Search

Changes in land-use practices have been a central element of human adaptation to Holocene climate change. Many practices that result in the short-term stabilization of socio-natural systems, however, have longer-term, unanticipated consequences that present cascading challenges for human subsistence strategies and opportunities for subsequent adaptations. Investigating complex sequences of interaction between climate change and human land-use in the past—rather than short-term causes and effects—is therefore essential for understanding processes of adaptation and change, but this approach has been stymied by a lack of suitably-scaled paleoecological data. Through a high-resolution paleoecological analysis, we provide a 7000-year history of changing climate and land management around Lake Acopia in the Andes of southern Peru. We identify evidence of the onset of pastoralism, maize cultivation, and possibly cultivation of quinoa and potatoes to form a complex agrarian landscape by c. 4300 years ago. Cumulative interactive climate-cultivation effects resulting in erosion ended abruptly c. 2300 years ago. After this time, reduced sedimentation rates are attributed to the construction and use of agricultural terraces within the catchment of the lake. These results provide new insights into the role of humans in the manufacture of Andean landscapes and the incremental, adaptive processes through which land-use practices take shape. [ABSTRACT FROM AUTHOR]

Examining the ecological consequences of the late Quaternary megafaunal extinctions within biodiversity hotspots is crucial for our understanding of the potential consequences of contemporary extinctions. We present the first multi-species record of spores of coprophilous fungi (SCF) from Monquentiva and the high-Andean forests of Colombia to reconstruct Late Pleistocene and Holocene megafaunal abundance. Fossilised pollen and charcoal are used to examine the consequences of megafaunal declines on the surrounding vegetation and fire activity. Our SCF record indicates the presence of Pleistocene megafauna at least since 30,290 BP, with two waves of megafaunal decline at ca. 22,900 BP and 10,990 BP. At Monquentiva, megafaunal decline in the Early Holocene resulted in transitional non-analogue vegetation, loss of some herbivore-dispersed plant taxa, an encroachment of palatable and woody flora, and a rise in fire activity. Differences with other published South-American records suggest that ecological consequences of megafaunal declines were habitat-specific. Overall, we show that ecosystems in the eastern Colombian Cordillera were highly sensitive to the decline of megafaunal populations. Under the current biodiversity crisis, management and conservation efforts must account for the effects of local herbivore declines on plant dispersal, on fire activity, and the potential loss of ecosystem services. [ABSTRACT FROM AUTHOR]

Aim: To 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. Location: The Junín Plateau, Peru. Taxon: Flowering plants and Ascomycetes. Methods: The 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. Results: Megafaunal 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 Conclusion: The 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. [ABSTRACT FROM AUTHOR]

The article provides an update on the dung-inhabiting members of the Sporormiaceae in Ukraine. Overall, 26 species of Sporormia and the Preussia/Sporormiella species complex have been recorded in the country to date. Based on examination of specimens collected in 2007-2020, we report one species of Sporormia (S. fimetaria), two of Preussia s. str. (P. fleischhakii, P. funiculata) and 11 of Sporormiella (S. affinis, S. commutata, S. grandispora, S. heptamera, S. kansensis, S. leporina, S. longisporopsis, S. megalospora, S. muskokensis, S. octomera and S. pulchella). Of these, the genus Sporormia and four species of the other genera (P. fleischhakii, S. affinis, S. commutata and S. longisporopsis) are newly recorded in Ukraine. For all fourteen species, their morphological characters are described, illustrated and discussed; occurrence records, habitat and distribution data are also provided. This study extends the distribution ranges of these fungi eastwards within Europe and contributes to their substrate list. [ABSTRACT FROM AUTHOR]

