One wheel track plot gave higher than expected runoff and soil loss (based on its cover) and a corresponding higher P loss in runoff than other wheel track furrows (point labelled 'high runoff' in Fig.
Concentrations of total N responded differently to cover for wheel and non-wheel track plots. For wheel tracks, concentrations of total N in runoff increased with greater cover (Fig.
Ockenfels and Bissonette (1983) developed a track plot system to monitor habitat use and seasonal activity levels in white-tailed deer (Ockenfels and Bissonette, (1982).
An occupancy index (number of tracks/day) was calculated from repeated readings of 56 track plots (3 [m.sup.2]).
In Block 2, all cover treatments were studied (3 cotton treatments and the 2 levels of wheat cover), each with a wheel and a non-wheel track plot. An additional pair of plots (wheel and non-wheel track) was run for the bare treatment to fulfil the requirements of a companion study of pesticide transport.
The furrow in wheel track plots had been used for tractor wheel traffic over the previous several seasons, whereas the furrow in non-wheel track plots had (as far as we know) received no traffic from either tractor or implement wheels.
This is further illustrated by results from one wheat stubble-wheel track plot (labelled `high runoff amount' in Fig.
The effect of soil loss is further illustrated by one non-wheel track plot which had higher than average furrow slope and gave higher than expected soil loss (based on its cover) and gave a corresponding higher DDE loss in runoff than other non-wheel track plots (point labelled `steeper slope' in Fig.
Our principal method was systematic camera trap surveys, but we also used track plots
, searched for burrows and tracks, and compiled anecdotal information from local people.
Simulations can be replayed in video format with track plots
and data information printed or saved electronically providing an opportunity to analyse the vessel performance.
Supported eclipse phenomena include solar and lunar events (umbral and penumbral track plots
and circumstances), Galilean satellite events, occultations of stars by the Moon, and transits of Mercury and Venus.