Comparative study of forest biomass and carbon stocks of Margalla Hills National Park, Pakistan

Figures & data

Figure 1. (a) Location of Study Area in Pakistan (b) Study Area with Land Cover Classes and Location of Sampling Plots in SCPF and SBEF.

Table 1. Structural characteristics of forests of MHNP.

Forests	SCPF	SBEF	Combined
Mean AGC (Mg C ha^−1)	73.36 ± 32.55^a	16.88 ± 25.81^b***	50.62 ± 40.84
Mean AGB (Mg ha^−1)	146.73 ± 65.11^a	33.77 ± 51.63^b***	101.25 ± 81.68
Mean Tree Volume (m^3 ha^−1)	198.75 ± 87.76^a	37.82 ± 50.38^b***	133.96 ± 108.96
Mean Basal Area (m^2 ha^−1)	14.48 ± 4.80^a	4.28 ± 3.43^b***	10.37 ± 6.60
Mean Density ha^−1	139.13 ± 22.88^a	142.90 ± 32.37^a	140.64 ± 26.96
Mean DBH (cm)	36.37 ± 6.51^a	18.64 ± 6.03^b***	29.23 ± 10.77
Mean Tree Height (m)	27.34 ± 3.67^a	10.62 ± 1.99^b***	20.61 ± 8.81

Mean ± SD.

Different letters indicate on the superscripts denote the significant differences (Wilcoxon Rank Sum Test; ***p < 0.01, **p < 0.05, *p < 0.1) between the two forests.

Table 2. Spearman correlation coefficients for SCPF (n = 46).

Variables	Volume (m^3 ha^−1)	Basal Area (m^2 ha^−1)	Mean DBH (cm)	Mean Tree Height (m)
AGB (Mg ha^−1)	0.99^a	0.94^a	0.91^a	0.75^a
Volume (m^3 ha^−1)	1	0.94^a	0.91^a	0.75^a
Basal Area (m^2 ha^−1)		1	0.87^a	0.59^a
Mean DBH (cm)			1	0.71^a

^aCorrelation is significant at the 0.05 level.

Table 3. Spearman correlation coefficients for the SBEF (n = 31).

Variables	Volume (m^3 ha^−1)	Basal Area (m^2 ha^−1)	Mean DBH (cm)	Mean Tree Height (m)
AGB (Mg ha^−1)	0.95^a	0.89^a	0.87^a	0.68^a
Volume (m^3 ha^−1)	1	0.93^a	0.90^a	0.70^a
Basal Area (m^2 ha^−1)		1	0.89^a	0.52^a
Mean DBH (cm)			1	0.64^a

^aCorrelation is significant at the 0.05 level.

Figure 2. DBH Distribution of the Two Forests of the MHNP.

Figure 3. AGB (Mg ha⁻¹) of SCPF against the Mean DBH (cm) and the Mean Height (m).

Figure 4. AGB (Mg ha⁻¹) of SBEF against the Mean DBH (cm) and the Mean Height (m).

Table 4. AGC contribution of different trees species in SCPF.

Species	Total AGC (Mg C ha^−1)	AGC Percentage (%)
Pinus roxburghii Sarg.	3336.13	98.85
Bombax ceiba L.	27.01	0.81
Bauhinia variegata L.	11.66	0.34
Total	3374.80	100

Table 5. AGC contribution of different trees species in SBEF.

Species	Total AGC (Mg C ha^−1)	AGC Percentage (%)
Eucalyptus camaldulensis Dehnh.	176.14	33.65
Ficus palmata subsp. virgata Forssk.	94.24	18
Bauhinia variegata L.	73.35	14.01
Acacia modesta Wall.	42.29	8.08
Bombax ceiba L.	36.94	7.06
Grewia optiva J. R. Drumm. ex Burret	30.84	5.89
Mallotus philippensis (Lam.) Muell. Arg.	20.78	3.97
Cassia fistula L.	10.99	2.1
Broussonetia papyrifera (L.) L'Herit ex Vent.	9.86	1.88
Celtis australis L.	9.29	1.77
Albizia lebbeck (L.) Benth	8.44	1.61
Ziziphus mauritiana Lam.	6.14	1.17
Ficus benghalensis L.	3.67	0.7
Flacourtia indica (Burm. f.) Merr.	0.51	0.1
Total	523.47	100

Table 6. Relationship type, equation, and R² value of main trees species from MHNP.

Species	Parameters	Relationship Type	Equation	R^2
Pinus roxburghii	DBH & H	Linear	H = 11.55 + 0.45DBH	0.74***
	BA & V	Linear	V=-58.96 + 17.87BA	0.96***
	DBH & AGB	Power Curve	AGB = 0.0007 * DBH^2.62	0.98***
Bauhinia variegata	DBH & H	Linear	H = 5.60 + 0.25DBH	0.36***
	BA & V	Linear	V = 0.07 + 5.86BA	0.92***
	DBH & AGB	Power Curve	AGB = 0.002 * DBH^2.21	0.93***
Grewia optiva	DBH & H	Linear	H = 4.69 + 0.33DBH	0.42***
	BA & V	Linear	V=-0.20 + 5.95BA	0.97***
	DBH & AGB	Power Curve	AGB = 0.002 * DBH^2.33	0.59***

H: height (m); V: volume (m³ ha⁻¹); BA: basal area (m² ha⁻¹); AGB (Mg ha⁻¹); DBH (cm).

*** p < 0.01, ** p < 0.05, * p < 0.1.

Table 7. Mean AGC of SCPF Reported by Different Studies.

Authors/Workers	Region/Study Area	Mean AGC (Mg C ha^−1)
(Amir et al. 2018)	Murre Hills, Pakistan	40 to 264.5
(Nizami 2012)	Ghoragali and Lehterar, Pakistan	119 and 92
(Shaheen et al. 2016)	Muzaffarabad District, AJK	154 and 264.5
(Mannan et al. 2019)	Foothills of the Himalayan mountains, Pakistan	173.38
(Ali et al. 2020a)	KPK, Pakistan	24.77
This study	MHNP, Pakistan	73.36

Table 8. Mean AGC for SBEF from Different Studies.

Authors	Region/Study Area	Mean AGC (Mg C ha^−1)
(Nizami 2012)	Kherimurat and Sohawa, Pakistan	25.54 and 20.23
(Ali et al. 2020b)	KPK, Pakistan	4.52
(Mannan et al. 2019)	Foothills of the Himalayan mountains, Pakistan	73.81
(Ali et al. 2019)	Swat, Dir Upper, Dir Lower, and Buner Districts, Pakistan	49.54
(Ali et al. 2018)	Khanpur Range, Khyber Pakhtunkhwa, Pakistan	39.02
This study	MHNP, Pakistan	16.88

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