Abstract
Aim:
The present investigation was carried out to understand the impact of
controlled/prescribed burning on understorey vegetation in chir pine (Pinus
roxburghii) forests of Shiwalik region to manage the summer fire damage.
Methodology: Chir pine forest areas of two hectares (ha) each were
selected at three sites in Shiwalik region of Himalaya for prescribed
burning. Each forest area was delineated into three plots of which one plot
was burnt during mid-winter in the year 2017 (B1) and another plot
burnt twice (B2) during 2017 and 2018 whereas the third was kept
unburnt plot (C) in each site. The phytosociological attributes of
understorey vegetation were studied in November, 2018. The difference in
density of shrubs (plants 25 m-2) and herbs (plants m-2)
in unburnt (C), once burnt (B1) and twice burnt (B2)
was analyzed through critical difference (CD).
Results:
Total density (plants 25m-2) of shrubs ranged from 7.15 to 12.95
in unburnt (C), 3.90 to 8.40 in once burnt (B1) and 2.25 to 4.65
in twice burnt (B2) plots whereas total density (plants m-2)
of herbs varied from 25.83 to 44.95 in unburnt (C), 33.20 to 75.92 in once
burnt (B1) and 29.31 to 90.93 in twice burnt (B2)
plots. The density of shrubs was significantly higher in unburnt plots (C) as
compared to burnt plots and vice versa for herbs. The Shanonn Wiener
Index (H) ranged from 1.76 to 2.39 for shrubs and 2.32 to 3.15 for herbs.
Interpretation: The density of herbs was higher in burnt
plots and it was vice versa for shrubs. The prescribed burning
enhanced diversity of herbs while shrubs diversity decreased with burning.
Key words: Chirpine forests, Density, Diversity, Prescribed
burning, Shiwalik hills
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