The quantitative analysis of plant diversity of semi evergreen forest of Hollongapar Gibbon Wildl... more The quantitative analysis of plant diversity of semi evergreen forest of Hollongapar Gibbon Wildlife Sanctuary in upper Assam was investigated during 2010-2011 by random plot sampling method. A total of 202 plant species (75 trees, 23 shrubs, 85 herbs including herbaceous climbers, 9 lianas, 3 bamboos, 6 rattans and 1 palm) belonging to 169 genera and 87 families were recorded from the sanctuary. Vatica lanceaefolia Bl., a critically endangered species, emerged as the dominant tree species. The highest plant density and diversity were found in herbaceous species. Shannon-Wiener diversity index (1.93 to 3.81) and Simpson's index (0.05 to 0.17) were within the range reported for different Indian tropical forests which indicated that the sanctuary is a species diverse forest. Plant species diversity and their quantitative features recorded from the present study may provide baseline information for conservation and management strategies of the present forest.
ABSTRACT A study on diversity of butterfly fauna was carried out in the North Eastern Regional In... more ABSTRACT A study on diversity of butterfly fauna was carried out in the North Eastern Regional Institute of Science and Technology (NERIST) Campus of Nirjuli, Itanagar; Arunachal Pradesh, India. The habitat was divided into four major categories namely home garden, forest patch, road side plantation and open grassland. A total of 63 species of butterflies belonging to the five families were recorded during the survey and Nymphalidae were the most commonly recorded, accounting for 44% of total species recorded followed by Lycaenidae 17%, Pieridae 16% and Papilionidae 14% of total species and minimum was recorded for Hesperidae 8% (n=5) Maximum 51 species were recorded in the forest patches followed by home garden (46), road side plantation (44) and minimum in open grassland (36). A total of 398 individuals were recorded from the campus with highest abundance in home garden (n=129) followed by open grassland (n=96), forest patch (n=89) and road side plantation (n=84). The diversity was found high in the forest patch (H=3.76) followed by roadside plantation (H=3.68), home garden (H=3.65) and open grassland (H=3.39). Conservation of butterfly fauna in a small landscape particularly in human dominated might be a good model for maintaining optimal habitat within fragments and in that case academic institutional campus with high plant diversity might be a very good option for the conservation of the species.
Abstract An ecological study was conducted to evaluate the levels and effects of heavy metals on ... more Abstract An ecological study was conducted to evaluate the levels and effects of heavy metals on forest surface soils along highways. We hypothesized that vehicles in highways emit considerable levels of metals, affecting plant diversity and productivity. Pearson correlation, cluster, and regression analysis were used to prove these relationships. Furthermore, ecological risk assessments were quantified using the geo-accumulation index, pollution index, pollution load index, and ecological risk index. Results indicated soil samples from Site II (roadway) had higher levels of metals than Site I (control), suggesting that highway traversing via forests emit considerable amounts of metals into the surface soil. The most intriguing aspect is that species such as Bidens Pilosa and Arundo donax were frequently recorded at Site II. The predominance of such species indicates contaminated sites favouring metal tolerance species. Ecological risk indices revealed that Cd, Mn, and Pb contributed to ecological risk; their pollution ranged from unpolluted to heavily polluted ecosystem. Correlation analysis found a pronounced negative link between metals and diversity; the correlation matrix was −83%, −94%, −65%, −75%, −47%, −57% and − 38% for grass diversity, and − 59%, −74%, −89%, −66%, −81%, −81% and − 83% for forb diversity with Cd, Cr, Ni, Pb, Zn, Cu and Mn, respectively. Furthermore, negative correlations for tree production of −80%, −79%, −76%, −71%, −67%, −53% and − 41% were recorded with Cd, Cr, Ni, Pb, Zn, Cu and Mn, respectively. Nevertheless, metals accounted for 74% variance in tree productivity. The strong negative link observed in this study demonstrates the effects of metals on diversity and productivity, which requires monitoring for preventing serious environmental consequences. Highlights • Excessive road traffic contributes to the release of heavy metal in forests. • Heavy metals in surface soils threaten plant diversity and productivity. • Cd, Mn and Pb are the most substantial contributors to ecological risks.
