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1.
Nat Plants ; 8(3): 204-208, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35318448

RESUMO

The olive tree was an iconic plant for most of the past Mediterranean civilizations, for which it had important economic value. Here we report the earliest use of fruits and wood from olive trees in Africa so far, around 100,000 years ago. These findings suggest the presence of olive trees on the Atlantic coast of Morocco during most of the last glacial period, and the use of olives by the early Homo sapiens for fuel management and most probably for consumption.


Assuntos
Olea , África , Frutas
2.
Sci Rep ; 8(1): 716, 2018 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-29335417

RESUMO

8000 years ago, prior to Neolithic agriculture, Europe was mostly a wooded continent. Since then, its forest cover has been progressively fragmented, so that today it covers less than half of Europe's land area, in many cases having been cleared to make way for fields and pasture-land. Establishing the origin of Europe's current, more open land-cover mosaic requires a long-term perspective, for which pollen analysis offers a key tool. In this study we utilise and compare three numerical approaches to transforming pollen data into past forest cover, drawing on >1000 14C-dated site records. All reconstructions highlight the different histories of the mixed temperate and the northern boreal forests, with the former declining progressively since ~6000 years ago, linked to forest clearance for agriculture in later prehistory (especially in northwest Europe) and early historic times (e.g. in north central Europe). In contrast, extensive human impact on the needle-leaf forests of northern Europe only becomes detectable in the last two millennia and has left a larger area of forest in place. Forest loss has been a dominant feature of Europe's landscape ecology in the second half of the current interglacial, with consequences for carbon cycling, ecosystem functioning and biodiversity.


Assuntos
Biodiversidade , Florestas , Dispersão Vegetal , Plantas/classificação , Densidade Demográfica , Europa (Continente) , Fósseis , Humanos , Pólen , Datação Radiométrica
3.
Glob Chang Biol ; 21(2): 676-97, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25204435

RESUMO

We present quantitative reconstructions of regional vegetation cover in north-western Europe, western Europe north of the Alps, and eastern Europe for five time windows in the Holocene [around 6k, 3k, 0.5k, 0.2k, and 0.05k calendar years before present (bp)] at a 1° × 1° spatial scale with the objective of producing vegetation descriptions suitable for climate modelling. The REVEALS model was applied on 636 pollen records from lakes and bogs to reconstruct the past cover of 25 plant taxa grouped into 10 plant-functional types and three land-cover types [evergreen trees, summer-green (deciduous) trees, and open land]. The model corrects for some of the biases in pollen percentages by using pollen productivity estimates and fall speeds of pollen, and by applying simple but robust models of pollen dispersal and deposition. The emerging patterns of tree migration and deforestation between 6k bp and modern time in the REVEALS estimates agree with our general understanding of the vegetation history of Europe based on pollen percentages. However, the degree of anthropogenic deforestation (i.e. cover of cultivated and grazing land) at 3k, 0.5k, and 0.2k bp is significantly higher than deduced from pollen percentages. This is also the case at 6k in some parts of Europe, in particular Britain and Ireland. Furthermore, the relationship between summer-green and evergreen trees, and between individual tree taxa, differs significantly when expressed as pollen percentages or as REVEALS estimates of tree cover. For instance, when Pinus is dominant over Picea as pollen percentages, Picea is dominant over Pinus as REVEALS estimates. These differences play a major role in the reconstruction of European landscapes and for the study of land cover-climate interactions, biodiversity and human resources.


Assuntos
Biodiversidade , Mudança Climática , Modelos Teóricos , Dispersão Vegetal , Europa (Continente) , Pólen
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