Dynamics of decline and mortality of Chamaecyparis nootkatensis in southeast Alaska

1990 ◽  
Vol 68 (3) ◽  
pp. 651-662 ◽  
Author(s):  
P. E. Hennon ◽  
E. M. Hansen ◽  
C. G. Shaw III
Keyword(s):  
Basal Area ◽  
Understory Vegetation ◽  
Aerial Photographs ◽  
Ecological Gradient ◽  
Southeast Alaska ◽  
Apparent Lack ◽  
Chamaecyparis Nootkatensis ◽  
Local Spread ◽  
Species Specific

Alaska-cedar, Chamaecyparis nootkatensis (D. Don) Spach, has been dying in undisturbed forests throughout southeast Alaska for the last 100 years. To determine if decline spreads, boundaries of mortality at seven sites with decline were mapped using aerial photographs taken in 1927, 1948, 1965, and 1976. Mortality was present at all seven sites in 1927. The boundaries of mortality have since expanded, but not by more than 100 m beyond the 1927 limit. In ground surveys, dead Alaska-cedar trees, classified according to their degree of deterioration, were recorded in 427 plots along 39 transects. Fifty-five taxa of understory vegetation were also recorded from 280 plots along these 21 transects; an ordination was produced from their distribution that represented a gradient from bogs to sites with better drainage. Most mortality was associated with bog and semibog sites. Alaska-cedar has a disproportionate level of mortality (65% of basal area dead) relative to other conifers. Local spread of cedar decline occurred along this gradient, as plots with more recently killed cedar trees had high average ordination scores (better drainage) and plots with cedars killed long ago had low average scores (boggy). Snags that probably date from the onset of extensive mortality were relatively common (at least 8% of all snags) on all 23 sites where intensive mortality was surveyed on the ground. As all sites with mortality that we investigated throughout southeast Alaska have these snags, decline does not appear to have spread to new sites since its onset. Although decline is relatively species specific and has patterns of local spread, the spread of mortality is along a specific, preexisting ecological gradient. These results, and the apparent lack of any site to site spread in the last 100 years, suggest that Alaska-cedar decline is not caused by some biotic agent.

Relations between red alder composition and understory vegetation in young mixed forests of southeast Alaska

2006 ◽  
Vol 36 (3) ◽  
pp. 738-748 ◽  
Author(s):  
Thomas A Hanley ◽  
Robert L Deal ◽  
Ewa H Orlikowska
Keyword(s):  
Carrying Capacity ◽  
Basal Area ◽  
Picea Sitchensis ◽  
Understory Vegetation ◽  
Wildlife Habitat ◽  
Red Alder ◽  
Southeast Alaska ◽  
Net Production ◽  
Understory Biomass ◽  
Young Growth

Interest in mixed red alder (Alnus rubra Bong.) – conifer young-growth stands has grown in southeast Alaska, USA, because they appear to provide much more productive understory vegetation and wildlife habitat than do similar-aged pure conifer stands. We studied understory vegetation in nine even-aged young-growth stands (38–42 years old) comprising a gradient of red alder – conifer overstory composition, with red alder ranging from 0% to 86% of stand basal area. Conifers were Sitka spruce (Picea sitchensis (Bong.) Carr.), western hemlock (Tsuga heterophylla (Raf.) Sarg.), and western redcedar (Thuja plicata Donn ex D. Don). We measured understory biomass and net production (current annual growth) in each stand by species and plant part and estimated carrying capacity for black-tailed deer (Odocoileus hemionus sitkensis Cowan) with a food-based habitat model. Highly significant positive relations (P < 0.002) were found between red alder basal area and all of the following: total understory biomass (r2 = 0.743), net production of shrubs (r2 = 0.758) and herbs (r2 = 0.855), and summer carrying capacity for deer (r2 = 0.846). The high correlation between red alder and herbaceous production is especially important, because herbs are least abundant and most difficult to maintain in young-growth conifer forests of this region. Red alder offers prospects for increasing understory vegetation biomass and its food value for deer and other wildlife when included as a hardwood overstory species in mixed hardwood–conifer young-growth forests.

