- Email: [email protected]
Contrasting modern and Holocene denudation rates for small river basins in Southeast Spain
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Abstracts / Quaternary International 279-280 (2012) 9–120
Recent advances in ultra-high-throughput DNA sequencing technology and in species identification (‘barcoding’) tools based on ancient DNA preserved in permafrost soils are opening up a novel research avenue for paleoecological reconstruction. This project is part of the BarFrost (Barcoding of permafrost) project, which aims at reconstructing past ecosystems based on pyrosequencing several groups of organisms (bryophytes, fungi, insects, vertebrates) preserved in dated permafrost cores. We have developed new DNA barcoding markers that are specific for fungi and short enough to amplify from degraded DNA. Reference databases such as UNITE will be used for species identification. Vascular plant data will soon be available from a European project (Ecochange) and we will amplify fungi from the same permafrost cores to facilitate direct comparison between the historic plant and fungal communities. A high proportion of fungal diversity is known to be associated with plants, as mycorrhizal symbionts, parasites, endophytes or decomposers. Hence, a shift in the plant composition due to e.g. climate change is expected to lead to changes in the fungal communities. The aims of this project are: 1) to investigate to what degree the historic plant and fungal communities are associated; 2) to assess to what degree the fungal communities change through time and 3) to evaluate the dominance of different fungal functional groups in permafrost cores from various sites (Siberia, Alaska, Greenland, Svalbard), various ages and various systems such as rivers, lakes, tundras, and forests. Preliminary results from Ecochange suggest that the reconstructions will be considerably improved compared to traditional fossil analyses. The results can therefore have immediate bearing on various central ecological issues, such as past species turnover dynamics in assemblages, niche stability in time and space, and backward testing of predictive species distribution models. CONTRASTING MODERN AND HOLOCENE DENUDATION RATES FOR SMALL RIVER BASINS IN SOUTHEAST SPAIN
faunal endemism. The ability of humans to transverse biogeographic corridors or to be impeded by them is evident by similarities or differences in typo-technological cultures across regions. Comparison of the cultural and biochronological relationships between the Southern Levant and the Caucasus was based on analyses of lithic and faunal remains from a new site from the Lower Paleolithic of Armenia compared to earlier and later sites in the two regions. Kurtan is a new Lower Paleolithic site situated in the Lori Plateau of Armenia. Fossil and artifact bearing sediments overlie a pumiceous volcanic ash, which provides a lower age estimate for the deposits. The site yielded ca. 200 lithic artifacts, which included choppers, picks, core scrapers and primitive small tools as well as a rather large unique handaxe. The lithic assemblage is attributed to the Early-Middle Acheulian tradition with typo-technological similarities with sites in the Southern Levant, and specifically Latamne in Syria (ca. 1 Ma). Indicative fauna recovered from the sediments provides a biochronological date for the site ca. 1.4-0.8 Ma. Analysis of the lithic and faunal materials was augmented with additional fauna, housed in the Geological Museum of the Institute of Geological Sciences, National Academy of Sciences of The Republic of Armenia in Yerevan. Results suggest that biogeographic corridor between the Levant and the Caucasus was present during the Early Pleistocene; however, this biogeographic corridor may not have existed during the Middle Paleolithic. The presence or absence of such a corridor has implication for human dispersal patterns between the two regions and the development of local refugia. THE BULL CREEK VALLEY STREAM TERRACES, BURIED SOILS, AND PALEO-ENVIRONMENT DURING THE YOUNGER DRYAS IN THE OKLAHOMA PANHANDLE, USA Lee Bement. University of Oklahoma, United States E-mail address: [email protected]
Nicolas Bellin. Earth and Life Institute, Georges Lemaître Centre, Belgium E-mail address: [email protected]
