THE AFFECT OF LAND USE CHANGE ON STABLE ISOTOPE (δ13C AND δ15N) VALUES IN CONNECTICUT WETLANDS DURING THE HOLOCENE

Anthropogenic land-use change and ecosystem management have a demonstrable impact on modern fire regimes. However, when in time this influence was first felt is still an open question. We investigate whether an anthropogenic signal can be identified in Holocene fire records from the Iberian Peninsula, a region with abundant palaeoenvironmental and archaeological data. We analyse sedimentary charcoal data from 49 sites across the Peninsula covering part or all of the past 12,000 years to construct the fire history for the region. We compare these records to the summed probabilities of radiocarbon-dated archaeological sites, which provides an index for changes in human impact on land use and land cover due to the growth or decrease in human population through time. This reconstruction is based on 8200 radiocarbon dates covering the timespan between12000 and 3500 uncal BP.&#160; Our analyses confirm that the broad trends in fire history are well aligned with the likely impact of climate changes during the Holocene. The charcoal records indicate a rapid increase in fire at the end of the Younger Dryas, a reduction in fire during the middle Holocene as a result of wetter conditions across the Peninsula, and an increase in fire concordant with the increased aridity registered during the interval after 3000 yr BP. However, finer-scale temporal variations are superimposed upon these broadscale changes. Similarly, although the most pronounced change in population reflects population growth associated with the onset of agriculture in the mid-Holocene, the summed probability record of population shows considerable finer-scale temporal variation. In addition to analyses of the temporal correlations between the two data sets, we consider whether there are distinct geographic patterns that could provide additional insights into the relationship between human activities and fire across Iberia.

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Contribution of forcings to Holocene climate evolution

10.5194/egusphere-egu21-4304 ◽

2021 ◽

Author(s):

Peter Hopcroft ◽

Paul Valdes

Keyword(s):

Land Use ◽

Land Use Change ◽

General Circulation ◽

Volcanic Eruptions ◽

Reconstruction Method ◽

Major Advance ◽

Model Ensemble ◽

The Holocene ◽

The Past ◽

Climate Evolution

The climate evolution of the past few thousand years is essential for understanding the context in which civilisation arose and for understanding the natural background of anthropogenic influence. Proxy-inferred records show a complex picture of earlier warming and later cooling during the Holocene depending on region and reconstruction method. In contrast climate model simulations almost uniformly show warming throughout the past 10,000 years and for example also fail to reproduce a major advance of rainbelt over the Sahara. &#160;These discrepancies raise questions about the reliability of climate models on longer-time scales.We present a suite of four new transient Holocene simulations covering the last 8500 years using the HadCM3B-M21aD coupled general circulation. We use an optimised version of this model which is able to replicate the greening of the Sahara through changes to the atmospheric convection and vegetation schemes. We apply transient changes in Earth&#8217;s orbit, ice-sheets and sea-level and greenhouse gases, and optionally solar output, volcanic eruptions and anthropogenic land-use change. &#160;The simulations without land-use show a warming throughout the Holocene, albeit with significantly higher variability once volcanic eruptions are included. With the inclusion of land-use change temperature trends in Northern Hemisphere are reversed from around 4000 years before present.We explore the contribution of different forcings to the regional trends in the model ensemble and we compare the simulations against the Holocene reconstructions to evaluate the relative importance of each forcing. We also use the model ensemble to quantify the terrestrial coverage of proxy locations that is required to reliably infer global mean temperature variations.

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Stable isotope analysis of vegetation history and land use change at Laguna Santa Elena in southern Pacific Costa Rica

Vegetation History and Archaeobotany ◽

10.1007/s00334-019-00755-0 ◽

2019 ◽

Vol 29 (4) ◽

pp. 477-492 ◽

Cited By ~ 1

Author(s):

Matthew T. Kerr ◽

Sally P. Horn ◽

Chad S. Lane

Keyword(s):

Land Use ◽

Costa Rica ◽

Stable Isotope ◽

Land Use Change ◽

Stable Isotope Analysis ◽

Vegetation History ◽

Isotope Analysis ◽

Santa Elena

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Autogenic succession, land-use change, and climatic influences on the Holocene development of a kettle-hole mire in Northern Poland

Review of Palaeobotany and Palynology ◽

10.1016/j.revpalbo.2008.01.009 ◽

2008 ◽

Vol 151 (1-2) ◽

pp. 21-40 ◽

Cited By ~ 78

Author(s):

Mariusz Lamentowicz ◽

Milena Obremska ◽

Edward A.D. Mitchell

Keyword(s):

Land Use ◽

Land Use Change ◽

The Holocene ◽

Kettle Hole ◽

Northern Poland ◽

Autogenic Succession

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Effects of land-use change on soil organic carbon and nitrogen in density fractions and soil δ13C and δ15N in semiarid grasslands

Plant and Soil ◽

10.1007/s11104-015-2435-3 ◽

2015 ◽

Vol 390 (1-2) ◽

pp. 419-430 ◽

Cited By ~ 17

Author(s):

Liping Qiu ◽

Xiaorong Wei ◽

Tiane Ma ◽

Yanchun Wei ◽

Robert Horton ◽

...