Inoptimality losses in forest management decisions caused by errors in an inventory based on airborne laser scanning and aerial photographs

2010 ◽  
Vol 40 (12) ◽  
pp. 2427-2438 ◽  
Author(s):  
Md. Nurul Islam ◽  
Mikko Kurttila ◽  
Lauri Mehtätalo ◽  
Timo Pukkala
Keyword(s):  
Input Data ◽  
Laser Scanning ◽  
Basal Area ◽  
Airborne Laser Scanning ◽  
Aerial Photographs ◽  
Stand Age ◽  
Inventory Data ◽  
Airborne Laser ◽  
Mean Diameter ◽  
The Mean

Errors in inventory data may lead to inoptimal decisions that ultimately result in financial losses for forest owners. We estimated the expected monetary losses resulting from data errors that are similar to errors in laser-based forest inventory. The mean loss was estimated for 67 stands by simulating 100 realizations of inventory data for each stand with errors that mimic those in airborne laser scanning (ALS) based inventory. These realizations were used as input data in stand management optimization, which maximized the present value of all future net incomes (NPV). The inoptimality loss was calculated as the difference between the NPV of the optimal solution and the true NPV of the solution obtained with erroneous input data. The results showed that the mean loss exceeded €300·ha–1 (US$425·ha–1) in 84% of the stands. On average, the losses increased with decreasing stand age and mean diameter. Furthermore, increasing errors in the basal area weighted mean diameter and basal area of spruce were found to significantly increase the loss. It has been discussed that improvements in the accuracy of ALS-based inventory could be financially justified.

Assessing 3D point clouds from aerial photographs for species-specific forest inventories

2016 ◽  
Vol 32 (1) ◽  
pp. 68-79 ◽  
Author(s):  
Stefano Puliti ◽  
Terje Gobakken ◽  
Hans Ole Ørka ◽  
Erik Næsset
Keyword(s):  
Point Clouds ◽  
Aerial Photographs ◽  
Forest Inventories ◽  
3D Point Clouds ◽  
Species Specific

Long-term impact of liming on growth and vigor of northern hardwoods

2011 ◽  
Vol 41 (6) ◽  
pp. 1295-1307 ◽  
Author(s):  
Robert P. Long ◽  
Stephen B. Horsley ◽  
Thomas J. Hall
Keyword(s):  
Acer Saccharum ◽  
Sugar Maple ◽  
Keystone Species ◽  
Basal Area ◽  
Fagus Grandifolia ◽  
Northern Hardwood ◽  
Crown Health ◽  
Lime Application ◽  
Species Specific

Sugar maple (Acer saccharum Marsh.) is a keystone species in the northern hardwood forest, and decline episodes have negatively affected the growth and health of sugar maple in portions of its range over the past 50+ years. Crown health, growth, survival, and flower and seed production of sugar maple were negatively affected by a widespread decline event in the mid-1980s on the unglaciated Allegheny Plateau in northern Pennsylvania. A long-term liming study was initiated in 1985 to evaluate responses to a one-time application of 22.4 Mg·ha–1 of dolomitic limestone in four northern hardwood stands. Over the 23-year period ending in 2008, sugar maple basal area increment (BAINC) increased significantly (P ≤ 0.05) in limed plots from 1995 through 2008, whereas American beech (Fagus grandifolia Ehrh.) BAINC was unaffected. For black cherry (Prunus serotina Ehrh.), the third principal overstory species, BAINC and survival were reduced in limed plots compared with unlimed plots. Foliar Ca and Mg remained significantly higher in sugar maple foliage sampled 21 years after lime application, showing persistence of the lime effect. These results show long-term species-specific responses to lime application.