Temporal changes in Holocene and modern erosion rates can learn us about the drivers of desertification in semi-arid environments. In Europe, Southeast Spain was identified as one of the regions with major treat of desertification in the context of future land use and climate change. During the last decades, significant progress has been made to understand spatial patterns of modern erosion rates in this kind of semi-arid degraded environments. Numerous European projects have contributed to the collection of modern erosion data at different spatial scales for Southeast Spain. However, these data are rarely analysed in the context of long-term changes in vegetation, climate and human occupation in that region. In this paper, we present modern and Holocene denudation rates for fifteen small river basins (1 to 10 km2) located in the Spanish Betic Cordillera. Long-term erosion data were derived from cosmogenic nuclide analyses of river-borne sediment. Modern erosion data were quantified through analysis of sediment deposition volumes behind checkdams, and represent average erosion rates over the last 10 to 40 years. Our data show that modern erosion rates are surprisingly low (1.35 t/ha/year; n¼36), given the rough topography of the Betic Cordillera. Preliminary data indicate that Holocene erosion rates are roughly of the same magnitude, but show strong spatial variation. Contrasting modern with Holocene erosion rates indicates that land degradation is a complex phenomenon, and that Holocene changes in vegetation, climate and human occupation should be considered in order to fully understand the present state of the environment. EARLY PLEISTOCENE CULTURAL CONNECTIONS BETWEEN THE LEVANT AND THE LESSER CAUCASUS: NEW EVIDENCE FROM A NEW LOWER PALEOLITHIC LOCALITY IN KURTAN, LORI PLATEAU, ARMENIA
Controversy exists over a recent hypothesis that an extra-terrestrial (ET) event initiated, or at least coincided with the onset of the Younger Dryas chronozone (YDC). Sites across the USA, including the Bull Creek Valley (BCV) contain ET event markers, including nanodiamonds, in buried soils and sediments. However, several unanswered questions remain including: Does the distribution of nanodiamonds correlate with other environmental events or only the YDC? Does evidence exist for a disruptive event at w11,000 rybp within the BCV? Radiocarbon analyses from the upper 10 cm of buried BCV soils indicate that these soil surfaces were buried from 18,000 to 6,200 rybp. A nanodiamond spike was identified by Kennett et al. (2009) in an 11,070+60 rybp buried BCV soil horizon. A short duration aeolian event occurred immediately after burial of this soil. Particle-size analysis identifies alluvial and colluvial deposition prior to 13,210 through 9,850 rybp, changing to loess deposition after 9,850 through at least 6,200 rybp. The pollen data identifies the Bolling/Allerod warm period; the beginning of the YDC; and beginning of the early Holocene. Phytoliths suggest that prior to 11,070 rybp the valley contained a cool-season grassland with an understory of perennial warm-season grasses and forbs. Between 11,070 through 10,400 rybp, the cool-season dominated grassland contained more perennial warm-season grasses compared to the pre11,070 rybp period. After 10,400 rybp a mixed cool/warm season grassland occurred including numerous forbs. The occurrence of bison, camel, and mammoth remains before 11,070, but only bison after that time; the positive correlation of 13C/12C from buried soils with the changes in icecore oxygen isotopes; and the presence of a short-lived aeolian event with poor pollen preservation immediately after 11,070 rybp identify a disruption at w11,000 rybp, however a long-lasting perturbation is not observed in overall plant assemblages. LATE PLEISTOCENE RELATIVE SEA LEVEL HIGH STAND DEPOSITS OF PORTUGUESE ESTREMADURA
Miriam Belmaker. Harvard University, United States E-mail address: [email protected]
Michael Benedetti. University of North Carolina Wilmington, United States E-mail address: [email protected]
The Levant is a unique biogeographic entity within southwestern Asia situated at the crossroads of Africa and Eurasia. Geological changes altered the “permeability” of this land bridge. Periods of biogeographic connections are visible by more homogenous fauna compared to periods of high
Evidence from the Estremadura coast of central Portugal records relative sea level changes and widespread landscape instability during the last glacial stage, Marine Isotope Stages 2-5 (MIS 2-5). High stand deposits
