Anthropogenic effects on the physical and chemical properties of subtropical coastal urban soils

We investigated the effects of various anthropogenic factors on urban soil properties in subtropical, coastal Tampa, FL, USA. Specifically, we explored the influence of (i) urbanization as measured by land use, land cover, population density and years since urban development and (ii) socioeconomic conditions as reflected in household income and property values on bulk density (BD) and several key soil chemical properties. Results indicate that Tampa’s urban soils were affected to varying degrees by these factors with chemical properties being more variable than BD. Across land uses significant differences were found for Mehlich‐1 (M1) extractable P, Ca and Na. A similar trend was observed for land‐cover classes, although significant differences were also found for pH and M1‐Cu. Soil properties had no statistically significant relationship with population density. However, time since urbanization did with M1‐P and Na varying significantly across age categories. For our socioeconomic analyses, M1‐K and Mg levels differed significantly by household income while pH, P, Ca and Na values differed significantly by property value. Overall, our findings indicate that despite their inherent heterogeneity, there are identifiable patterns among subtropical coastal urban soil properties. We suggest that a more thorough understanding of these patterns and their drivers is an essential first step towards developing soil management strategies aimed at maintaining environmental quality and ecosystem services in subtropical cities.     

Phylogenetic network analysis of South and North American Corynespora cassiicola isolates from tomato,cucumber, and novel hosts

European Journal of Plant Pathology - Corynespora cassiicola isolates display morphological, pathogenic, and ecological diversity, inducing target spot-like diseases in more than 500 hosts...     

Forest Structure Under Different Management Regimes in the Western Lowlands of Nepal

ABSTRACT

For landscape level conservation and rural sustenance, forests outside of protected areas are becoming increasingly important. Since most outside forests in the lowlands of Nepal are under government control and utilized as open access resources, their feasibility to achieve these objectives is questionable. We compared forests inside (with three decades of strict protection) and outside of protected areas (under government control and proposed as community forests) to assess the ecological sustainability of outside forests and to provide baseline data on structure of outside forests so that effectiveness of community forestry (after implementation) can be evaluated in the future. Our results indicate that outside forests were in a degraded condition with low tree, sapling and seedling densities and lower species diversity. Trees in lower dbh (diameter at breast height) classes were absent in these forests. Although the canopy layer was not significantly different, the ordination of plots and species showed that species composition of understory and the ground layer were different than protected forests. The present condition of outside forests is not only ecologically unsustainable but also cannot fulfill the demands for forest products of local people. The inefficiency of government to monitor against exploitation has been responsible for present conditions. We recommend that community forestry programs, which are successful in improving conditions of degraded forests in the mountains of Nepal, should be widely implemented in lowland areas (Terai) and proposed community forests should be handed over to local communities as soon as it is practicable.     

Evidence of User Participation in Community Forest Management in the Mid-hills of Nepal: A Case of Rule Making and Implementation

User participation in Community Forestry (CF) regarding forest-related activities from user group formation to implementation of an operational plan is crucial for evaluating the social and biophysical outcomes of a CF program. This study assesses factors responsible for the participation of member households in the planning and implementation process of a CF program in Nepal. Data were collected through a survey of 116 households from six community forest user groups, key informant interviews, and focus group discussions. Simple random sampling was used to collect both qualitative and quantitative information from 10 % of households participating in CF, utilizing a semi-structured questionnaire. Binary logistic regression was used to analyze the factors associated with participation in planning and implementations of CF activities. Six socio-demographic and biophysical explanatory variables were included in the analysis, of which Caste, Sex, Age, and Forest Condition were found statistically significant. The results indicate that if the condition of the community forest is perceived as satisfactory, User Committees receive higher user participation in regards to forest development activities and fund mobilization. The results also suggest activities involving physical work attract younger participants. The existing equal access to forest products does not promote equity. However, promoting women and disadvantaged user participation in CF activities may help achieve higher equitability of CF user groups.