Keyword(s):

Land Use ◽

Organic Carbon ◽

Land Use Change ◽

Soil Organic Carbon ◽

Δ13c And Δ15n ◽

Density Fractions ◽

Carbon And Nitrogen ◽

Effects Of Land Use

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Biospheric Sustainability in a Changing World

People and the Land through Time ◽

10.12987/yale/9780300225808.003.0011 ◽

2019 ◽

pp. 197-218

Author(s):

Emily W. B. Russell Southgate

Keyword(s):

United States ◽

Land Use ◽

Land Use Change ◽

Species Composition ◽

Plant Communities ◽

Critical Factor ◽

Human Populations ◽

Northeastern United States ◽

The Holocene ◽

Time Changes

This chapter discusses the concept of sustainability using as a specific example concerns about the sustainability of oak-dominated forests in the northeastern United States. The discussion from the first edition is updated with current research, leading to the conclusion that climate is the most critical factor in determining species ranges even in human-dominated landscapes, and that fluctuations during the Holocene have been reflected not only in altered species composition of forests, but also in human populations and thus land use. At the same time, changes wrought by people have influenced decadal dynamics, such as secondary successional patterns, and often all but eliminated species within some plant communities, by land use change. Merely comparing present to inferred processes in the past misses vital factors in change; inference must be supported by historical data. Worldwide, droughts inferred from multi-proxy data can be correlated with declines in human populations as well as with changed vegetation, regardless of the complexity of the civilizations and agricultural systems. Managing systems for sustainability, requires consideration of legacies left by past land use.

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Soil carbon and nitrogen under different land-use and landscape loca-tions in central Brazil

Journal of Biotechnology and Biodiversity ◽

10.20873/jbb.uft.cemaf.v9n2.santos ◽

2021 ◽

Vol 9 (2) ◽

pp. 178-186

Author(s):

Fábio Luís de Souza Santos ◽

Antônio Felipe Couto Júnior ◽

Adriana Reatto ◽

Éder de Souza Martins ◽

Arminda Moreira de Carvalho ◽

...

Keyword(s):

Land Use ◽

Organic Matter ◽

Soil Organic Matter ◽

Stable Isotope ◽

Isotope Ratios ◽

Native Vegetation ◽

Stable Isotope Ratios ◽

Δ13c And Δ15n ◽

Central Brazil ◽

C And N

In Central Brazil, plateaus, the most common geomorphologic form, have been undergoing intense conversion from native vegetation to pasture and agriculture in recent decades. We used carbon stable isotope ratios (δ13C) and nitrogen stable isotope ratios (δ15N) to assess possible changes in soil organic matter dynamics under such land use modifications. This study aimed to evaluate the differences in soil δ13C and δ15N and C and N stocks between native vegetation and agricultural or pasture areas in different locations of a plateau in the savannas of Central Brazil. We sampled soil up to 100 cm depth in pasture areas in the summit of the plateau and no-tillage and conventional tillage on the border of a plateau, as well as soils under native vegetation in both landscape locations. Both soil δ13C and δ15N, and C and N stocks showed no differences between land uses. The different relationships between δ15N and C/N ratio at different locations indicated distinct behavior of the soil organic matter between the summit and border of the plateau. Therefore, in addition to land-use, landscape location contributes to both δ13C and δ15N, and C and N stocks in the soil of the plateau.

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Environmental factors influencing δ13C and δ15N in three Chesapeake Bay fishes

ICES Journal of Marine Science ◽

10.1093/icesjms/fst143 ◽

2013 ◽

Vol 71 (3) ◽

pp. 689-702 ◽

Cited By ~ 6

Author(s):

Lori A. Davias ◽

Matthew S. Kornis ◽

Denise L. Breitburg

Keyword(s):

Land Use ◽

Stable Isotope ◽

Environmental Factors ◽

Chesapeake Bay ◽

Fundulus Heteroclitus ◽

White Perch ◽

Isotope Analysis ◽

Habitat Type ◽

Trophic Relationships ◽

Δ13c And Δ15n

Abstract Stable isotope analysis has become a common tool for mapping trophic relationships, describing foodweb changes, and assessing ecosystem health. Clear interpretation of stable isotopes is facilitated by understanding how environmental factors can affect isotopic values; in estuarine systems, these factors may include salinity, land use, and shoreline habitat. To evaluate these factors, fish were collected from shallow-water habitats next to hardened (bulkhead and riprap) and unhardened (beach and marsh) shorelines within five subestuaries of the Chesapeake Bay that differed in predominant land use and salinity. This study focused on three common mid-Atlantic fish species: mummichog, Fundulus heteroclitus, Atlantic silverside, Menidia menidia, and white perch, Morone americana. Multiple regression analyses pointed to standard length, salinity, % of watershed as developed or crop land, and shoreline habitat type as important predictors for δ15N in all three species and for δ13C in mummichog and white perch. Further analysis controlling for the effects of salinity, land use, and fish size demonstrated that δ13C and δ15N were lower in tissues of fish collected next to marsh compared with hardened or beach habitat. Habitat effects were strongest for mummichog. This study focused on overarching patterns driving stable isotope signatures in fish; however, it also indicated potentially important interactions between nearshore habitat type and land use or salinity that deserve further analysis. Results have implications for the scale of isotope inquiry and give justification for more detailed follow-up studies of foodweb structure along modified and natural shorelines.

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