Influence of woody and herbaceous vegetation control on leaf gas exchange, water status, and nutrient relations of eastern white pine (Pinus strobus L.) seedlings planted in a central Ontario clearcut

Influence of herbaceous and woody vegetation control on seedling microclimate, leaf gas exchange, water status, and nutrient relations of Pinus strobus L. seedlings planted in a shelterwood

“…In our study, increased A n and G wv following vegetation control was associated with improved light and soil moisture availability, consistent with earlier findings for white pine plantations (Elliott and Vose, 1993;Parker et al, 2010). Treatments had similar comparative effects on A n and G wv , such that WUE was unaffected by vegetation control.…”

“…Treatments had similar comparative effects on A n and G wv , such that WUE was unaffected by vegetation control. Although higher WUE of white pine growing in moderate shade compared to open field conditions has been reported (Powers et al, 2009;Parker et al, 2010), we observed no comparative difference in WUE of seedlings exposed to heavy and moderate shade. Similar to results of Elliott and Vose (1993) and Parker et al (2010), leaf gas exchange was independent of leaf w m , perhaps because sampling did not coincide with severe drought and/or leaf w m was above threshold levels associated with decreased A n and G wv (Maier and Teskey, 1992;Dang et al, 1997).…”

“…Previously, we reported the effects of four growing seasons (GS) of herbaceous and woody vegetation control, alone and in combination, on survival, growth, and ecophysiology of white pine seedlings planted in a clearcut Parker et al, 2009Parker et al, , 2010. In a parallel study established in a nearby uniform shelterwood, and using the same experimental design (Pitt et al, 2011), we addressed three primary research questions:…”

Influence of herbaceous and woody competition on white pine regeneration in a uniform shelterwood

“…In this paper, we present the resulting age-6 response surfaces for white pine survival and growth as guides to the development of more effective and consistent early vegetation management prescriptions for white pine regeneration in a uniform shelterwood. The results of a companion study employing the same experimental design within in an Ontario clearcut were reported previously (Pitt et al 2009;Parker et al 2009Parker et al , 2010.…”

“…There, the early suppression of herbaceous vegetation alone allowed pine to realize maximum height growth potential, yet some woody vegetation control was also required for near-maximum diameter growth. Thus, although light is not limiting in the clearcut environment, optimum vegetation management there involves a delicate balance between allowing some woody overtopping/shading to minimize weevil impacts, and reducing competition from herbaceous and woody vegetation to free up adequate soil moisture and nutrients for acceptable diameter growth (Parker et al 2009(Parker et al , 2010Wetzel and Burgess 2001). Subsequent periodic intervention(s) would likely be required to maintain the balance of pine and hardwood in long-term stand dynamics.…”