Sporormiella Spores Research Articles

Pleistocene megafaunal extinction in the grasslands of Junín‐Peru

AbstractAimTo determine the timing of megafaunal extinction in the high plains of Peru and also to determine if the timing was delayed in grasslands compared with previously published forested settings to dissociate the effects of succession from human or climatic impacts.LocationThe Junín Plateau, Peru.TaxonFlowering plants and Ascomycetes.MethodsThe sediments used in this analysis were collected from the edge of Lake Junín, Peru. Eleven ages derived from 14C accelerator mass spectrometry provide a chronology. We provide a paleoecological reconstruction of past climate and vegetation change, fire history and megafaunal herbivore presence from c. 20,000–7000 years ago based on fossil pollen, charcoal and Sporormiella spores. Data were analysed using multivariate analysis and Bayesian change point analysis.ResultsMegafaunal populations appear to have been positively impacted by dry climatic oscillations until c. 15,200 years ago. A reduction in Sporormiella abundance between 13,000 and 12,300 years before the present coincides with increased charcoal abundance and is identified as the period of megafaunal population collapse leading to extinction. The timing of the extinction does not differ substantially from that observed in wooded Andean settings.Main ConclusionThe timing of the collapse of megafaunal populations in high grasslands was very similar to that of lower, now‐forested settings. Upticks in fire activity, during what is generally seen to be a wet period, formed the backdrop to extinction and are strongly associated with human activity.

Multiproxy analysis on Indian wild ass (Equus hemionus khur) dung from Little Rann of Western India and its implications for the palaeoecology and archaeology of arid regions

The dung of the Indian wild ass was analyzed using biotic and abiotic proxies to determine its dietary habits in relation to the plant diversity and ecology in the arid region of western India. The presence of both micro and macrobotanical remains of Poaceae, Chenopodiaceae, and Fabaceae indicates they are the primary food plants of the wild ass. The continuous recovery of arboreal pollen taxa chiefly, Prosopis, Acacia, and Ephedra is indicative of dry thorny forest under semi-arid to arid conditions which display the existing vegetation and climate in the region. The recovery of marshy pollen taxa like Cyperaceae and Onagraceae along with Arcella indicates utilization of water-logged environments in the habitat. Spores of coprophilous fungi, Sporormiella, Sordaria, and Podospora are also present in the dung samples. The low value of stellate trichomes in winter dung samples reflects the seasonal migration of wild ass. Average δ13C values ranging between −15.8‰ and–26.3‰ are indicative of a mixed diet of both C3 and C4 plants. The generated multiproxy data from dung samples can provide a reliable counterpart to modern data for the interpretation of the palaeoecology in relation to the palaeoherbivory and palaeodietary analysis in the region. This study also provides a basis to distinguish between wild and domesticated herbivores by analyzing coprolites and cultural sediments in archaeological sites.

The adoption of agropastoralism and increased ENSO frequency in the Andes

Humans have been present in the Andes since about 12,000 calibrated years before present (cal yr BP), transitioning from hunter-gatherers to agropastoralist societies in the mid-Holocene. Yet, the timing and effects of this change in behavior on the ecosystem are largely unknown. Using titanium from XRF analysis, loss-on-ignition (LOI), fossil pollen, Sporormiella, and charcoal, we present a high-resolution 12,000-yr paleoecological history of Lake Llaviucu, a mid-elevation lake in the Ecuadorian Andes. For the entire period of study, humans were active in this landscape, with signs of agropastoralism being present since c. 6100 cal yr BP. Apparent ENSO activity, inferred from titanium inputs to the sediment is also heightened at c. 6100 cal yr BP. A trajectory of increasing landuse seems to have peaked in terms of maize production between c. 2900 and 800 cal yr BP. Thereafter, larger abundances of Sporormiella spores suggest that pastoralism was of increasing importance; a pattern disrupted by European arrival. Apparent peaks in El Niño Southern Oscillation (ENSO) appears to be linked to fire and maize frequency. We investigated the relationship between the Lake Llaviucu record and that of nearby Lake Pallcacocha, which is often cited as providing a regional ENSO history.

