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J Cihlar

Publications and source records attributed to J Cihlar.

3 recordsLinked to original sources
PubMed2007

Quantification of the regional carbon cycle of the biosphere: policy, science and land-use decisions.

This paper addresses some issues related to the carbon cycle and its utilization by society. Traditional uses for agriculture, forestry, as a source of fuel and other products, and for pastoral farming, among others, have recently been supplemented by identifying its potential for mitigating the increasing concentration of greenhouse gases in the atmosphere. Through the Kyoto Protocol, carbon has become a commodity and the CO(2)-absorbing capability of the vegetation and soils an economically valuable asset. The multi-facetted roles of the C cycle and its sensitivity to human activities present a demand for techniques that permit accurate, timely and affordable characterization of the various components of this cycle, especially on land where most human activities take place. Such techniques must satisfy a range of demands in terms of purpose, clients for the information, and biosphere properties. However, if successful, they offer the potential to support monitoring, reporting, policy setting, and management of terrestrial biospheric resources. The context for these requirements and possibilities is illustrated with reference to the China Carbon Sequestration Project and its findings.

Agriculture↗
PubMed2001

Remotely sensed habitat diversity predicts butterfly species richness and community similarity in Canada.

Although there is no shortage of potential explanations for the large-scale patterns of biological diversity, the hypothesis that energy-related factors are the primary determinants is perhaps most extensively supported, especially in cold-temperate regions. By using unusually high-resolution biodiversity and environmental data that have not previously been available, we demonstrate that habitat heterogeneity, as measured by remotely sensed land cover variation, explains Canadian butterfly richness better than any energy-related variable we measured across spatial scales. Although species-richness predictability declines with progressively smaller quadrat sizes, as expected, we demonstrate that most variability (>90%) in butterfly richness may be explained by habitat heterogeneity with secondary contributions from climatic energy. We also find that patterns of community similarity across Canada are strongly related to patterns of habitat composition but not to differences in energy-related factors. Energy should still be considered significant but its main role may be through its effects on within-habitat diversity and perhaps, indirectly, on the sorts of habitats that may be found in a region. Effects of sampling intensity and spatial autocorrelation do not alter our findings.

Animals↗