ASSESSMENT OF UNDERSTOREY VEGETATION OF MALAM JABBA FOREST, KPK AFTER CLEANUP OPERATION USING MULTIVARIATE TECHNIQUES

Abstract

In this study vegetation composition of understorey species of Malam Jabba forest is evaluated by multivariate analysis. Thirteen stands were quantitatively sampled by point centered quarter method. Environmental variables were recorded and correlate them with vegetation characteristic. In 13 stands 49 understory species were recorded. Multivariate techniques were employed to assess the vegetation groups and underlying group structure. Agglomerative Cluster analysis (Ward’s method) discloses four main groups of vegetation while Principle Component Analysis (PCA) clearly ordinate these groups on all three axes. The most common species distributed in all four groups were Adiantum capillus veneris, Adiantum venestum, Berberis lyceum, Chrysopogon aucheri, Oxalis corniculata, Pteris cretica and Trifolium repens while these species were observed in three groups i.e.  Punica granatum and Plantago amplexicaulis. The Group 1 comprises on 23 species and the dominant species were Androsace rotundifolia, Aristida cynantha, Berberis lyceum, Dryopteris filix, Oxalis corniculata, Pteris cretica and Trifolium repens while Group 2 comprises on 18 species, the dominant were Pteris cretica, Adiantum venestum, Duchesnea indica while some other species included, Berberis lyceum, Chrysopogon aucheri, Chrysopogon aucheri, Dryopteris juxtapostia and Morus alba. Group 3 & 4 comprises 31 species each, in which 18 species were common i.e. Adiantum capillus veneris, Adiantum venustum, Arisaema jacquemontii,  Berberis lyceum, Chrysopogon aucheri,  Dryopteris filix, Dryopteris juxtapostia, Duchesnea indica, Oxalis corniculata, Plantago amplexicaulis, Polygala erioptera,  Prunus avium, Pteris cretica, Punica granatum, Ranunculus muricatus, Rosa macrophylla, Trifolium fragiferum and Trifolium repens.  Among the environmental variables elevation and slope played an overriding role in the distribution of vegetation. The relationships between the six PCA ordination axes with environmental factors generally showed few significant relations, only axis 2 showed marked relationship with all edaphic variables (except pH), suggesting that the edaphic gradient has an overriding role in the composition and distribution of understorey vegetation.  Some other environmental factors showed weak correlations with ordination axes, it could be spurious correlation. Malam Jabba forests are highly disturbed due to civil war and anthropogenic causes. Slope of the forests prove to be an overriding role in the distribution of vegetation as evaluated by analysis of variance.