Studies on vegetation structure and species diversity of Sathan Gally, District Mansehra

Abstract

This study was designed for the first phytosociological exploration of the floristic exploration of Sathan Gally, District Mansehra, Pakistan. The study area, part of the Western Himalayas, shows rich floristic diversity. In this investigation, an effort was made to document the phyto diversity and vegetation structure of the area by using quadrat method and standard phytosociological tools. A sum of 35 sampling sites were selected randomly for vegetation analysis and 20 quadrats were laid down for herbs, 10 for shrubs and 5 for trees at each sampling site. The study area was visited frequently during flowering seasons of 2013 and 2014. Plant species were collected from a range of localities, identified, preserved and deposited in the Herbarium of Hazara University, Mansehra. The current investigation was conducted to explore the floristic diversity and vegetation structure in context of environmental gradients of investigated area. A total of 170 plants species, belonging to 154 genera of 73 families were recorded in 35 stands. Angiosperms were represented by 92.85%, Gymnosperms by 2.97% and Pteridophytes by 2.16% species. The leading family was Asteraceae represented by 20 species, followed by Rosaceae by 14 species, Poaceae by 12 species, Lamiaceae by 10, Polygonaceae by 5, Primulaceae by 4 species and Caryophyllaceae and Moraceae by an equal sharing of three species each. TWINSPAN multivariate classification and ordination method by CANOCO software which is being used in most of the phytosociological surveys across the world, was applied. TWINSPAN identified six plant communities viz., Pteris-Urtica-Pinus, Pinus-DigitariaSarcococca, Dryopteris-Cedrus-Pinus, Pinus-Cedrus-Indigofera, Pinus-AbiesViburnum and Themeda-Indigofera-Ailanthus. The phytosociological attributes like density, frequency, cover, importance values index, leaf size spectra, life form, index of diversity, species richness and species maturity were recorded. Microphyll contributing 40.47% species were leading leaf spectra class followed by Mesophyll containing 26.78% species, Nanophyll by 24.4% species, Macrophyll and Leptophyll 4.14% species by each. Therophytes were found as leading life form class of the area contributing 30.35% species, followed by Hemicryptophytes 20.23%, Megaphanerophytes 16.66%, Geophytes and Nanophanerophytes by 12.5%, and Chamaephytes by 7.14% species. The Reserved forest showed rich floristic diversity as compared to Guzara forest. In the current study a total of 127 plants species consisting of 59 common and 68 different were found in 13 stands of reserved forest. Angiosperms were represented by 118 (92.91%), plant species Pteridophytes 5(3.93%) species and Gymnosperms 4 (3.14%) species were recorded in Reserved forest. Only single species of climber was documented. The dominant family was Asteraceae (13 species, 10.7%) followed by Labiateae (10 species, 7.75%), Poaceae and Rosaceae (8 species, 6.2%) each, Polygonaceae and Pteridaceae by (5 species, 3.87%) each. Four different plant communities were recognized by TWINSPAN in Reserved forest. A total of 103 plant species of 55 families including 61 common in both forest types and 42 species different to Reserved Forest. These plant species were documented from 22 sampling stands. Angiosperms by (92.3%) plant species Gymnosperms (2.88%) and Pteridophytes (4.8%) were recorded. The dominant family was Poaceae by 11 plant species followed by Asteraceae and Rosaceae each represented by 10 species and Pteridaceae by five plant species. Three plant communities were recognized in Guzara forest by TWINSPAN. The study revealed that the indigenous peoples of the area exploited 86 (51.19%) species as traditional medicinal plants, 136 (80.95%) species for fodder, 48 (28.57%) for fuel wood, 28 (16.66%) for timber woods, 07 (4.16%) for wild vegetable and 02 (1.19%) for ethno-veterinary therapies. Similarly, 17 (10.11%) species for wild edible fruits, 2 (1.19%) species for making agricultural tools, 1 (0.59%) species for fencing field borders. It was observed that the local inhabitants used plant resources for single and multiple purposes. Palatable flora was also documented and it showed that 79.16% of the total recorded flora were grazed by goat, cow, sheep and buffalo in the study area while 20.83% flora was found non-palatable. This study will assist ecologists, botanists, taxonomist, conservationists and policy makers to manage the current status of plants. The present investigation will also serve as baseline for future researches on the Himalaya Regions.