Tree species diversity and its relationship with carbon stock in the parkland agroforestry of Northern Ethiopia

Figures & data

Figure 1. Map of Western Zone of Tigray, Northern Ethiopia

Figure 2. Dendrogram showing plant community types of Parkland agroforestry of Western Zone of Tigray, Northern Ethiopia

Table 1. Mean (± standard error) Species richness, evenness, Shannon-Weiner Diversity and Simpson’s index of diversity for each of the three plant communities and results of one-way ANOVA (at α = 0.05, significant differences between)

Plant Community	Species richness	Species evenness	Shannon-Weiner Diversity	Simpson’s index of diversity
1	4.33 (0.18)^a	0.88 (0.01)	1.24 (0.04)^a	0.67 (0.01)^a
2	2.36 (0.12)^b	0.53 (0.02)	0.46 (0.04)^c	0.25 (0.02)^c
3	2.23 (0.08)^b	0.84 (0.02)	0.67 (0.03)^b	0.43 (0.02)^b
Mean	3.02	0.81	0.82	0.46
F-value	88.417	0.602	51.587	26.542
P-value	***	0.4403	***	***

Figure 3. Woody species diversity of parkland agroforestry system of Western Zone of Tigray

Table 2. Mean (± standard error) Aboveground (AGC) and belowground (BGC), soil organic (SOC) and total (TC) carbon stocks (Mg C ha-1) for each of the plant communities and results of one-way ANOVA (at α = 0.05, significant difference)

Plant Community	AGC	BGC	SOC	TC
1	11.49 (2.60)^a	4.27 (0.87)^a	21.02 (1.7)	36.77 (3.8)^a
2	6.71 (0.95)^ab	2.66 (0.35)^ab	21.05 (1.6)	30.42 (1.8)^ab
3	5.17 (1.10)^b	2.06 (0.37)^b	18.27 (1.6)	25.50 (2.6)^b
Mean	7.90	3.03	20.07	31
F-value	6.6634	6.8379	1.479	7.7081
P-value	*	*	0.2278	**

Figure 4. Carbon stock of parkland agroforestry system of Western Zone of Tigray

Table 3. Relationship between plant species diversity and carbon stock in three plant communities of parkland agroforestry of western zone of Tigray Northern Ethiopia for each of plant communities and result of Pearson correlation (at α = 0.05, significant difference)

Diversity measurements	Plant Community 1		Plant Community 2		Plant Community 3
	AGC	TC	AGC	TC	AGC	TC
Species evenness	−0.359	−0.331	−0.558**	−0.552**	−0.451*	−0.225
Shannon-Weiner Diversity	−0.285	−0.379	−0.403	−0.643**	−0.258	−0.185
Simpson’s index of diversity	−0.195	−0.328	−0.443	−0.646**	−0.352	−0.215

Figure 5. Relationship between plant species diversity and the aboveground carbon stock of plant community 1

Figure 6. Relationship between plant species diversity and the aboveground carbon stock of plant community 2

Figure 7. Relationship between plant species diversity and the aboveground carbon stock of plant community 3

Figure 8. Relationship between plant species diversity and the total carbon stock of plant community 1

Figure 9. Relationship between plant species diversity and the total carbon stock of plant community 2

Figure 10. Relationship between plant species diversity and the total carbon stock of plant community 3