INVASIVE PLANT SPECIES AFFECT SODOM APPLE (CALOTROPIS PROCERA (AITON) W. T. AITON) AND ASSOCIATED PLANTS BY ALTERING SOIL PHYSIOCHEMICAL CHARACTERISTICS IN NORTHWEST PAKISTAN

Abstract

Invasive plant species have deliberately affected and reduced the populations of native species, thereby increasing their risk of extinction. The objective of this research was to compare the effects of the two most aggressive invasive alien species currently invading habitats of Calotropis procera “an ecologically and medicinally important native plant” in northwest Pakistan, most probably by altering vegetation and soil physical and chemical characteristics. We sampled invaded and non-invaded vegetation of exotic invasive and native species in diverse habitats with corresponding environmental and soil parameters for multiple comparisons like species richness, diversity, and total plant coverage to assess the invasion effects. Our results exposed that soil physiochemical characteristics significantly differed among the native and exotic invaded-derived soils. Principal component analysis revealed that C. procera dominated vegetation was strongly affected by the invasion of X. strumarium and P. hysterophorus as a result of altered soil characteristics, thereby offering strong evidence that invasion of both exotic invasive species alter soil chemistry and ecology, which may create conditions favourable for invasive plants over native plants. Likewise, results showed that invasive species have completely dominated invaded sites (IV ≥45%) whereas in native vegetation both species are overlapping (IV ≥15%) and might be the strong competitors affecting community structure in the future.