Table 3.

Statistics of the stepwise multiple linear regression models for standardized basal area increment (BAI) chronologies of male and female Ilex aquifolium trees with the significant climatic predictors over the period 1942–2001 (n = 60).

Sex	Model radj2	Model F	Model P-value	Predictor variablea	β	t-value	P-value
Male	0.304	9.58	<0.001	SPEI11 Jan	0.375	3.43	0.001
				Tmed Jun	0.272	2.35	0.022
				PET Aug	0.240	2.06	0.044
Female	0.376	12.83	<0.001	SPEI30 Oct	0.340	3.18	0.002
				Cld MayJun(−1)	0.325	3.06	0.003
				Tmed AugSep(−1)	–0.309	–2.78	0.004

^aCode interpretation for climate predictors: Cld, cloudiness; PET, potential evapotranspiration; SPEI, standardized precipitation evapotranspiration index; Tmed, mean temperature. Jan to Dec means the months of the year, from January to December; (−1), year before tree growth. Two months indicate that the average of two adjacent months has been calculated. SPEI11 and SPEI30 refer to the accumulated SPEI of the last 11 and 30 months, respectively.