AN ANALYSIS OF MEASURES OF DENSITY IN EVEN-AGED BALSAM FIR AND JACK PINE STANDS

1964 ◽  
Vol 40 (4) ◽  
pp. 474-481 ◽  
Author(s):  
P. E. Vezina
Keyword(s):  
Pinus Banksiana ◽  
Abies Balsamea ◽  
Basal Area ◽  
Stand Density ◽  
Jack Pine ◽  
Balsam Fir ◽  
Aerial Photographs ◽  
Growing Stock ◽  
The One ◽  
Crown Closure

The concept of stand density in relation to thinning is examined and its development over the years is discussed. Present difficulties of objectively measuring stand density are recognized and probable future trends towards the development of better formulae to express stand density are outlined. Researchers should continue to collect information on interrelationships among stand variables. Certain merits accrue from description of stand density in terms of variables, such as crown closure, that can be measured with some precision from aerial photographs. Conversely, valid estimates of crown closure which are often difficult to obtain by means of devices from the ground, could be predicted from stand density. Three stand variables, used as expressions of stand density, were tested in crown closure simple regressions in even-aged, unmanaged stands of balsam fir (Abies balsamea (L.) Mill.) and jack pine (Pinus banksiana Lamb.). These are: total number of trees, number of trees 4 inches and up, and basal area per acre. The strongest relationship found was the one where crown closure is compared with basal area; it was stronger for jack pine than for balsam fir. This was explained by differences in tolerance among the two species. The significance of these relationships for the stand development, and the feasibility of using height-and diameter-based indices as measures of growing stock in studies of yield are discussed.

The effects of partial cutting on forest plant communities of western hemlock – Sitka spruce stands in southeast Alaska

2001 ◽  
Vol 31 (12) ◽  
pp. 2067-2079 ◽  
Author(s):  
Robert L Deal
Keyword(s):  
Species Richness ◽  
Community Structure ◽  
Plant Community ◽  
Basal Area ◽  
Plant Species Richness ◽  
Plant Community Structure ◽  
Old Growth ◽  
Partial Cutting ◽  
Southeast Alaska ◽  
Clear Cutting

The effects of partial cutting on plant species richness, community structure, and several understory species that are important for deer forage were evaluated on 73 plots in 18 stands throughout southeast Alaska. These partially cut stands were harvested 12–96 years ago when 16–96% of the former stand basal area was removed. The species richness and community structure of understory plants were similar in uncut and partially cut plots. However, plots where more than 50% of the basal area was cut had a significantly different plant community structure. Species composition and abundance also appeared to be distinctly different between hemlock-dominated and spruce-dominated stands. Partial cutting did not significantly change abundance for most of the important forage species for deer. The similarity in plant community structure between partially cut and uncut old-growth stands may be related to forest stand structures. The heterogeneous stand structures that develop after partial cutting are more similar to old-growth stands than to the uniform young-growth stands that develop after stand replacing disturbances such as clear-cutting.

scholarly journals Potential of Modern Photogrammetry Versus Airborne Laser Scanning for Estimating Forest Variables in a Mountain Environment

2019 ◽  
Vol 11 (6) ◽  
pp. 661 ◽  
Author(s):  
Sami Ullah ◽  
Matthias Dees ◽  
Pawan Datta ◽  
Petra Adler ◽  
Mathias Schardt ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Digital Terrain Model ◽  
Basal Area ◽  
Point Clouds ◽  
Airborne Laser Scanning ◽  
Aerial Photographs ◽  
Data Types ◽  
Viable Option ◽  
Airborne Laser ◽  
Mountain Environment

Digital stereo aerial photographs are periodically updated in many countries and offer a viable option for the regular update of information on forest variables. We compared the potential of image-based point clouds derived from three different sets of aerial photographs with airborne laser scanning (ALS) to assess plot-level forest attributes in a mountain environment. The three data types used were (A) high overlapping pan-sharpened (80/60%); (B) high overlapping panchromatic band (80/60%); and (C) standard overlapping pan-sharpened stereo aerial photographs (60/30%). We used height and density metrics at the plot level derived from image-based and ALS point clouds as the explanatory variables and Lorey’s mean height, timber volume, and mean basal area as the response variables. We obtained a RMSE = 8.83%, 29.24% and 35.12% for Lorey’s mean height, volume, and basal area using ALS data, respectively. Similarly, we obtained a RMSE = 9.96%, 31.13%, and 35.99% and RMSE = 11.28%, 31.01%, and 35.66% for Lorey’s mean height, volume and basal area using image-based point clouds derived from pan-sharpened stereo aerial photographs with 80/60% and 60/30% overlapping, respectively. For image-based point clouds derived from a panchromatic band of stereo aerial photographs (80%/60%), we obtained an RMSE = 10.04%, 31.19% and 35.86% for Lorey’s mean height, volume, and basal area, respectively. The overall findings indicated that the performance of image-based point clouds in all cases were as good as ALS. This highlights that in the presence of a highly accurate digital terrain model (DTM) from ALS, image-based point clouds offer a viable option for operational forest management in all countries where stereo aerial photographs are updated on a routine basis.

