Table 1. General description of communities.
Ⅰ Ⅱ Ⅲ
Elevation (m a.s.l.) 700–800 700–800 700–800
Slope (°) 18 17 17
Aspect E30°S E S
Soil type Eutric Cambisols Eutric Cambisols Eutric Cambisols
Density (Individual/ha) 1900 2033 2183
Standing tree volume (m3 ha–1) 266.32 297.66 285.39
Ⅰ: Pinus tabuliformis forest, Ⅱ: coniferous-broadleaved P. tabuliformis mixed forest, Ⅲ: Quercus mongolica forest
Table 2. Plant individual important value (IV) in different forest types.
Forest types Trees Shrubs Herbs
Species IV Species IV Species IV
Ⅰ Pinus tabuliformis Carrière 49.01 Deutzia parviflora Bunge 38.54 Athyrium multidentatum Ching 20.14
Evodia daniellii Hemsl. 16.56 Philadelphus incanus Koehne 34.86 Arthraxon hispidus Makino 12.57
Carpinus turczaninowii Hance. 9.66 Spiraea trilobata L. 7.82 Diarrhena mandshurica Maxim. 10.51
Tilia mandshurica Rupr. et Maxim. 9.23 Thalictrum aquilegifolium var. sibiricum Regel et Tiling 9.35
Lithospermum erythrorhizon Sieb. et Zucc. 7.86
Mentha haplocalyx Briq. 7.54
Others 15.54 Others 18.76 Others 32.03
Ⅱ Pinus tabuliformis Carrière 29.94 Actinidia arguta Planch.ex Miq. 27.38 Clematis heracleifolia DC. 16.35
Quercus variabilis Blume 27.65 Deutzia parviflora Bunge 25.17 Melica scabrosa Trin. 10.15
Evodia daniellii Hemsl. 12.57 Myripnois dioica Bunge 8.40 Solanum japonense Nakai 10.04
Acer truncatum Bunge 9.57 Ampelopsis humulifolia Bunge 8.16 Carex callitrichos V. Krecz. 9.95
Quercus mongolica Fisch. ex Ledeb. 3.45 Rubus crataegifolius Bunge 7.98 Artemisia brachyloba Franch. 8.15
Polygonatum sibiricum Delar. ex Redoute 6.48
Vicia unijuga A. Braun 5.72
Others 16.82 Others 22.91 Others 33.16
Ⅲ Quercus mongolica Fisch. ex Ledeb. 30.21 Spiraea trilobata L. 22.22 Synurus deltoides Nakai 15.42
Pinus tabuliformis Carrière 17.51 Rhamnus davurica Pall. 18.38 Melica scabrosa Trin. 14.02
Quercus aliena Blume 10.77 Ampelopsis humulifolia Bunge 12.33 Polygonum lapathifolium L. 12.92
Betula dahurica Pall. 9.82 Rhododendron micranthum Turcz. 9.39 Phlomis umbrosa Turcz. 12.89
Fraxinus chinensis Roxb. 8.96 Rubus crataegifolius Bunge 9.31 Dioscorea nipponica Makino 9.67
Deutzia parviflora Bunge 8.89 Spodiopogon sibiricus Trin. 8.22
Others 22.73 Others 19.48 Others 26.86
Ⅰ: Pinus tabuliformis forest, Ⅱ: coniferous-broadleaved P. tabuliformis mixed forest, Ⅲ: Quercus mongolica forest.
Table 3. Species diversity in different forest types.
Layer Diversity index Ⅰ Ⅱ Ⅲ
Trees Richness index 10 14 14
Shannon-Wiener index 1.639 1.981 2.162
Simpson index 0.709 0.804 0.842
Pielou index 0.712 0.751 0.819
Shrubs Richness index 4 9 11
Shannon-Wiener index 1.248 1.962 2.189
Simpson index 0.688 0.827 0.868
Pielou index 0.900 0.893 0.913
Herbs Richness index 11 16 12
Shannon-Wiener index 2.315 2.618 2.349
Simpson index 0.891 0.916 0.894
Pielou index 0.965 0.944 0.945
Ⅰ: Pinus tabuliformis forest, Ⅱ: coniferous-broadleaved P. tabuliformis mixed forest, Ⅲ: Quercus mongolica forest
Table 4. Forest floor and soil nutrition concentration (mean±SE) in different forest types. View in new window/tab.

Fig. 1. Bars marked with different lowercase letters represent significant difference at the forest floor layer under different forest types at the 0.05 level (Duncan test). Bars marked with different uppercase letters represent significant difference at the mineral soil layer (0–20 cm soil depth) under different forest types at the 0.05 level (Duncan test).
Ⅰ: Pinus tabuliformis forest, Ⅱ: coniferous-broadleaved P. tabuliformis mixed forest, Ⅲ: Quercus mongolica forest.

Fig. 2. Cation exchange capacity (CEC), pH, and bulk density in two soil depths under different forest types. Bars marked with the same letters are not significantly different from each other at the 0.05 level (Duncan test).
Ⅰ: Pinus tabuliformis forest, Ⅱ: coniferous-broadleaved P. tabuliformis mixed forest, Ⅲ: Quercus mongolica forest.

Fig. 3. Bacterial biomass (a), Gram+ biomass (b), Gram- biomass (c), fungal biomass (d), total microbial biomass (e), and fungi/bacterial ratio (f) in two soil depths under different forest types. Bars marked with the same letters are not significantly different from each other at the 0.05 level (Duncan test).
Ⅰ: Pinus tabuliformis forest, Ⅱ: coniferous-broadleaved P. tabuliformis mixed forest, Ⅲ: Quercus mongolica forest.

Fig. 4. Principal component analysis (PCA) of microbial species at 0–10 cm and 10–20 cm soil depths under different forest types. Bars indicate the standard errors of means.
Ⅰ: Pinus tabuliformis forest, Ⅱ: coniferous-broadleaved P. tabuliformis mixed forest, Ⅲ: Quercus mongolica forest.