Understory Light Conditions Associated with Partial Overstory Removal and Midstory/Understory Control Applications in a Bottomland Hardwood Forest

Forests

K. Kyle Cunningham²  Stephen E. Peairs⁴  Andrew W. Ezell³  Keith L. Belli¹ 

[1] Department of Forestry, Wildlife, and Fisheries, University of Tennessee, 425 Plant Biotech. Bldg, Knoxville, TN 37996-4563, USA; E-Mail:;University of Arkansas Division of Agriculture, 2301 S. University Avenue, Little Rock, AR 72203, USA;Department of Forestry, Mississippi State University, Box 9681, Mississippi State, MS 39765, USA; E-Mails:;Tennessee Division of Forestry, 500 Firetower Road, Dickson, TN 37055, USA; E-Mail:

关键词: canopy closure;    sunlight;    solar irradiance;    midstory/understory control;    herbicide injection;    partial overstory removal;    hemispherical photography;    hardwood;    Quercus;    oak;    regeneration;    bottomland;   

DOI  :  10.3390/f2040984

来源: mdpi

【 摘 要 】

Changes in understory light levels following a partial overstory harvest with three retention levels, combined with midstory/understory removal of selected species were examined. Overstory retention levels were set at basal areas (ba) 16.1 (BA16), 11.6 (BA11), and 6.9 (BA6) m² per hectare (ha). Prior to mechanical overstory removal, non-oak unmerchantable midstory/understory stems ≥ 5.1 cm were injected with an aqueous herbicide solution. Hemispherical photographs were used to calculate percent canopy closure and total understory light at 1.4 m above ground. Percent canopy closure was reduced 3, 14, 24, and 30 percent for injection only (IO), BA16, BA11, and BA6, respectfully, compared to the non-harvest control (NHC) (∼95 percent canopy closure). Understory light levels for NHC, IO, BA16, BA11, and BA6 were 7–9 percent, 11–14 percent, 24–28percent, 37–46 percent, and 44–52 percent of full sunlight, respectively. Post-harvest understory light of BA16 was significantly lower than BA11 and BA6, which were similar. Understanding partial harvest impacts on canopy closure and subsequent understory light conditions will aid forest managers with regeneration harvest planning to promote oak reproduction.

【 授权许可】

CC BY   
© 2011 by the authors; licensee MDPI, Basel, Switzerland.