Despite the importance of pastoralism, as an alternative or adjunct to farming in China's long history, a clear understanding of the spreading routes and mechanisms of pastoralism in China is lacking. Fungal spores can be a useful addition to zooarchaeological evidence and have been widely used to explore the origins and development of pastoralism in different regions of the globe. The northern Loess Plateau is one of the most important areas for the emergence and development of pastoralism in early China. The aim of this paper was to take the fungal spores in the Baihemiao (BHM) core that we extracted from a site in the Yulin region, combine them with the zooarchaeological records to explore their relationship with climate and environmental changes, and reconstruct the evolution of animal husbandry in the northern Loess Plateau since the mid-Holocene. The results indicate that the climatic conditions in the northern Loess Plateau during the first period of 6–4.2 ka were relatively humid, the number of domesticated herbivores was small, animal husbandry was not developed, and the spores of coprophilous fungi in the sediments mainly originated from wild herbivores. Fungal spores as well as zooarchaeological evidence reveal that cattle and sheep grazing developed rapidly in the region during the second period, c. 4.2–3 ka. We suggest that the arid climatic conditions during this period facilitated the development of pastoral activities in the northern Loess Plateau. However, this pastoral economy gradually weakened after 1.2 ka. • Sporormiella suggests a high volume of herbivore activities in the Baihemiao area in 6–4.2 ka. • Fungal spores and zooarchaeological record from the archaeological sites indicate that grazing activity was strong in 4.2-3 ka. • Arid climatic conditions facilitated the development of pastoral activities in the northern Loess Plateau in 4.2–3 ka. • Pastoralism weakened and declined during the period from 3 ka to 1.2 ka. [ABSTRACT FROM AUTHOR]

Being a crucial subsistence strategy for the steppe communities, transhumant pastoralism has played a pivotal role in facilitating early communication of East and West civilizations. However, despite its significance, there remains a paucity of research regarding how and when transhumant pastoralism emerged at the eastern end of the Eurasian Steppe. Situated at the crossroads of East-West exchanges, the Tongtian Cave site has yielded a diverse range of archaeological materials, including sheep bones, sheep coprolites, and the earliest remains of wheat and barley in China. In order to explore the herding strategies employed at the Tongtian Cave, the microfossil contents from site's stratigraphy and the sheep coprolites are investigated in this study. Analytic results reveal the presence of elm tree pollen and probably phytoliths within the coprolites, suggesting that the site once served as a spring pasture. Wheat remains recovered from the same stratum as the coprolites date the transhumant practice at the site as far back as ca. 4300 B.P., establishing the Tongtian Cave as not only the earliest pastoralist site in China but likely also in the eastern Eurasian Steppe. Overall, our studies of the Tongtian Cave materials provide crucial evidence that deepens our understandings of the timing and mechanism of the eastward expansion of transhumant pastoralism across prehistoric Eurasia. The methodological potential of pollen and fungal spore analyses in revealing the seasonality of ancient site use is also explored in this article. • The transhumance at the Tongtian Cave site dates back to ca. 4300 B.P. • Microfossil analyses were used in revealing the seasonality of ancient site use. • The materials provide crucial evidence about thetranshumant pastoralism across prehistoric Eurasia. [ABSTRACT FROM AUTHOR]

The Spanish conquest of the Cuchumatanes Highlands (1524–1541 ce) led to dramatic land use changes adhering to colonial practices and values, which included the rearing of livestock, agriculture, timber extraction, mining, and the relocation of indigenous populations to new settlements. These changes are often recorded in historical accounts and official records; however, these are sparse, incomplete, and have been lost over the passage of time. Here, we present a high-resolution palaeoenvironmental reconstruction for Cenote Kail (Guatemala) since the Spanish Conquest, to provide additional evidence of land use changes from an integrated multi-proxy perspective. We analysed: (i) fossil pollen; (ii) macroscopic and microscopic charcoal; and (iii) dung fungal spores (Sporormiella) from a lake sediment core extracted from Cenote Kail in the Cuchumatanes highlands, combining these analyses with remotely sensed satellite data. We reconstructed: (i) forest composition and dynamics; (ii) burning, (iii) fauna abundance, and (iv) agricultural activities. High resolution age-depth modelling was conducted using a combination of 210Pb and 14C dates. The high temporal resolution enabled a novel integrated validation of the charcoal data sets with remotely sensed satellite data and the historical record. Three stages of floral compositional change were discerned from the palynological assemblage data encompassing: (i) the decline of mixed hard wood forests (MHWF), associated with the building of new settlements, agriculture and timber extraction for fuel (1550–1675 ce); (ii) pastoral expansions involving the rearing of livestock (1700–1800 ce); and (iii) the expansions of urban settlements and increasing management of the land (1821–2015 ce). Seed predation is suggested as the dominant factor preventing MHWF from re-establishing in the Cuchumatanes Highlands over the past 500 years. Burning is limited locally and regionally and in line with the modern regime, which suggests that fire has been managed and controlled since European contact. [ABSTRACT FROM AUTHOR]