Long-term herbivore population dynamics in the northeastern Qinghai-Tibetan Plateau and its implications for early human impacts

Large herbivores are keystone species on the Qinghai-Tibet Plateau (QTP), but their past population ecology is the product of a complex combination of climatic changes and human activities that span the Holocene. In this study we use the record of dung-residing fungal spores (Sporormiella) in the stratified lake sediments of Genggahai Lake in the northeastern QTP to track changes in large herbivore populations. We hypothesize that the abundance of Sporormiella spores would decrease with the reduction of herbivore populations with the retreat of the summer monsoon after the mid-Holocene and the resulting vegetation degradation which is indicated by the pollen record. However, our results reveal an increase in Sporormiella spores after 5.7 ka (1 ka = 1000 cal yr BP), suggesting an increase in herbivore populations. Combined with regional archeological evidence, we infer that hunter–gatherers may have influenced the regional herbivore ecology and that the early Tibetan people may have domesticated or managed yaks and other herbivores in the northeastern QTP since 5.7 ka. The records of Sporormiella spores are interpreted within a robust chronostratigraphic framework provided by numerous radiocarbon dates from regional archeological sites, and the representation of Sporormiella spores during the Tang Dynasty is tested by a comparison with historical records of the livestock population of the region. Our findings potentially improve understanding of early human adaptation to environmental changes and past herbivore-steppe ecology in the QTP during the Holocene.

Comparison of Sporormiella dung fungal spores and oribatid mites as indicators of large herbivore presence: evidence from the Cuzco region of Peru

The ability of sedimentary proxies (especially dung fungal spores) to reflect the past presence and density of large herbivores on a landscape has been receiving increasing scrutiny. Here we examine the Sporormiella spore record from a well-dated, multi-proxy, highly organic sedimentary record from the small lake basin of Marcacocha in the Cuzco region of Peru. The basin, a wetland since ca. AD 1840, existed as a small lake for at least 4000 years prior. Previous work at Marcacocha has shown that changes in herbivore densities reflect the abundances of oribatid mites preserved in the lake sediments. This study tests the assumption that both the Sporormiella and the oribatid mite records responded in broadly the same way to changes in herbivore densities over the past 1200 years.Analysis reveals a very low covariance between concentrations of Sporormiella spores and the two major components of the oribatid mite assemblage: a single aquatic species of Hydrozetes and a less abundant, wider grouping comprising members of the mostly terrestrial superfamily Ceratozetoidea (referred to as the ‘ceratozetoids’). Variations in the Hydrozetes assemblage clearly dovetail with known historical events, including the massive decline of indigenous and camelid populations following the collapse of the Inca Empire in the mid-sixteenth century. Comparison with other environmental proxies from the Marcacocha sequence, including diatoms and charophyte oospores, suggests that the ceratozetoids appear to reflect increasing terrestrialization. In contrast, although the Sporormiella record indicates the presence of livestock, it fails to register the major historical changes in herbivore presence, though reflects well episodes of lake-level lowering. In small lake settings, therefore, the use of Sporormiella to estimate the density of herbivores in the catchment might be considered a relatively blunt instrument when compared with some other indicators.

What does the occurrence of Sporormiella (Preussia) spores mean in Australian fossil sequences?

ABSTRACTUnderstanding the loss of the final few species of Australian megafauna is beset by a paucity of data on human arrival, well‐provenanced megafauna, human/megafauna population range and distribution (coexistence and interaction), and the range, scale and impact of environmental changes spanning the human–megafauna period. To overcome these shortcomings, the occurrence and decline of coprophilous fungal spores of Sporormiella in sediments have been used as a proxy for extinct megaherbivores. The Sporormiella evidence is presented as the key indicator of extinction timing and these reports are often from locations where there is no known archaeological record or megafauna remains. However, interpreting fungal spore occurrence is not straightforward, as demonstrated by studies investigating taphonomy, taxonomy and the types of animal dung where Sporormiella occurs. No detailed studies on these problems exist for Australia and no evidence supporting the use of Sporormiella as a valid proxy has been reported. Here we examine the occurrence of Sporormiella spores from Cuddie Springs in south‐eastern Australia. Despite a well‐preserved suite of megafauna fossils, Sporormiella occurrence is sporadic and frequencies are low. We conclude that using Sporormiella alone as an indicator for the presence of megafauna is premature for the Australian context.

