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Photosynthesis and productivity in heterogeneous arctic tundra: consequences for ecosystem function of mixing vegetation types at stand edges

Journal Articles & Books
декабря, 2012

1. Arctic vegetation tends to be spatially heterogeneous and can have large areas of mixed ‘transition zone’ vegetation between stands dominated by a single or few species. If plant photosynthesis and growth within these transition zones differs significantly from main vegetation stands, and if transition zones are not considered when extrapolating stand‐level findings to larger scales in space, then transition zones will provide considerable error to landscape‐level estimates of gross primary productivity (GPP).

Environmental effects on species richness of macrophytes in Slovak streams

Journal Articles & Books
декабря, 2012

The effect of 19 environmental variables on species richness of macrophytes was studied in 39 Slovak streams. The studied streams were poor in species; in total, 88 macrophyte taxa were found and the average number of macrophytes per sampling site was 4, ranging from 0 to15. The most frequently occurring macrophytes were filamentous algae (occurrence at 38.6% of sampling sites), followed by Rhynchostegium riparioides (28.4%) and Phalaris arundinacea (19.3%).

Genetic data suggest a natural prehuman origin of open habitats in northern Madagascar and question the deforestation narrative in this region

Journal Articles & Books
декабря, 2012
Madagascar

The impact of climate change and anthropogenic deforestation on biodiversity is of growing concern worldwide. Disentangling how past anthropogenic and natural factors contributed to current biome distribution is thus a crucial issue to understand their complex interactions on wider time scales and to improve predictions and conservation strategies. This is particularly important in biodiversity hotspots, such as Madagascar, dominated by large open habitats whose origins are increasingly debated.

Comparison of interannual variability modes and trends of seasonal precipitation and streamflow in southern quebec (canada)

Journal Articles & Books
декабря, 2012

The interactions between precipitation, streamflow and groundwater are very complex. In cold temperate regions characterized by harsh winters, winter streamflow is mainly derived from aquifers that are recharged in the spring, during snowmelt, and in the fall, when evapotranspiration is subdued.

benefits of considering land cover seasonality in multi-spectral image classification

Journal Articles & Books
декабря, 2012

Effects of incorporating multi-seasonal information into image classifications for large-scale land cover mapping are investigated. Data from four Landsat7 ETM+ scenes (March, May, June 2002, September 1999) were included step-wise into classifications by discriminant analysis to document their relevance for classification accuracy. The classification using all four images reached a maximum accuracy of 69.2%, significantly higher compared with single-date classifications and showing less fluctuations in classification accuracy.

Formalized interpretation of compound land use objects – Mapping historical summer farms from a single satellite image

Journal Articles & Books
декабря, 2012

Notions of land cover relating to physical landscape characters are readily captured by satellite imagery. Land use on the other hand relates more to the societal aspects of a landscape. We argue that much of the spatial configuration of landscape characters is related to land use and that satellite data can be used to represent and investigate interpretations of land use. We propose and demonstrate the joint use of a novel SRPC procedure for satellite imagery together with an explicit representation of category semantics.

Land cover attributes and their utility within land cover mapping: a practical example

Journal Articles & Books
декабря, 2012

A disaggregated approach to land cover survey is developed utilising data primitives. A field methodology is developed to characterise five attributes: species composition, cover, height, structure and density. The utility of these data primitives, as land cover ‘building blocks’ is demonstrated via classification of the field data to multiple land cover schema. Per-pixel classification algorithms, trained on the basis of the classified field data, are utilised to classify a SPOT 5 satellite image. The resultant land cover maps have overall accuracies approaching 80%.

effects of land-use and land-cover changes on carbon storage in forest timber biomass: a case study in Torul, Turkey

Journal Articles & Books
декабря, 2012
Turkey

This study presents spatial and temporal changes of carbon storages of forest timber biomass in a typical forest management unit of the northeastern part of Turkey. The effects of land-use and land-cover changes on the amount of carbon storage are analyzed. Temporal changes of carbon storage of the area were estimated using forest inventory data. The spatial distribution of carbon densities was mapped using Geographic Information Systems (GISs). As an overall change between 1984 and 2005, there was a net increase of 12,379 ha in forested areas.

Impacts Of Land Cover Change Scenarios On Storm Runoff Generation: A Basis For Management Of The Nyando Basin, Kenya

Journal Articles & Books
декабря, 2012
Kenya

The effects of conceptual land cover change scenarios on the generation of storm runoffs were evaluated in the Nyando Basin. The spatial scenarios represented alternatives that vary between full deforestation and reforestation. Synthetic storm events of depths 40, 60 and 80mm were formulated according to the rainfall patterns and assumed to have durations corresponding to the runoff times of concentration.

UNCCD Impact Indicators Pilot Tracking Exercise: Results and Conclusions

Reports & Research
декабря, 2012
Global

This report presents results and conclusions from a Pilot exercise undertaken to assess the experience of
affected country Parties to the United Nations Convention to Combat Desertification (UNCCD) with
reporting on impact indicators under the Convention’s Performance Review and Assessment of the
Implementation System (PRAIS). The experiences and recommendations presented in this report should
be used to guide the 2012–2013 reporting and review process.

PowerPoint Presentation: Towards a better understanding of land and soil degradation in Europe

Multimedia
ноября, 2012
Global

We recognize the economic and social significance of good land management, including soil, We stress that desertification, land degradation and drought are challenges of a global dimension and continue to pose serious challenges to the sustainable development of all countries, We recognize the need for urgent action to reverse land degradation. In view of this, we will strive to achieve a land-degradation neutral world in the context of sustainable development. Measuring Land degradation is a challenge ①Declining land-productivity ≠ Land degradation e.g.