J. Hansford, E. Saupe, S. Turvey, Heidi Ma, I-Ting Tu, Grace L. Varnham, P. Mannion
Species distribution modelling is a widely applied tool for forecasting future distributions of species under different climatic scenarios, informing conservation strategies and rewilding programs. Forecasting, however, is typically based on very recent species’ records (last ~50 years). This is problematic, given that these records are strongly affected by human interactions, and we do not know whether current distributions reflect the full suite of environmental parameters a species can inhabit. If we only model data from current distributions in future projections, we are thus likely to get misleading predictions that might misdirect conservation planning. The Critically Endangered Chinese alligator (Alligator sinensis) is currently restricted to a single Chinese province. Historical, zooarchaeological and fossil records demonstrate a greater range across mainland China, extending its past distribution even further, to Taiwan and Japan. Species distribution models (SDMs) based only on the present-day distribution of the Chinese alligator are poorly constrained, whereas incorporation of past archives improves model fit and changes projected suitable habitat. By combining past and present data, we can provide a closer approximation of the full ecological niche of a species. For endangered species with restricted present-day ranges, additional occurrence data from past archives is critical for constraining SDMs, with potentially major misinterpretations of suitable habitats for conservation and rewilding. This research is the principal case study for an IUCN Green status of species/Conservation Paleontology Network Pre-impact distributions working group, and a test case for the inclusion of past archives in the development of species recovery baselines.
{"title":"Using Past Archives to Better Constrain The Future of Alligator Sinensis","authors":"J. Hansford, E. Saupe, S. Turvey, Heidi Ma, I-Ting Tu, Grace L. Varnham, P. Mannion","doi":"10.58782/flmnh.xwfy9716","DOIUrl":"https://doi.org/10.58782/flmnh.xwfy9716","url":null,"abstract":"Species distribution modelling is a widely applied tool for forecasting future distributions of species under different climatic scenarios, informing conservation strategies and rewilding programs. Forecasting, however, is typically based on very recent species’ records (last ~50 years). This is problematic, given that these records are strongly affected by human interactions, and we do not know whether current distributions reflect the full suite of environmental parameters a species can inhabit. If we only model data from current distributions in future projections, we are thus likely to get misleading predictions that might misdirect conservation planning. The Critically Endangered Chinese alligator (Alligator sinensis) is currently restricted to a single Chinese province. Historical, zooarchaeological and fossil records demonstrate a greater range across mainland China, extending its past distribution even further, to Taiwan and Japan. Species distribution models (SDMs) based only on the present-day distribution of the Chinese alligator are poorly constrained, whereas incorporation of past archives improves model fit and changes projected suitable habitat. By combining past and present data, we can provide a closer approximation of the full ecological niche of a species. For endangered species with restricted present-day ranges, additional occurrence data from past archives is critical for constraining SDMs, with potentially major misinterpretations of suitable habitats for conservation and rewilding. This research is the principal case study for an IUCN Green status of species/Conservation Paleontology Network Pre-impact distributions working group, and a test case for the inclusion of past archives in the development of species recovery baselines.","PeriodicalId":106523,"journal":{"name":"Bulletin of the Florida Museum of Natural History","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130381228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Palaeontological data provide a unique avenue to evaluate the impact of climatic, habitat and ecosystem change over longer temporal scales than typically examined in ecology and conservation, contributing critical data on extinction dynamics that can help contextualize the current biodiversity crisis. However, the fossil record is biased by a variety of factors. In particular, the issue of data absence causes a genuine concern when attempting to discern spatial patterns. Does the lack of a fossil occurrence indicate genuine absence or imperfect detection (i.e., pseudo-absence)? Failing to quantify, discern and mitigate both the main drivers and impacts of data absence will have major implications for any attempt to reconstruct past diversity dynamics, limiting the applicability of paleontological data for addressing questions pertaining to present-day biodiversity. Occupancy modelling, a technique commonly applied in the fields of ecology and conservation, provides a novel way to evaluate the impact of both spatial and temporal biases on the fossil record. By distinguishing between true (taxon genuinely absent) and false (taxon present, but not observed) absences, occupancy modelling produces independent and simultaneous probability estimates for both occupancy and detection. Here, we show how paleontological occurrences can be adapted for use alongside relevant modern and paleo covariate data in both single season models run using the R package ‘unmarked’ and dynamic occupancy models using a Bayesian framework. We additionally test the impact of varying spatial scale, as well as uneven numbers of repeated site visits, on model outcomes, and provide recommendations for conservation paleobiologists intending to run these models. Finally, we outline additional benefits of applying occupancy modelling within conservation paleobiology.
