The Holocene Spread of Spruce in Scandinavia
The Holocene Spread of Spruce in Scandinavia
复制标题
全新世云杉在斯堪的纳维亚半岛的传播
DOI:
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发表时间:
2004
期刊:
影响因子:
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通讯作者:
T. Giesecke
中科院分区:
文献类型:
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作者:
T. Giesecke
The Holocene increase in Picea abies around four central Swedish lakes was analysed using extended pollen counts over the sections comprising the tail of frequent, but discontinuous, occurrences and the beginning of the continuous curve. Simple landscape scenarios were simulated to test possible mechanisms of the spread and population expansion of P. abies in Scandinavia. Predicted patterns of pollen accumulation rates from the landscape scenarios were compared to patterns observed at the four sites to explore how the observed curves could have come about. Simulations of a moving front scenario indicate that pollen accumulation rates should rise faster than the exponential and logistic increase observed at the four sites. Exponential increase of pollen values at the sites is most likely due to locally increasing populations. However, the geography of expanding populations may influence the shape of the curve. Empirical and model results are discussed to gain new insights into the pattern and processes of the spread of P abies in central Sweden. Propagule pressure and self-fertilisation are considered as possible explanations of why small outpost populations that may have existed before the regional expansion of P. abies did not expand earlier.