One major challenge in the study of late-Quaternary extinctions (LQEs) is providing better estimates of past megafauna abundance. To show how megaherbivore population size varied before and after the last extinctions in interior Alaska, we use both a database of radiocarbon-dated bone remains (spanning 25–0 ka) and spores of the obligate dung fungus, Sporormiella, recovered from radiocarbon-dated lake-sediment cores (spanning 17–0 ka). Bone fossils show that the last stage of LQEs in the region occurred at about 13 ka ago, but the number of megaherbivore bones remains high into the Holocene. Sporormiella abundance also remains high into the Holocene and does not decrease with major vegetation changes recorded by arboreal pollen percentages. At two sites, the interpretation of Sporormiella was enhanced by additional dung fungal spore types (e.g., Sordaria). In contrast to many sites where the last stage of LQEs is marked by a sharp decline in Sporormiella abundance, in interior Alaska our results indicate the continuance of megaherbivore abundance, albeit with a major taxonomic turnover (including Mammuthus and Equus extinction) from predominantly grazing to browsing dietary guilds. This new and robust evidence implies that regional LQEs were not systematically associated with crashes of overall megaherbivore abundance. [ABSTRACT FROM AUTHOR]

Fossil spores of coprophilous fungi preserved in lake and bog sediments are well-established palaeoecological tracers for the local history of pastoralism and other animal husbandry. However, applications in Africa are limited by the lack of information on the exact relationship between human activity and fungi growing on large-herbivore dung. Here we use 25 small crater-lake basins in western Uganda, which cover the complete regional gradient of natural vegetation and human impact intensity, as a natural laboratory to assess the relationship between coprophilous fungal spores recovered from recently deposited bottom sediments and the presence and abundance of large domestic herbivores in the surrounding crater basins. We find that the summed abundances of Sporormiella, Sordaria, Podospora and Delitschia, or of these four types plus Cercophora, are the most useful and robust fungal-spore indicators for the presence of domestic large herbivores in an East African context. Chaetomium could also be added to this list, particularly as it may help reduce stochasticity in the often low fossil counts of obligate coprophilous types. Our results suggest that domestic large herbivores, at least when associated with some degree of crop agriculture, leave a clearer signature on fungal-spore assemblages in the lakes' sediments than large wildlife. Furthermore, they indicate that the typically small number of livestock kept by mixed-subsistence farmers leave a stronger imprint on fungal-spore assemblages than the much larger herds of specialist pastoralists occasionally visiting the lake to drink or bathe. [ABSTRACT FROM AUTHOR]

Mountain tropical forests of the Southern Maya Area (Pacific Chiapas and Guatemala, El Salvador, and Northern Honduras) predominantly comprise pine and oak formations, which form intricate mosaics and complex successional interactions following large–scale fire. These forests have been transformed by the peoples of the Maya civilization through practices of horticulture, agriculture, and architectural developments over thousands of years. Anthropogenic impacts and the extent of early human interaction with these upland forests is currently poorly understood. In this study we identify: (i) the natural baseline vegetation of the region; (ii) when human impact and agrarian practices began in the Maya uplands; and (iii) what impacts the Maya had on forest structure, composition, and successional regeneration. Past vegetation, anthropogenic use of fire, and faunal abundance were reconstructed using proxy analysis of fossil pollen, macroscopic charcoal, microscopic charcoal, and dung fungal spores (Sporormiella). Three phases of forest succession were identified from 4000B.C.E. to 1522CE that broadly overlap with the well–defined archaeological periods of (i) the Archaic (10,000–2000B.C.E.); (ii) Pre–Classic (2000B.C.E.−100C.E.); (iii) Terminal Pre–Classic (100–250C.E.); (iv) Classic (250–950C.E.); and (v) Post–Classic (950–1522C.E.). These results also include the earliest evidence for agriculture within the Southern Maya Area through presence of peppers (Capsicum) from 3850B.C.E. and the rise of maize cultivation (Zea mays) from 970B.C.E. Persistent high intensity burning driven by agricultural practices and lime production during the Late–Pre-Classic (400–100B.C.E.) to Classic Period resulted in a compositional change of forest structure c.150B.C.E. from oak (Quercus) dominated forests to pine (Pinus) dominated forests. The legacy of Pre–Columbian anthropogenically driven fire in these mountain tropical forests demonstrates the resilience and thresholds for fire driven succession. These findings are particularly relevant for addressing current land use and management strategies involving agriculture, fire, and forest management in the mountain tropical forests of the Southern Maya Area.