{"title":"Detecting Genuine Versus Pseudo-Absence in The Fossil Record: Applications of Occupancy Modelling For Conservation Palaeobiology","authors":"C. Dean, P. Mannion","doi":"10.58782/flmnh.bflu9472","DOIUrl":"https://doi.org/10.58782/flmnh.bflu9472","url":null,"abstract":"Palaeontological data provide a unique avenue to evaluate the impact of climatic, habitat and ecosystem change over longer temporal scales than typically examined in ecology and conservation, contributing critical data on extinction dynamics that can help contextualize the current biodiversity crisis. However, the fossil record is biased by a variety of factors. In particular, the issue of data absence causes a genuine concern when attempting to discern spatial patterns. Does the lack of a fossil occurrence indicate genuine absence or imperfect detection (i.e., pseudo-absence)? Failing to quantify, discern and mitigate both the main drivers and impacts of data absence will have major implications for any attempt to reconstruct past diversity dynamics, limiting the applicability of paleontological data for addressing questions pertaining to present-day biodiversity. Occupancy modelling, a technique commonly applied in the fields of ecology and conservation, provides a novel way to evaluate the impact of both spatial and temporal biases on the fossil record. By distinguishing between true (taxon genuinely absent) and false (taxon present, but not observed) absences, occupancy modelling produces independent and simultaneous probability estimates for both occupancy and detection. Here, we show how paleontological occurrences can be adapted for use alongside relevant modern and paleo covariate data in both single season models run using the R package ‘unmarked’ and dynamic occupancy models using a Bayesian framework. We additionally test the impact of varying spatial scale, as well as uneven numbers of repeated site visits, on model outcomes, and provide recommendations for conservation paleobiologists intending to run these models. Finally, we outline additional benefits of applying occupancy modelling within conservation paleobiology.","PeriodicalId":106523,"journal":{"name":"Bulletin of the Florida Museum of Natural History","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115314353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Herbert, A. Kramer, Stephen P. Geiger, Ana Jimenez Bustos, Stephanie R. Sanders, N. Seiden, Jaime Rogers
Marine species assessments rely heavily on baseline surveys conducted after the 1960s, long after many anthropogenic pressures began, which could lead to misinformed management decisions and poor conservation outcomes. In this study, we collaborated with Florida Fish and Wildlife to conduct stock assessments for mollusks of the west Florida shelf that incorporate shell death assemblages. One of our first assessments was of the Florida Fighting Conch, Strombus alatus, an abundant gastropod that is also under consideration as a replacement fishery for the threatened Queen Conch. Live and dead shells were collected from >300 dredge tows between 2008-2018 covering the entire west Florida shelf. Shells were age-partitioned by 14C- and AAR-calibrated taphonomic criteria. Counts were converted to densities per m2. Inverse distance weighting interpolation of S. alatus death assemblages reveals multiple population centers along the coast and a rapid decrease in density with depth from 25-120 m. In contrast, live conchs were absent in our dredge samples from shelf depths deeper than 40 m. These differences are confirmed by single-visit occupancy methods that account for variation in detectability across the samples. Live-dead differences in spatial distribution are probably influenced by time averaging in death assemblages, which increases detectability of conchs in deeper habitats, where they may be too rare to be sampled alive. However, extirpation of offshore populations was also indicated by independent natural history collection occurrence records, which show numerous live-collected conchs from 1940-1980 but none afterwards, despite an increase in sampling effort. These results suggest that live-dead comparisons can reveal biodiversity loss at the scale of large marine ecosystems.
