-term historical extreme WDs with gradual drying trends in the 1970s have increased the adaptability of humid tropical forests in Africa to droughts.

African elements (fossil woods) from the upper Cenozoic sediments of western India and their palaeoecological and phytogeographical significance

Shukla, A., Mehrotra, R.C. & Guleria, J.S. iFirst article. African elements (fossil woods) from the upper Cenozoic sediments of western India and their palaeoecological and phytogeographical significance. Alcheringa, 1–20. ISSN 0311-5518. Fossil woods resembling tropical African taxa are described from late Neogene–Pleistocene sediments of western India. They resemble the extant representatives of Baphia Afzel., Brachystegia Benth., Erythrophleum Afzel. (Fabaceae), Entandrophragma C. DC., Khaya A. Juss. (Meliaceae) and Milicia Sim (Moraceae). The discovery of these taxa indicates the invasion of African elements into the Indian subcontinent during the Plio-Pleistocene and palaeogeographic connections between the two continents. All these genera include both evergreen and deciduous representatives and grow mainly in the tropical forests of Africa. On this basis, the presence of semi-evergreen to deciduous forest is inferred in western India during the Neogene in contrast to the semi-arid to arid climate with xeric vegetation occupying parts of Rajasthan and Gujarat (western India) at present. A sub-tropical to tropical climate is also supported by the woods' physiognomic features. Two new species, including one new genus are added to the fossil assemblage of western India. Anumeha Shukla [anu_bsip@yahoo.co.in], R.C. Mehrotra [rcmehrotra@yahoo.com], Birbal Sahni Institute of Palaeobotany, 53 University Road, Lucknow-226007, India; J.S. Guleria, C-2488, Aravali Marg, Indira Nagar, Lucknow-220016, India. Received 5.1.2012, revised 12.4.2012, accepted 24.4.2012.

Diversification of the phaseoloid legumes: effects of climate change, range expansion and habit shift.

Understanding which factors have driven the evolutionary success of a group is a fundamental question in biology. Angiosperms are the most successful group in plants and have radiated and adapted to various habitats. Among angiosperms, legumes are a good example for such successful radiation and adaptation. We here investigated how the interplay of past climate changes, geographical expansion and habit shifts has promoted diversification of the phaseoloid legumes, one of the largest clades in the Leguminosae. Using a comprehensive genus-level phylogeny from three plastid markers, we estimate divergence times, infer habit shifts, test the phylogenetic and temporal diversification heterogeneity, and reconstruct ancestral biogeographical ranges. We found that the phaseoloid lineages underwent twice dramatic accumulation. During the Late Oligocene, at least six woody clades rapidly diverged, perhaps in response to the Late Oligocene warming and aridity, and a result of rapidly exploiting new ecological opportunities in Asia, Africa and Australia. The most speciose lineage is herbaceous and began to rapidly diversify since the Early Miocene, which was likely ascribed to arid climates, along with the expansion of seasonally dry tropical forests in Africa, Asia, and America. The phaseoloid group provides an excellent case supporting the idea that the interplay of ecological opportunities and key innovations drives the evolutionary success.

A Synoptic Revision ofCarapa(Meliaceae)

Abstract. Carapa comprises trees confined to tropical forests in Africa and America. Previous revisions of the genus based primarily on herbarium specimens recognized few variable species, but also stressed the need for further research to clarify and understand the patterns of morphological variation in these species complexes. In the present revision, 27 species are recognized in Carapa of which 16 occur in Africa and 11 in America. Nine new species are described and illustrated, and a new combination is proposed. The remaining 17 species correspond to either recently described species or previously described species that had been placed in synonymy. A key to the 27 species and their distribution maps are provided.