Abstracts / Quaternary International 279-280 (2012) 9–120
Recent advances in ultra-high-throughput DNA sequencing technology and in species identification (‘barcoding’) tools based on ancient DNA preserved in permafrost soils are opening up a novel research avenue for paleoecological reconstruction. This project is part of the BarFrost (Barcoding of permafrost) project, which aims at reconstructing past ecosystems based on pyrosequencing several groups of organisms (bryophytes, fungi, insects, vertebrates) preserved in dated permafrost cores. We have developed new DNA barcoding markers that are specific for fungi and short enough to amplify from degraded DNA. Reference databases such as UNITE will be used for species identification. Vascular plant data will soon be available from a European project (Ecochange) and we will amplify fungi from the same permafrost cores to facilitate direct comparison between the historic plant and fungal communities. A high proportion of fungal diversity is known to be associated with plants, as mycorrhizal symbionts, parasites, endophytes or decomposers. Hence, a shift in the plant composition due to e.g. climate change is expected to lead to changes in the fungal communities. The aims of this project are: 1) to investigate to what degree the historic plant and fungal communities are associated; 2) to assess to what degree the fungal communities change through time and 3) to evaluate the dominance of different fungal functional groups in permafrost cores from various sites (Siberia, Alaska, Greenland, Svalbard), various ages and various systems such as rivers, lakes, tundras, and forests. Preliminary results from Ecochange suggest that the reconstructions will be considerably improved compared to traditional fossil analyses. The results can therefore have immediate bearing on various central ecological issues, such as past species turnover dynamics in assemblages, niche stability in time and space, and backward testing of predictive species distribution models. CONTRASTING MODERN AND HOLOCENE DENUDATION RATES FOR SMALL RIVER BASINS IN SOUTHEAST SPAIN
faunal endemism. The ability of humans to transverse biogeographic corridors or to be impeded by them is evident by similarities or differences in typo-technological cultures across regions. Comparison of the cultural and biochronological relationships between the Southern Levant and the Caucasus was based on analyses of lithic and faunal remains from a new site from the Lower Paleolithic of Armenia compared to earlier and later sites in the two regions. Kurtan is a new Lower Paleolithic site situated in the Lori Plateau of Armenia. Fossil and artifact bearing sediments overlie a pumiceous volcanic ash, which provides a lower age estimate for the deposits. The site yielded ca. 200 lithic artifacts, which included choppers, picks, core scrapers and primitive small tools as well as a rather large unique handaxe. The lithic assemblage is attributed to the Early-Middle Acheulian tradition with typo-technological similarities with sites in the Southern Levant, and specifically Latamne in Syria (ca. 1 Ma). Indicative fauna recovered from the sediments provides a biochronological date for the site ca. 1.4-0.8 Ma. Analysis of the lithic and faunal materials was augmented with additional fauna, housed in the Geological Museum of the Institute of Geological Sciences, National Academy of Sciences of The Republic of Armenia in Yerevan. Results suggest that biogeographic corridor between the Levant and the Caucasus was present during the Early Pleistocene; however, this biogeographic corridor may not have existed during the Middle Paleolithic. The presence or absence of such a corridor has implication for human dispersal patterns between the two regions and the development of local refugia. THE BULL CREEK VALLEY STREAM TERRACES, BURIED SOILS, AND PALEO-ENVIRONMENT DURING THE YOUNGER DRYAS IN THE OKLAHOMA PANHANDLE, USA Lee Bement. University of Oklahoma, United States E-mail address: [email protected]
Nicolas Bellin. Earth and Life Institute, Georges Lemaître Centre, Belgium E-mail address: [email protected]
