Forest ecosystem soil attributes influence density of Pseudomonas fluorescens

Pseudomonas fluorescens is a common, multi-flagellated, Gram-negative, rod-shaped bacteria, which are anti-phytopathogenic and plant growth promoting rhizo-bacteria. Study was conducted at the College of Forestry, Sirsi with the objective of measuring the bacterial copiousness in ten different forest and plantation ecosystem i.e., evergreen, semi evergreen, moist deciduous, dry deciduous, myristica swamp, mangroves, scrub forest, teak, Acacia and Eucalyptus plantation; and correlated with different soil parameter viz., soil p^H, electrical conductivity (EC) and soil moisture percentage (SMP). In each ecosystem plots were laid randomly; soil samples and site description were collected. P. fluorescens was isolated using Kings B agar as the selective media. Gram's reaction and morphological characterization were used to identify bacterial isolates. Myristica swamp had the highest 99,311.60 CFU/gm (4.997 Log (CFU/gm) bacterial abundance, followed by evergreen (4.937) and semi-evergreen (4.913). Myristica swamps with a p^H of 5.03 showed the highest levels of soil acidity, mangroves had the highest electrical conductivity (0.195 dSm^-1). The highest percentage of soil moisture was found in mangrove Forest (142.67%). Soil pH wasnegatively correlated with P. fluorescens abundance (r = -0.376) and soil electrical conductivity was positively correlated (r = 0.238). p^H and bacterial density were inversely correlated; EC, SMP and canopy density were directly related to bacterial density in sequentially sere ecosystems, viz., Dry deciduous, Moist deciduous, Semi-evergreen, and Evergreen forests.