Vegetation management practices in plantation forests of Australia and New Zealand

Abstract

Radiata pine (Pinusradiata D. Don) is the predominant species in plantation forests of Australia and New Zealand. Removal or suppression of noncrop vegetation is often carried out to enhance crop growth and survival by reducing competition for water, light, and nutrients. Other reasons for vegetation removal include microclimate modification, providing access into stands, and fire hazard reduction. Many studies have demonstrated large increases in crop growth from removing noncrop vegetation. Vegetation management can also mean introducing noncrop species to improve site quality, to suppress unwanted species, or to provide fodder for grazing. While herbicides are still the most widely used weed control tool, nonchemical methods are of increasing importance. The role of machinery is likely to increase in both countries as the use of fire for vegetation management and general site preparation declines. To calculate the long-term cost–benefit of vegetation management, a better understanding of the crop growth response to these treatments is essential. This requires experiments that focus on the role of both crop and noncrop species in hydrological and nutrient cycles. Personal computer based decision support systems are likely to play an increasing role as an aid to cost-effective vegetation management decision making.

Early vegetation control for the regeneration of a single-cohort, intimate mixture of white spruce and aspen on upland boreal sites – 10thyear update

“…There is also evidence that the adjacent aspen are benefitting from this herbaceous weed control through increased stem diameter and stem volume index ( Table 2). These responses are consistent with other studies that have isolated the effects of herbaceous competition (Richardson 1993, Zutter and Miller 1998, Rose et al 1999, Wagner et al 1999, Pitt et al 2009). To date, however, results suggest that there is little additional benefit to control of herbaceous vegetation beyond the second year.…”

Cutting versus herbicides: Tenth-year volume and release cost-effectiveness of sub-boreal conifer plantations

“…Although many studies provide economic insight into plantation silviculture (McKenney et al 1992, Richardson 1993, Biblis et al 1998, Holgen et al 2000, George and Brennan 2002, Ahtikoski and Pulkkinen 2003, Huang and Kronrad 2004, Kimberley et al 2004, only one such North American boreal study investigates vegetation release treatment (controlling weed species with herbicide and non-herbicide options) cost-effectiveness (Bell et al 1997a). This is corroborated by the review paper by Thompson and Pitt (2003).…”

Impact of the timing and duration of weed control on the establishment of a rubber tree plantation

“…Grasses and herbaceous broad-leaved weed species are commonly found during crop establishment and constitute a major impediment to the successful early growth and development of tree crops (knowe et al 1985, Boomsma and Hunter 1990, Richardson 1993, Savill et al 1997, Adams et al 2003. Weed interference can range from the significant suppression of crop growth to widespread crop mortality (Adams et al 2003).…”

“…While no scientific papers were found in literature regarding the effect of Increased growth in response to weed control is usually explained in terms of improved access of the trees to water (Sands and Nambiar 1984) or nutrients (Ellis et al 1985, Smethurst and Nambiar 1989, örlander et al 1996. This access leads to the enhancement of the trees' physiological activity (Boomsma and Hunter 1990, Richardson 1993, Mohammed et al 1998, leading to an increase in the leaf area, light interception and photosynthetic activity of the crop (Adams et al 2003). In this study, when the weeds were controlled during the first year of the investigation, the leaf number increased 122%.…”