Abstract A new fossil pollen, Sporormiella, and sediment chemistry record from Lake Llaviucu, Ecuador, spanning the period from 16,280–9000 years Before Present, provides a high-resolution record of paleoecological change in the high Andes. The deglacial transition from super-páramo through páramo grasslands, to Andean forest is traced, with near-modern systems being established by c. 11,900 years ago. It is suggested that forest elements probably existed in microrefugial populations close to the ice front. Sporormiella is used as a proxy for megafaunal abundance, and its decline to background levels is inferred to indicate a local extinction event at c. 12,800 years ago. About 1800 years prior to the extinction, charcoal becomes a regular sedimentary component in this very wet valley. An early date for human activity in the valley is suggested, with the direct implication of humans in the extinction of the megafauna. Highlights • Analysis of fossil Sporormiella showed the local extinction of megafauna at c. 12.8 k cal BP in Ecuador's Llaviucu valley. • Increased fire frequency at c. 14.6 k cal BP is interpreted as a signal of early human activity. • Humans and megafauna co-existed for about 1.8 k years in the study region. • We infer that humans caused the ultimate extinction of megafauna in this portion of the Andes. [ABSTRACT FROM AUTHOR]

Abstract 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. [ABSTRACT FROM AUTHOR]

The use of spores of coprophilous fungi from sedimentary sequences as proxy evidence for large herbivore abundance has garnered pronounced attention and scrutiny over the past three decades. In response to the rapid rate at which new information is being discovered on this topic, this paper presents a brief review of the archaeological applications so far, and outlines opportunities and limitations of using Sporormiella as a proxy for herbivore abundance. Specific archaeological uses of this proxy include understanding megaherbivore extinctions and human land use patterns such as pastoralism and agriculture. We analyse how dung fungal records are formed and review the mycological literature to outline factors affecting spore reproduction and preservation. These include how strongly each commonly used dung fungal taxon relies on dung as a substrate and environmental factors affecting dung fungal reproduction and coprophilous fungi deposition. Certain laboratory preparation techniques adversely affect spore representation on pollen slides. The methods of analysis and quantification of spore records also impact our understanding. We describe good practice to increase precision of analytical methods. Due to limitations imposed by some of these factors, it is possible that an absence of dung fungi from a palaeoecological record does not imply an absence of herbivores. However, consideration of these factors and inclusion of as wide a range of coprophilous spore records as possible increases the reliability of such inferences. [ABSTRACT FROM AUTHOR]

The timing and cause of megafaunal extinctions are an enduring focus of research interest and debate. Despite the developments in the analysis of coprophilous fungal spores (CFS), the proxy for reconstructing past megaherbivore changes, the environmental consequences of this fauna loss remain understudied. This is partly due to the general obscurity of such a signal in pollen records, as well as limitations in disentangling human and extinction ecological impact, and the lack of spatial information of megafauna changes in site-level sedimentary records. In Australia, the debate centres on the possibility that habitat loss through climate change, vegetation-fire change, human intervention, or a combination of these factors led to the extinction of some large animals during the Late Pleistocene. Pollen and plant isotope studies have also demonstrated that vegetation-fire responses following the Late Pleistocene megafaunal extinctions were characterized by increased vegetation density and fire activity due to reduced grazing/browsing pressure. Here, we use a well-dated marine sedimentary core record from the Murray Darling Basin in southern Australia and apply palynological and functional palaeoecological approaches to reconstruct the Late Pleistocene megafaunal abundance changes, the timing and potential cause of extinction across the basin and investigate if extinction was associated with any signal of trait-based vegetation changes. We infer megafaunal abundance changes from the abundance of CFS and compare this with climatic proxies from the same core. We then link modern observations of fruit, seed and fire response traits of plant genera within the basin to the fossil pollen record to reconstruct palaeo vegetation community traits and determine if extinction was associated with any changes in plant community trait composition. Closely-spaced 14C dates obtained from planktonic foraminifera and δ18O tie points place a major decline in CFS, and thus the timing of extinction, within the basin at ∼43.3 ka. While climate-driven environmental changes largely controlled megafaunal presence, human arrival and frequent landscape burning are considered the most likely primary cause of extinction or, at the very least, megafauna decline in the Murray Darling Basin. We also found that the proposed period of megafaunal decline was also accompanied and followed by a decline in the prevalence of plants with larger seeds and fruits that were likely to have been once dispersed by megaherbivores. Our study supports the idea of a human-driven megafaunal extinction in mainland Australia and that the extinction caused changes in vegetation due to reduced plant dispersal and herbivory. However, high fire activity primarily linked to these vegetation changes was not observed, as humans were already practicing landscape burning before the period of megafaunal extinction and likely continued to do so afterward. • Dung fungi from marine core identify the timing of megafaunal extinction. • Megafaunal extinction occurred in southern Australia ∼43.5 ka. • Human pressure primarily drove extinction. • Plant trait and fossil pollen reveal vegetation changes associated with extinction. • Declines in large-seeded and fruited plants accompanied and followed extinction. [ABSTRACT FROM AUTHOR]

