scholarly journals Biomass and dynamics of attached dead branches in the canopy of 450-year-old Douglas-fir trees

2006 ◽  
Vol 36 (2) ◽  
pp. 378-389 ◽  
Author(s):  
Hiroaki Ishii ◽  
Tomoko Kadotani
Keyword(s):  
Tree Height ◽  
Dry Mass ◽  
Tsuga Heterophylla ◽  
Important Variable ◽  
Douglas Fir ◽  
Dead Branch ◽  
Western Washington ◽  
Term Monitoring ◽  
Branch Death

The amount, physical characteristics, and spatial distribution of attached dead branches in the canopy of 450-year-old Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) trees were studied over a 5-year period (1998–2003) to quantify their contribution to the canopy woody detritus pool of an old-growth Douglas-fir – western hemlock (Tsuga heterophylla (Raf.) Sarg.) forest in the western Washington Cascades. We developed a five-class decay rating for attached dead branches. From the size distribution and relative amounts and vertical distribution of attached dead branches in the five decay classes, we inferred that death of large original branches had occurred in the recent past, followed by the production and death of epicormic branches. Tree height was an important variable for predicting branchwood dry mass per tree. We estimated that attached dead branches of Douglas-fir contributed 63.8% of the total canopy woody detritus pool of the stand. During the study period, 0.24%·year–1 of live branchwood mass died attached, and 0.37%·year–1 and 4.34%·year–1, respectively, of live- and dead-branch mass were lost due to branchfall and fragmentation. Because branch death and branchfall are stochastic processes, long-term monitoring in the canopy and on the ground is needed to understand the dynamics of canopy woody detritus.

Influence of nutrient supply and water vapour pressure on root architecture of Douglas-fir and western hemlock seedlings

2006 ◽  
Vol 33 (10) ◽  
pp. 941 ◽  
Author(s):  
Timothy S. S. Conlin ◽  
R. van den Driessche
Keyword(s):  
Vapour Pressure ◽  
Root Architecture ◽  
Soil Nutrient ◽  
Dry Mass ◽  
Tsuga Heterophylla ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Nutrient Concentrations ◽  
Water Vapour Pressure ◽  
Growth Responses

Root growth responses of Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] and western hemlock (Tsuga heterophylla Raf. Sarg.) seedlings to three nutrient concentrations and two shoot vapour pressure deficits were measured. Both species gained dry mass at high and medium nutrient treatments throughout the experiment, but not at low nutrition. Low nutrition gave highest ratios of projected leaf surface area to total root length in both species. Douglas-fir geometry differed from that of hemlock, with longer interior link lengths, particularly at the lowest nutrition. Douglas-fir showed greater numbers of exterior–interior links than hemlock. More links were observed at medium and high nutrition than at low nutrition for both species. Exterior–interior links increased over time for the two highest nutrient treatments. Significant topological differences were observed between species, the lowest and two highest nutrient treatments, and high and low vapour pressure deficits. Both species showed herring-bone root architecture at the lowest nutrition. This architectural configuration became more pronounced in hemlock seedlings grown under higher vapour pressure deficits. Faster-growing Douglas-fir had a dichotomous architecture at medium and high nutrition that was not influenced by increased vapour pressure deficits. Douglas-fir topology appears to be adapted to exploit soil nutrient patches while hemlock appears to rely on efficient exploitation of soil volume.

Multi-decadal establishment for single-cohort Douglas-fir forests

2014 ◽  
Vol 44 (9) ◽  
pp. 1068-1078 ◽  
Author(s):  
James A. Freund ◽  
Jerry F. Franklin ◽  
Andrew J. Larson ◽  
James A. Lutz
Keyword(s):  
Pseudotsuga Menziesii ◽  
Temporal Patterns ◽  
Tsuga Heterophylla ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Old Growth ◽  
Old Growth Forests ◽  
Western Washington ◽  
Century Development ◽  
Single Cohort

