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in an endangered forest within the Gold Coast in Australia. In a 29 ha remnant of Blackbutt
(Eucalyptus pilularis) forest there were 116 unauthorised features, mostly jumps, ditches and
mounds, which collectively resulted in an area of 1601m2 of bare soil and 4010m2 of undergrowth
cleared. Features differed in their size, construction materials used, and their impacts on the
environment. Although nearly two thirds had low to moderate safety, most were in moderate to
good condition, had fall zones and optional routes for riders. Management options for land
managers, in this case a publicly funded University, include (1) feature removal and site
rehabilitation, (2) conversion to official features, (3) removal and provision of an alternative
location for official features, or (4) maintain the status quo. There are social, financial and
environmental benefits and limitations to each of these options highlighting that unauthorised trail
technical features are a challenge for planners and managers that often have no easy solution. A
229 word abstract from Pickering et al. (2010).
Dispersal is critical step in plant invasions but there is limited information about human-mediated
long distance seed dispersal, including in protected areas. Seed dispersal by hikers was quantified
for five invasive species (the native Acaena novae-zelandiae, and the non-native weeds Rumex
acetosella Anthoxanthum odoratum, Dactylis glomerata and Festuca rubra) in part of Australia’s
Kosciuszko National Park. The proportion of seeds remaining attached to trousers and socks was
quantified for replicated short (150 m) and long (5,000 m) distance walks. Functions were fitted for
each dataset, and parameters compared among species and between trousers and socks. Dispersal
data were combined with attachment rates and the number of people undertaking walks to estimate
the total number of weed seeds that might be dispersed. The power exponential function gave the
best fit for the majority of datasets, indicating that detachment probability decreased with distance.
Seeds of all five species were more tightly attached to socks than trousers, with some seeds still
present on socks at 5,000 m. Anthoxanthum and Acaena seeds were more tightly attached to
clothing than the other species. Theoretically 1.9 million seeds could be dispersed on socks or 2.4
million seeds on trousers through a season but the actual numbers are likely to be much lower
because of limited weed seed at the start of the walks. Because of differences in attachment and
detachment rates, seeds from Acaena were more likely to be dispersed longer distances. Long
distance human mediated seed dispersal is potentially a major cause of spread of invasive weeds
into protected areas that favours some invasive species over others. A 262 word abstract from
Pickering et al. (2011a).
Mountain biking is an increasingly popular, but sometimes controversial, activity in protected
areas. Limited research on its impacts, including studies comparing biking with hiking, contributes
to the challenges for mangers in assessing its appropriateness. The impacts of mountain bike
riding off trail were compared to those of hiking on subalpine grassland
in Australia using a
modification of a common trampling experimental methodology. Vegetation and soil parameters
were measured immediately and two weeks after different intensities of mountain biking (none, 25,
75, 200 and 500 passes across slope, 200 pass up and down slope) and hiking (200 and 500 passes
across slope). There were reductions in vegetation height, cover and species richness, as well as
changes in species composition and increases in litter and soil compaction with riding. Riding up
and down a moderate slope had a greater impact than riding across the slope. Hiking also affected
vegetation height, cover and composition. Mountain biking caused more damage than hiking but
only at high use (500 passes). Further research including other ecosystems, topography, styles of
riding, and weather conditions are required, but under the conditions tested here, hiking and
mountain biking appear to be similar in their environmental impacts. A 197 word abstract from
Pickering et al. (2011b).