They are certainly the most evil-tempered of all creatures to say they are touchy is a dangerous understatement. Grues have sharp claws and fangs, and an uncontrollable tendency to slaver and gurgle. Of those who have seen grues, few ever survived to tell the tale. The map was computed in R 3.4.2.They are famous for their horrible fear of light: No grues have ever been seen by the light of day, and only a few have been observed in their underground lairs. Hot colour ramp represents important connectivity cells with a z > 0, and grey scale colour ramp represents unimportant connectivity cells with z < 0. Map (c) is clipped to Alberta extent and current density values were standardized and centred at a 100 m resolution. Red to yellow colour ramp represents higher values of current density while darker purple to blue colour ramp represents lower values of current density. Map (b) is the current density map resulting from GFlow’s electric current simulation at a 100 m resolution. The map was computed in R 3.4.2 and QuantumGIS. Map (a) shows resistance map calculated at 100 m resolution where darker values represent high resistance and brighter values represent lower resistance (red dots, nodes used to compute the following current density map). Main map was calculated using an average combination ( H FU) of physical human footprint, H F, and intensity of human use, H U, resistance values. Validation of structural connectivity or potential functional connectivity based models could also be done with appropriate biological data, to assess actual functional connectivity. When biodiversity data are available for many taxa, multi-species overlay can also be an efficient option to model connectivity for land-use planning and conservation programs for a representative suite of species. Species-agnostic modelling of landscape connectivity may be most suitable in a land-use planning context, whereas focal species approaches may be most suitable in a conservation management context. These values are reflected in policy that aims to preserve ecosystem services, biodiversity in general, or designated species of concern. The vertical axis (grey) illustrates how the focus shifts from natural processes in basic ecology to human values and actions in a policy context. The horizontal axis (black) illustrates how the landscape definition shifts from a multi-functional landscape in the context of land-use planning to an organism perspective in the context of species conservation. We conclude that every parameter in species-agnostic connectivity modelling requires attention, not only the definition of often-criticized expert-based degrees of human modification.Ĭonceptual framework: different perspectives on the landscape ( a) and corresponding goals and approaches to connectivity modelling ( b). We observed higher concordance among cells with high (standardized) current density values than among cells with low values, which supports the identification of cells contributing to larger-scale connectivity based on a cut-off value. Connectivity maps were most sensitive to the consideration of water as barrier to movement, followed by the choice of scaling function, whereas maps were more robust to different conceptualizations of the degree of human modification. We directly compared the uncertainty related to (1) the definition of the degree of human modification, (2) the decision whether water bodies are considered barriers to movement, and (3) the scaling function used to translate degree of human modification into resistance values. We propose a conceptual framework, apply it to model connectivity as current density across Alberta, Canada, and assess map sensitivity to modelling decisions. In the context of multi-functional land-use planning, there is growing interest in species-agnostic approaches, modelling connectivity as a function of human landscape modification. Commonly-used species-specific connectivity models are difficult to generalize for a wide range of taxa. Sustainable land-use planning should consider large-scale landscape connectivity.
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