Response of Pinus massoniana Leaf Area Index (LAI) to Climate Indicators in Fujian Province

To understand spatial and temporal distribution regularity of Pinus massoniana, we used leaf area index (LAI) to achieve Dendrolimus punctatus Walker damage spatial monitoring and early warning. We used six climate indicators, namely average temperature, average temperature anomalies, precipitation, precipitation anomalies, sunshine hours and sunshine hour anomalies measured from 38 climate stations in 2010 in Fujian Province and 90 field measured LAI, and analysed the response of P. massoniana LAI to the climate from provincial and city scales, respectively. Results showed that: (1) in addition to sunshine anomalies, the other five climate indicators significantly influenced P. massoniana LAI in the order average temperature > precipitation > sunshine hours > average temperature anomalies > precipitation anomalies with the coefficients; (2) seen from the provincial scale, the response of P. massoniana LAI to average temperature presented as an open side down parabola, and the response to average anomalies was explained by a cubic curve; the response of LAI to precipitation was negative and the influence of precipitation anomalies was similar to average temperature, while response to sunshine hours presented as an open side upward parabola; (3) seen from the prefecture-level city scale, the LAI of Nanping, Sanming, and Longyan, the main producing areas of P. massoniana in Fujian, were generally lower than that in non- or low-producing coastal areas, with the LAI of Nanping being the lowest. On one hand, why the LAI of Nanping, Sanming, and Longyan being lower than other areas was because of the direct response of P. massoniana LAI to climate indicators, and on the other hand, by the impact of climate on the distribution of Dendrolimus punctatus Walker, LAI showed the spatial characteristics of coastal high and inland low.