Screening Exotic Firs for the Midwestern United States: Interspecific Variation in Adaptive Traits

Abstract

<jats:p>Conifers represent a sizeable portion of nursery and landscape sales in the upper midwestern U.S. Several conifer species have been overplanted to the point where disease problems and insect pressures have developed. Although more than 40 true fir (<jats:italic>Abies</jats:italic> Mill.) exist throughout the northern hemisphere, use of firs in the landscape and Christmas tree industry has been limited to relatively few species. This is largely due to perceived intolerance of many site conditions. However, recent research suggests <jats:italic>Abies</jats:italic> are more tolerant of varying site conditions than originally thought. Successful introduction of new exotic fir species for landscape use will require a systematic approach to identify species that are adapted to environmental stresses. In this article we review the extent and nature of inter-specific variation among <jats:italic>Abies</jats:italic> species in traits commonly associated with tolerance of stresses found in the upper midwestern U.S. Specifically, we focus on cold hardiness, budbreak, photosynthetic gas exchange and water relations, and response to soil pH. It is important to match plants possessing necessary adaptive characteristics with the existing site conditions. Therefore, multiple screening factors should be met when identifying species or trees from different provenances for future introduction.</jats:p>

Survival, Frost Susceptibility, Growth, and Disease Resistance of Corkbark and Subalpine Fir Grown for Landscape and Christmas Trees

“…Because of early budbreak and high frost susceptibility, nursery production and landscape use on sites subject to frequent and severe late spring frosts may be questionable for the seed sources tested. This conclusion supports that of Jones and Cregg (2006) regarding site adaptability of subalpine fir.…”

“…As suggested by Jones and Cregg (2006), the fir seedlings proved susceptible to spring frosts, with 66% to 100% and 74% to 100% of corkbark and subalpine trees, respectively, exhibiting frost damage during 2002-06 at SREC (Table 3). Frost injury percentages were similar at the commercial nurseries (data not shown).…”

“…Subalpine fir adapts to a range of soil types, although growth is reported to be poor on shallow and coarse-textured soils. Jones and Cregg (2006) hypothesized that subalpine fir is more adaptable to higher pH soils ( ‡6.0) and drought conditions than previously thought, but considered subalpine and corkbark fir risky choices for midwestern U.S. landscapes because of limited drought tolerance and earlyemerging, frost-susceptible shoots in spring. Dirr (1998) mentions subalpine fir's limited adaptability.…”

Synchronisms and correlations of spring phenology between apical and lateral meristems in two boreal conifers

“…This behaviour could also be explained by genetic differences related to the species-specific capacity to perceive exogenous signals through hormones (Aloni 2001). Jones and Cregg (2006) studied the timings of bud break in different types of North American firs, showing that the date varied with locations, species and years. As expected, in all the years considered, open bud occurred first in trees at lower elevation.…”

Remote sensing-based determination of understory grass greening stage over boreal forest

“…The rationale behind better performance of AGDD-based predictions might be associated with the fact that temperature regimes would often dominate the dynamics of boreal forested regions as spring snow-melting may provide the required soil water. 25 Besides, it would not be possible to link satellite-based surface reflectance (thus, NDWI) with the understory situation due to overstory barrier/forest structure, 12 which might cause inferior NDWI-based predictions. Relation between ground-based observed and NDWI-based predicted understory grass greening stage (GGS) periods at each of the lookout tower sites during 2007 to 2008 using the optimal NDWI threshold of 0.45.…”