Climate and human induced 2000-year vegetation diversity change in Yunnan, southwestern China

The Holocene ◽  
2021 ◽  
pp. 095968362110417
Author(s):  
Yongbo Wang ◽  
Ying Xie ◽  
Xingqi Liu ◽  
Ji Shen ◽  
Yong Wang ◽  
...  
Keyword(s):  
Human Activities ◽  
Vegetation History ◽  
Southwestern China ◽  
Fossil Pollen ◽  
Pollen Assemblage ◽  
Vegetation Diversity ◽  
Climate Fluctuations ◽  
Isotope Record ◽  
Hill Numbers ◽  
Dominant Condition

Understanding long-term vegetation diversity patterns and their potential responses to climate and/or human driven processes are important for ecosystem modeling and conservation. Late-Holocene fossil pollen assemblage and associated vegetation diversity estimates provide an opportunity to explore the interactions among vegetation, climate, and human activities. A continuous 2000-year palynological record was obtained from the Beihai Wetland, southwestern China, to represent regional vegetation history, particularly the vegetation diversity changes. The results indicate that regional vegetation was dominated by deciduous broadleaved forest components (e.g. Alnus, deciduous Quercus), which showed a gradual decrease accompanied by expansion of herbaceous taxa (mainly Poaceae) after AD 800. Such progressive decline of forest was attributed to regional deforestation driven by intensified human activities, which was further confirmed by the increasing non-pollen polymorph abundance, particularly an abrupt rise after AD 1350. Vegetation diversity based on the Hill numbers ( N0, N1, and N2) showed a dramatic decline between ca. AD 200–400, which was triggered by regional fire events as shown by increased charcoal abundance from a nearby lake. The vegetation diversity reduced gradually after AD 800, especially the vegetation richness reflected by N0, revealing the transitional process from climate-driven to human-dominated vegetation changes. Minor increases of vegetation diversity occurred during Chinese dynastical transitions, probably due to reduced human activities following war-induced population crises. On the multidecadal scale, variations in vegetation diversity correlated significantly with climate fluctuations (revealed by synthesized temperature of China and stable oxygen isotope record from Dongge Cave) before AD 800, indicating a climate dominant condition. Then, the correlation between vegetation diversity and climate declined after AD 800, representing a progressive transition to human-dominant condition. In addition, the compositional turnover based on DCCA of the fossil pollen assemblage revealed a stepwise decrease, indicating reduced vegetation turnovers under anthropogenic influences.

Holocene vegetation history in the Northern Vosges Mountains (NE France): Palynological, geochemical and sedimentological data

The Holocene ◽  
2020 ◽  
Vol 30 (6) ◽  
pp. 888-904
Author(s):  
Emilie Gouriveau ◽  
Pascale Ruffaldi ◽  
Loïc Duchamp ◽  
Vincent Robin ◽  
Annik Schnitzler ◽  
...  
Keyword(s):  
Bronze Age ◽  
Human Activities ◽  
Vegetation History ◽  
Second Phase ◽  
Human Occupation ◽  
Vosges Mountains ◽  
The Past ◽  
History Of ◽  
Geochemical Analyses ◽  
Evolution Of Vegetation

Palynological data from the Northern Vosges Mountains (NVM) are very rare, unlike for the Southern and Central Vosges Mountains, where the past vegetation history is relatively well known. As a consequence, the beginning of human activities has never been clearly identified and dated in the NVM. In order to reconstruct the evolution of vegetation in this region, multiproxy studies (pollen, non-pollen palynomorphs, sedimentological and geochemical analyses) were conducted in two peatlands. Overall, the results, extending from about 9500 cal. BP to recent times, show a classical vegetation succession with local particularities resulting from human activities. In the La Horn peatland, a strong human impact related to pastoralism is attested from the late Bronze Age onwards. The second phase of human occupation, mainly characterized by crop cultures, begins during the Hallstatt period. The geochemical results (x-ray fluorescence) also highlight the presence of metallic elements, which, combined with significant quantities of carbonized particles, point to potential metal working. In the Kobert-Haut peatland, human occupation began much later (1500 cal. BP), but lasted from the Gallo-Roman period to the beginning of the Modern Period. Unlike for the vegetation history of the rest of the Vosges, Pinus remains a prevailing taxon throughout the Holocene in the NVM. Another particularity is the early establishment of Picea, long before the 18th to 19th century plantations.

