Tag Archives: Species

Effects of Tides on the Zooplankton of the Great Kwa River, Calabar, Nigeria (Published)

This study investigated the tidal effects on the composition, diversity, abundance and distribution of zooplankton species in the Great Kwa river, Nigeria. Zooplankton samples were collected fortnightly between July 2019 and September 2019 at low, mid and high tidal regimes. A total of 59 zooplankton species belonging to 41 taxa (genera) and 16 classes groups were identified and recorded during the study. Zooplankton comprised of 199 individuals of which 49 were recorded in low tide, 95 (mid tide) and 55 (high tide). Generally, Rhizopoda (37.19%) were dominant, followed by Copepods (25.13%) while invertebrate, Lepidoptera and Malacostracan were less than 1% each. Copepods were dominant at low tide, while Rhizopoda were dominant at mid-tide and high-tide. Weiner Index (H) showed that zooplankton species was high at low tide (3.95), followed by high tide (2.95) and least in mid tide (2.22). The absence of some zooplankton species at Mid tide and High tide suggests that zooplankton species had vertically migrated downward the river before high tide and mid tide. Despite the highest number of individuals recorded at mid-tide, an evenness value of 0.49 compared to 0.74 (high-tide) and 0.85 (low-tide), suggests that the numerical abundance was less evenly distributed among species.

Keywords: Great Kwa River, Sampling Station, Species, Tides, Zooplankton

IMPACT OF INDISCRIMINATE LANDUSES ON SPECIES ABUNDANCE:CASE STUDY OF SILK COTTON TREE CEIBA PETENDRA COLONY AT SOUTHERN SUBURB OF ZARIA CITY – NIGERIA (Published)

The case of silk cotton tree (Ceiba petendra ) that has colonized an area of more than 1,000 hectres at the southern suburb of Zaria city for almost 5 centuries’ is the subject of the study. It aims at documenting how indiscriminate human activities led to the gradual depletion of the vegetal cover. Landuse characterization, botanical and ecological parameters were focused and an alarming negative results were evident in such indices as species density, species ‘regeneration, surface cover, soil erosion and fertility status. This negative development is assiduously affecting not only the tree colony but also soil quality, crop yield and the water table of the entire city. Consequently, a re-reservation and the re-plantation of the colony was proposed as a panacea to the ever increasing deterioration of the fragile ecosystem

Keywords: Ecology, Flora, Silk-Cotton, Species, Zaria, land use

The Relative Abundance of Floraspecies in the Tropical Rainforest Ecosystem of Boki Nigeria (Published)

This study was conducted with the view to analysing flora species abundance in the tropical rainforest ecosystem of Boki. Despite the spate of indiscriminate logging, this area still remains one of the few ecosystems that have been highly valued for its species diversity. Two forest formations the protected and the unprotected forest were used for the analysis. Six forest enclaves – Kanyang, Borum, Isobendeghe, Okwa I, Okwa II and Okwango were chosen for the study. Transects were laid from the centre of each forest enclave to the heart of the forest. Actual measurement of the quadrat started at a distance of 2km away from each enclave. A quadrat of 100m by 100m was demarcated for flora species identification and enumeration. The relative abundance was computed using the frequency of each species as percentage of the total species in the quadrat. The mean (x-) proportional abundance was computed to determine levels of flora species abundance. This was also complemented with the lognormal curve. Here, the number of flora species was plotted against individual species. The girth of each flora species was determined at breast height of 1.5m. The result of the analysis revealed that very few flora species were of low and high abundance whereas majority were in moderate abundance. Also majority of the trees in the area were in the category of 6-10 metre girth at breast height in the protected forest and 0-5 metre girth at breast height in the unprotected forest.

Keywords: Abundance, Ecosystem, Forest, Frequency, Species