{"title":"Mapping Past Distributions of Marine Mollusks Using Shell Death Assemblages","authors":"G. Herbert, A. Kramer, Stephen P. Geiger, Ana Jimenez Bustos, Stephanie R. Sanders, N. Seiden, Jaime Rogers","doi":"10.58782/flmnh.cpmy8278","DOIUrl":"https://doi.org/10.58782/flmnh.cpmy8278","url":null,"abstract":"Marine species assessments rely heavily on baseline surveys conducted after the 1960s, long after many anthropogenic pressures began, which could lead to misinformed management decisions and poor conservation outcomes. In this study, we collaborated with Florida Fish and Wildlife to conduct stock assessments for mollusks of the west Florida shelf that incorporate shell death assemblages. One of our first assessments was of the Florida Fighting Conch, Strombus alatus, an abundant gastropod that is also under consideration as a replacement fishery for the threatened Queen Conch. Live and dead shells were collected from >300 dredge tows between 2008-2018 covering the entire west Florida shelf. Shells were age-partitioned by 14C- and AAR-calibrated taphonomic criteria. Counts were converted to densities per m2. Inverse distance weighting interpolation of S. alatus death assemblages reveals multiple population centers along the coast and a rapid decrease in density with depth from 25-120 m. In contrast, live conchs were absent in our dredge samples from shelf depths deeper than 40 m. These differences are confirmed by single-visit occupancy methods that account for variation in detectability across the samples. Live-dead differences in spatial distribution are probably influenced by time averaging in death assemblages, which increases detectability of conchs in deeper habitats, where they may be too rare to be sampled alive. However, extirpation of offshore populations was also indicated by independent natural history collection occurrence records, which show numerous live-collected conchs from 1940-1980 but none afterwards, despite an increase in sampling effort. These results suggest that live-dead comparisons can reveal biodiversity loss at the scale of large marine ecosystems.","PeriodicalId":106523,"journal":{"name":"Bulletin of the Florida Museum of Natural History","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125574427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N. Suárez-Mozo, M. Brenner, W. Kenney, Misael Díaz Asencio, J. Curtis, M. Aquino-López, E. Guerra-Castro, Nuno Simões
Biotic remains have been used in paleoecological studies to provide information on past environmental conditions. Death assemblages can be used to make inferences about past environmental conditions if modern optima and ranges of taxa are known. Gaps in knowledge about historical biotic changes often stem from a paucity of information regarding species distributions, community species richness and evenness, community structure, ecological interactions, and possible factors that caused past biotic shifts. We studied mollusc assemblages in sediment cores from Río Lagartos coastal lagoon (Mexico) and compared them to present-day mollusc communities to gain insights into environmental changes that occurred in the lagoon throughout the last century. A total of 18,779 mollusc specimens, representing 20 bivalve and 45 gastropod species, and belonging to 32 families and 48 genera, were identified in three short sediment cores collected from the coastal lagoon in 2017. Molluscs in the sediment cores were compared to an inventory of modern fauna from the lagoon, which was collected along a salinity gradient in 2017 and 2018 to link species distributions with environmental variables. Mollusc communities from the sediment cores and present-day datasets possess the same ubiquitous species and feeding guilds. Nearly twice as many species, however, were identified in the sediment cores as in the present-day inventory. We report differences in mollusc abundance and taxonomic composition in the cores across space and time, which may be related to the salinity gradient in the lagoon, temporal shift in salinity, and recent human-mediated modifications of the nearby terrestrial environment. Biotic changes driven by shifts in salinity could have been reduced salinity. Such inputs may have been driven by hurricanes, along with associated high wind velocities and geomorphologic transformations. This paleobiology study will be of use for future conservation efforts in the coastal lagoon.
{"title":"Molluscs Across Space and Through Time in a Hypersaline Coastal Lagoon, Mexico","authors":"N. Suárez-Mozo, M. Brenner, W. Kenney, Misael Díaz Asencio, J. Curtis, M. Aquino-López, E. Guerra-Castro, Nuno Simões","doi":"10.58782/flmnh.frvf2187","DOIUrl":"https://doi.org/10.58782/flmnh.frvf2187","url":null,"abstract":"Biotic remains have been used in paleoecological studies to provide information on past environmental conditions. Death assemblages can be used to make inferences about past environmental conditions if modern optima and ranges of taxa are known. Gaps in knowledge about historical biotic changes often stem from a paucity of information regarding species distributions, community species richness and evenness, community structure, ecological interactions, and possible factors that caused past biotic shifts. We studied mollusc assemblages in sediment cores from Río Lagartos coastal lagoon (Mexico) and compared them to present-day mollusc communities to gain insights into environmental changes that occurred in the lagoon throughout the last century. A total of 18,779 mollusc specimens, representing 20 bivalve and 45 gastropod species, and belonging to 32 families and 48 genera, were identified in three short sediment cores collected from the coastal lagoon in 2017. Molluscs in the sediment cores were compared to an inventory of modern fauna from the lagoon, which was collected along a salinity gradient in 2017 and 2018 to link species distributions with environmental variables. Mollusc communities from the sediment cores and present-day datasets possess the same ubiquitous species and feeding guilds. Nearly twice as many species, however, were identified in the sediment cores as in the present-day inventory. We report differences in mollusc abundance and taxonomic composition in the cores across space and time, which may be related to the salinity gradient in the lagoon, temporal shift in salinity, and recent human-mediated modifications of the nearby