RELATIONSHIP BETWEEN TREE ECOLOGICAL PARAMETERS AND SOIL ORGANISMS ABUNDANCE IN ECOLOGICAL ZONES OF BAYELSA STATE, NIGERIA

Abstract

The study examined the relationship between tree ecological parameters and abundance of soil organisms in ecological zones of Bayelsa State, Nigeria. The study adopted quasi experimental research design. A quadrat of 100m x 100m was delimited in the relatively less disturbed forest in each ecological zone from which twenty (20) sub-quadrats were randomly selected for data collection on plants and soil organisms (earthworm, arthropods, fungi and bacteria) abundance at different soil depths (0-15cm, 15-30cm, 30-45cm). Both descriptive and inferential statistics were used for data analysis. Findings showed that a total of 251 earthworm population was found in the entire area with the highest (52.1%) at the topsoil in the freshwater swamp (FWS) while 176 individual species of earthworm recorded in the mangrove (MG) with highest in the topsoil (63.64%). Soil arthropods abundance was significantly higher between FWS and MG at p<0.05. Earthworm abundance was significantly correlated with tree composition (r=-0.459), tree density (r=0.543) and tree density (r=0.581) in the FWS while soil fungi was significantly correlated with tree richness (r=0.445) at the topsoil in the FWS. In addition, at 15-30cm soil depth in the FWS, only soil fungi was correlated with tree composition (r=0.668) and tree richness (r=0.550). At the soil depth of 30-45, only soil bacteria was significantly correlated with tree richness (r=0.624) and tree density (r=0.464). In MG, at the soil depth of 0-15cm, soil arthropods abundance was significantly correlated with tree composition (r=0.464). At 15-30cm, soil bacteria was significantly correlated with tree richness (r=0.582) and tree density (r=0.632) while soil fungi was significantly correlated with number of trees (r=0.611), tree diversity (r=0.624), tree richness (r=0.520) and tree density (r=0.632). At the soil depth of 30-45cm, soil fungi correlated significantly with number of trees (r=0.474). The study recommended that plant conservation is important to protect the survival of soil organisms. quasi experimental research design. A quadrat 100m 100m forest not disturbed each ecological of Bayelsa This quadrat was sub-divided into quadrats of 20m x 20m which twenty (20) quadrats were randomly selected for data collection on plants and soil organisms in each ecological belt. The sample plots were delimited with pegs and tagged with red coloured ribbon for easy identification of the boundaries. The sampling methods adopted for this study were stratified and simple random sampling techniques. The tree plants species were identified with the of a Taxonomist University within the sixteen sub-quadrats for the study. Thereafter, overstorey data were collected on the total tree composition and number of individual trees. The tree composition and number of individual trees were used to determine the plant richness and diversity in each ecological zone. Species composition of vascular plants in the study area was determined by identifying the plant species while the population of individual species was determined by direct counting of the population of each plant species in the 20m x 20m quadrats. species composition of the vascular plants species density, diversity, richness, the The species diversity value H