Understory plant community classifications as predictors of forest site quality for lodgepole pine and white spruce in west-central Alberta

1988 ◽  
Vol 18 (7) ◽  
pp. 875-887 ◽  
Author(s):  
George H. La Roi ◽  
Wayne L Strong ◽  
Donald J. Pluth

Understory vegetation of 103 lodgepole pine (Pinuscontorta Loudon var. latifolia Engelm.) and white spruce (Piceaglauca (Moench) Voss) stands, 70–150 years old, in a 16 000 km2 region of west-central Alberta was classified by 14 methods using species cover or log2 cover classes. Six classifications, including five selected by dendrogram and ordination elucidation of understory community types (UCTs), were evaluated by analysis of variance to identify UCTs with significantly different site indices of pine and spruce. Each classification consists of three to five UCTs, referable to two forest types, both levels distinguished by differences in constancy and cover of understory species. Significant differences (P < 0.05) in pine site index at 70 years occur between UCTs belonging to the same and different forest types, using divisive two-way indicator species analysis (TSL) and agglomerative furthest neighbour (FNL) and minimum variance (MVL) cluster analysis classifications, all based on log2 cover classes. Comparable differences between UCTs for spruce occur within one forest type, using FNL, MVL, and minimum variance cluster analysis based on raw percent cover (MVR). Ordination of stands based on understory species cover reveals that spatially segregated UCTs usually have significantly different site indices. If a single classification method is desired for both lodgepole pine and white spruce, MVL appears most suitable for predicting site indices in the region.

1991 ◽  
Vol 21 (11) ◽  
pp. 1675-1683 ◽  
Author(s):  
W. L Strong ◽  
D. J. Pluth ◽  
G. H. La Roi ◽  
I. G. W. Corns

The feasibility was explored of using cover estimates of a few understory species with high indicator value, rather than total species lists, to evaluate site quality for lodgepole pine (Pinuscontorta Loudon var. latifolia Engelm.) and white spruce (Piceaglauca (Moench) Voss). Analysis of 112 vascular and 7 nonvascular understory plant species from 211 lodgepole pine and white spruce dominated forests revealed that 39 and 30 of these species had significantly different percent cover among site-index classes for stem-analyzed pine and spruce, respectively. Individual species cover values were then used in simple and multiple linear regression equations to predict the site index (at 70 years) for pine and spruce in 60–90 year and 91–160 year stand age subsets. Equations for pine based on understory species cover explained 38% of the variance in site index in younger stands and 59% in older stands; comparable maxima for spruce were 42% in younger stands and 50% in older stands. These percentages may be too low for stand-alone predictions of site index. Several possible sources of error may cause the low explained variance, including crude field estimates and seasonal variations of cover. Many of these potential sources of error could be minimized, allowing better prediction of forest site quality.


1965 ◽  
Vol 41 (4) ◽  
pp. 432-437
Author(s):  
A. D. Kiil

A simple and practical method is described for predicting slash weight and proportion of fine fuels. Sixty white spruce and 101 lodgepole pine trees in west central Alberta differing in site and stand conditions were felled, measured and the unmerchantable stem and all branchwood weighed. A graphical analysis showed that the slash weight-merchantable cubic foot ratios for both species varied inversely with tree diameter for the range of diameters sampled. White spruce has a higher slash weight-merchantable cubic foot ratio and a higher proportion of fine fuels than lodgepole pine.


1992 ◽  
Vol 22 (8) ◽  
pp. 1089-1093 ◽  
Author(s):  
R. Trowbridge ◽  
F.B. Holl

An overdense lodgepole pine (Pinuscontorta Dougl. ex Loud.) stand was knocked down and the site was prepared by broadcast burn, windrow burn, or mechanical forest floor removal. Inoculated alsike clover (Trifoliumhybridum L.) was seeded at 0, 10, 20, and 30 kg/ha for the three different site preparation treatments to determine the effects of (i) site preparation on infection and effectiveness of the clover–Rhizobium symbiosis and clover percent cover and (ii) the clover–Rhizobium N2-fixing symbiosis on survival, early growth, and foliar nitrogen concentration of lodgepole pine seedlings. The N2-fixing symbiosis established well in all treatments. Clover percent cover increased with increasing rate of seeding, although by relatively few percent in the clover seeded plots. Broadcast burning, windrow burning, and mechanical forest floor removal did not affect the establishment of the N2-fixing symbiosis or clover percent cover. Lodgepole pine survival was not affected by the seeding treatments in any year, nor were height measurements during the first three growing seasons. Seedling height was slightly less in clover-seeded plots compared with controls in the fourth growing season. Lodgepole pine seedlings on clover-seeded plots had decreased diameter growth compared with controls during the first three growing seasons, but incremental diameter growth no longer showed this effect by the fourth growing season. Needle mass (g/100 needles) was less in clover-seeded plots at the end of the second growing season, but this effect was reversed by the fourth growing season, when both needle mass and foliar nitrogen concentration in lodgepole pine foliage were greater in clover-seeded plots.


