Abstract: The spatial pattern of diversity of the coniferous forest in the lower Huaihe valley and its relation to the climate were studied in the paper.Species diversity index(SDI),community evenness index(CEI)and ecological dominance index(EDI)were used to measure the diversity. The potential evapo-transpiration by Penman’s method was adopted to analyse the characteristics of the climate. The results showed:(1)SDI, CEI and EDI for coniferous forest were 0.07～1.52,0.07～0.59 and 0.36～0.98 respectively. The diversity of coniferous forest increased from the north/west to the south/east.(2)Diversity pattern of the coniferous forest corresponded to the regional differentiation of aridity. Finnally, the proposals for the biodiversity conservation in the study region were put forward.

Key words: Koelreuteria paniculata, seed germination, polyethylene glycol, exogenous Ca²⁺, drought stress.