Recovery of Vegetation Structure and Species Diversity after Shifting Cultivation in Northwestern Vietnam, with Special Reference to Commercially Valuable Tree Species
Table 1
Total number of species and stem densities of tree, sapling and seedling strata in each one-hectare plot, as well as those (mean ±SD) in the subplots for the 32-year-old fallow stand and old-growth forest. Diversity indices (mean ± SD) are also given for both stands.
Thirty-two-year-old fallow stand (FS)
Old-growth forest (OGF)
One-ha plot
Mean of 16 sub-plots ( each)
One-ha plot
Mean of 16 sub-plots ( each)
Percent recovery
Numberof species
Density (stems )
Number of species
Density (stems )
Number of species
Density (stems )
Number of species
Density (stems )
Number of species
Density
Total
32
5,550
***11.5 ± 1.4
**5,554 ± 2,472
74
7,670
***18.6 ± 3.6
**7,570 ± 1,410
43.2
72.4
Tree stratum
26
540
***9.2 ± 1.9
541 ± 167
69
550
***15.7 ± 2.7
553 ± 128
37.7
98.2
Sapling stratum
29
1,190
10.3 ± 1.6
*1,193 ± 432
65
940
11.1 ± 1.9
*906 ±182
44.6
126.6
Seedling stratum
32
3,820
***11.2 ± 1.0
**3,819 ± 2,691
61
6,180
***8.8 ± 1.1
**6,111 ± 1,458
52.5
61.8
2.66
**2.15 ± 0.13
3.44
**2.60 ± 0.21
77.3
0.77
0.89 ± 0.03
0.80
0.90 ± 0.03
96.3
2.99
1.88 ± 0.42
3.37
1.96 ± 0.39
88.7
0.65
0.54 ± 0.11
0.63
0.49 ± 0.08
103.2
Basal area )
14.2
26.7
53.2
Seedling stratum (), sapling stratum ( and ), and tree stratum (); The t-test was used for comparisons of , , , and ; Mann-Whitney U-test was used for other pair comparisons between OGF and FS for the means of mm sub-plots; ***significant at 2%, **significant at 5%, and *significant at 10%.
