Vegetation dynamics and human activities over the past 1300 years revealed by pollen record at the Tongguan kilns, lower Xiangjiang River, China

Abstract

The Xiangjiang River region witnessed intensive economic and cultural activities in the past two millennia. In particular, the thriving ceramic production during the Tang Dynasty had a far-reaching impact on the local environment. However, the lack of palaeo-ecological and archaeological research at and around historical production sites hinders our understanding on the relationship between human activities and vegetation dynamics in this region. We examined the Shizhuping (SZP) profile at the Tongguan kilns, and conducted palynological analysis to reconstruct vegetation dynamics in response to human activities in the study area over the past 1300 years. Our results showed that mixed evergreen and deciduous broadleaf forest, which was primarily composed of Cyclobalanopsis and Quercus, was the dominant vegetation type at ca. 1300 a BP. From 1300 to 950 a BP, the percentage of arboreal pollen reduced considerably, while the percentage of pollen of herbaceous plant species including Poaceae, Artemisia, and Aster types increased significantly. The latter might be attributed to an increasingly arid climate, and intensified human activities during this period. Increased fuel demand due to the thriving porcelain production led to large scale wood logging and deforestation. During 950–600 a BP the percentage of pollen of plant species growing in wet habitats including hydrophytes (mainly Cyperaceae and Typha), ferns and freshwater algae increased significantly, which suggested a relatively wet condition and expansion of wetlands. However, due to the severe devegetation and the expansion of cultivated lands caused by rapid population growth from the previous phase, vegetation in this area did not experience an evident restoration under the favorable climate at this stage. Since 600 a BP, the content of Pinus increased significantly, exceeding that of broadleaf trees, which demonstrated that secondary pine forest was established in the mountain and/or hills around the Tongguan kilns. In addition, the increase in the percentages of human-related pollen types reflected the growing anthropogenic impact on the environment. We concluded that the native vegetation in the Tongguan kilns area had been severely affected by human activities especially porcelain production activity and agricultural reclamation since 1300 a BP, resulting in a deteriorating regional human-land relationship.