Biffin E.,University of Adelaide |
Brodribb T.J.,University of Tasmania |
Hill R.S.,University of Adelaide |
Thomas P.,Royal Botanic Gardens Edinburgh |
Lowe A.J.,University of Adelaide
Proceedings of the Royal Society B: Biological Sciences | Year: 2012
The angiosperm radiation has been linked to sharp declines in gymnosperm diversity and the virtual elimination of conifers from the tropics. The conifer family Podocarpaceae stands as an exception with highest species diversity in wet equatorial forests. It has been hypothesized that efficient light harvesting by the highly flattened leaves of several podocarp genera facilitates persistence with canopy-forming angiosperms, and the angiosperm ecological radiation may have preferentially favoured the diversification of these lineages. To test these ideas, we develop a molecular phylogeny for Podocarpaceae using Bayesianrelaxed clock methods incorporating fossil time constraints.We find several independent origins of flattened foliage types, and that these lineages have diversified predominantly through the Cenozoic and therefore among canopy-forming angiosperms. The onset of sustained foliage flattening podocarp diversification is coincident with a declining diversification rate of scale/needle-leaved lineages and also with ecological and climatic transformations linked to angiosperm foliar evolution. We demonstrate that climatic range evolution is contingent on the underlying state for leaf morphology. Taken together, our findings imply that as angiosperms came to dominate most terrestrial ecosystems, competitive interactions at the foliar level have profoundly shaped podocarp geography and as a consequence, rates of lineage diversification. © 2011 The Royal Society.
Kettle C.J.,ETH Zurich |
Finger A.,Royal Botanic Gardens Edinburgh
Conservation Genetics Resources | Year: 2013
On the 23rd of February, some 50 Conservation Geneticists from around the global gathered for a half day symposium entitled 'Fragmentation Genetics in the Tropics' held at the Friedrich-Alexander University, Erlangen, Germany as part of the German Tropical Ecology Society annual meeting 2012. The overall aim of this symposium was to showcase the latest novel research applying molecular methods (landscape genetics, conservation genetics and phylogeography) to advance our understanding of genetic consequences of fragmentation in the tropics, particularly in the context of how population size and isolation influences population and species extinction. I provide a brief overview of the symposium and finish with a call for papers for a special issue of the sister journal Conservation Genetics, for which submission is now open. © 2012 Springer Science+Business Media B.V.
Kettle C.J.,ETH Zurich |
Hollingsworth P.M.,Royal Botanic Gardens Edinburgh |
Burslem D.F.R.P.,University of Aberdeen |
Maycock C.R.,University of Aberdeen |
And 2 more authors.
Perspectives in Plant Ecology, Evolution and Systematics | Year: 2011
Fine-scale spatial genetic structure (FSGS) within plant populations is an emergent property of the recruited adult trees, influenced by pollen and seed mediated gene flow, selection and demographic processes. This study aims to increase our understanding of the individual species traits that contribute to the generation of FSGS in the Dipteropcarpaceae, which is an ecologically and economically important family of tropical trees that dominate lowland forests in Southeast Asia. We examined FSGS in three co-occurring dipterocarp species at a single site in Borneo. Shorea xanthophylla, Parashorea tomentella and Dipterocarpus grandiflorus share limited seed dispersal but differ markedly in flower size, pollinator body size and pollen dispersal. Here we explore the role of pollen dispersal limitation in shaping FSGS in these three species. Using six microsatellite loci, we explore patterns of FSGS and landscape genetic structure and compare these across species. Significant FSGS was observed in S. xanthophylla and P. tomentella, both of which are known to have relatively limited pollen dispersal, but no clear signal of FSGS was observed in D. grandiflorus. Significantly greater FSGS was observed in P. tomentella (Sp= 0.012) than S. xanthophylla (Sp= 0.007) despite greater pollen dispersal in P. tomentella. Bayesian clustering analysis revealed significant structure in P. tomentella at the scale of the forest reserve (4000. ha). We discuss the alternative explanations for the observed patterns of FSGS emphasising the complexity of the mechanisms that can generate FSGS in long-lived trees. The extent of species-specific pollen dispersal is one factor that can contribute to differences in FSGS across species, but is not the only determinant. The observed patterns of FSGS and landscape scale genetic structure in S. xanthophylla and P. tomentella illustrate the potential of gap regeneration to counter act pollen dispersal and contribute to increased aggregation of related individuals (FSGS). © 2010 Perspectives in Plant Ecology, Evolution and Systematics.
