Table 2. Topographical and climatic variables considered in the study.

Variable	Abbreviation	Units	Mean	SD	Max	Min
Terrain ruggedness index	TRI	m	20.33	6.66	35.90	4.69
Vector ruggedness measure	VRM	NA	0.005	0.007	0.13	0
Slope	S	°	28.38	8.92	48.34	3.42
Aspect*	A	°	190.51	68.72	350.44	20.55
Elevation*	E	m	1,302.41	124.96	1,631	1,010
Mean annual temperature*	MAT	°C	16.57	0.38	17.4	15.5
Mean annual precipitation*	MAP	mm	229.56	19.95	288	184
Growing season precipitation, April–September*	GSP	mm	79.08	9.60	108	57
Mean temperature in the coldest month*	MTCM	°C	10.85	0.37	11.7	9.8
Minimum temperature in the coldest month*	MMIN	°C	3.42	0.41	4.3	2.3
Mean temperature in the warmest month	MTWM	°C	24.52	0.31	25.2	23.5
Maximum temperature in the warmest month	MMAX	°C	34.10	0.31	34.7	33.1
Julian date of the last freezing data of spring*	SDAY	Days	82.57	7.86	106	60
Julian date of the first freezing data of autumn*	FDAY	Days	331.28	2.62	339	324
Length of the frost-free period*	FFP	Days	259.22	8.36	285	240
Degree days ˃5 °C*	DD5	Days	4,245.26	137.52	4,550	3,852
Degree days ˃5 °C accumulating within the frost-free period*	GSDD5	Days	3,491.82	164.76	3,944	2,995
Julian date when the sum degree days ˃5 °C reaches 100*	D100	Days	17.07	1.10	20	15
Degree days ˂0 °C*	DD0	Days	0	0	0	0
Minimum degree days ˂0 °C*	MMINDD0	Days	8.07	20.29	145	45
Spring precipitation	SPRP	mm	7.54	0.71	10	6
Summer precipitation*	SMRP	mm	43.74	6.29	62	29
Winter precipitation*	WINP	mm	110.93	7.93	133	93

Note:

^*Variables for which no significant difference between the medians was obtained after Bonferroni correction (α = 0.0005) were excluded from further analysis.