- Department of Earth Sciences
University of Bristol
Wills Memorial Building
Queen's Road
Bristol, England BS8 1RJ
Sarda Sahney
University of Bristol, Department of Earth Sciences, Department Member
-
University of Bristol, Earth Sciences, Graduate Student add
-
Paleobiology, Macroevolution, Biology, Ecology, Biodiversity, Biogeography, and 31 moreDiversity, Vertebrate Paleontology, Plant Ecology, Palaeoenvironment, Vertebrate Palaeontology, Community Ecology, Conservation, Earth Sciences, Paleoanthropology, Palaeontology, Spatial Ecology, Paleontology, Evolution, Climate Change, Vertebrate Evolution, Palaeoecology, Paleoclimatology, Anthropology, Evolutionary Biology, Education, Archaeology, Geology, Philosophy, Geography, Conservation Biology, Environmental History, Environmental Philosophy, Paleoecology, Species Distribution Models, Mass extinctions, and Environmental Sustainability edit
-
My research interests include:
- The biodiversity of tetrapods (amphibians, reptiles, mammals and birds) from their evolution in the Devonian to the present day
- The structure of terrestrial communities
- Impacts of mass extinction and patterns of recovery
- Natural and anthropogenic causes of change in Earth systems (eg. climate change).edit
Abrupt collapse of the tropical rainforest biome (Coal Forests) drove rapid diversification of Carboniferous tetrapods (amphibians and reptiles) in Euramerica. This finding is based on analysis of global and alpha diversity databases in a... more
Abrupt collapse of the tropical rainforest biome (Coal Forests) drove rapid diversification of Carboniferous tetrapods (amphibians and reptiles) in Euramerica. This finding is based on analysis of global and alpha diversity databases in a precise geologic context. From Visean to Moscovian time, both diversity measures steadily increased, but following rainforest collapse in earliest Kasimovian time (ca. 305 Ma), tetrapod extinction rate peaked, alpha diversity imploded, and endemism developed for the first time. Analysis of ecological diversity shows that rainforest collapse was also accompanied by acquisition of new feeding strategies (predators, herbivores), consistent with tetrapod adaptation to the effects of habitat fragmentation and resource restriction. Effects on amphibians were particularly devastating, while amniotes ('reptiles') fared better, being ecologically adapted to the drier conditions that followed. Our results demonstrate, for the first time, that Coal Forest fragmentation influenced profoundly the ecology and evolution of terrestrial fauna in tropical Euramerica, and illustrate the tight coupling that existed between vegetation, climate, and trophic webs.
Research Interests:
Landscape Ecology, Evolutionary Biology, Paleobiology, Environmental Geography, Earth Sciences, and 73 moreEnvironmental Science, Paleontology, Environmental Philosophy, Ecosystems Ecology, Plant Ecology, Climate Change, Palaeoenvironment, Natural Resources, Paleoclimatology, Conservation Biology, Diversity, Conservation, Climate Change Adaptation, Macroevolution, Environmental Studies, Species Distribution Models, Adaptation to Climate Change, Philosophy Of Climate Change, Climate change policy, Environmental History, Landscape History And Conservation, Plant-Herbivore Interactions, Community Ecology, Tropical Ecology, Conservation Ecology, Global Diversity Management, Plant Biology, Climatic Changes, Biodiversity and Ecosystem Function, Paleoenvironment, Paleoecology, Wildlife Ecology And Management, Biology, Invasive species ecology, Rainforest Restoration, Environment and natural resources conservation, Evolutionary ecology (Ecology), Ecology, Plant-Animal Interactions, Invasive Species, Biodiversity Informatics, Climate change biology, Diversity Management, Vertebrate Palaeontology, Animal Ecology, Climate Change Adaptation And Mitigation Strategies, Palaeoecology, Biogeography, Biodiversity, Evolutionary Ecology, Environmental Sustainability, Palaeodiet, Animal Species Loss and Decline, Ecosystem ecology, Invasive species (Environment), Wildlife Conservation, Paleoclimate, Philosophy of Environment, Vertebrate Paleontology, Climate Change and Philosophy, Species invasions, Palaeontology, Species, Glacial geology and climate change, Climate Change and Biodiversity, Climate Change Impacts, Natural Resources (Environment), Management and evaluation of habitat for wildlife, Global Warming, Habitat Mapping, Species diversification, Ecology, Sustainability, Climate Change and Biodiversity, and Fossil record
