Impact of plant invasion on soil nutrient parameters
Analysis of soil physicochemical properties revealed that pH, EC, TDS
and WC differed significantly (p <0.001) between plots
(Table 1). Soil pH, TDS, SAL and WC values were higher in the invaded
plots as compared to uninvaded, whereas EC showed the opposite trend.
Furthermore, pH, EC, TDS and SAL were highest at KZ site and showed a
gradual decrease along the increasing altitude, while WC revealed the
opposite trend (Table1). Significant differences were found in TOC, N
and P between the plots at all the sites except KD site where P did not
show any significant difference (p = 0.9). TOC and N were higher
in the invaded plots at all sites and P showed an opposite trend.
Between the plots, K differed significantly and showed progressively
increasing trend from KZ to KU followed by decline at KD site.
Furthermore, micronutrients were lower in concentration in the invaded
plots as compared to uninvaded plots and increased gradually along the
altitude (Table 1).
PCA analysis illustrated that first two axes (PC1, 52.4% and PC2,
32.4%) explained approximately 85% of total variance (Fig. 5). There
was a striking pattern for soil physicochemical properties observed at
different sites with invaded and uninvaded plots separated distinctly.
WC, TOC, K, N and Cu were positively related with invaded plots at the
higher-altitudinal KU and KD sites whereas Fe, Zn, Mn and P were
strongly associated with uninvaded plots at these two sites. Similarly,
pH, TDS and SAL were positively related with invaded plots at the
lower-altitudinal KZ and TM sites but negatively associated with invaded
plots at KU and KD sites. EC was strongly associated with uninvaded plot
at KZ site, but negatively related to uninvaded plots at KU and KD sites
(Fig. 5).