Whether humans or climate change caused the extinction of megafaunal populations is actively debated. Caves in the Lagoa Santa provide mixed assemblages of megafauna and human remains; however, it remains uncertain the extent to which humans and megafauna interacted or overlapped temporally. Here we present the first paleoecological record from lowland South America that tracks the decline of megafauna and its ecological implications. We provide a data set for pollen, charcoal, and Sporormiella, from two lakes in southeastern Brazil that span the last 23,000 yr. The data showed reduced abundances of Sporormiella and an inferred megafaunal population decline that began 18,000 yr ago, with the functional extinction occurring between 12,000 and 11,500 yr ago. Population declines coincided with wet events. The age of the final megafaunal decline is within the range of the first human occupation of the region. Our data are consistent with climate causing the population collapse, with humans preventing population recovery and inducing extinction. We did not observe some of the ecological repercussions documented at other sites and attributed to the megafaunal extinction. Habitat-specific ecological consequences of the extinction add to the heterogeneity of late Pleistocene and early Holocene landscapes. [ABSTRACT FROM PUBLISHER]

The Central American Dry Corridor (CADC) is the most densely populated area of the Central American Isthmus and is subject to the greatest variability in precipitation between seasons. The vegetation of this region is composed of Dry Tropical Forests (DTF), which are suggested to be highly susceptible to variations in climate and anthropogenic development. This study examines the vulnerability of past DTF surrounding the Asese peninsula, Nicaragua to climatic and anthropogenic disturbances over the past c. 1200 years. Past vegetation, climate, burning, and animal abundance were reconstructed using proxy analysis of fossil pollen, diatoms, macroscopic charcoal, and Sporormiella. Results from this research suggest that DTF have been highly resilient to past climatic and anthropogenic perturbations. Changes in DTF structure and composition appear to be linked to the abundance and intensity of fire. Pre-Columbian anthropogenic impacts on DTF are not detected in the record; however, DTF taxa decline slightly after European contact (1522 C.E.). Overall the DTF for the Nicaraguan region of the CADC were found to be highly resilient to both climatic and anthropogenic disturbances, suggesting that this region will continue to be resilient in the face of future population expansion and climatic variation.

Data on anatomical, morphological, ecological features, and distribution of 10 species of Sporormiella (Pleosporales, Dothideomycetes) of Ukraine are presented. Three species of Sporormiella (S. australis (Speg.) S.I. Ahmed & Cain, S. minima (Auersw.) S.I. Ahmed & Cain, S.vexans (Auersw.) S.I. Ahmed & Cain) were not previously described for the Steppe zone of Ukraine. The detailed description of all the species, synonyms, substrates, and localities in Ukraine and world distribution are also provided as well as the identification key. [ABSTRACT FROM AUTHOR]

