Does the edge effect influence plant community structure in a tropical dry forest?

Edge effects are considered a key factor in regulating the structure of plant communities in different ecosystems. However, regardless to few studies, edge influence does not seem to be decisive in semiarid regions such as the Brazilian tropical dry forest known as Caatinga but this issue remains inconclusive. The present study tests the null hypothesis that the plant community of shrubs and trees does not change in its structure due to edge effects. Twenty-four plots (20 x 20 m) were set up in a fragment of Caatinga, in which 12 plots were in the forest edges and 12 plots were inside the fragment. Tree richness, abundance and species composition did not differ between edge and interior plots. The results of this study are in agreement with the pattern previously found for semiarid environments and contrasts with previous results obtained in different environments such as Rainforests, Savanna and Forest of Araucaria, which indicate abrupt differences between the border and interior of the plant communities in these ecosystems, and suggest that the community of woody plants of the Caatinga is not ecologically affected by the presence of edges.

Value co-creation through virtual community participation

Consumers create a great deal of content in the Internet. As they do not get a monetary compensation for doing so, it seems apparent that other types of reward are derived from giving up one's time and other resources. The purpose of this study is to describe value creation and user participation in a virtual community. It can be broken down into three research questions. 1. What is the value creation logic of a virtual community? 2. What value is perceived by virtual community users? 3. What is the association between value perceived by virtual community users and their participation in a community? The study employs the discussion on value co-creation as well as perspectives on the notion of value for consumers to create a theoretical framework for value creation. To understand value creation in the context of virtual communities and to create a theoretical framework for user participation, existing literature and research on virtual communities is discussed. The empirical part of the study employs quantitative methodology to analyze data collected by sending a survey questionnaire to the users of a Finnish wellbeing-based virtual community. The results indicate that virtual community users perceive self-development, enjoyment, reputation-building and community commitment value when using the service and that value perceptions are associated with community participation. Moreover, it was found that different types of value are associated with different forms of participation. Based on the findings, it is suggested that the four types of value make up a considerable share of value for virtual community users. Moreover, as the results indicate that different value types are associated with different forms of participation, it suggested that virtual community organizers consider what forms of participation they want to promote and design their virtual communities to support creation of the different types of value accordingly.

Value Co-Creation Through Virtual Community environment, Case: Oma Olivia

The purpose of this thesis is to examine what elements of value co-creation create value for participants of Oma Olivia magazine through Olivia magazine’s virtual community environment. Furthermore the aim is to discover why readers take part in creating Oma Olivia in order to discover is Oma Olivia worth publishing in the future. The data is collected from secondary and primary sources by scanning the existing academic literature and by conducting interviews and surveys. The empirical results state that the hypothesis model created from the academic literature is statistically significant and the elements of value co- creation process create value for readers. Magazine publishing organization may want to consider publishing Oma Olivia also in the future due to its nature of creating value for customers.

Weed community and growth under the canopy of trees adapted to the brazilian semi-arid region

The objectives of this work were to evaluate the floristic composition and dry biomass of weeds under the canopy of seven perennial species adapted to the Semi-Arid region of Brazil, and correlate these characteristics with growth traits of the perennial species. The following perennial species were evaluated in two experiments (E1 and E2): mesquite (Prosopis juliflora), jucá (Caesalpinia ferrea), white popinac (Leucaena leucocephala), mofumbo (Combretum leprosum), neem (Azadirachata indica), sabiá (Mimosa caesalpiniaefolia) and tamarind (Tamarindus indica). In E1, the seven species were evaluated in a random block design with four replicates and nine plants per plot. In E2, evaluation comprised four species (mesquite, jucá, white popinac, and tamarind) in a random block design with eight replicates and nine plants per plot. A circle with an area of 1.77 m² was established around the trunk of each plant, two years after they were transplanted to the permanent location. The weeds collected within this circle were cut even with the ground, classified and weighed. At this time, plant height, and crown and stem diameters were evaluated in all trees of each plot. In E1 there were no differences between tree species as to weed frequency under their canopies; however, weed growth was smaller under the canopy of sabiá trees. Mesquite and sabiá had the greatest plant height and crown diameter means, but only sabiá had the greatest stem diameter. In E2, the perennial species were not different with regard to weed frequency and growth under their canopies, but mesquite had the greatest growth, as measured by plant height (with significant results for jucá as well) and crown and stem diameter.

