COS 226-2 - Influence of foraging and edaphic factors on the distribution of Bermudagrass (Cynodon dactylon Pers.) in an arid area of Pakistan

Background/Question/Methods

Cynodon dactylon is a perennial, commonly growing grass in the Sukkur, an arid area of Pakistan. It is extremely valuable for cattle grazing here as it becomes a sole source of food for them in the dryer months of the year. However, its density is not consistent in all places. Therefore, this study was executed to determine the potential effects of foraging and various edaphic factors (texture, organic matter, pH, EC, TDS, NaCl, CaCO₃, N, C, P, K⁺, Ca⁺², Na⁺², Mg⁺², Zn⁺², Pb, Cd) on the distribution of C. dactylon in the summer and winter seasons of the year 2020. 9 different sites were selected for the collection of data based on differential land-use types. The quadrate method was employed to find out the frequency and percentage cover of C. dactylon. Five quadrates of size 50cm² were used at each study site. Pearson’s correlation was employed to correlate grass with potential ecological factors. In order to determine the spatial heterogeneity of C. dactylon influenced by various edaphic factors, the canonical correspondence analysis (CCA) was used. The beta-diversity was determined through non-metric multidimensional scaling (NMDS) based on Bray-Curtis dissimilarity matrices.

Results/Conclusions

The highest frequency of this grass was found at cattle grazing site, more even compared to the site where goats were used to graze. Also, sites with more alkaline soil pH (maximum pH 8.9 at the abandoned site) showed a higher frequency of C. dactylon. The lowest frequency was recorded at the shady site. The low frequency at sites near urban and roadside could be attributed to high concentrations of Pb and Cd heavy metals there. The frequency and percentage cover also showed a significant positive correlation with soil nitrogen, organic carbon, and mineral content such as K⁺, Ca⁺², and Mg⁺². NMDS ordination also explained significant variation among sites. The results of this study could be identified as an ecological tool to restore the growth of C. dactylon in degraded environments.