The relationship between large herbivore numbers and landscape cover over time is poorly understood. There are two schools of thought: one views large herbivores as relatively passive elements upon the landscape and the other as ecosystem engineers driving vegetation succession. The latter relationship has been used as an argument to support reintroductions of large herbivores onto many landscapes in order to increase vegetation heterogeneity and biodiversity through local-scale disturbance regimes. Most of the research examining the relationship between large herbivores and their impact on landscapes has used extant studies. An alternative approach is to estimate the impact of variations in herbivore populations through time using fossil dung fungal spores and pollen in sedimentary sequences. However, to date, there has been little quantification of fossil dung fungal spore records and their relationship to herbivore numbers, leaving this method open to varied interpretations., In this study, we developed further the dung fungal spore method and determined the relationship between spore abundance in sediments (number cm−2 year−1) and herbivore biomass densities (kg ha−1). To establish this relationship, we used the following: (i) the abundance of Sporormiella spp., Sordaria spp. and Podospora spp. spores in modern sediments from ponds and (ii) weekly counts of contemporary wildlife over a period of 5 years from the rewilded site, Oostvaardersplassen, in the Netherlands., Results from this study demonstrate that there is a highly significant relationship between spore abundance and local biomass densities of herbivores that can be used in the calibration of fossil records. Mammal biomass density (comprising Konik horses, Heck cattle and red deer) predicts in a highly significant way the abundance of all dung fungal spores amalgamated together. This relationship is apparent at a very local scale (<10 m), when the characteristics of the sampled ponds are taken into account (surface area of pond, length of shoreline). In addition, we identify that dung fungal spores are principally transported into ponds by surface run-off from the shores., These results indicate that this method provides a robust quantitative measure of herbivore population size over time. [ABSTRACT FROM AUTHOR]

Controversy exists over the cause and timing of the extinction of the Pleistocene megafauna. In the tropical Andes, deglaciation and associated rapid climate change began ~8,000 years before human arrival, providing an opportunity to separate the effects of climate change from human hunting on megafaunal extinction. We present a paleoecological record spanning the last 25,000 years from Lake Pacucha, Peru (3,100 m elevation). Fossil pollen, charcoal, diatoms, and the dung fungus Sporormiella, chronicle a two-stage megaherbivore population collapse. Sporormiella abundance, the proxy for megafaunal presence, fell sharply at ~21,000 years ago, but rebounded prior to a permanent decline between ~16,800 and 15,800 years ago. This two-stage decline in megaherbivores resulted in a functional extinction by ~15,800 years ago, 3,000 years earlier than known human occupation of the high Andes. Declining megaherbivore populations coincided with warm, wet intervals. Climatic instability and megafaunal population collapse triggered an ecological cascade that resulted in novel floral assemblages, and increases in woody species, fire frequency, and plant species that were sensitive to trampling. Our data revealed that Andean megafaunal populations collapsed due to positive feedbacks between habitat quality and climate change rather than human activity. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The reconstruction of past pastoral activities based on microscopic methods (pollen and coprophilous fungal ascospores) does not accurately identify the domestic species involved. In contrast, source-specific DNA markers, commonly employed in water quality microbial source tracking (MST) studies, may represent a promising tool for retrospectively identifying species-specific fecal contamination in sediment deposition. In the present study, molecular methods were used to quantify Bacteroidales and identify ovine and bovine mitochondrial DNA extracted from sediment cores from two forest hollows comprising 2000 years of deposition. The DNA marker abundance was contrasted with the abundance of ascospores and plant-specific pollen throughout the sediment chronosequence. The distribution of DNA markers indicated an agro-pastoral practice transition from pasture/crop production to forested landscape from the second Iron Age/classical Antiquity to the end of the Roman period/modernity, in correlation with microscopic markers. During the second Iron Age/classical Antiquity, hollows were likely used to water herds, whereas during the late Antiquity, low Bacteroidales abundances and the sporadic detection of bovine and ovine DNA markers confirm the progressive afforestation observed using pollen data. For the end of the Roman period and modern times, reforested areas are characterized by the absence of ovine and bovine DNA markers while low Bacteroidales abundances suggest the presence of wild herbivores. The present study has established that in tandem with microscopic methods, sediment-archived fecal-specific bacterial and mitochondrial DNA are extremely useful for reconstructing agricultural practice over timeframes of millennia. [ABSTRACT FROM AUTHOR]

Fungi which produce their spores on the dung of large herbivores show promise as indicators of the distribution and relative abundance of large herbivores in past environments. Recently, several studies have used counts of spores of such fungi, Sporormiella in particular, to resolve the timing and reveal the ecological consequences of extinction of Pleistocene megafauna. However, there are several problems in the interpretation of the dung-fungus proxy, relating mostly to taphonomic effects on spore accumulation. Here, we describe these problems and show how they can be solved, using new data from the Lynch's Crater site in northeastern Australia. Effects of variation in spore accumulation in relation to position in the sedimentary basin can be controlled by comparing cores from different locations; temporal variation in spore accumulation rates can be attributed to changes in herbivore populations, as distinct from time-varying taphonomic effects, by comparing trends in fungi exclusively associated with herbivore dung to trends for fungi that also sporulate on other substrates; effects of changing vegetation composition can be removed by measuring spore influx rates rather than expressing counts relative to the pollen sum. At Lynch's Crater, these approaches increase our confidence that a decline in dung fungi at ∼40 ka indicates an unprecedented drop in biomass of large herbivores. We also show that before this decline, the biomass of large herbivores at this site was evidently similar to that in North America and western Europe. [ABSTRACT FROM AUTHOR]

