Impacts of close-to-nature management on the stand states of Masson pine forests

Figures & data

Table 1. Close-to-nature management measures at different development stages of Masson pine plantation

Development stages	Stand DBH	CTNM measures	Target density(trees/hm^2)
Young forest	DBH<5 cm	regulate stand density and remove overlord wood and bent trees	about 2500
Middle-aged forest	5 cm≤DBH<15 cm	combination of target tree and thinning density control	1200–1700
Near-mature	15 cm≤DBH<34 cm	combination of target tree and thinning density control	300–850

Table 2. Definition and measurement of stand parameters

Dimension	Stand parameter	Abb.	Definition and measurement	References
Tree	Tree Shannon-Wiener index	T.SW	Calculated according to the formula:$H=-\sum _{i=1}^s{p}_i\mathrm{l}\mathrm{n}\left(p_i\right)$; S = number of tree species; pi = ni/N; ni = number of tree species i in the tree community, and N= all individual trees	(Shannon and Weaver 1949)
	Shannon-Wiener index of DBH class	T.DSW	Calculated according to the formula:$H=-\sum _{i=1}^s{p}_i\mathrm{l}\mathrm{n}\left(p_i\right)$; S = number of DBH class (2 cm); pi = ni/N; ni = number of trees in DBH class i and N= all individual trees	(Burkhart and Tome 2012)
	Shannon-Wiener index of height class	T.HSW	Calculated according to the formula:$H=-\sum _{i=1}^s{p}_i\mathrm{l}\mathrm{n}\left(p_i\right)$; S = number of height class (1 m); pi = ni/N; ni = number of trees in height class i and N= all individual trees
	Canopy closure (%)	T.CC	Expressed as the proportion (0–100) of the plot covered by tree canopy (DBH ≥ 5 cm)	(Chai and Wang 2016)
	Tree volume (t hm^−2)	T.VLM	Calculated according to the reported formulas	(Guiyang forestry afforestation investigation planning and design institute and Guizhou forestry investigation planning and design institute 2016)
Regeneration	Regeneration density (trees hm^−2)	R.DEN	Number of saplings (tree height ≥1.3 m and DBH < 5 cm) per hectare	(Chai and Wang 2016)
Shrub	Shrub Shannon-Wiener index	S.SW	Calculated according to the formula:$H=-\sum _{i=1}^s{p}_i\mathrm{l}\mathrm{n}\left(p_i\right)$; S = number of shrub species; pi = ni/N; ni = number of shrub species i in the shrub community, and N = all individual shrub plants	(Shannon and Weaver 1949)
	Shrub cover (%)	S.CC	Expressed as the proportion (0–100) of the plot covered by shrub canopy	(Duncan et al. 1993)
	Shrub biomass (t hm^−2)	S.BS	See the field sampling in the Materials and Methods	(Zhang et al. 2014)
Herb	Herb Shannon-Wiener index	H.SW	Calculated according to the formula:$H=-\sum _{i=1}^s{p}_i\mathrm{l}\mathrm{n}\left(p_i\right)$; S = number of herb species; pi = ni/N; ni = number of herb species i in the herb community, and N= all individual herb plants	(Shannon and Weaver 1949)
	Herb cover (%)	H.CC	Expressed as the proportion (0–100) of the plot covered by herb canopy	(Duncan et al. 1993)
	Herb biomass (t hm^−2)	H.BS	See the field sampling in the Materials and Methods	(Zhang et al. 2014)

Table 3. Descriptive statistics of stand parameters

Dimension	Stand parameters	Abb.	Min.	Max.	Mean	SD
Tree	Tree Shannon-Wiener index	T.SW	0.000	1.807	0.549	0.440
	Shannon-Wiener index of height class	T.DSW	1.682	2.637	2.247	0.223
	Shannon-Wiener index of diameter class	T.HSW	1.465	2.869	2.196	0.394
	Canopy closure (%)	T.CC	70.000	95.000	80.263	6.571
	Tree volume (m^3 hm^−2)	T.VLM	168.758	671.490	365.553	145.548
Regeneration	Regeneration density (trees hm^−2)	R.DEN	0.000	7000.000	1947.368	1947.935
Shrub	Shrub Shannon-wiener index	S.SW	0.000	2.212	1.561	0.441
	Shrub cover (%)	S.CC	10.000	60.000	28.816	12.326
	Shrub biomass (t hm^−2)	S.BS	0.304	3.553	1.257	0.710
Herb	Herb Shannon-wiener index	H.SW	0.000	1.959	1.422	0.383
	Herb cover (%)	H.CC	10.000	80.000	37.105	17.920
	Herb biomass (t hm^−2)	H.BS	0.046	1.436	0.432	0.421

Table 4. Stand parameters for Masson pine forest under close-to-nature management and natural restoration (control)

