TAXONOMIC DIVERSITY AND PHYTOSOCIOLOGICAL DYNAMICS OF THE FLORA OF SHISHI KOH VALLEY, CHITRAL, PAKISTAN

Abstract

The current research work was carried out during 2014-16 to study the taxonomic diversity and phytosociological dynamics of the flora of Shishi Koh Valley, Chitral, Pakistan. Gymnosperms were represented by two families Ephedraceae and Pinaceae. The dominant family was Pinaceae comprised of three (3) genera and four (4) species. In Angiosperms, Monocots were represented by five (5) families, seventeen (17) genera and twenty (20) species. Family Poaceae was found to be the dominant monocot family contributing thirteen (13) genera and sixteen (16) species. Dicots were represented by one hundred and thirty five (135) species belonging to ninety seven (97) genera of thirty eight (38) families. In dicots family Papilionaceae was found the dominant family represented by 12 genera and 22 species. Plant communities were studied in the Shishi Koh Valley, Chitral, Pakistan along an elevation gradient between 1831-2723m. Out of the total plants collected 13 (8%) were trees, 11 (7%) were shrubs and one hundred and thirty six (85%) were herbs. Five plant communities were established. Diagnostic, constant and dominant species were assigned based on fidelity threshold (40%), frequency threshold (25%) and cover threshold (35%) respectively. The communities were grouped into two main clusters on the basis of altitudinal variations. Cotoneaster-Rosa-Aristida and Pistacia-Quercus-Cannabis communities formed part of the first cluster. In the second cluster three communities were present in such a manner that Cedrus-Elaeagnus-Salix community formed part of the second cluster directly while the other two communities Cedrus-Ailanthus-Salix community and Abies-Cedrus-Pinus community were present as sub-groups of the second cluster. DCA1 axis had more contribution in overall variation of communities' diversity in the research area. Biological spectrum of the vegetation in the research area revealed that dominant life from class was Therophyte (35.43%). Among the other life form classes Hemicryptophyte were 20.47%, Nanophanerophyte 14.96%, Geophyte 13.39%, v Megaphanerophyte (11.02%), Chamaephyte 3.94%) and Mesophanerophyte were 0.79%. The dominant leaf size class was Nanophyll (41.73%). Representation of the other classes was Mesophyll 25.98%, Microphyll 20.47%, Leptophyll 9.45% and Macrophyll 2.36%. In regard to leaf persistence, 87.40% plants were deciduous and 12.60% plants were evergreen. Simple leaves were present in 71.65% plants, compound in 22.05% while incised leaves were present in 6.30% plants. Spiny nature was shown by 9.45% plants while 90.55% plants were non-spiny. In relation to water present in the habitat wise 74.02% plants were in xeric, 23.62% in mesic while 2.36% plants inhabited moist and aquatic habitats. In response to light 94.49% plants were heliophytes while 5.51% were sciophytes. Analysis of minerals showed that soil samples collected from all the five communities in the research area have low concentrations of Cu, Fe and Zn as compared to Mn. While Ca and Mg were present in considerable amount in all the soil samples analyzed. Organic matter ranged from 0.3 to 2.77%. Organic matter was present in the highest range in the Abies-Cedrus-Pinus community. Analysis of soil samples obtained from the research area showed that most of the soils are very nutrient poor and less fertile as most of the area is arid therefore mostly supporting xeric annual plants. Although in all communities sand particles was much higher however soils were comparatively fine textured in Pistacia-Quercus-Cannabis community as compared to all others. The current study pointed out that the research area has great taxonomic diversity but plant communities are under the threats of overgrazing and medicinal plants collection. Similarly plant communities are mostly being exploited for fuel and furniture woods resulting in flood hazards each year. Another factor is overgrazing, mostly due to the herds of local gujjars and nomadic visitors in the start and middle of the valley. The herbaceous flora is under serious threat of extinction due to these devastating factors. Control measures must be taken to avoid further damages. Some rehabilitation programs may also be started to recover damage to the forests in the research area.