Sporormiella as a tool for detecting the presence of large herbivores in the Neotropics

The reliability of using the abundance of Sporormiella spores as a proxy for the presence and abundance of megaherbivores was tested in southern Brazil. Mud-water interface samples from nine lakes, in which cattle-use was categorized as high, medium, or low, were assayed for Sporormiella representation. The sampling design allowed an analysis of both the influence of the number of animals using the shoreline and the distance of the sampling site from the nearest shoreline. Sporormiella was found to be a reliable proxy for the presence of large livestock. The concentration and abundance of spores declined from the edge of the lake toward the center, with the strongest response being in sites with high livestock use. Consistent with prior studies in temperate regions, we find that Sporormiella spores are a useful proxy to study the extinction of Pleistocene megafauna or the arrival of European livestock in Neotropical landscapes.

Palaeoecological signatures of vegetation change induced by herbivory regime shifts on subantarctic Enderby Island

The stratigraphic relationships of palaeoecological proxies and use of changepoint analyses to determine the cause and effect relationships between past events has allowed a better understanding of the relative contributions of humans and environmental drivers to Late Quaternary extinctions and of their effects on terrestrial ecosystems. Few studies, however, have validated these approaches at localities where past interactions between vegetation communities and large herbivores are well-documented. Here, we use a peat core from subantarctic Enderby Island to present the first study tracing the spores of dung fungi alongside pollen at a site where the history of mammalian herbivore introductions (and subsequent eradication), and their effects on the vegetation, are precisely known. We find a strong connection between spore influx rates of the dung-fungus Sporormiella and PCA axis 1 of the pollen assemblages, suggesting that past vegetation change caused by herbivore introductions and eradications at the core site can be readily deduced from the palaeoecological record. The response of the vegetation community to the removal of herbivores was so rapid, however, that a difference in timing between changepoints relating to specific pollen taxa, the overall pollen community, and the decline of Sporormiella spores, could not be resolved in our record, despite a sampling resolution of <5 years. We suggest that further case-studies, spanning different vegetation and herbivore communities, are required to provide increased confidence in inferences drawn about cause-and-effect relationships using proxy changepoint offsets in palaeoecological records.

Sporormiella Spore Analysis Could Help Explain Ice Age Extinctions

Sporormiella spores found in Pleistocene-age dung specimens, which were recovered from Appleman Lake in Indiana, are helping to explain what led to the sudden disappearance of 135 species of Pleistocene animals in North America between 14,800 and 13,700 years ago, according to Jacquelyn Gill from the University of Wisconsin, Madison, and her collaborators. Although their report in the November 20th Science does not say exactly what abruptly killed off several dozen species, it tends to rule out two leading hypotheses that sought to explain those extinctions. The arrival of humans in North America during this period was likely behind the demise of those species, she suggests.

Modern pollen rain and fungal spore assemblages from pasture woodlands around Lake Saint-Point (France)

Modern analogs are commonly used to investigate the relationships between modern pollen rain and the surrounding present vegetation and to improve our interpretation of fossil data. We collected modern pollen and spore rain in 18 more or less grazed and/or forested sites around Lake Saint-Point (Jura Mountains, France). Multivariate numerical techniques were applied to understand how modern pollen and non-pollen palynomorphs (NPP) taxa, collected in moss and dung samples, record local vegetation in the surroundings, and to identify indicators of tree cover or grazing. We show a strong relationship between current local herbaceous vegetation and pollen but underline the limits of past vegetation reconstructions based on AP/NAP ratio. In moss samples, we identified Picea, Abies, Fagus and Corylus pollen as well as Trichocladium, Kretschmaria deusta and Cirrenalia as indicators of tree cover. Spores of Sporormiella and some undetermined palynomorphs such as new NPP LCE-13 were positively correlated with openness while LCE-23 and LCE-32 could represent grazing indicators and/or coprophilous types. As compared to moss samples, dung samples contained much more pollen grains from Trifolium repens-type, Trifolium pratense-type, Plantago lanceolata-type and Plantago major/media-type taxa (grassland species eaten by cattle) and spores from coprophilous fungi.