Temporal changes in Holocene and modern erosion rates can learn us about the drivers of desertification in semi-arid environments. In Europe, Southeast Spain was identified as one of the regions with major treat of desertification in the context of future land use and climate change. During the last decades, significant progress has been made to understand spatial patterns of modern erosion rates in this kind of semi-arid degraded environments. Numerous European projects have contributed to the collection of modern erosion data at different spatial scales for Southeast Spain. However, these data are rarely analysed in the context of long-term changes in vegetation, climate and human occupation in that region. In this paper, we present modern and Holocene denudation rates for fifteen small river basins (1 to 10 km2) located in the Spanish Betic Cordillera. Long-term erosion data were derived from cosmogenic nuclide analyses of river-borne sediment. Modern erosion data were quantified through analysis of sediment deposition volumes behind checkdams, and represent average erosion rates over the last 10 to 40 years. Our data show that modern erosion rates are surprisingly low (1.35 t/ha/year; n¼36), given the rough topography of the Betic Cordillera. Preliminary data indicate that Holocene erosion rates are roughly of the same magnitude, but show strong spatial variation. Contrasting modern with Holocene erosion rates indicates that land degradation is a complex phenomenon, and that Holocene changes in vegetation, climate and human occupation should be considered in order to fully understand the present state of the environment. EARLY PLEISTOCENE CULTURAL CONNECTIONS BETWEEN THE LEVANT AND THE LESSER CAUCASUS: NEW EVIDENCE FROM A NEW LOWER PALEOLITHIC LOCALITY IN KURTAN, LORI PLATEAU, ARMENIA
Controversy exists over a recent hypothesis that an extra-terrestrial (ET) event initiated, or at least coincided with the onset of the Younger Dryas chronozone (YDC). Sites across the USA, including the Bull Creek Valley (BCV) contain ET event markers, including nanodiamonds, in buried soils and sediments. However, several unanswered questions remain including: Does the distribution of nanodiamonds correlate with other environmental events or only the YDC? Does evidence exist for a disruptive event at w11,000 rybp within the BCV? Radiocarbon analyses from the upper 10 cm of buried BCV soils indicate that these soil surfaces were buried from 18,000 to 6,200 rybp. A nanodiamond spike was identified by Kennett et al. (2009) in an 11,070+60 rybp buried BCV soil horizon. A short duration aeolian event occurred immediately after burial of this soil. Particle-size analysis identifies alluvial and colluvial deposition prior to 13,210 through 9,850 rybp, changing to loess deposition after 9,850 through at least 6,200 rybp. The pollen data identifies the Bolling/Allerod warm period; the beginning of the YDC; and beginning of the early Holocene. Phytoliths suggest that prior to 11,070 rybp the valley contained a cool-season grassland with an understory of perennial warm-season grasses and forbs. Between 11,070 through 10,400 rybp, the cool-season dominated grassland contained more perennial warm-season grasses compared to the pre11,070 rybp period. After 10,400 rybp a mixed cool/warm season grassland occurred including numerous forbs. The occurrence of bison, camel, and mammoth remains before 11,070, but only bison after that time; the positive correlation of 13C/12C from buried soils with the changes in icecore oxygen isotopes; and the presence of a short-lived aeolian event with poor pollen preservation immediately after 11,070 rybp identify a disruption at w11,000 rybp, however a long-lasting perturbation is not observed in overall plant assemblages. LATE PLEISTOCENE RELATIVE SEA LEVEL HIGH STAND DEPOSITS OF PORTUGUESE ESTREMADURA
Miriam Belmaker. Harvard University, United States E-mail address: [email protected]
Michael Benedetti. University of North Carolina Wilmington, United States E-mail address: [email protected]
The Levant is a unique biogeographic entity within southwestern Asia situated at the crossroads of Africa and Eurasia. Geological changes altered the “permeability” of this land bridge. Periods of biogeographic connections are visible by more homogenous fauna compared to periods of high
Evidence from the Estremadura coast of central Portugal records relative sea level changes and widespread landscape instability during the last glacial stage, Marine Isotope Stages 2-5 (MIS 2-5). High stand deposits