Vol. 9 No. 1 (2019)

Influences of Human Activities on Tree Density and Diameter Distribution in Museve and Mutuluni Dryland Forest Fragments; Kitui County, Kenya

2019-01-01T00:00:00Z

Influences of Human Activities on Tree Density and Diameter Distribution in Museve and Mutuluni Dryland Forest Fragments; Kitui County, Kenya Musau, J.M.; Mugo, J.M.

Deriving Tree Crown Distributions from Diameter at Breast Height

2019-01-01T00:00:00Z

Deriving Tree Crown Distributions from Diameter at Breast Height Ogana, F.N.; Dau, J.H. The distribution of crown diameter is important for assessing crown social class, monitoring forest health and wildlife management. However, the direct measurement of crown diameter is relative difficult, and as such, it is often predicted from diameter at breast based on a simple relationship. Therefore, in this study, the crown diameter distribution of Parkia biglobosa was derived from Dbh using Weibull and Log-Logistic functions. A total of 284 trees were measured from Parkia biglobosa plantation in Makurdi, Nigeria. Four methods were used for Weibull distribution including maximum likelihood (MLE), moments, percentiles and cumulative distribution function regression (CDFreg). MLE and CDFreg were used for Log-Logistic function. Transformation technique was used to transform the Dbh to crown distribution based on a simple allometric relationship between the variables. Kolmogorov-Smirnov (Dn), Cramer-von Mises statistic (W2) and Reynolds error index (EI) were used to assess the derived crown diameter distribution. The result showed that the underlying diameter distribution followed Weibull and Log-Logistic distributions. The fitted allometric equation was of the form: . MLE and CDFreg were the best methods for Weibull and Log-Logistic functions, respectively. The Dn, W2 and EI were 0.071, 0.0265 and 0.3434, respectively for MLE; and 0.0931, 0.0367 and 0.4171, respectively for CDFreg. In all methods, the observed and derived crown distributions were not significant at 20% (Dα=0.339). Thus, given the diameter distribution, the tree crown distribution of Parkia biglobosa can be derived. This would be useful for determination of the crown social class.

Perception of Generation Y on Waste Disposal and Waste Management in Sri Lanka with special reference to undergraduates of private universities in Colombo

2019-01-01T00:00:00Z

Perception of Generation Y on Waste Disposal and Waste Management in Sri Lanka with special reference to undergraduates of private universities in Colombo Wanodya, W.G.M.U.; Perera, H.P.N. Solid waste piling has become a serious problem to Sri Lanka. Urbanisation, industrialisation, and improvements in quality of life lead the increase in quantity and complexity of generated waste. The main purpose of this study is to determine the perception of undergraduates on waste, waste disposal mechanisms and waste management techniques in their living area. The research data obtained from one hundred and seventy three (n=173) undergraduate respondents from private universities located in Western Province, Colombo 07. A self-administered pre-validated questionnaire was used and the questionnaire was developed according to the literature survey and adapted accordingly to suit the Sri Lankan context. The data collection method was cross sectional. SPSS16.0 was used for data analysis. Data were analysed using cross-tab and chi square test. Cronbach’s alpha with the present sample was 0.63. The results revealed that 51% of the respondents do not have any clue of where their service providers are dumping their waste and 53% had reported that they are not concerned about it. Even though the responses are as such, 80% of the respondents had stated that they are aware that environmental degradation affects their families. The results revealed (based on p-value) that there is no association between gender and student perception on waste management. Furthermore student’s concern about the environment and waste management was moderate. Research reveals that there should be a proper mechanism to improve young generation’s concern about the environment and waste management to attain a sustainable future in the long term.

Microhabitat Utilisation of Endemic Lizard Calotes nigrilabris in the Grasslands of Horton Plains National Park, Sri Lanka, W.A.D.

2019-01-01T00:00:00Z

Microhabitat Utilisation of Endemic Lizard Calotes nigrilabris in the Grasslands of Horton Plains National Park, Sri Lanka, W.A.D. Jayasekara, E.G.D.P.; Prabhath, M.C.; Mahaulpatha, W.A.D. The endemic endangered agamid lizard Calotes nigrilabris inhabits the grasslands of Horton Plains National Park (HPNP) and it is restricted to a few localities in the central highlands of Sri Lanka. In this study, the microhabitat utilisation of Calotes nigrilabris was investigated utilising line transects and quadrate method. The comparison of available microhabitat variables with occupied microhabitat variables revealed that there was a significant difference between some of the variables (Man-Whiteney U test, p<0.05) indicating that C. nigrilabris was selective in its microhabitat utilisation. Based on PCA analysis, amount and type of vegetation was the main determining factor of microhabitat preference of this species. Ulex sp. cover (PC1, 0.606) and Rhododendron sp. cover (PC2,-0.603) were significantly affecting the occupied microhabitat structure. Microhabitat utilisation varied in the temporal and spatial scales also indicating clear resource partitioning between different maturity stages. The results of this study indicate that C. nigrilabris actively selects and utilises the most suitable grassland microhabitats of HPNP and provide important insights for the conservation and management of the species as well as its natural habitat.