Buses, cars, bicycles and walkers the influence of the type of human transport on the flight responses of waterbirds

One way to manage disturbance to waterbirds in natural areas where humans require access is to promote the occurrence of stimuli for which birds tolerate closer approaches, and so cause fewer responses. We conducted 730 experimental approaches to 39 species of waterbird, using five stimulus types (single walker, three walkers, bicycle, car and bus) selected to mimic different human management options available for a controlled access, Ramsar-listed wetland. Across species, where differences existed (56% of 25 cases), motor vehicles always evoked shorter flight-initiation distances (FID) than humans on foot. The influence of stimulus type on FID varied across four species for which enough data were available for complete cross-stimulus analysis. All four varied FID in relation to stimuli, differing in 4 to 7 of 10 possible comparisons. Where differences occurred, the effect size was generally modest, suggesting that managing stimulus type (e.g. by requiring people to use vehicles) may have species-specific, modest benefits, at least for the waterbirds we studied. However, different stimulus types have different capacities to reduce the frequency of disturbance (i.e. by carrying more people) and vary in their capacity to travel around important habita

Mechanistic modelling of soil-plant-atmosphere systems.

Based on the concepts of mechanistic mathematical modelling the foundations of plant growth models are explained and some examples provided. It is illustrated how model modularity can be helpful to describe more complex eco-systems and how mechanistic plant growth models can be based on a multitude of sub-models that describe the important eco-physiological processes needed to determine plant growth dynamics. Modelling concepts for the simulation of phenological development, of photosynthesis, of nutrient allocation and of water and solute transport within the soil–plant continuum are presented. Moreover, two newly developed mechanistic plant growth models will be introduced. One model is the individual-based model PLATHO, which focuses on the description of the plant internal regulation of carbon allocation and nutrient uptake, and the other model is the stand model BALANCE, which in particular considers allocation strategies of trees in dependence on competition within the canopy