Variations in weed population densities, rate of change and community diversity in RR-soybeans and RR-maize strip crops under two herbicide strategies

Concerns about the sustainability of large-scale, direct-drilled RR-soybeans (Glycine max), and RR-maize (Zea mays) under monoculture in central Argentina are growing steadily. An experiment was conducted during three consecutive years to determine the effects of crops and systems (monocultures and strips) and herbicide strategy on weed density, population rate of change (l), b community diversity (H´), crop yields and Land Equivalent Ratio (LER). Not only crops but also crop systems differentially influenced weed densities along their growth and development. For crop harvests, weed densities increased in both maize crop systems as compared to in the one for soybeans, but the lowest increase occurred in soybean strips. Differences were leveled by both herbicide strategies, which achieved 73% efficacy during the critical periods in both crops. l of annual monocotyledonous increased, thus shifting the weed community composition. Species richness and H´ were not affected by crop systems, but both herbicide strategies, particularly POST, either in soybeans in monoculture or in maize strips, significantly enhanced H´. Crop yields significantly increased in the maize-strip system with POST (Year 1) or PRE (Years 2 and 3) strategies, thus increasing LER above 1. Herbicide Environmental Load treatments fall within very low or low field use rating.

Aquatic plant community in porto primavera reservoir

Aiming to identify the populations of aquatic plants present in the Porto Primavera reservoir and evaluate the behavior of Hydrilla verticillata colonization of this water body a survey was carried out in 2007. The data was based on presence or absence, only were assessed the presence or absence of the species and the data were subjected to cluster analysis to establish differences in distribution and occurrence of populations. The community of aquatic plants showed 24 species distributed in 16 botanical families. Cyperaceae and Pontederiaceae were the most representative in terms of species richness. The submerged macrophyte Hydrilla verticillata showed the highest frequency of occurrence in the water body, showing a different behavior from the other populations of the water body. Species like Eichhornia crassipes, Eichhornia azurea, Typha dominguensis and Oxycaryum cubense also showed different behavior in relation to other populations within the community, forming large populations in lagoons and backwater areas.

SobekCM’s Community Ecosystems & Socio-Technical Practices

Presentation at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014

What is behind the OpenDOAR? New Development and Community Benefits

Presentation at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014

Building Successful, Open Repository Software Ecosystems: Technology and Community

Panel at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014

Weed Community in a Raw Sugarcane Renovation Area Submitted to Different Soil Managements

The objective of this study was to evaluate the weed community in a raw sugarcane renovation area with three soil managements and peanut sowing in succession. The experiment was conducted during the 2007/08 season on a raw sugarcane area harvested without prior burning in the last five cuts. A randomized block design with treatments arranged in a split plot and arranged in four replications was used. The main treatments consisted of three cropping systems: conventional tillage, minimum tillage and direct planting, and subplots consisted in the absence (resting) or presence of crop rotation with peanuts. After 135 days from planting peanuts and 180 days of sugarcane harvest, the number of weeds m-2 was counted and the shoot dry biomass of the weeds collected was determined. The data were interpreted by analysis of variance and the means were compared by Tukey's test at 5% probability so that phytosociological indices a, b, c e d were calculated. The use of soil conservation tillage and peanut in rotation with sugarcane in the renovation areas is effective in controlling weeds and suppression of weed species difficult to control like Cyperus rotundus, Commelina bengalensis, Urochloa plantaginea, and Digitaria nuda.

Islandora Archipelago: Update on the Project & Community

Presentation at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014

Open Preservation: Community Approaches to Ensuring Long-Term Access to Digital Collections

Presentation at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014