terrestrial environment. Biotic changes driven by shifts in salinity could have been reduced salinity. Such inputs may have been driven by hurricanes, along with associated high wind velocities and geomorphologic transformations. This paleobiology study will be of use for future conservation efforts in the coastal lagoon.","PeriodicalId":106523,"journal":{"name":"Bulletin of the Florida Museum of Natural History","volume":"198 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124424631","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Conservation Paleobiology (CPB) has many aims, but ultimately depends upon our uncovering, for a target region, the history of environmental pressures and history of biological change, particularly biological change that signifies a response to anthropogenic stress: this is how we detect and correctly attribute deterioration, how we design and evaluate recovery, and how we ultimately assess resilience and sustainability. The focus of concern might be a single taxon of economic or other particular value, or larger-scale changes in biomass, taxonomic or phylogenetic diversity, or trophic complexity. One of the biggest challenges for natural scientists can be building the requisite history of cultural stressors – i.e., uncovering the diverse economic, industrial, social, and regulatory activities that might have affected the system. Such information is commonly not accessible via the Web of Science; it can be extremely important but qualitative or can be quantitative but highly variable in units or methods of measurement; and, with the exception of data on commercial harvesting (e.g., fishing, logging) and human population size, useful time-series are scarce. The CPB scientist thus typically needs to compile their own, original history of human activities having potential to affect natural systems, either to evaluate the (paleo)biological data that they already have on hand (from biomonitoring, live-dead analysis, sedimentary cores) or to frame a new campaign of data collection. Here, I describe approaches to finding and merging cultural data that have worked both for research and for class projects, using two coastal marine examples: (1) testing the effects of historical over-fishing (meta-analyses from the early 2000s), and (2) the unexpected role of land-use in the collapse of the open-shelf benthic ecosystem of southern California.
{"title":"Developing Testable Hypotheses of Anthropogenic Stress: Some Approaches That Work","authors":"S. Kidwell","doi":"10.58782/flmnh.kywo4390","DOIUrl":"https://doi.org/10.58782/flmnh.kywo4390","url":null,"abstract":"Conservation Paleobiology (CPB) has many aims, but ultimately depends upon our uncovering, for a target region, the history of environmental pressures and history of biological change, particularly biological change that signifies a response to anthropogenic stress: this is how we detect and correctly attribute deterioration, how we design and evaluate recovery, and how we ultimately assess resilience and sustainability. The focus of concern might be a single taxon of economic or other particular value, or larger-scale changes in biomass, taxonomic or phylogenetic diversity, or trophic complexity. One of the biggest challenges for natural scientists can be building the requisite history of cultural stressors – i.e., uncovering the diverse economic, industrial, social, and regulatory activities that might have affected the system. Such information is commonly not accessible via the Web of Science; it can be extremely important but qualitative or can be quantitative but highly variable in units or methods of measurement; and, with the exception of data on commercial harvesting (e.g., fishing, logging) and human population size, useful time-series are scarce. The CPB scientist thus typically needs to compile their own, original history of human activities having potential to affect natural systems, either to evaluate the (paleo)biological data that they already have on hand (from biomonitoring, live-dead analysis, sedimentary cores) or to frame a new campaign of data collection. Here, I describe approaches to finding and merging cultural data that have worked both for research and for class projects, using two coastal marine examples: (1) testing the effects of historical over-fishing (meta-analyses from the early 2000s), and (2) the unexpected role of land-use in the collapse of the open-shelf benthic ecosystem of southern California.","PeriodicalId":106523,"journal":{"name":"Bulletin of the Florida Museum of Natural History","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127750008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The La Brea Tar Pits and Museum in Los Angeles is home to over 4 million Pleistocene fossils that help us better understand California during the last Ice Age. While the focus of Rancho La Brea research has often been on understanding the site’s megafauna, the plant fossils of this site hold a wealth of information that remains untapped. Seeds, nuts, pods, leaves, and entire trees have been preserved in the asphalt to such a degree that researchers have identified over 150 different species of plants. These plants document the environmental changes Southern California has experienced from before the Last Glacial Maximum until today. The plants found at La Brea Tar Pits have proven their resilience during extreme climatic changes. Their botanical characteristics and traits are valuable for conservationists and land managers to consider as they plan landscapes for the changing climatic circumstances of today. To translate this deeper-time information into actionable conservation recommendations, we are developing a database of biological, environmental, and ethnobotanical characteristics for each of the 163 species of plant fossils identified at La Brea Tar Pits. By recording botanical temperature ranges, drought tolerances, soil preferences, fire responses, and organisms associated with each species, we can recommend which La Brea plants can thrive in certain regions, maximizing functional ecosystem services with minimal human investment. Researchers, land managers, conservation specialists, urban planners, and homeowners can use this database to create sustainable climate change-resistant parks, gardens, habitats, and recreational/educational spaces utilizing plants native to Los Angeles for the past 50,000+ years.