The use of non-pollen palynomorphs, and among them spores of coprophilous fungi, has become greatly important in palaeoecological studies. Particularly, the genus Sporormiella has been demonstrated to be the most valuable proxy for the presence of wild and domestic herbivores. This genus could also be used to determine livestock density and reconstruct pastoral pressure during the Holocene. Non-standard counting methods have been established to determine coprophilous fungal spore abundance in sediments. Moreover, these analyses are faced with the recurrent problem of setting the minimum counting sum as small as possible to save time. We researched the reliability of Sporormiella concentration estimates based on different counting sums, using low to high count samples. Box-plots indicate that the variability of inferred Sporormiella concentrations decreases progressively with increasing sums. Statistical comparisons show that the means of box-plots became stabilised after the counts have reached 300-350 exotic marker grains. Moreover, a count of 300-350 exotic marker grains is sufficient to produce a Sporormiella concentration estimate, whatever the amount. Finally, we propose that this counting limit is valid for other fungal spores as well. [ABSTRACT FROM AUTHOR]

As a result of the late Quaternary megafaunal extinctions (50 000-10 000 before present ( BP)), most continents today are depauperate of megaherbivores. These extinctions were time-transgressive, size- and taxonomically selective, and were caused by climate change, human hunting, or both. The surviving megaherbivores often act as ecological keystones, which was likely true in the past. In spite of this and extensive research on the causes of the Late Quaternary Extinctions, the long-term ecological consequences of the loss of the Pleistocene megafauna remained unknown until recently, due to difficulties in linking changes in flora and fauna in paleorecords. The quantification of Sporormiella and other dung fungi have recently allowed for explicit tests of the ecological consequences of megafaunal extirpations in the fossil pollen record. In this paper, I review the impacts of the loss of keystone megaherbivores on vegetation in several paleorecords. A growing number of studies support the hypothesis that the loss of the Pleistocene megafauna resulted in cascading effects on plant community composition, vegetation structure and ecosystem function, including increased fire activity, novel communities and shifts in biomes. Holocene biota thus exist outside the broader evolutionary context of the Cenozoic, and the Late Quaternary Extinctions represent a regime shift for surviving plant and animal species. [ABSTRACT FROM AUTHOR]

Abstract: The importance of herbivory as a long-term driver of ecosystem change is a topic that has been hotly debated over the past few years. An understanding of the interaction between herbivores and ecosystems is particularly important for conservation policies aimed at re-wilding. Dung fungal spores have been highlighted as an important potential proxy to reconstruct large herbivore densities across past landscapes. However, this proxy appears to have been used and interpreted in a variety of ways in addition to highly variable taxonomic identification of dung fungal spores. Here we review studies that have utilised fungal spore assemblages to assess past herbivore presence and test the validity of this method. We aim to determine whether there is a set of identifiable dung fungal spores that can unequivocally track variation of large herbivore activity through time and across regions. Our meta-analysis identifies: (1) spore types that are commonly found to be indicative of large herbivores and their geographical ranges, (2) linkages between these spores and their biological origin, and (3) the most appropriate quantitative method to express their abundance for comparisons through time and across sites. [Copyright &y& Elsevier]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Abstract: Novel plant assemblages are a long-recognized feature of late-glacial North America, but identifying their causes has been hampered by inaccurate radiocarbon chronologies and the multiplicity of ecological and climatic events during the late Pleistocene. Recently we reported that the formation of no-analog vegetation may have been linked to declines in Pleistocene megafaunal communities, based on pollen and spores from the coprophilous fungus Sporormiella at sites in Indiana and New York. We present a new, multi-proxy analysis from Silver Lake, OH, which 1) updates the radiocarbon chronology of a classic pollen record with a well-established zone of no-analog vegetation, 2) combines a new sub-centennial pollen record with charcoal, Sporormiella, and x-ray fluorescence (XRF) spectroscopy analyses for an integrated record of landscape change before, during, and after the period of no-analog vegetation, and 3) replicates both the absolute and relative temporal patterns of landscape change at Appleman Lake, IN. At Silver Lake, the decline in Sporormiella at 13.9 ka BP was immediately followed by the formation of novel plant assemblages, as well as the highest-magnitude charcoal peak in the record. Increased Ca and Sr concentrations during the no-analog interval indicate either increased moisture, increased input of nutrients from deciduous litter, or both. The duration of the no-analog assemblages (13.9–11.8 ka BP) roughly corresponds to the period of peak insolation dissimilarity, but is more temporally constrained than previously reported in subcontinental-scale syntheses (17–11 ka BP). We propose a hierarchy of controls on late-glacial plant communities, where biotic interactions such as megaherbivory mediate climate-driven vegetation change. [Copyright &y& Elsevier]

