Carbon budget estimation of a subarctic catchment using adynamic ecosystem model at high spatial resolution

A large amount of organic carbon is stored in highlatitude soils. A substantial proportion of this carbon stock is vulnerable and may decompose rapidly due to temperature increases that are already greater than the global average. It is therefore crucial to quantify and understand carbon exchange between the atmosphere and subarctic/arctic ecosystems. In this paper, we combine an Arctic-enabled version of the process-based dynamic ecosystem model, LPJGUESS (version LPJG-WHyMe-TFM) with comprehensive observations of terrestrial and aquatic carbon fluxes to simulate long-term carbon exchange in a subarctic catchment at 50m resolution. Integrating the observed carbon fluxes from aquatic systems with the modeled terrestrial carbon fluxes across the whole catchment, we estimate that the area is a carbon sink at present and will become an even stronger carbon sink by 2080, which is mainly a result of a projected densification of birch forest and its encroachment into tundra heath. However, the magnitudes of the modeled sinks are very dependent on future atmospheric CO2 concentrations. Furthermore, comparisons of global warming potentials between two simulations with and without CO2 increase since 1960 reveal that the increased methane emission from the peatland could double the warming effects of the whole catchment by 2080 in the absence of CO2 fertilization of the vegetation. This is the first process-based model study of the temporal evolution of a catchment-level carbon budget at high spatial resolution, including both terrestrial and aquatic carbon. Though this study also highlights some limitations in modeling subarctic ecosystem responses to climate change, such as aquatic system flux dynamics, nutrient limitation, herbivory and other disturbances, and peatland expansion, our study provides one process-based approach to resolve the complexity of carbon cycling in subarctic ecosystems while simultaneously pointing out the key model developments for capturing complex subarctic processes

Automatisk skadeklassning av lovtrad i stadsbebyggelse med hjalp av digitaliserade IR-fargflygbilder

In August 1986 some parks in central Malmo were photographed from a height of 760 meters with colour infrared film. Two simultaneous studies were performed to evaluate the feasibility of manual and digital classification of trees with different degrees of crown damage. This damage is mostly due to exhaustion fumes from heavily trafficked roads, mechanical damage to roots and de-icing salt. This paper describes the method and results of the digital classification and compares the results with the manual interpretation. -English summar

THE EFFECT OF LAND USE CHANGE ON LAND SURFACE TEMPERATURE IN THE NETHERLANDS

The Netherlands is a small country with a relatively large population which experienced a rapid rate of land use changes from 2000 to 2008 years due to the industrialization and population increase. Land use change is especially related to the urban expansion and open agriculture reduction due to the enhanced economic growth. This research reports an investigation into the application of remote sensing and geographical information system (GIS) in combination with statistical methods to provide a quantitative information on the effect of land use change on the land surface temperature. In this study, remote sensing techniques were used to retrieve the land surface temperature (LST) by using the MODIS Terra (MOD11A2) Satellite imagery product. As land use change alters the thermal environment, the land surface temperature (LST) could be a proper change indicator to show the thermal changes in relation with land use changes. The Geographical information system was further applied to extract the mean yearly land surface temperature (LST) for each land use type and each province in the 2003, 2006 and 2008 years, by using the zonal statistic techniques. The results show that, the inland water and offshore area has the highest night land surface temperature (LST). Furthermore, the Zued (South)-Holland province has the highest night LST value in the 2003, 2006 and 2008 years. The result of this research will be helpful tool for urban planners and environmental scientists by providing the critical information about the land surface temperature

On the ground estimation of vegetation cover in Australian rangelands

A number of field techniques were assessed on their reliability for estimating vegetation cover in Australian rangelands. The field sampling was undertaken using visual estimation, line intercepts, a crown cover model, and images acquired from a digital camera. The results from these methods were compared and analysed. The data obtained from these differing methods agree with each other in relative rather than absolute terms. This suggests that the methods can provide a reasonable basis for qualitative remote sensing studies, but are not suitable for quantitative investigations

Geospatial tools address emerging issues in spatial ecology: A review and commentary on the special issue

Spatial ecology focuses on the role of space and time in ecological processes and events from a local to a global scale and is particularly relevant in developing environmental policy and (mandated) monitoring goals. In other words, spatial ecology is where geography and ecology intersect, and high-quality geospatial data and analysis tools are required to address emerging issues in spatial ecology. In this commentary and review for the International Journal of GIS Special Issue on Spatial Ecology, we highlight selected current research priorities in spatial ecology and describe geospatial data and methods for addressing these tasks. Geoinformation research themes are identified in population ecology, community and landscape ecology, and ecosystem ecology, and these themes are further linked to the assessment of ecosystem services. Methods in spatial ecology benefit from explicit consideration of spatial autocorrelation, and applications discussed in this review include species distribution modeling, remote sensing of community and ecosystem properties, and models of climate change. The linkages of the Special Issue papers to these emerging issues are describe

Patterns of consumption and connectedness in GIS Web sources

Every day, practitioners, researchers, and students consult the Web to meet their information needs about GIS concepts and tools. How do we improve GIS in terms of conceptual organisation, findability, interoperability and relevance for user needs? So far, efforts have been mainly top-down, overlooking the actual usage of software and tools. In this article, we critically explore the potential of Web science to gain knowledge about tool usage and public interest in GIScience concepts. First, we analyse behavioural data from Google Trends, showing clear patterns in searches for GIS software. Second, we analyse the visits to GIScience-related websites, highlighting the continued dominance of ESRI, but also the rapid emergence of Web-based new tools and services. We then study the views of Wikipedia articles to enable the quantification of methods and tools’ popularity. Fourth, we deploy web crawling and network analysis on the ArcGIS documentation to observe the relevance and conceptual associations among tools. Finally, in order to facilitate the study of GIS usage across the Web, we propose a linked-data inventory to identify Web resources related to GI concepts, methods, and tools. This inventory will also enable researchers, practitioners, and students to find what methods are available across software packages, and where to get information about them