Instrumental records indicate a close relationship between the El Niño‐Southern Oscillation and the East Asian winter monsoon (EAWM) on interannual to decadal time scales. However, few studies have examined possible links between them on centennial/millennial time scales. In Northeast China, modern observations show that the immigration of temperate forest trees such as Pinus (pine) and Quercus (oak) into cold temperate boreal forest is sensitive to changes in winter temperature. Here we present a continuous high‐resolution pollen record from Lake Moon in the central part of the Great Khingan Mountain Range, Northeast China. The record reveals increasing contents of Pinus and Quercus pollen after ~6.0 ka cal. BP, which may indicate a gradual weakening of the EAWM. It is broadly coupled with an increasing El Niño frequency since the middle Holocene, and we observe a statistically significant correlation between the percentages of Pinus and Quercus and a time series of El Niño events. On the centennial to millennial time scale, the results of wavelet analysis and band‐pass filtering show that the occurrence and development of El Niño have also promoted a weaker EAWM after ~6.0 ka cal. BP, which is inversely correlated with the variation of the ca. 500‐year cycle originated from changes in solar output. These results imply that the climate transition in the mid‐Holocene is caused by the change of variations in solar activity and amplified by ocean circulation El Niño‐Southern Oscillation to influence the East Asian Monsoon system, especially the EAWM, and finally change the vegetation in Great Khingan Mountain Range.

The Great Khingan Mountain range, Northeast China, is located on the northern limit of modern East Asian Summer Monsoon (EASM) and thus highly sensitive to the extension of the EASM from glacial to interglacial modes. Here, we present a high-resolution pollen record covering the last glacial maximum and the early Holocene from a closed crater Lake Moon to reconstruct vegetation history during the glacial-interglacial transition and thus register the evolution of the EASM during the last deglaciation. The vegetation history has gone through distinct changes from subalpine meadow in the last glacial maximum to dry steppe dominated by Artemisia from 20.3 to 17.4 ka BP, subalpine meadow dominated by Cyperaceae and Artemisia between 17.4 and 14.4 ka BP, and forest steppe dominated by Betula and Artemisia after 14.4 ka BP. The pollen-based temperature index demonstrates a gradual warming trend started at around 20.3 ka BP with interruptions of several brief events. Two cold conditions occurred around at 17.2–16.6 ka BP and 12.8–11.8 ka BP, temporally correlating to the Henrich 1 and the Younger Dryas events respectively, 1and abrupt warming events occurred around at 14.4 ka BP and 11.8 ka BP, probably relevant to the beginning of the Bølling-Allerød stages and the Holocene. The pollen-based moisture proxy shows distinct drought condition during the last glacial maximum (20.3–18.0 ka BP) and the Younger Dryas. The climate history based on pollen record of Lake Moon suggests that the regional temperature variability was coherent with the classical climate in the North Atlantic, implying the dominance of the high latitude processes on the EASM evolution from the Last Glacial Maximum (LGM) to early Holocene. The local humidity variability was influenced by the EASM limitedly before the Bølling-Allerød warming, which is mainly controlled by the summer rainfall due to the EASM front covering the Northeast China after that.

Fluctuations in monsoonal climate on orbital‐ to millennial‐timescales have had a major impact on vegetation change in East Asia since the last deglaciation. However, the influence of centennial‐scale oscillations on the spatio‐temporal characteristics of vegetation and climate during the last deglaciation remains controversial. We present a well‐dated, decadal‐resolution pollen record from the sediments of annually laminated Lake Xiaolongwan in Northeast Asia, which reveals major orbital‐/millennial‐scale and minor quasi‐periodic, that is, ∼500‐year (yr) cyclic, vegetation changes from ∼19.96 to ∼10.79 Kyr ago (covering the last deglaciation). The ∼500‐yr cycles are characterized by alternations in broadleaved forest/boreal coniferous forest with tundra steppe representing warm and humid/cold and dry phases of the monsoonal climate. This cyclicity may be related to El Niño‐like/La Niña‐like state and low‐latitude atmosphere‐ocean processes, against the background of the long‐term trend of the deglacial climatic evolution. Our findings demonstrate a close relationship between ecosystem succession and climate change on centennial scale.

In an open economic system, tourism spillover occurs widely between cities, making it a useful index for regional tourism cooperation or competition. This article improves the gap model on tourism spillover between two cities, suggested by S. Li and Wang(2009a Li, S. and Wang, Z. 2009a. Computable models on regional spillovers of tourism industry: A case study of the Yangtze River Delta. Tourism Tribune, 24(7): 18–26. [Google Scholar] ), in three aspects: (a) an impact factor is added to the model; (b) more objective indicators are applied to the definitions of variables; and (c) more rational methods are used to estimate parameters. The case of the Yangtze River Delta is reexamined based on the improved model. The results show that the new gap model explains tourism spillover more effectively than the original one; it could also provide more help and advisement in developing regional tourism cooperation.