Agency: GTR | Branch: NERC | Program: | Phase: Research Grant | Award Amount: 41.00K | Year: 2015
This proposal aims to meet the urgent need to extend monitoring of biodiversity, carbon stock, carbon balance, tree growth, and tree mortality in Latin America beyond rain forests and into dry biomes. Most concerns about biodiversity and ecosystem function in the tropics focus on rain forests, but this neglects the fact that 50% of the lowland tropics globally is climatically seasonal, with a natural vegetation of dry forest or savanna. In South America in particular, the rain forests of Amazonia monopolise research and conservation, but dry forests and woody savannas can house equal numbers of plant species, many of which are endemic. We need to understand far better how these dry biomes contribute to global biogeochemical cycles and how their unique species react to environmental changes. In particular, little is known about how dry forests will respond to climate change. Initiatives such as RAINFOR have been highly successful in connecting a large network of scientists who have established permanent inventory plots in Neotropical rain forests. Collectively, hundreds of plots distributed across Amazonia have been central to describing patterns of biodiversity across the basin, and how the forest participates in global biogeochemical cycles. No corresponding network connecting a large number of plots over broad geographic scales exists in Brazil or more widely in the Neotropics for dry biomes. This project aims to start a process of connecting researchers who have established dozens of inventory plots in these biomes. We propose to: 1. Re-census, using methodologies agreed by the RAINFOR network, 10 permanent 0.2Ha plots in tropical dry forest in Rio de Janeiro state for carbon stock, above ground biomass (C) gain, tree growth, tree mortality, and biodiversity. 2. Contribute data for five existing 1 Ha plots in dry forests and neighbouring forest biomes in Rio de Janeiro state and c. 100 dry forest plots from elsewhere in Brazil to the ForestPlots.net database, thereby making it available to the global research community. We will prioritise dry forests, but we also have plot-based data from the Mata Atlântica rain forests (not covered by RAINFOR), and from the tree-savanna biome of the cerrado in Central Brazil, and we hope additionally to start a process of adding this information to ForestPlots.net. 3. Convene a workshop to bring together key workers from RJ and across Brazil who have established inventory plots in dry biomes to encourage them to join a new network that can take forward dry forest monitoring at a continental scale. This workshop will be held in the Universidade Estadual do Norte Fluminense (UENF), Campos dos Goytacazes, RJ, Brazil. This workshop will be preceded by a two day training course in phylogenetics and phylogenetic diversity delivered by Dexter and Pennington at the Escola de Botânica in Rio, and will be followed a course for the same student pool on ecological niche modelling taught by Antje Ahrends (Royal Botanic Garden Edinburgh). In addition, training will be provided to Brazilian co-Is in the UK to build capacity to make some simple growth, leaf area and respiration measurements, led by Meir and Grace, with plot curation and analysis training using the ForestPlots.net facility, led by Gabriela Lopez in Leeds. 4. Compare phylogenetic diversity between dry forests and neighbouring rain forests in RJ to determine if these dry forests house unique lineage diversity, thereby adding a further argument for their conservation (7). Additionally, we will examine the impact of landscape history and fragmentation on phylogenetic diversity and phylogenetic community structure in these dry forests. 5. We will develop a database of key functional traits, environmental parameters and principal carbon stocks and fluxes, and of the structure, floristics and phylogeny of Atlantic tropical semi-deciduous seasonal forest.
Agency: GTR | Branch: NERC | Program: | Phase: Research Grant | Award Amount: 316.94K | Year: 2012
Summary (for general audience, 4000 characters) Tropical plant communities are famed for their high diversity but we still have little knowledge about the evolutionary processes that have created wide differences in the composition and species richness of different kinds of tropical ecosystem. Understanding these processes is of fundamental and practical importance - for example, planning conservation strategies increasingly uses information on evolutionary relationships as part of prioritising decisions about individual species. However, for tropical plants communities, sufficiently large datasets based on DNA sequences are only just beginning to reveal the evolutionary relationships between species. As a result, the implications of threats, either through land-use or climate change, for the conservation of the evolutionary history of these communities remains almost entirely unknown. Our research will take advantage of impressive existing data of tree inventories, covering more than 1000 sites in three major biomes in tropical South America: rain forests, dry forests and savannas. We will link these data with new information on the evolutionary relationships of all genera, and all species of the legume family, which is dominant in all three biomes, using DNA sequence data. A genus-level evolutionary tree will allow us to make analyses deep into evolutionary time, whereas a species-level legume tree will give a view of recent evolution. We will investigate how many times lineages of trees have switched between the different biomes, which will deliver important knowledge for conservation and future studies of evolutionary diversification. If lineages have rarely switched between biomes, then each biome will contain a distinct subset of evolutionary diversity, and destruction of a single biome could wipe out an entire part of evolutionary history. Such scenarios of the destruction of an entire biome are not unlikely. One important aspect of this proposal is that it will not focus solely on the rain forests of the Amazon Basin, but will also consider the forgotten biomes of tree-dominated savannas and tropical dry forests. These formations deserve greater attention from scientists and conservationists because they are species-rich, and have suffered greater destruction - more than 70% of the original two million km2 of the Brazilian savannas have been destroyed, whereas c. 70% of Amazonia is intact. Tropical dry forests, of which less than 5% remain in many areas, are the most threatened tropical forest type in the world. We believe our research will highlight the importance and plight of tropical dry forests and savannas, characterised by many decision makers and commentators as worthless - fair game for destruction if this might save rain forest areas - exemplified by a recent leader in the Economist magazine (28.08.2010; Brazils agricultural miracle: Plant the plains, save the forests; http://www.economist.com/node/16889019). In addition to biome switching, we will also investigate how adaptations to specific climatic and soil conditions have changed during evolution in these groups. This work will enable us to understand the processes driving the biome shifts we observe. In addition, these analyses may help to understand how climate change will affect communities: for example, if changes in climatic preferences of species have occurred infrequently related species will tend to have similar climatic niches, and whole groups of related species might be vulnerable to extinction from particular trajectories of climate change. The final stage of our study will examine the implications for loss of evolutionary diversity in different biomes under projected scenarios of climate and land-use change. Our results will be of relevance to conservation planning by national government agencies in South America and international organisations, such as the WWF, involved in setting priorities for tropical conservation.