2004 ◽  
Vol 118 (4) ◽  
pp. 504 ◽  
Author(s):  
D. G. Sobey ◽  
W. M. Glen

Our aim was to produce maps showing the distribution on Prince Edward Island of five forest-types previously identified from a TWINSPAN analysis of ground flora data collected at 1200 sampling points in a field survey. For this purpose we had available two databases: one on the composition of the tree canopy of 82,957 forest stands, as determined by photointerpretation of a 1990 aerial photographic survey of the island; the other on the drainage properties of the same stands from a published soil survey. The tree canopy and drainage criteria for sorting these stands into five stand-types were chosen in the light of the equivalent properties of the TWINSPAN forest-types as evident from the field survey. These criteria were perfected in four trial computer-sortings, followed by the computer-printing of maps showing the distribution of the standtypes. These maps, which were then evaluated by comparing them with the properties of the TWINSPAN forest-types, are the first fine-scale maps of the main forest-types of the island. They reveal that, of the three “primary” forest-types, the upland hardwood forest occurs especially in the central and south-eastern hill-lands, as well as in scattered parcels elsewhere, whereas the Black Spruce forest and the wet species-rich woodland occur primarily in areas of lower elevation in the east and west of the island. The two forest-types resulting from human disturbance, the White Spruce woods and the “disturbed forest”, have a more scattered distribution, with the White Spruce woods being found especially in the central and eastern parts of the island and the disturbed forest in the west and east of the island. A secondary aim was to map the conjectured distribution before European settlement of the three primary forest-types: two maps have been produced, one showing the distribution of upland hardwood forest, the other of the wet forest-types.


Author(s):  
V. P. Tkach ◽  
O. V. Kobets ◽  
M. G. Rumiantsev

The forest site capacity using was quantitatively assessed for the stands of the main forest-forming species of Ukraine, Scots pine and common oak, taking into account natural zones and forest types. The tables of productivity of modal and highly productive pine and oak stands have been developed. It has been found that the stands use an average of 50–75 % of the forest site capacity of lands. The average weighted value of the capacity used by pine forests was 68–76 % in the Polissya zone, 70–78 % and 68–73 % in the Right-bank and Left-bank Forest-Steppe zones respectively, and 54–78 % in the Steppe zone. For oak stands, the value was 71–75 % and 63–71 % for the Right-bank and Left-bank Forest-Steppe zones respectively and 65–75 % for the Steppe zone. The basis for increasing the productivity of forests was confirmed to be the differentiation of forest management systems and individual forestry activities on a zonal and typological basis.


2017 ◽  
Vol 47 (8) ◽  
pp. 1116-1122 ◽  
Author(s):  
Rongzhou Man ◽  
Pengxin Lu ◽  
Qing-Lai Dang

Conifer winter damage results primarily from loss of cold hardiness during unseasonably warm days in late winter and early spring, and such damage may increase in frequency and severity under a warming climate. In this study, the dehardening dynamics of lodgepole pine (Pinus contorta Dougl. ex. Loud), jack pine (Pinus banksiana Lamb.), white spruce (Picea glauca (Moench) Voss), and black spruce (Picea mariana (Mill.) B.S.P.) were examined in relation to thermal accumulation during artificial dehardening in winter (December) and spring (March) using relative electrolyte leakage and visual assessment of pine needles and spruce shoots. Results indicated that all four species dehardened at a similar rate and to a similar extent, despite considerably different thermal accumulation requirements. Spring dehardening was comparatively faster, with black spruce slightly hardier than the other conifers at the late stage of spring dehardening. The difference, however, was relatively small and did not afford black spruce significant protection during seedling freezing tests prior to budbreak in late March and early May. The dehardening curves and models developed in this study may serve as a tool to predict cold hardiness by temperature and to understand the potential risks of conifer cold injury during warming–freezing events prior to budbreak.


2003 ◽  
Vol 20 (4) ◽  
pp. 167-174
Author(s):  
Nobutaka Nakamura ◽  
Paul M. Woodard ◽  
Lars Bach

Abstract Tree boles in the boreal forests of Alberta, Canada will split once killed by a stand-replacing crown fire. A total of 1,485 fire-killed trees were sampled, 1 yr after burning, in 23 plots in 14 widely separated stands within a 370,000 ha fire. Sampling occurred in the Upper and Lower Foothills natural subregions. The frequency of splitting varied by species but averaged 41% for all species. The order in the frequency of splitting was balsam fir, black spruce, white spruce and lodgepole pine. The type of splitting (straight, spiral, or multiple) varied by species, as did the position of the split on the tree bole. Aspect or solar angle was not statistically related to the type or occurrence of splitting.


1992 ◽  
Vol 68 (1) ◽  
pp. 53-63 ◽  
Author(s):  
Jean-François Bergeron ◽  
Jean-Pierre Saucier ◽  
Denis Robert ◽  
André Robitaille

In 1986, the ministère des Forêts du Québec instituted a provincial program to study forest ecosystems entitled the "Forest Ecological Classification (FEC) Program." Under this program, a multidisciplinary team was charged with conducting ecological surveys, analyzing and characterizing the variables of the physical environment, classifying vegetation and preparing integrated forest inventory maps. Their goal is to complete the ecological classification of the forests in all territories south of the 52nd parallel. To undertake such a vast project, it was necessary to prepare detailed methodological guides for data collection, data analysis and mapping. The following products are now available for many different ecological regions: classifications of forest types, toposequences, physiographic and surface deposit maps and integrated forest inventory maps. Multivariate analysis methods are used in analyzing ecological data; in this way, hierarchical classifications and ordinations can be used as the basis for identifying and describing forest types, vegetation-physical environment relationships and successional patterns. Such ecological classification products are an indispensable tool for forest managers and users. Key words: ecological classification, forest ecology, forest management, forest site classification, multivariate analysis, physical environment, Québec.


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