scholarly journals Pattern of Deterioration and Recovery of Wood from Dead Yellow-Cedar in Southeast Alaska

2000 ◽  
Vol 15 (2) ◽  
pp. 49-58
Author(s):  
Paul E. Hennon ◽  
Dustin T. Wittwer ◽  
John Stevens ◽  
Ken Kilborn
Keyword(s):  
Southeast Alaska ◽  
Chamaecyparis Nootkatensis ◽  
Measurable Difference ◽  
Volume Recovery ◽  
Modest Reduction

Abstract Live yellow-cedar (Chamaecyparis nootkatensis) trees and five classes of snags dead up to 81 yr were contrasted based on the following: the retention of bark and sapwood; the penetration of stain, decay, and weather checks; and the volume and grade of lumber recovered. Of 138 sample trees, most bark was retained on the boles of trees dead &lt;14 yr but thereafter sloughed away and was generally missing by 51 yr after death. Stain, decay, and weather checks were limited to the narrow sapwood on snags 26 yr after tree death (n = 280 log end surfaces). Weather checking, the most serious deterioration defect in snags, did not encroach on heartwood until the sapwood was missing some 51 yr after death. Checking penetration averaged 1.3 in. for the last two snag classes. Cubic volume recovery from 305 mill-length logs did not differ significantly by classes of live trees or snags dead up to 26 yr, and the significant reduction in recovery from snags dead 51 and 81 yr was less than 15%. Grades of lumber were generally similar among the classes of trees, but no clear lumber was recovered from the oldest snag class. These results indicate little to no measurable difference of recovered wood from live trees and the first three snag classes, dead up to 26 yr, and a modest reduction in volume and grade in snags dead up to 81 yr. West. J. Appl. For. 15(2):49-58.

scholarly journals The influence of competition and species mixture on plantation-grown white spruce: Growth and foliar nutrient response after 20 years

2014 ◽  
Vol 90 (01) ◽  
pp. 70-79 ◽  
Author(s):  
Breanne A. Neufeld ◽  
Dave M. Morris ◽  
Nancy Luckai ◽  
Douglas E.B. Reid ◽  
F. Wayne Bell ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Basal Area ◽  
White Spruce ◽  
Mixed Stands ◽  
Density Control ◽  
Foliar Nutrient ◽  
Thinning Operations ◽  
Species Specific ◽  
Foliar Sampling ◽  
Physical And Chemical

A 20-year-old experimental white spruce plantation was used to identify key stand (neighbourhood competition) and soil (physical and chemical properties) factors influencing spruce growth (Periodic Basal Area Increment) and foliar nutrients. Total and species-specific competition was estimated using Hegyi’s distance-dependent index for 39 individual spruce trees. Twelve trees, covering the range of total HCI (2 to 8) and aspen competition (0% to >75%), were selected for repeated (May through October) foliar sampling. Spruce PBAI declined approximately 10% for each additional unit of total HCI; species did not significantly affect this decline. Increasing aspen presence significantly influenced spruce foliar N (1.17% to 1.31%), P (0.15% to 0.23%), and K (0.68% to 0.88%), but led to declines in Ca (0.81% to 0.48%). Multiple linear regression indicated that soil carbon (partial r2 = 0.386) and available soil moisture (partial r2 = 0.131) together explained more of the variation in spruce growth than did competition factors alone (partial r2 = 0.251). The results suggest that, at this stage of stand development, precommercial thinning operations should focus on density control and inter-tree spacing, while retaining an aspen component resulting in well-spaced, free-growing mixed stands of white spruce and aspen.

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