{"title":"Understanding Botanical Traits of Rancho La Brea Fossils for Conservation Purposes","authors":"Steven Joseph Mendoza","doi":"10.58782/flmnh.smlu1018","DOIUrl":"https://doi.org/10.58782/flmnh.smlu1018","url":null,"abstract":"The La Brea Tar Pits and Museum in Los Angeles is home to over 4 million Pleistocene fossils that help us better understand California during the last Ice Age. While the focus of Rancho La Brea research has often been on understanding the site’s megafauna, the plant fossils of this site hold a wealth of information that remains untapped. Seeds, nuts, pods, leaves, and entire trees have been preserved in the asphalt to such a degree that researchers have identified over 150 different species of plants. These plants document the environmental changes Southern California has experienced from before the Last Glacial Maximum until today. The plants found at La Brea Tar Pits have proven their resilience during extreme climatic changes. Their botanical characteristics and traits are valuable for conservationists and land managers to consider as they plan landscapes for the changing climatic circumstances of today. To translate this deeper-time information into actionable conservation recommendations, we are developing a database of biological, environmental, and ethnobotanical characteristics for each of the 163 species of plant fossils identified at La Brea Tar Pits. By recording botanical temperature ranges, drought tolerances, soil preferences, fire responses, and organisms associated with each species, we can recommend which La Brea plants can thrive in certain regions, maximizing functional ecosystem services with minimal human investment. Researchers, land managers, conservation specialists, urban planners, and homeowners can use this database to create sustainable climate change-resistant parks, gardens, habitats, and recreational/educational spaces utilizing plants native to Los Angeles for the past 50,000+ years.","PeriodicalId":106523,"journal":{"name":"Bulletin of the Florida Museum of Natural History","volume":"260 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132415102","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Lauer, A Michelle Lawing, Rachel A. Short, F. Manthi, Johannes Müller, J. Head, Jenny L. McGuire
Mammalian megafauna have been critical to the functioning of Earth’s biosphere for millions of years. However, since the Plio-Pleistocene, their biodiversity has declined, concurrent with dramatic environmental change and hominin evolution. While these biodiversity declines are well-documented, their impacts on the ecological function of megafaunal communities remain uncertain. Here, we adapt ecometric methods to evaluate whether biodiversity losses since 7.5 Ma were coincident with disruptions to the functional link between communities of herbivorous, eastern African megafauna and their environments (i.e., functional trait-environment relationships). Herbivore taxonomic and functional diversity began to decline during the Pliocene, as open grassland habitats emerged, persisted, and expanded. In the mid-Pleistocene, grassland expansion intensified and Acheulean hominin tools emerged. It was then that phylogenetic diversity declined and the trait-environment relationships of herbivore communities shifted significantly. Our results divulge the varying implications of different losses in megafaunal biodiversity. Only the losses that occurred since the environmental and anthropogenic changes of the Pleistocene were coincident with a disturbance to community ecological function. Such a disturbance may occur in even greater magnitude in the future, as climate change and human impacts intensify. Preventing it will require that species move across landscapes, so that their traits may track changing environmental conditions. We build an ecometric model of modern megafaunal communities in Africa, and we use it to identify communities whose species will need to shift across space so that trait-environment relationships remain undisturbed. Conservation efforts that focus on movement routes between these communities will be critical if megafauna are to persist and continue providing essential ecological functions.