Influence of sample location and livestock numbers on Sporormiella concentrations and accumulation rates in surface sediments of Lake Allos, French Alps

Spores of coprophilous fungi, especially Sporormiella, are often well preserved in lake sediment cores. It has been hypothesized that such spores can be used to quantify past livestock abundance. The quantitative relationship between fungal spore abundance and livestock populations, however, is not well established, nor are the mechanisms of spore transport and deposition in lacustrine systems. Multiple cores from Lake Allos, a large high-elevation lake in the French Alps, were used to map the modern abundance of Sordaria and Sporormiella spores throughout the lake. We observed high spatial heterogeneity with respect to spore numbers. No correlation with the distance from shoreline was found. There was, however, a relation with distance from the two main lake inlets. These results were used to select two fungi-rich sediment cores to investigate grazing pressure over the last two centuries. Comparisons were made between spore influx and historic data on livestock densities in the catchment. A sharp decrease in Sporormiella influx ca. 1894–1895 was associated with a reported reduction in sheep in the Allos catchment at that time. Mean influx of Sporormiella decreased by a factor of three between the nineteenth and twentieth centuries, reflecting a reduction in the reported number of animals in the Lake Allos catchment, from 6,000 to 2,000. This study confirmed that Sporormiella spore abundance in lake sediments can be used as a proxy for catchment herbivore numbers in paleoecological reconstructions. Nevertheless, our data indicate that before spore accumulation can be used to infer past domestic herbivore density, one must understand the processes of coprophilous spore transfer from the catchment to the lake and the influence of core location on spore numbers in the sediment.

Influences of climate, cattle density, and lake morphology on Sporormiella abundances in modern lake sediments in the US Great Plains

Sporormiella, a genus of coprophilous fungus, is increasingly used as a qualitative proxy for megafaunal density. Decreased spore abundances in Late-Pleistocene and Holocene sediments are thought to signal prehistoric megafaunal population declines and extinctions. However, much remains unknown regarding the dispersal, deposition, and preservation of Sporormiella, hindering interpretation. Here we collected lake-center and lake-margin surface-sediment samples from 24 lakes in a west–east transect across South Dakota, Minnesota, and Wisconsin to test whether Sporormiella abundances varied along a precipitation gradient and areas of varying grazing intensity. Unlike other pollen types, relative abundances and concentrations of Sporormiella spores were uncorrelated between lake-center and lake-margin samples. For lake-margin samples, distance-to-shoreline and county-scale cattle density were significant predictors of Sporormiella relative abundances. Only distance to shoreline was a significant predictor of Sporormiella concentrations. The positive relationship between shoreline proximity and Sporormiella abundances differs from prior reports that Sporormiella concentrations decrease away from shoreline. For lake-center samples, Sporormiella relative abundances were negatively correlated with precipitation and Sporormiella concentrations had no significant predictors. These results suggest that Sporormiella representation in lake sediments is controlled by multiple factors, including but not limited to local megaherbivore density. Sporormiella concentrations appear to be ‘noisier’ than Sporormiella relative abundances, due to within-basin sedimentary effects on pollen and spore accumulation rates. More work on Sporormiella taphonomy is critically needed to better understand the controls on its representation in late-Quaternary sediments.

Wetland soil moisture complicates the use of Sporormiella to trace past herbivore populations

AbstractSpores of the dung‐fungi Sporormiella provide a proxy for assessing past changes in herbivore abundance, and for temporally linking these with shifts in vegetation communities (pollen) and fire frequency (charcoal). Although the proxy is now widely used, potential influences of local environmental conditions are poorly understood. Here we assess the reliability of Sporormiella as a proxy of herbivores by presenting five new spore records from the South Island of New Zealand; a land where the herbivore extinction/introduction chronology is well established, and where extinctions occurred independently of major climate change. We show that Sporormiella spores from relatively dry soils provide a good proxy for herbivore extinctions and introductions. However, spore abundances from saturated soil sites appear to fluctuate in close correlation with changes in local hydrology (represented by wetland herb pollen, testate amoebae and moisture sensitive mosses). Our results suggest Sporormiella records derived from wetlands require cautious interpretation, and that proxies for hydrological conditions should also be considered when interpreting such records. Copyright © 2011 John Wiley &amp; Sons, Ltd.

