TCMGIS-II based prediction of medicinal plant distribution for conservation planning: a case study of Rheum tanguticum

Table 1 Variables extracted from the native habitats of Rheum tanguticum Maxim. ex Balf based on TCMGIS-II combined geographic, climate and soil type databases

Variable	Unit	Range	Mean ± SE	F-value	C_v(%)
Elevation	m	1980, 4550	3630 ± 44	191.2***	17.4
Relative humidity	%	54.8, 69.0	63.7 ± 2.2	219.3***	49.6
Sunshine duration	hr/yr	1897, 2704	2450 ± 13	301.7***	7.6
Annual precipitation	mm	331, 839	574 ± 7	233.2***	17.5
Accumulated temperature	°C	3193, 22451	9517 ± 951	277.1***	143.4
Mean annual temperature	°C	5.1, 13.1	8.6 ± 0.1	92.6***	16.7
Mean March temperature	°C	-8.0, -2.0	-4.5 ± 0.2	42.3***	63.8
Minimum temperature	°C	-24.8, -10.6	-19.1 ± 0.2	165.8***	15.0
Maximum temperature	°C	12.9, 24.4	17.2 ± 0.2	119.5***	16.7
Mean minimum temperature	°C	-15.6, -5.1	-11.2 ± 0.2	129.8***	25.6
Mean maximum temperature	°C	6.0, 18.2	10.4 ± 0.2	103.3***	27.6
Soil type*	pH	5.9, 8.5	6.8 ± 0.1	112.4***	21.1

* Soil type was assigned according to soil grade division in TCMGIS-II program.
Values of pH were employed as an indicator of soil types for statistical analysis.
F-value indicates the difference in target variable extracted from different native habitats (*** P < 0.001, ** P < 0.01, and * P < 0.05).
SE: standard error of means
C_v: coefficient of variation

ISSN: 1749-8546