{"title":"Pleistocene Disruption of Trait-Environment Relationships Informs the Future Conservation of African Megafauna","authors":"D. Lauer, A Michelle Lawing, Rachel A. Short, F. Manthi, Johannes Müller, J. Head, Jenny L. McGuire","doi":"10.58782/flmnh.cpwc5265","DOIUrl":"https://doi.org/10.58782/flmnh.cpwc5265","url":null,"abstract":"Mammalian megafauna have been critical to the functioning of Earth’s biosphere for millions of years. However, since the Plio-Pleistocene, their biodiversity has declined, concurrent with dramatic environmental change and hominin evolution. While these biodiversity declines are well-documented, their impacts on the ecological function of megafaunal communities remain uncertain. Here, we adapt ecometric methods to evaluate whether biodiversity losses since 7.5 Ma were coincident with disruptions to the functional link between communities of herbivorous, eastern African megafauna and their environments (i.e., functional trait-environment relationships). Herbivore taxonomic and functional diversity began to decline during the Pliocene, as open grassland habitats emerged, persisted, and expanded. In the mid-Pleistocene, grassland expansion intensified and Acheulean hominin tools emerged. It was then that phylogenetic diversity declined and the trait-environment relationships of herbivore communities shifted significantly. Our results divulge the varying implications of different losses in megafaunal biodiversity. Only the losses that occurred since the environmental and anthropogenic changes of the Pleistocene were coincident with a disturbance to community ecological function. Such a disturbance may occur in even greater magnitude in the future, as climate change and human impacts intensify. Preventing it will require that species move across landscapes, so that their traits may track changing environmental conditions. We build an ecometric model of modern megafaunal communities in Africa, and we use it to identify communities whose species will need to shift across space so that trait-environment relationships remain undisturbed. Conservation efforts that focus on movement routes between these communities will be critical if megafauna are to persist and continue providing essential ecological functions.","PeriodicalId":106523,"journal":{"name":"Bulletin of the Florida Museum of Natural History","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114894710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Seabirds are the most threatened of any living group of birds, continuing a larger pattern of elevated Holocene bird extinctions on islands and coastlines. The Great Auk (Charadriiformes: Pinguinus impennis) was found on both coasts of the Atlantic during the Holocene until its last sighting on Iceland in 1844. Far more is known about the population structure and genetic diversity of NE Atlantic populations, and the latest surviving populations were documented from the British Isles in 1834. While sightings from Canada suggest Great Auks disappeared by 1800, no systematic evaluation of extinction timing has been conducted for this coast. Determining extinction timing of the Great Auk in Maine allows a comparison to be made to populations in other areas of the Atlantic Ocean, and raises the question: was the Maine population’s fate different due to regional, cultural, or other factors? There is a single eye-witness record in the late 17th century at “Black Point”, now Scarborough, Maine. To address this gap, we compiled a radiocarbon dataset on associated material from Maine archaeological shell middens. These 91 dates from 13 sites situate the Great Auk in Maine from about 180 to 4,555 years before present. The majority of these dates are from charcoal samples, but also include shells, ceramics, and bone, and cultural contexts span the Middle and Late Ceramic Periods. To account for differences in stratigraphic control and sampling material, we assigned quality scores, and used these scores to run a sensitivity analysis in extinction timing with the GRIWM model. Disentangling the spatiotemporal dynamics of the Great Auk extinction in Maine is useful in determining how to conserve current species in decline and modern insular seabirds in Maine, such as the puffin. Future study will include new radiocarbon dating of bones as well as isotopic and morphometric analysis to unfold more chapters of the Maine Great Auk’s narrative.
