Weed Research (2011) 51, 63-70
J.S. Conn, N.R. Werdin-Pfisterer and K.L. Beattie (2011)
Development of the Alaska agricultural weed flora 1981-2004: a case for prevention
Weed Research 51 (1), 63-70
Abstract: Alaska provides a unique laboratory to study the development of agricultural weed floras, since fields were first cleared in 1900-1985. Changes in weed species composition between 1981 and 2004 were studied in 80 agricultural fields near Fairbanks, Nenana, Delta Junction and Palmer, Alaska. Cover and density of all plants were measured in quadrats along a transect in each field. Environmental and management information were collected, including field age, weed control methods, crop, elevation, latitude, longitude, surrounding vegetation type and canopy shading. Detrended correspondence analysis was used to ordinate fields based on weed vegetation. Spearman correlations and graphical overlays were used to examine relationships between environmental and management variables and ordination axes. We found seven weed species that were new to Alaskan agriculture since 1981. Crop, canopy shading, elevation, latitude and longitude were important weed flora determinants. Two distinct weed community/crop associations were identified: (i) vegetables + potatoes and (ii) perennial grass (hay + grass seed). Non-native weed species colonised fields that were largely weed-free in 1981, when a similar weed survey was made. The failure to use weed prevention programmes since 1981, resulted in 40 000 ha of new agricultural land that must be managed for non-native weeds.
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Link to article at publishers website
Research topic(s) for pests/diseases/weeds:
surveys/sampling/distribution