Late Glacial/Early Holocene environmental changes in Thuringia, Germany: Stable isotope record and vegetation history

2009 ◽  
Vol 203 (1-2) ◽  
pp. 105-112 ◽  
Author(s):  
Tatjana Boettger ◽  
Achim Hiller ◽  
Frank W. Junge ◽  
Dietrich Mania ◽  
Konstantin Kremenetski
Keyword(s):  
Stable Isotope ◽  
Environmental Changes ◽  
Vegetation History ◽  
Late Glacial ◽  
Early Holocene ◽  
Isotope Record ◽  
Stable Isotope Record

Holocene to Middle Last Glaciation vegetation history at Tullabardine Dam, western Tasmania

1986 ◽  
Vol 229 (1255) ◽  
pp. 177-207 ◽  
Keyword(s):  
New Zealand ◽  
Lake Sediments ◽  
Pollen Analysis ◽  
Temperate Forest ◽  
Vegetation History ◽  
Late Glacial ◽  
Pollen Assemblage ◽  
Temperate Rainforest ◽  
Last Glaciation ◽  
Peat Swamp

Pollen analysis of 4 m of peat, swamp-soil and lake sediments dated from 0 to > 43800 years b.p. indicates the occurrence of three major pollen assemblage zones. During Zone 1 (11000-0 years b.p.) the area had temperate rainforest and the climate was warm, moist and interglacial. During Zone 2 ( ?25000-l 1000 years b.p.), correlated approximately with the last period of glaciation, the vegetation was mainly grassland and the climate was considerably colder than present. In late glacial times (14000-11000 years b.p.) pollen of shrub and tree taxa increased, especially during the later part of the period as the climate became warmer and moister. During Zone 3 (more than 4 3 0 0 0 -?25000 years b.p.) the vegetation was predominantly sub-alpine and alpine. This vegetation represents an interstadial assemblage for a lowland site. The climate was cool and moist. The results are compared with sites of similar age in Tasmania, and with sites from temperate forest environments in Chile and New Zealand.

scholarly journals Sedimentation and vegetation history of a buried Meuse terrace during the Holocene in relation to the human occupation history (Limburg, the Netherlands)

2016 ◽  
Vol 96 (2) ◽  
pp. 131-163 ◽  
Author(s):  
Frieda S. Zuidhoff ◽  
Johanna A.A. Bos
Keyword(s):  
Bronze Age ◽  
Middle Ages ◽  
Human Activities ◽  
Vegetation History ◽  
Roman Period ◽  
Early Holocene ◽  
Late Bronze Age ◽  
The Holocene ◽  
River Terraces ◽  
Main River Channel

AbstractDuring several archaeological excavations on a river terrace of the river Meuse near the village of Lomm (southeast Netherlands) information was gathered for a reconstruction of the sedimentation and vegetation history during the Holocene. Various geoarchaeological methods – geomorphological, micromorphological and botanical analyses – were applied, while accelerator mass spectrometry (AMS) 14C and optically stimulated luminescence (OSL) dating provided an accurate chronology for the sediments.During the Early Holocene, many former braided river channels were deepened due to climate amelioration. Later, river flow concentrated in one main river channel to the west, at the location of the modern Meuse. The other channels were only active during floods, and infilling continued until the Bronze Age. Because of the higher setting of the Lomm terrace, it was only occasionally flooded and therefore formed an excellent location for habitation. Humans adapted to the changing landscape, as most remains were found on the higher river terraces or their slopes, a short distance from the Maas river. The Lomm terrace was more or less continuously inhabited from the Mesolithic onwards.During the Early Holocene, river terraces were initially densely forested with birch and pine. From the Boreal (Mesolithic) onwards, dense mixed forests with deciduous shrubs and trees such as hazel, oak, elm and lime developed. During the Atlantic (Meso/Neolithic), the deciduous forests became dominated by oak. Due to human activities from the Late Subboreal (Late Bronze Age) onwards, forests slowly became more open, yet remained relatively dense in comparison to other Dutch areas. The botanical data, however, show that within the Lomm study area there was a large difference in the composition, distribution and openness of the vegetation. The spatial variation in openness came into existence during the Late Bronze Age, as soon as the higher areas started to be used for human activities (i.e. habitation, agriculture and livestock herding). Due to human activities, the northern part of the study area became very open during the Early Roman period. In the lower-situated areas of the southern part, however, forests remained present much longer, until the Early Middle Ages. Due to large-scale deforestation in the Lomm area and hinterland during the Roman period and Middle Ages, the sediment load of the river increased, large floods occurred and overbank sediments were deposited, burying the archaeological remains. The largest increase in sedimentation occurred after the Middle Ages.

scholarly journals Late Holocene vegetation changes in relation with climate fluctuations and human activities in Languedoc (Southern France)

2015 ◽  
Vol 11 (5) ◽  
pp. 4123-4157 ◽  
Author(s):  
J. Azuara ◽  
N. Combourieu-Nebout ◽  
V. Lebreton ◽  
F. Mazier ◽  
S. D. Müller ◽  
...  
Keyword(s):  
Bronze Age ◽  
Middle Ages ◽  
Iron Age ◽  
Human Activities ◽  
Late Holocene ◽  
Forest Cover ◽  
Forest Recovery ◽  
Southern France ◽  
Climate Fluctuations ◽  
Climatic Impacts