{"title":"A Holocene Seabird Extinction in Maine: The Great Auk","authors":"Lucia S. Snyderman, A. Mychajliw, A. Spiess","doi":"10.58782/flmnh.awfg4811","DOIUrl":"https://doi.org/10.58782/flmnh.awfg4811","url":null,"abstract":"Seabirds are the most threatened of any living group of birds, continuing a larger pattern of elevated Holocene bird extinctions on islands and coastlines. The Great Auk (Charadriiformes: Pinguinus impennis) was found on both coasts of the Atlantic during the Holocene until its last sighting on Iceland in 1844. Far more is known about the population structure and genetic diversity of NE Atlantic populations, and the latest surviving populations were documented from the British Isles in 1834. While sightings from Canada suggest Great Auks disappeared by 1800, no systematic evaluation of extinction timing has been conducted for this coast. Determining extinction timing of the Great Auk in Maine allows a comparison to be made to populations in other areas of the Atlantic Ocean, and raises the question: was the Maine population’s fate different due to regional, cultural, or other factors? There is a single eye-witness record in the late 17th century at “Black Point”, now Scarborough, Maine. To address this gap, we compiled a radiocarbon dataset on associated material from Maine archaeological shell middens. These 91 dates from 13 sites situate the Great Auk in Maine from about 180 to 4,555 years before present. The majority of these dates are from charcoal samples, but also include shells, ceramics, and bone, and cultural contexts span the Middle and Late Ceramic Periods. To account for differences in stratigraphic control and sampling material, we assigned quality scores, and used these scores to run a sensitivity analysis in extinction timing with the GRIWM model. Disentangling the spatiotemporal dynamics of the Great Auk extinction in Maine is useful in determining how to conserve current species in decline and modern insular seabirds in Maine, such as the puffin. Future study will include new radiocarbon dating of bones as well as isotopic and morphometric analysis to unfold more chapters of the Maine Great Auk’s narrative.","PeriodicalId":106523,"journal":{"name":"Bulletin of the Florida Museum of Natural History","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133607867","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Gymnophallid trematodes are complex life cycle parasites that induce characteristic pits in their bivalve intermediate hosts, which serve as their sole fossil record. Previous work demonstrated that trematode prevalence increases with rising sea levels, but little has been done to investigate patterns of trematode pit size in relation to Holocene sea-level and environmental changes. Here we focus on trematode pits preserved in the bivalve Chamelea gallina from five late Holocene core samples (2510-3140 y BP) and eight modern death assemblages from the Po-Adriatic system (northern Italy). Using ImageJ, we measured 838 total pits, with 715 from the core samples and 123 from the death assemblages. The geometric mean of the primary and secondary axis was used as a proxy for trace size, which ranges from 0.117 mm to 1.708 mm. The median size of Holocene pits (0.497 mm) is significantly larger (pWilcoxon = 1.73e-05) than the median size of modern pits (0.396 mm), indicating a decrease in trematode metacercariae body size over this time. There was no significant relationship between trematode pit size and host bivalve body size and only whole, well-preserved Holocene valves were analyzed to minimize the influence of taphonomy. We interpret a change in C. gallina-trematode parasite-host interactions over the last 3 ky, which could be the result of several scenarios. Modern pits could be created by different taxa, which have smaller body sizes, or the pits could be formed by the same parasitic taxa which now may have a decreased body size, perhaps due to stress. These results, coupled with a survey of modern metacercariae sizes, suggest that the trematode pit size record can provide relevant information on parasite paleoecology and, perhaps, identity. Such information will enable more nuanced analyses of parasite-host response to environmental change in the past with an eye to the future.
裸子吸虫是一种复杂的生命周期寄生虫，它们在双壳类中间寄主体内诱导出特有的凹坑，这是它们唯一的化石记录。先前的研究表明，吸虫的流行率随着海平面的上升而增加，但很少有人研究吸虫坑大小与全新世海平面和环境变化的关系。本文重点研究了5个全新世晚期(2510-3140 y BP)双壳变色龙(Chamelea gallina)岩心样本中保存的吸虫坑和8个来自意大利北部亚得里亚海盆地的现代死亡组合。使用ImageJ，我们总共测量了838个坑，其中715个来自岩心样本，123个来自死亡组合。用主、次轴的几何平均值作为迹线尺寸的代表，其范围为0.117 mm ~ 1.708 mm。全新世坑的中位数尺寸(0.497 mm)显著大于现代坑的中位数尺寸(0.396 mm) (pWilcoxon = 1.73e-05)，表明吸虫囊蚴体尺寸在此期间减小。吸虫穴大小与寄主双壳体大小之间没有显著的关系，为了尽量减少埋藏的影响，只分析了完整的、保存完好的全新世双壳体。在过去的3天里，我们解释了鸡螺旋体-吸虫寄生虫-宿主相互作用的变化，这可能是几种情况的结果。现代的坑可能是由体型较小的不同分类群形成的，也可能是由同样的寄生分类群形成的，这些分类群现在可能由于压力而体型变小了。这些结果，加上对现代囊蚴大小的调查，表明吸虫坑大小记录可以提供寄生虫古生态学的相关信息，甚至可能提供身份信息。这些信息将使我们能够更细致地分析寄生物-宿主对过去环境变化的反应，并着眼于未来。
{"title":"Paleoecological Implications of Trematode-Induced Pit Size in Chamelea Gallina from the Adriatic Sea, Italy","authors":"E. Fitzgerald, D. Scarponi, J. Huntley","doi":"10.58782/flmnh.gvjd1610","DOIUrl":"https://doi.org/10.58782/flmnh.gvjd1610","url":null,"abstract":"Gymnophallid trematodes are complex life cycle parasites that induce characteristic pits in their bivalve intermediate hosts, which serve as their sole fossil record. Previous work demonstrated that trematode prevalence increases with rising sea levels, but little has been done to investigate patterns of trematode pit size in relation to Holocene sea-level and environmental changes. Here we focus on trematode pits preserved in the bivalve Chamelea gallina from five late Holocene core samples (2510-3140 y BP) and eight modern death assemblages from the Po-Adriatic system (northern