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Methods of analysis are needed that quantitatively characterize the response of organisms to anthropogenic disturbance. Herein a method is presented that characterizes bryophyte morphological variability in response to timber harvest treatments (clearcut and partial cut). Samples (n = 6196) of the semi-aquatic bryophyte Brachythecium frigidum were collected from clearcut, partial cut and full forest stream reaches between August 2003 and October 2005 and analyzed to obtain mass to stem length ratios (M:SL). Results show that relative to a full forest (i.e. full canopy cover condition), average M:SL ratios were reduced approximately 18% in the partial cut and 37% in the clearcut, indicating a decrease in biomass per unit stem length with increasing harvest intensities. Increased light intensities and higher air temperatures resulting from decreased canopy cover in the harvest treatments corresponded to lower M:SL ratios (0.31 and 0.24 for the partial cut and clearcut, respectively). Results quantify the morphological response of B. frigidum to habitat perturbation, thereby validating the method as a useful assessment of anthropogenic disturbance in post-timber harvest environments. Additional work should be conducted to test the method in other physiographic regions and to isolate bryophyte response to alterations of distinct environmental variables.
presented here investigated the influence of creative dance training on mental
rotation performance. Two groups of second graders solved
a paper-pencil mental rotation test and a motor performance test.
Afterwards one group received five weeks of normal physical education lessons,
while the other group received five weeks of creative dance training. At the
end of the training period all children solved the mental rotation again. The
results show that the dance-training group improved their mental rotation
performance more than the physical education group. Further studies should investigate whether this positive effect of creative dance training
transfers to cognitive, social, and emotional skills, such as a possible
enhancement of self-esteem.