Quantity And Quality Of Litterfall In Pure Pine And Pine/Gmelina Mixed Plantations In Umuahia, Abia State

An assessment of the pattern of litterfall and quality of litter were carried out in plantations of pure exotic Pine and Pine/Gmelina mixed plantations at Forestry Research Institute of Nigeria (FRIN) station Umuahia, Abia State. Litterfall was continuous with much of the litter falling between March and April in the pure Pine stand. April 2004 gave significantly (

Levels of Biologically Active Compounds and some Essential Metal in Parts of African Oil Bean Tree (Pentaclethra macrophylla)

The study assessed the phytochemical and mineral content in leaves, root and bark of Pentaclethra macrophylla in Amumara Mbaise, Imo State. The qualitative analysis show that the root extract had the highest tannin (++), flavonoid (+++), alkaloid (+++), and saponin (+++) with high degree of precipitation while phenol (+++) and phytate (+++) occurred in the leaves extract. Quantitatively, the highest significant (P<0.05) content of tannin (1.42±0.00 %), flavonoid (3.75±0.35 %, alkaloid (1.30±0.14 %), and saponin (3.40±0.00 %) were obtained in the root while the highest significant (P<0.05) content of the minerals: Mg (158.00±0.00 mg/100 g), Fe (16.50±0.00 mg/100 g), Na (165.00±0.00 mg/100 g), and Ca (224.15±0.00 mg/100 g) were observed in the leaves. The results indicate that P. macrophylla is a promising tree species that can improve the health of man.Key words: Mineral, phytochemical, leaves, root

Seed germination and root sprouting characteristics of chromolaena odorata (I)R.M King and Robinson in Southwestern Nigeria

No Abstract

Dynamics of Soil Nutrient and Macro-organism Population Following Land Conversion from Fallow to cultivated Farm

An assessment of soil physical and chemical features as well as the species richness of macro-organisms was carried out in a 2-year cultivated farm, 3-year fallow,8-year fallow and a 50 –year undisturbed relic forest all located within 1 km radius within Umudike. The 3-year cultivated plot had the lowest levels of N, P, k, Ca and organic matter which were 0.14%, 2.3, 0.012, 1.6 and 0.226, respectively. The percentage sand was highest in the 3-year cultivated plot while clay % was highest in the 50 year undisturbed vegetation. The difference in textural characteristics was more pronounced between 3-year cultivated soil and the 8 year fallow than between the 8 year fallow and the 50-year undisturbed relic forest, a condition attributable to the loosening of the soil and increased run-off occurring in the 3-year cultivated farm. The abundance of soil macro-organisms increased with advance in years of fallow and it was found to be associated with increased level of organic matter and species diversity of the vegetation cover. Only species in the annelida phyla occurred in all field conditions. Keywords: Fallow, Cultivation, Nutrient status and Soil macro-organism Journal of Agriculture and Food Sciences Vol. 4 (2) 2006: pp. 93-10

Determinants of Tree Assemblage Composition at the Mesoscale within a Subtropical Eucalypt Forest

A variety of environmental processes, including topography, edaphic and disturbance factors can influence vegetation composition. The relative influence of these patterns has been known to vary with scale, however, few studies have focused on environmental drivers of composition at the mesoscale. This study examined the relative importance of topography, catchment flow and soil in influencing tree assemblages in Karawatha Forest Park; a South-East Queensland subtropical eucalypt forest embedded in an urban matrix that is part of the Terrestrial Ecosystem Research Network South-East Queensland Peri-urban SuperSite. Thirty-three LTER plots were surveyed at the mesoscale (909 ha), where all woody stems ≥1.3 m high rooted within plots were sampled. Vegetation was divided into three cohorts: small (≥1-10 cm DBH), intermediate (≥10-30 cm DBH), and large (≥30 cm DBH). Plot slope, aspect, elevation, catchment area and location and soil chemistry and structure were also measured. Ordinations and smooth surface modelling were used to determine drivers of vegetation assemblage in each cohort. Vegetation composition was highly variable among plots at the mesoscale (plots systematically placed at 500 m intervals). Elevation was strongly related to woody vegetation composition across all cohorts (R2: 0.69-0.75). Other topographic variables that explained a substantial amount of variation in composition were catchment area (R2: 0.43-0.45) and slope (R2: 0.23-0.61). Soil chemistry (R2: 0.09-0.75) was also associated with woody vegetation composition. While species composition differed substantially between cohorts, the environmental variables explaining composition did not. These results demonstrate the overriding importance of elevation and other topographic features in discriminating tree assemblage patterns irrespective of tree size. The importance of soil characteristics to tree assemblages was also influenced by topography, where ridge top sites were typically drier and had lower soil nutrient levels than riparian areas