The rate at which trees regenerate following stand-replacing wildfire is an important but poorly understood process in the multi-century development of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and western hemlock (Tsuga heterophylla (Raf.) Sarg.) forests. Temporal patterns of Douglas-fir establishment reconstructed from old-growth forests (>450 year) have generated contradictory models of either rapid (<25 year) or prolonged (>100 year) periods of establishment, while patterns of tree establishment in mid-aged (100 to 350 year) forests remains largely unknown. To determine temporal patterns of Douglas-fir establishment following stand-replacing fire, increment cores were obtained from 1455 trees in 18 mature and early old-growth forests in western Washington and northwestern Oregon, USA. Each of the stands showed continuous regeneration of Douglas-fir for many decades following initiating fire. The establishment period averaged 60 years (range: 32–99 years). These results contrast both with the view of rapid (one- to two-decade) regeneration of Douglas-fir promoted in the early forestry literature and with reports of establishment periods exceeding 100 years in older (>400 year) Douglas-fir–western hemlock stands. These results have important implications for management designed to create and promote early-seral forest characteristics.

Effect of thinning, fertilization with biosolids, and weather on interannual ring specific gravity and carbon accumulation of a 55-year-old Douglas-fir stand in western Washington

2010 ◽  
Vol 40 (1) ◽  
pp. 72-85 ◽  
Author(s):  
Rapeepan Kantavichai ◽  
David G. Briggs ◽  
Eric C. Turnblom
Keyword(s):  
Specific Gravity ◽  
Carbon Storage ◽  
Dry Mass ◽  
Douglas Fir ◽  
Carbon Accumulation ◽  
Moisture Deficit ◽  
Biomass Equations ◽  
Mass Conversion ◽  
Western Washington ◽  
Average Wood

Marketing timber is shifting from logs, lumber, and veneer measured volumetrically to include carbon storage and energy that are based on dry mass. Conversion between volume and dry mass relies on accurate estimates of wood specific gravity (SG). We measured width and SG of growth rings and their earlywood and latewood components with X-ray densitometry on trees from controlled, thinned, biosolid fertilized, and combined treatments applied to a 55-year-old Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco) stand. We developed models to predict interannual SG from climate and treatment effects and compared 20 year changes in dry mass and carbon storage with estimates from biomass equations and from the Wood Handbook average SG. Thinning increased latewood width but did not affect ring SG. Biosolid fertilization increased earlywood and latewood width and decreased ring SG 8% by decreasing earlywood SG, latewood SG, and latewood percentage. SG decreased with increased July soil moisture deficit; alternatively, SG increased with increased July total precipitation. Warmer mean March–May or August–November temperatures also increased SG. Because of the effects on SG, dry mass and carbon storage changes differed from volume changes produced by the treatments. Dry mass estimates using the average Wood Handbook SG or those calculated from biomass equations were inconsistent between treatments, with errors up to 50%.

Firebrand generation from burning vegetation

2007 ◽  
Vol 16 (4) ◽  
pp. 458 ◽  
Author(s):  
Samuel L. Manzello ◽  
Alexander Maranghides ◽  
William E. Mell
Keyword(s):  
Mass Distribution ◽  
Pseudotsuga Menziesii ◽  
Tree Height ◽  
Dry Mass ◽  
Douglas Fir ◽  
Large Fire ◽  
Precision Balance ◽  
Real Scale ◽  
Fire Laboratory ◽  
Fire Experiments

A series of real-scale fire experiments were performed to determine the size and mass distribution of firebrands generated from Douglas-fir (Pseudotsuga menziesii) trees. The experiments were performed in the Large Fire Laboratory at the National Institute of Standards and Technology. The Douglas-fir trees used for the experiments ranged in total height from 2.6 to 5.2 m and the tree moisture content was varied. An array of pans filled with water was used to collect the firebrands that were generated from the burning trees. This ensured that firebrands would be quenched as soon as they made contact with the pans. The firebrands were subsequently dried and the sizes were measured using callipers and the dry mass was determined using a precision balance. For all experiments performed, the firebrands were cylindrical in shape. The average firebrand size measured from the 2.6-m Douglas-fir trees was 3 mm in diameter, 40 mm in length. The average firebrand size measured for the 5.2-m Douglas-fir trees was 4 mm in diameter with a length of 53 mm. The mass distribution of firebrands produced from two different tree sizes under similar tree moisture levels was similar. The only noticeable difference occurred in the largest mass class. Firebrands with masses up to 3.5 g to 3.7 g were observed for the larger tree height used (5.2 m). The surface area of the firebrands scaled with firebrand weight.