The end-Permian mass extinction, 251 million years (Myr) ago, was the most devastating ecological event of all time, and it was exacerbated by two earlier events at the beginning and end of the Guadalupian, 270 and 260 Myr ago. Ecosystems... more
The end-Permian mass extinction, 251 million years (Myr) ago, was the most devastating ecological event of all time, and it was exacerbated by two earlier events at the beginning and end of the Guadalupian, 270 and 260 Myr ago. Ecosystems were destroyed worldwide, communities were restructured and organisms were left struggling to recover. Disaster taxa, such as Lystrosaurus, insinuated themselves into almost every corner of the sparsely populated landscape in the earliest Triassic, and a quick taxonomic recovery apparently occurred on a global scale. However, close study of ecosystem evolution shows that true ecological recovery was slower. After the end-Guadalupian event, faunas began rebuilding complex trophic structures and refilling guilds, but were hit again by the end-Permian event. Taxonomic diversity at the alpha (community) level did not recover to pre-extinction levels; it reached only a low plateau after each pulse and continued low into the Late Triassic. Our data showed that though there was an initial rise in cosmopolitanism after the extinction pulses, large drops subsequently occurred and, counter-intuitively, a surprisingly low level of cosmopolitanism was sustained through the Early and Middle Triassic.
Research Interests:
Evolutionary Biology, Paleobiology, Earth Sciences, Environmental Science, Paleontology, and 38 moreEnvironmental Philosophy, Palaeoenvironment, Conservation Biology, Diversity, Macroevolution, Environmental Studies, Species Distribution Models, Environmental History, Community Ecology, Biodiversity and Ecosystem Function, Paleoecology, Biology, Evolutionary ecology (Ecology), Ecology, Survival Analysis, Evolution, Biodiversity Informatics, Vertebrate Palaeontology, Palaeoecology, Biodiversity, Evolutionary Ecology, Vertebrate Ecology, Environmental Sustainability, Vertebrate Evolution, Animal Species Loss and Decline, Philosophy of Environment, Vertebrate Paleontology, First Aid, Palaeontology, Vertebrate Palentology, Mass extinctions, Anybody, Recovery from Mass Extinction Events, Species diversification, Fossil record, Palaeobiology, Mass Extinctions, Phylogeny, Kinds of Fitness: Survival Of fittest, and Fastest to Propagate
Tetrapod biodiversity today is great; over the past 400 Myr since vertebrates moved onto land, global tetrapod diversity has risen exponentially, punctuated by losses during major extinctions. There are links between the total global... more
Tetrapod biodiversity today is great; over the past 400 Myr since vertebrates moved onto land, global tetrapod diversity has risen exponentially, punctuated by losses during major extinctions. There are links between the total global diversity of tetrapods and the diversity of their ecological roles, yet no one fully understands the interplay of these two aspects of biodiversity and a numerical analysis of this relationship has not so far been undertaken. Here we show that the global taxonomic and ecological diversity of tetrapods are closely linked. Throughout geological time, patterns of global diversity of tetrapod families show 97 per cent correlation with ecological modes. Global taxonomic and ecological diversity of this group correlates closely with the dominant classes of tetrapods (amphibians in the Palaeozoic, reptiles in the Mesozoic, birds and mammals in the Cenozoic). These groups have driven ecological diversity by expansion and contraction of occupied ecospace, rather than by direct competition within existing ecospace and each group has used ecospace at a greater rate than their predecessors.