A comparison of potential labor-saving sampling methods for assessing large mammal damage in corn

Engeman, Richard M.; Sterner, Ray T.

doi:10.1016/s0261-2194(01)00068-0

Cited by 17 publications

(13 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Estimation typically improved as transect width increased. This effect also has been observed empirically in an experiment on damage sampling in row crops (Engeman and Sterner, 2002). Nevertheless, there are logistical limits to the transect width for any sampling situation whereby observations can be effectively and accurately made.…”

Section: Discussionsupporting

confidence: 54%

Evaluation of optimized variable area transect sampling using totally enumerated field data sets

2005

View full text Add to dashboard Cite

SUMMARYPlotless density estimators (PDEs) can be efficient alternatives to quadrat sampling for estimating the density of stationary objects. Variable area transect (VAT) sampling had been identified, and optimized relative to effort, in previous Monte Carlo simulated population studies as a low-labor field method that demonstrated superior estimation properties among many PDEs considered. However, natural populations tend to be much more complex and less predictable in spatial distribution than computer generated populations. Therefore, we carried out a Monte Carlo simulation study that used 17 fully enumerated field populations rather than simulated populations. These natural populations represented a variety of population densities and spatial patterns. We focused on assessing the effect of the number of population members searched for along each transect (r), sample size, and transect width on estimation quality. Using relative root mean-squared error and relative bias as criteria, the optimal range for r was 5 to 7 population members encountered from each start point. Sample size was best if n > 20, but returns in estimation quality diminished by n ¼ 40. Transect width was previously uninvestigated and found to be the most important design factor affecting estimation quality. Field studies should strive for transects as wide as logistically reasonable. Published in 2005 by John Wiley & Sons, Ltd.

show abstract

Section: Discussionsupporting

confidence: 54%

Evaluation of optimized variable area transect sampling using totally enumerated field data sets

2005

View full text Add to dashboard Cite

show abstract

“…Engeman et al (1998) made no mention of the width of the VAT used in their study, given that the ''objects'' in their simulations were dimensionless points and varied only by location. More recently, and Engeman and Sterner (2002) used VAT to estimate row crop damage due to herbivory. The behavior of decreasing density estimates with increasing sample width was not noted in their analysis, although an examination of their methods and results shows a congruent pattern.…”

Section: Discussionmentioning

confidence: 99%

A Practical Look at the Variable Area Transect

Dobrowski

Murphy

2006

Ecology

View full text Add to dashboard Cite

The variable area transect (VAT) is a plotless density estimator that has received little attention in the ecological literature despite having potentially robust estimation properties. VAT allows for density estimations without the lengthy search times associated with other plotless density estimators. In spite of this, little has been written about the effect of varying transect widths on its density estimation properties or on the practical implementation of the VAT in field settings. An artificial population sampler was used to examine the effect of transect width on density estimates obtained using the VAT. Three transect widths were chosen corresponding to the mean object size, the largest object size, and twice the size of the largest object. Transect width had a marked effect on the quality of the density estimation, with the largest transect width resulting in significant negative biases in estimation. For the narrowest width, most estimates were within 10% of the true value for a nonrandomly distributed population. The practical considerations of choosing a VAT transect width are enumerated.

show abstract

“…We assessed damage to corn in treatment and control fields in early August using a variable‐area‐transect sampling method (Engeman and Sugihara 1998, Engeman and Sterner 2002). The location of each sampling plot was chosen within treatment and control fields at random and with replacement.…”

Section: Methodsmentioning

confidence: 99%

Use of partially fenced fields to reduce deer damage to corn

Hildreth

Hygnstrom

Blankenship

et al. 2012

Wildlife Society Bulletin

View full text Add to dashboard Cite

White‐tailed deer (Odocoileus virginianus) damage agricultural crops, often leading to significant economic losses for farmers. We used poly‐mesh fence with wings to separate good deer cover from agricultural fields where crop damage by deer occurred primarily along this edge. In these cases, complete enclosure of the field with fencing may be unnecessary. The design used a 2.13‐m‐high polypropylene mesh fence erected along the wooded edge of a field with either 50‐m or 150‐m wings extending perpendicular from the fence line and wooded habitat. Fences reduced deer damage in cornfields 13.5% (F1,6 = ∞, P < 0.001). Average yield in fenced fields (10,211 kg/ha) was 1,708 kg/ha greater than in control fields, which, at US$0.155/kg, equals a net gain of US$265/ha. We found no difference in damage between fences with 50‐m and 150‐m wings (F1,1 = 0.26, P = 0.695). Costs for materials and labor for erecting partial poly‐mesh fences with wings were US$5.56/m and US$1.42/m, respectively. Mean total cost for partial poly‐mesh fences with 50‐m wings would be US$60.13/ha/year over a 10‐year period, compared with US$82.30/ha/year for 150‐m wings and US$184.16/ha/year for completely enclosing fields. Expected savings for partial poly‐mesh fences with 50‐m wings over a 10‐year period were US$205/ha/year, as compared with damaged fields without fences. We concluded that poly‐mesh fences with 50‐m wings were cost‐effective at reducing damage by deer to corn. Additional research should be conducted to determine efficacy of the more cost‐effective high‐tensile and poly‐tape fences with wings. © 2012 The Wildlife Society.

show abstract

A comparison of potential labor-saving sampling methods for assessing large mammal damage in corn

Cited by 17 publications

References 9 publications

Evaluation of optimized variable area transect sampling using totally enumerated field data sets

Evaluation of optimized variable area transect sampling using totally enumerated field data sets

A Practical Look at the Variable Area Transect

Use of partially fenced fields to reduce deer damage to corn

Contact Info

Product

Resources

About