Population structure and regeneration status of Shorea robusta and associated trees in Sal forests of Ranchi, Eastern In
- PDF / 3,412,977 Bytes
- 18 Pages / 595.276 x 790.866 pts Page_size
- 34 Downloads / 163 Views
Tropical Ecology https://doi.org/10.1007/s42965-020-00121-6
RESEARCH ARTICLE
Population structure and regeneration status of Shorea robusta and associated trees in Sal forests of Ranchi, Eastern India Rahul Kumar1 · Purabi Saikia1 Received: 17 August 2020 / Revised: 6 October 2020 / Accepted: 2 November 2020 © International Society for Tropical Ecology 2020
Abstract The present study was aimed to study the detailed population structure of Shorea robusta and its four dominant associated tree species (Diospyros melanoxylon, Buchanania cochinchinensis, Madhuca longifolia, and Butea monosperma) in Sal forests of Ranchi, Eastern India. In addition, the regeneration status of all recorded tree species and anthropogenic disturbance of Sal forests were also studied. Girth class distribution showed a reverse J-shaped population curve in the present study, and there was a decline in tree density with an increase in girth class, and mature trees with higher girth (> 120 cm) were very few (9.30%), that signifies the ongoing natural regeneration as well as both natural and anthropogenic disturbances within the studied Sal forest stands. Out of the 103 recorded tree species, 50 species (48.54%) had shown the total absence of regeneration (no regeneration), while 23 species each (22.33%) showed poor and good regeneration, and rest 07 species (6.80%) showed fair regeneration in the studied Sal forests stand. On the other hand, the maximum studied Sal forest stands of Ranchi (42.39%) had shown fair regeneration of S. robusta followed by good regenerating forests (36.96%), and 17.39% forests showed no regeneration. Disturbance index had a weak statistically significant negative correlation with density (ind. ha−1) (r = − 0.20; P adult, (ii) fair if seedlings > saplings ≤ adults, (iii) poor if species survives in only saplings stage or saplings ≤ adults but not as seedlings, (iv) no regeneration if species absent both in seedlings, and saplings
Table 1 Grouping of all individuals of trees into different age groups based on girth at breast height (GBH in cm) and height (in m) for population structure study of documented tree species GBH (cm)
Age group based on GBH
Height (m) Age group based on mean height
Height: ≤ 30 cm ≤ 10, and Height: > 30 cm > 10–30 > 30–60 > 60–90 > 90–120 > 120
Seedling Sapling
5–10 > 10–20 > 20
Understorey Canopy Emergent
450
35
400
30
350
Sun hours
Fig. 2 Monthly mean sun hours, mean rainy and mean sunny days of Ranchi, Eastern India from July 2017 to September 2019. J January, F February, Ma March, A April, M May, Ju June, Jul July, Au August, S September, O October, N November, D December
within the transects of adults. Girth at breast height (1.37 m above ground) and height of all individual adult trees were measured in each transect using a measuring tape and range finder, respectively. Grid generation techniques used in the vegetation sampling were adopted as per Kumar and Saikia (2020c).
25
300 250
20
200
15
150
10
100
5
50 0
S O N D J F Ma A M Ju JulAu S O
Data Loading...