Italy). Using ImageJ, we measured 838 total pits, with 715 from the core samples and 123 from the death assemblages. The geometric mean of the primary and secondary axis was used as a proxy for trace size, which ranges from 0.117 mm to 1.708 mm. The median size of Holocene pits (0.497 mm) is significantly larger (pWilcoxon = 1.73e-05) than the median size of modern pits (0.396 mm), indicating a decrease in trematode metacercariae body size over this time. There was no significant relationship between trematode pit size and host bivalve body size and only whole, well-preserved Holocene valves were analyzed to minimize the influence of taphonomy. We interpret a change in C. gallina-trematode parasite-host interactions over the last 3 ky, which could be the result of several scenarios. Modern pits could be created by different taxa, which have smaller body sizes, or the pits could be formed by the same parasitic taxa which now may have a decreased body size, perhaps due to stress. These results, coupled with a survey of modern metacercariae sizes, suggest that the trematode pit size record can provide relevant information on parasite paleoecology and, perhaps, identity. Such information will enable more nuanced analyses of parasite-host response to environmental change in the past with an eye to the future.","PeriodicalId":106523,"journal":{"name":"Bulletin of the Florida Museum of Natural History","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116906510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Angelina G. Perrotti, Miranda Siedelmann, Jocelyn Lam, J. Russell, John Williams
Ecosystems across the world are experiencing seemingly unprecedented fire activity due to changes in land use and climate. However, disentangling the drivers of fire regime intensification is difficult when climate and land use changes occur simultaneously. Thus, multi-proxy paleoecological records with evidence for climate, vegetation composition, and fire regime changes can provide valuable frameworks in which to interpret modern environmental shifts. Lake Tulane, Florida, offers an iconic record of vegetation responses to Heinrich Events and other climate variations over the last 60,000 years, but its fire history is unknown. Here we present the results of a 60,000-year fire history from Lake Tulane, Florida, based on sedimentary macro charcoal data at ca. 30-year resolution. Charcoal accumulation rates are highest in pre-32,000 year old sediments and decline toward the end of the Pleistocene. Fire activity was lowest during the period directly before the last glacial maximum (32,000 to 23,000 years ago). The end-Pleistocene record indicates on-going oscillations in fire activity from 22,000 to 10,000 years ago, but fire activity does not appear to be closely linked with pine/oak oscillations, thus indicating differential drivers of vegetation and fire change. Ultimately, the fire history at Lake Tulane is best understood in the context of other environmental factors such as millennial-scale climate variability, human influence, and megaherbivory.
{"title":"Does Fire Drive Quaternary Ecosystem Transformation at Lake Tulane, Florida?","authors":"Angelina G. Perrotti, Miranda Siedelmann, Jocelyn Lam, J. Russell, John Williams","doi":"10.58782/flmnh.bbxn9730","DOIUrl":"https://doi.org/10.58782/flmnh.bbxn9730","url":null,"abstract":"Ecosystems across the world are experiencing seemingly unprecedented fire activity due to changes in land use and climate. However, disentangling the drivers of fire regime intensification is difficult when climate and land use changes occur simultaneously. Thus, multi-proxy paleoecological records with evidence for climate, vegetation composition, and fire regime changes can provide valuable frameworks in which to interpret modern environmental shifts. Lake Tulane, Florida, offers an iconic record of vegetation responses to Heinrich Events and other climate variations over the last 60,000 years, but its fire history is unknown. Here we present the results of a 60,000-year fire history from Lake Tulane, Florida, based on sedimentary macro charcoal data at ca. 30-year resolution. Charcoal accumulation rates are highest in pre-32,000 year old sediments and decline toward the end of the Pleistocene. Fire activity was lowest during the period directly before the last glacial maximum (32,000 to 23,000 years ago). The end-Pleistocene record indicates on-going oscillations in fire activity from 22,000 to 10,000 years ago, but fire activity does not appear to be closely linked with pine/oak oscillations, thus indicating differential drivers of vegetation and fire change. Ultimately, the fire history at Lake Tulane is best understood in the context of other environmental factors such as millennial-scale climate variability, human influence, and megaherbivory.","PeriodicalId":106523,"journal":{"name":"Bulletin of the Florida Museum of Natural History","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132511480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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