润色段落使其更加地道：Combined with local meteorological data the tree-ring width standardized chronology and its standardized combined chronology were established to analyze the fluctuation cycle of tree-ring i

In conjunction with local meteorological data, a standardized tree-ring width chronology and its combined chronology were established to study the fluctuation cycle of the tree-ring index and its correlation with monthly average temperature and precipitation. The combined chronology exhibited quasi-periodic fluctuations of 8-12 years in the annual ring index, which were closely linked to sunspot activity. Through analyzing the magnitude of the annual ring index in five cycles, specific years were identified where tree growth was either promoted, normal or inhibited. The correlation analysis between the combined chronology and climatic factors revealed that the radial growth of trees in Zhumadian area was primarily affected by the average temperature in July (r=0.283, P<0.05), precipitation in December (r=0.349, P<0.05), and precipitation in October (r=0.259, P<0.05). The annual variation rate of precipitation and historical data of drought and flood disasters in the Zhumadian area provided evidence of the climatic conditions during years with narrow tree-rings. When tree growth was restrained, normal, and promoted, the parameter |Qi-1+Qi|/2 was found to be >20%, <10%, and 10%-20%, respectively. In Zhumadian area, two consecutive years of drought or flood and one year of severe drought or waterlogging would severely inhibit tree growth, resulting in obvious narrow rings.