The quantitative analysis of plant diversity of semi evergreen forest of Hollongapar Gibbon Wildl... more The quantitative analysis of plant diversity of semi evergreen forest of Hollongapar Gibbon Wildlife Sanctuary in upper Assam was investigated during 2010-2011 by random plot sampling method. A total of 202 plant species (75 trees, 23 shrubs, 85 herbs including herbaceous climbers, 9 lianas, 3 bamboos, 6 rattans and 1 palm) belonging to 169 genera and 87 families were recorded from the sanctuary. Vatica lanceaefolia Bl., a critically endangered species, emerged as the dominant tree species. The highest plant density and diversity were found in herbaceous species. Shannon-Wiener diversity index (1.93 to 3.81) and Simpson's index (0.05 to 0.17) were within the range reported for different Indian tropical forests which indicated that the sanctuary is a species diverse forest. Plant species diversity and their quantitative features recorded from the present study may provide baseline information for conservation and management strategies of the present forest.
ABSTRACT A study on diversity of butterfly fauna was carried out in the North Eastern Regional In... more ABSTRACT A study on diversity of butterfly fauna was carried out in the North Eastern Regional Institute of Science and Technology (NERIST) Campus of Nirjuli, Itanagar; Arunachal Pradesh, India. The habitat was divided into four major categories namely home garden, forest patch, road side plantation and open grassland. A total of 63 species of butterflies belonging to the five families were recorded during the survey and Nymphalidae were the most commonly recorded, accounting for 44% of total species recorded followed by Lycaenidae 17%, Pieridae 16% and Papilionidae 14% of total species and minimum was recorded for Hesperidae 8% (n=5) Maximum 51 species were recorded in the forest patches followed by home garden (46), road side plantation (44) and minimum in open grassland (36). A total of 398 individuals were recorded from the campus with highest abundance in home garden (n=129) followed by open grassland (n=96), forest patch (n=89) and road side plantation (n=84). The diversity was found high in the forest patch (H=3.76) followed by roadside plantation (H=3.68), home garden (H=3.65) and open grassland (H=3.39). Conservation of butterfly fauna in a small landscape particularly in human dominated might be a good model for maintaining optimal habitat within fragments and in that case academic institutional campus with high plant diversity might be a very good option for the conservation of the species.
Abstract An ecological study was conducted to evaluate the levels and effects of heavy metals on ... more Abstract An ecological study was conducted to evaluate the levels and effects of heavy metals on forest surface soils along highways. We hypothesized that vehicles in highways emit considerable levels of metals, affecting plant diversity and productivity. Pearson correlation, cluster, and regression analysis were used to prove these relationships. Furthermore, ecological risk assessments were quantified using the geo-accumulation index, pollution index, pollution load index, and ecological risk index. Results indicated soil samples from Site II (roadway) had higher levels of metals than Site I (control), suggesting that highway traversing via forests emit considerable amounts of metals into the surface soil. The most intriguing aspect is that species such as Bidens Pilosa and Arundo donax were frequently recorded at Site II. The predominance of such species indicates contaminated sites favouring metal tolerance species. Ecological risk indices revealed that Cd, Mn, and Pb contributed to ecological risk; their pollution ranged from unpolluted to heavily polluted ecosystem. Correlation analysis found a pronounced negative link between metals and diversity; the correlation matrix was −83%, −94%, −65%, −75%, −47%, −57% and − 38% for grass diversity, and − 59%, −74%, −89%, −66%, −81%, −81% and − 83% for forb diversity with Cd, Cr, Ni, Pb, Zn, Cu and Mn, respectively. Furthermore, negative correlations for tree production of −80%, −79%, −76%, −71%, −67%, −53% and − 41% were recorded with Cd, Cr, Ni, Pb, Zn, Cu and Mn, respectively. Nevertheless, metals accounted for 74% variance in tree productivity. The strong negative link observed in this study demonstrates the effects of metals on diversity and productivity, which requires monitoring for preventing serious environmental consequences. Highlights • Excessive road traffic contributes to the release of heavy metal in forests. • Heavy metals in surface soils threaten plant diversity and productivity. • Cd, Mn and Pb are the most substantial contributors to ecological risks.
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