Assessing measures of tree competition using fixed-area, variable-radius, and horizontal-line plot sampling

Schreuder, Hans T.; Williams, Mike

doi:10.1139/x95-172

Cited by 6 publications

(2 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Intertree competition is most often quantified using competition indices. A competition index is a mathematical formulation derived to represent or describe competition from adjacent trees that could be affecting the growth of any considered tree (Daniels 1976;Schreuder and Williams 1995). Opie (1968) proposed a "zone of influence" as a crucial component of any competition index based on the assumption that every tree has a certain area in which it exerts demand for limited resources.…”

Section: Quantifying Competitionmentioning

confidence: 99%

Intertree competition in uneven-aged ponderosa pine stands

Woodall¹,

Fiedler²,

Milner³

2003

Can. J. For. Res.

View full text Add to dashboard Cite

Intertree competition indices and effects were examined in 14 uneven-aged ponderosa pine (Pinus ponderosa var. scopulorum Engelm.) stands in eastern Montana. Location, height, diameter at breast height (DBH), basal area increment, crown ratio, and sapwood area were determined for each tree (DBH >3.8 cm) on one stem-mapped plot (0.2-0.4 ha) in each sample stand. Based on tree locations, various competition indices were derived for each sample tree and correlated with its growth efficiency by diameter class. In addition, trends in individual tree attributes by diameter class and level of surrounding competition were determined. For trees with a DBH <10 cm, growth efficiency was most strongly correlated with the sum of surrounding tree heights within 10.6 m. The index most highly correlated for larger trees was the sum of surrounding basal area within 6.1 m. Regardless of tree size, individual tree growth efficiency, basal area increment, and crown ratio all decreased under increasing levels of competition, with the effect more pronounced in smaller trees. These results suggest that individual trees in uneven-aged stands experience competition from differing sources at varying scales based on their size, with response to competition diminishing as tree size increases.

show abstract

Section: Quantifying Competitionmentioning

confidence: 99%

Intertree competition in uneven-aged ponderosa pine stands

Woodall¹,

Fiedler²,

Milner³

2003

Can. J. For. Res.

View full text Add to dashboard Cite

show abstract

“…A competition index is a mathematical formulation derived to represent or describe competition from adjacent trees that could be affecting the growth of any considered tree (Daniels, 1976;Schreuder andWilliams, 1995: Woodall et al, 2003). There are two major classes of competition index: those which utilize the individual tree location are termed distance-dependent, and those not using locations which are termed distanceindependent (Munro, 1974).…”

Section: Modifier Functionmentioning

confidence: 99%