Item	Young		Middle-aged		Near-mature
	Control	Managed	Control	Managed	Control	Managed
T.SW	0.227 ± 0.241	0.425 ± 0.251*	0.410 ± 0.514	0.722 ± 0.505**	0.362 ± 0.266	0.860 ± 0.408**
T.DSW	1.810 ± 0.199	1.968 ± 0.143*	2.314 ± 0.082	2.252 ± 0.129	2.397 ± 0.160	2.281 ± 0.201
T.HSW	2.205 ± 0.157	2.025 ± 0.452	2.557 ± 0.165	2.335 ± 0.471	1.988 ± 0.344	2.069 ± 0.382
T.CC	88.333 ± 5.774	76.667 ± 7.638*	86.429 ± 2.440	75.000 ± 4.082***	82.778 ± 4.410	75.556 ± 4.640**
T.VLM	190.107 ± 27.846	198.315 ± 43.154	391.159 ± 128.576	314.751 ± 69.451	466.810 ± 132.058	398.122 ± 162.081
R.DEN	0 ± 0	333 ± 289	643 ± 378	1500 ± 500***	1389 ± 697	5056 ± 1210***
S.SW	0.601 ± 0.559	1.203 ± 0.167	1.345 ± 0.183	1.46 ± 0.11	1.864 ± 0.164	1.944 ± 0.206*
S.CC	15 ± 5	28.333 ± 5.774*	20.714 ± 7.319	34.286 ± 7.868**	23.889 ± 9.280	40.556 ± 13.333**
S.BS	0.686 ± 0.332	0.972 ± 0.572	0.887 ± 0.331	1.457 ± 0.568*	0.995 ± 0.455	1.936 ± 0.889
H.SW	1.067 ± 0.351	1.545 ± 0.13	1.294 ± 0.247	1.467 ± 0.263*	1.228 ± 0.505	1.757 ± 0.233*
H.CC	11.667 ± 2.887	20 ± 8.66	22.143 ± 5.669	35 ± 8.165*	41.667 ± 7.500	60.000 ± 12.990***
H.BS	0.356 ± 0.502	0.368 ± 0.342	0.537 ± 0.585	0.511 ± 0.286	0.306 ± 0.396	0.462 ± 0.462

T.SW Tree Shannon-Wiener index; T.DSW Shannon-Wiener index of DBH class; T.HSW Shannon-Wiener index of height class; T.CC Canopy closure; T.VLM Tree volume; R.DEN Regeneration density; S.SW Shrub Shannon-Wiener index; S.CC Shrub cover; S.BS Shrub biomass; H.SW Herb Shannon-Wiener index; H.CC Herb cover: H.BS Herb biomass

Table 5. ANCOVA of Masson pine forest under close-to-nature management

Item	Treatment		Stand age		Treatment:Stand age
	Sum of squares	F value	Sum of squares	F value	Sum of squares	F value
T.SW	1.389	8.395**	0.0112	0.677	0.025	0.151
T.DSW	0.026	0.856	0.605	19.628***	0.157	5.104*
T.HSW	0.049	0.322	0.414	2.703	0.066	0.430
T.CC	852.630	43.707***	48.930	2.508	32.540	1.668
T.VLM	33,509.000	3.235	385,597.000	37.226***	12,532	1.210
R.DEN	42,105,263.000	49.165***	53,447,422.000	62.409***	15,724,243	18.361***
S.SW	0.291	3.983	4.297	58.880***	0.133	1.819
S.CC	2137.500	26.214***	681.90	8.363**	29.960	0.368
S.BS	4.670	14.256***	2.207	6.737*	0.659	2.012
H.SW	1.445	12.910**	0.039	0.352	0.149	1.328
H.CC	2063.200	24.966***	6765.900	81.763***	251.800	3.047
H.BS	0.041	0.217	0.003	0.017	0.034	0.176

T.SW Tree Shannon-Wiener index; T.DSW Shannon-Wiener index of DBH class; T.HSW Shannon-Wiener index of height class; T.CC Canopy closure; T.VLM Tree volume; R.DEN Regeneration density; S.SW Shrub Shannon-Wiener index; S.CC Shrub cover; S.BS Shrub biomass; H.SW Herb Shannon-Wiener index; H.CC Herb cover: H.BS Herb biomass

Figure 1. The distribution of the nineteen sample blocks

Figure 2. RDA plot of stand parameters for Masson pine forest under close-to-nature management and natural restoration (control)

Figure 3. The relationship of stand parameters with stand age for Masson pine forests under close-to-nature management and natural restoration (control) Note: T.SW Tree Shannon-Wiener index; T.DSW Shannon-Wiener index of DBH class; T.HSW Shannon-Wiener index of height class; T.CC Canopy closure; T.VLM Tree volume; R.DEN Regeneration density; S.SW Shrub Shannon-Wiener index; S.CC Shrub cover; S.BS Shrub biomass; H.SW Herb Shannon-Wiener index; H.CC Herb cover: H.BS Herb biomass

Shannon, C. E., and W. Weaver. 1949. The Mathematical Theory of Communication. University of Illinois press.

 Google Scholar

Burkhart, H., and M. Tome. 2012. Modeling Forest Trees and Stands. Springer.

 Google Scholar

Chai, Z. Z., and D. X. Wang. 2016. “Environmental Influences on the Successful Regeneration of Pine-oak Mixed Forests in the Qinling Mountains, China.” Scandinavian Journal of Forest Research 31: 368–381. doi:10.1080/02827581.2015.1062912.

 Web of Science ®Google Scholar

Guiyang forestry afforestation investigation planning and design institute and Guizhou forestry investigation planning and design institute. 2016. Pratice and Exprience of Forest-survey. Guiyang: Guizhou Renmin press.

 Google Scholar

Duncan, J., D. Stow, J. Franklin, and A. Hope. 1993. “Assessing the Relationship between Spectral Vegetation Indices and Shrub Cover in the Jornada Basin, New Mexico.” International Journal of Remote Sensing 14: 3395–3416. doi:10.1080/01431169308904454.

 Web of Science ®Google Scholar

Zhang, M. X., D. X. Wang, Z. Xu, and Q. J. Guo. 2014. “A Composite Index-based Approach for Hierarchical Assessment of Forest Ecosystem Health: An Example of Pinus Tabulaeformis.” International Journal of Multimedia and Ubiquitous Engineering 9: 415–426. doi:10.14257/ijmue.2014.9.7.35.

 Google Scholar

Availability of data and materials

All data generated or analyzed during this study are included in this published article.