The avifauna from the Glencrieff swamp deposit in North Canterbury, South Island, New Zealand, is described. Radiocarbon ages of moa bones bracket miring at the site to between 10,000 and 12,000 (uncalibrated) years BP. Heavy-footed moa (Pachyornis elephantopus) and eastern moa (Emeus crassus) dominated the moa assemblage at the site, while South Island giant moa (Dinornis robustus) and stout-legged moa (Euryapteryx curtus, formerly E. gravis (in part)) were rare. The total assemblage from the site consists of at least 1896 bones from 18 species of birds, of which nine are extinct and a further three locally extinct. In addition, we report on the discovery of the oldest known moa gizzard contents, the palynology of the Glencrieff deposit and comment on significant recent changes in site preservation conditions that are threatening the continued preservation of this significant fossil deposit. [ABSTRACT FROM AUTHOR]

Abstract: The Cochabamba Basin (Bolivia) is on the ancient road network connecting Andean and lowland areas. Little is known about the longevity of this trade route or how people responded to past environmental changes. The eastern end of the Cochabamba valley system constricts at the Vacas Lake District, constraining the road network and providing an ideal location in which to examine past human–environmental interactions. Multi-proxy analysis of sediment from Lake Challacaba has allowed a c. 4000year environmental history to be reconstructed. Fluctuations in drought tolerant pollen taxa and calcium carbonate indicate two periods of reduced moisture availability (c. 4000–3370 and c. 2190–1020calyr BP) compared to adjacent wetter episodes (c. 3370–2190 and c. 1020calyr BP–present). The moisture fluctuations broadly correlate to El Niño/Southern Oscillation variations reported elsewhere. High charcoal abundance from c. 4000 to 2000yr ago indicates continuous use of the ancient road network. A decline in charcoal and an increase in dung fungus (Sporormiella) c. 1340–1210calyr BP, suggests that cultural changes were a major factor in shaping the modern landscape. Despite undisputable impacts of human populations on the Polylepis woodlands today, we see no evidence of woodland clearance in the Challacaba record. [Copyright &y& Elsevier]

Abstract: This study proposes an ecological mechanism for the terminal Pleistocene population collapse and subsequent extinction of North American megafauna. Observations of modern ecosystems indicate that feedback mechanisms between plant nutrient content, nitrogen cycling, and herbivore–plant interactions can vary between a nutrient accelerating mode favoring increased herbivore biomass and a nutrient decelerating mode characterized by reduced herbivore biomass. These alternate modes are determined largely by plant nitrogen content. Plant nitrogen content is known to be influenced by atmospheric CO2 concentrations, temperature, and precipitation. It is argued that Lateglacial climate change, particularly increases in atmospheric CO2, shifted herbivore–ecosystem dynamics from a nutrient accelerating mode to a nutrient decelerating mode at the end of the Pleistocene, leading to reduced megafaunal population densities. An examination of Sporormiella records – a proxy for megaherbivore biomass – indicates that megafaunal populations collapsed first in the east and later in the west, possibly reflecting regional differences in precipitation or vegetation structure. The fortuitous intersection of the climatically driven nitrogen sink, followed by any one or combination of subsequent anthropogenic, environmental, or extra-terrestrial mechanisms could explain why extinctions took place at the end of the Pleistocene rather than during previous glacial–interglacial cycles. [Copyright &y& Elsevier]

Abstract: This study investigates stable carbon isotopes (δ 13C), 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 δ 13C 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 δ 13C values show that before cal 11ka, 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 10ka. 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 12ka, 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. [Copyright &y& Elsevier]