Abstract. Holocene climate fluctuations and human activities since the Neolithic have shaped present-day Mediterranean environments. Separating anthropogenic effects from climatic impacts to reconstruct Mediterranean paleoenvironments over the last millennia remains a challenging issue. High resolution pollen analyses were undertaken on two cores from the Palavasian lagoon system (Hérault, southern France). These records allow reconstruction of vegetation dynamics over the last 4500 years. Results are compared with climatic, historical and archeological archives. A long-term aridification trend is highlighted during the Late Holocene and three superimposed arid events are recorded at 4600–4300, 2800–2400 and 1300–1100 cal BP. These periods of climatic instability coincide in time with the rapid climatic events depicted in the Atlantic Ocean (Bond et al., 2001). From the Bronze Age (4000 cal BP) to the end of the Iron Age (around 2000 cal BP), the spread of evergreen taxa and loss of forest cover result from anthropogenic impact. The Antiquity is characterized by a major reforestation event related to the concentration of rural activities and populations in coastal plains leading to forest recovery in the mountains. A major regional deforestation occurred at the beginning of the High Middle Ages. Around 1000 cal BP, forest cover is minimal while cover of olive, chestnut and walnut expands in relation to increasing human influence. The present day vegetation dominated by Mediterranean shrubland and pines has been in existence since the beginning of the 20th century.

scholarly journals The modern pollen–vegetation relationship in Jammu, India: a comparative appraisal

2021 ◽  
Vol 61 (1) ◽  
pp. 1-19
Author(s):  
Md. Firoze Quamar ◽  
Pooja Tiwari ◽  
Biswajeet Thakur
Keyword(s):  
Deciduous Forest ◽  
Principal Component ◽  
Pollination Syndrome ◽  
Fossil Pollen ◽  
Pollen Assemblage ◽  
Long Distance ◽  
Modern Pollen ◽  
Long Distance Transport ◽  
High Production ◽  
Pollen Records

An understanding of the relationship between modern pollen and vegetation is a prerequisite for reconstruction of vegetation and climate change from fossil pollen records. We conducted palynological studies of thirty-five surface soil samples from the Jammu region of India, which revealed that Pinus, among the conifers (regional needle-leaved taxa), is over-represented in the pollen assemblage due to its high production and effective dispersal of pollen. Other coniferous and broadleaved (regional and/or extra-regional) taxa have comparatively lower values in the pollen assemblages, similar to the representation of subtropical deciduous forest elements (regional), as well as shrubby (regional and/or extra-regional) taxa. This inconsistency in the pollen assemblage could be due to long-distance transport of the former by wind and/or water from the higher reaches of the Himalayas, and also because the latter have an entomogamous pollination syndrome and are not high pollen producers. The recovered pollen assemblage presents a distorted picture of the extant vegetation; hence, caution should be exercised in interpreting fossil pollen records from the study area. Principal component analysis (PCA) shows variability in the distribution of pollen from different sites in the Jammu region, perhaps the result of transport (by wind and/ or water), altitude and/or edaphic factors of the Himalayan terrain. The study should improve our understanding of the modern pollen-vegetation relationship and aid further calibration and interpretation of fossil pollen records.

scholarly journals Landscape change and vegetation history in the city of Lisbon during Roman times and the Early Medieval Period

The Holocene ◽  
2020 ◽  
Vol 31 (1) ◽  
pp. 134-144
Author(s):  
Andrés Currás ◽  
Ana Maria Costa ◽  
Maria da Conceição Freitas ◽  
Randi Danielsen ◽  
Jacinta Bugalhão
Keyword(s):  
Land Use ◽  
Human Activities ◽  
Landscape Change ◽  
Vegetation History ◽  
Landscape Changes ◽  
Medieval Period ◽  
Early Medieval Period ◽  
Sedimentary Deposits ◽  
Socioeconomic Transformation ◽  
The City

Pollen and NPP analysis performed on the sedimentary deposits accumulated in the inter-tidal banks of the Tagus Estuary allow for the reconstruction of vegetation history and landscape changes that occurred in Lisbon from the 1st to the 6th century cal AD. The high chronological resolution of this investigation makes it possible to identify changes in human activities that took place during the Roman period and reveals the extent of land use in the 2nd century cal AD. However, the most considerable landscape transformation of this 600-year period dates back to the late 5th century cal AD, when significant deforestation and increasing human activity, particularly pasturing, spread throughout the territory. This feature bears witness to the outcome of a deep socioeconomic transformation following the disintegration of the Roman administration and sheds light on a poorly known period in this part of Iberia.

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