Sporormiella as a proxy for non-mammalian herbivores in island ecosystems

Spores of the dung-fungi Sporormiella are routinely used as a proxy for past megaherbivore biomass and to pinpoint the timing of extinctions. Further ecological insight can also be gained into the impacts that followed initial human arrival in a region through correlation of spore abundance with other proxies (e.g. pollen, charcoal). Currently, the use of Sporormiella as a palaeoecological proxy has been restricted to landmasses where large-herbivore guilds are dominated by mammals. Here, we use New Zealand as a case study to show that the method can also be applied effectively to islands dominated by large avian herbivores. We examine 44 dung samples from 7 localities to show that Sporormiella spores were widely distributed in the dung of endemic avian herbivores (South Island takahe ( Porphyrio hochstetteri), kakapo ( Strigops habroptilus), and several species of extinct moa, identified by ancient DNA analysis). In addition, we show that Sporormiella spores in a forest soil core from the Murchison Mountains, South Island, accurately trace the post-settlement decline of native avian herbivores, and combined with high-resolution radiocarbon dating reveal severely reduced local herbivore populations by the late 17th Century AD. The spores also trace the subsequent spread of Red deer ( Cervus elaphus) introduced to the area in the early 20th Century AD. Our results suggest Sporormiella spores may provide a useful new tool for examining extinctions on numerous islands where terrestrial herbivore guilds were dominated by birds or reptiles. Our findings also highlight the need to consider entire herbivore communities (including birds and reptiles) when examining Late Pleistocene continental Sporormiella records, where the focus has often been tracing the decline of populations of large mammals.

Late Quaternary environmental change inferred from phytoliths and other soil-related proxies: Case studies from the central and southern Great Plains, USA

Abstract This study investigates stable carbon isotopes (δ13C), opal phytolith assemblages, burnt phytoliths, microscopic charcoal and Sporormiella spores from modern soils and paleosols in Kansas and Oklahoma. Grass and dicot phytoliths in combination with δ13C are used as proxies for reconstructing the structure of grasslands and woodlands. Burnt grass phytoliths and microscopic charcoal are evaluated as proxies for reconstructing paleofire incidence. Concentrations of the fungal spore Sporormiella are used as a proxy for assessing large herbivore activity. These proxies were tested on various modern grassland communities of the central and southern Great Plains, including areas with bison, cattle, and small herbivores, and areas under different fire frequencies. Opal phytolith assemblages and δ13C values show that before cal 11 ka, C3 grasses and woody plants predominated in areas that today are dominated by C4 grasses. The origin of the shortgrass prairie dates back to about cal 10 ka. The origin of the tallgrass prairie, however, is not clear as phytolith data show variable assemblages throughout the Holocene (mixed-grass, tallgrass, and tallgrass–woodland mosaic). Different proxies (burnt phytoliths vs. charcoal) reveal different fire frequencies, but it is apparent that microfossil evidence for fire incidence is closely related to the abundance of woody plants in the landscape. Before cal 12 ka, soils show somewhat elevated concentration of Sporormiella, but lower concentrations than the modern high-density bison and cattle grazing areas. Throughout the Holocene, Sporormiella frequencies are low, which suggests lower large ungulate densities and perhaps high mobility.

Sporormiella fungal spores, a palynological means of detecting herbivore density

During the historic period, spores of the dung fungus Sporormiella are abundant in lake and cave sediment where livestock are plentiful in the western United States. Sporormiella spores occasionally exceed 50% of the upland pollen sum in samples from corral ponds and bed-grounds, and routinely reach 4% in lake and marsh samples in pastoral areas. Sporormiella spores are comparatively rare in mid-Holocene sedimentary records, but they reach values of 2–4% in Pleistocene samples from lake sediments. Sporormiella spores are directly linked to extinct megaherbivores by their presence in mammoth dung from Bechan Cave, Utah. In several sites in the western United States, a precipitous decline of Sporormiella percentages after ca. 10,800 radiocarbon yr B.P. (12,900 years ago) marks a decline of herbivore density, probably associated with the North American megaherbivore extinction.

Spores of the dung fungus Sporormiella: Increased abundance in historic sediments and before Pleistocene megafaunal extinction

Spores of the dung fungus Sporormiella become abundant following the historic introduction of grazing herbivores at seven sites in the western United States. During the Holocene they are generally rare, but at six sites Sporormiella spores are abundant before the extinction of Pleistocene megaherbivores ca. 11,000 yr B.P. Sporormiella spores are directly linked to extinct megaherbivores by their presence in mammoth dung preserved in Bechan Cave, Southern Utah. Their abundance in late-glacial sediments may reflect the abundance of megaherbivores during Quaternary, thereby indicating the age of Pleistocene extinctions where other indicators are absent.