Effects of long-term pruning, meristem origin, and branch order on the rooting of Douglas-fir stem cuttings

1992 ◽  
Vol 22 (12) ◽  
pp. 1888-1894 ◽  
Author(s):  
Donald L. Copes
Keyword(s):  
Flat Surface ◽  
Tree Height ◽  
Douglas Fir ◽  
Second Order ◽  
Stem Cuttings ◽  
First Order ◽  
Secondary Origin ◽  
Rooting Of Cuttings ◽  
Better Than

The rooting percentages of 14 Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) clones were examined annually from 1974 to 1988. The trees were 10 and 13 years old in 1974 and were pruned to 2.0 m in 1978 and 1979 and then recut annually to 0.5, 1.0, or 1.5 m, starting in 1983. The pruned trees showed no evidence of decreased rooting percentage even after 15 years; average rooting increased from 47% in 1974 to 74% in 1986. Rooting percentage was significantly influenced by tree height. Cuttings collected from 0.5 m tall ramets exhibited better rooting than cuttings from 1.0 or 2.0 m tall ramets, and cuttings from 1.0 m tall ramets rooted better than cuttings from 2.0 m tall ramets. Rooting of cuttings collected from 0.5 m high subinterval zones within trees showed a negative linear relation between rooting percentage and collection height. Cuttings collected from the 0–0.5 m zone rooted 25% better than cuttings from the 1.5–2.0 m zone of the 2 m tall trees. That difference was significant at p < 0.05. A test of rooting of larger, more orthotropic cuttings gathered from the upper flat surface of pruned ramets indicated that the cuttings from the top rooted significantly less than smaller, more plagiotropic cuttings from the contiguous side areas (24 versus 33%, respectively). Rooting comparisons of meristems of primary and secondary origin showed significantly greater rooting of secondary meristems. Comparison of rooting of second-order and first-order meristems of secondary origin indicated the second-order twigs averaged 26% better rooting than the first-order branch tips when the cuttings were collected in January and placed in the rooting beds in February.

Future Needs for Long-Term Monitoring Design

2003 ◽  
Author(s):  
Barbara S. Minsker ◽  
Charles Davis ◽  
David Dougherty ◽  
Gus Williams
Keyword(s):  
Monitoring Design ◽  
Future Needs ◽  
Long Term Monitoring ◽  
Term Monitoring

Enabling Community Well-being Self-Monitoring in the Context of Mining: The Naskapi Nation of Kawawachikamach

2016 ◽  
Vol 1 (2) ◽  
Author(s):  
Robert Klinck ◽  
Ben Bradshaw ◽  
Ruby Sandy ◽  
Silas Nabinacaboo ◽  
Mannie Mameanskum ◽  
...  
Keyword(s):  
Indigenous Peoples ◽  
Well Being ◽  
Aboriginal Community ◽  
Self Monitoring ◽  
Community Engaged Research ◽  
The Past ◽  
Mineral Development ◽  
Iron Deposits ◽  
Term Monitoring

The Naskapi Nation of Kawawachikamach is an Aboriginal community located in northern Quebec near the Labrador Border. Given the region’s rich iron deposits, the Naskapi Nation has considerable experience with major mineral development, first in the 1950s to the 1980s, and again in the past decade as companies implement plans for further extraction. This has raised concerns regarding a range of environmental and socio-economic impacts that may be caused by renewed development. These concerns have led to an interest among the Naskapi to develop a means to track community well-being over time using indicators of their own design. Exemplifying community-engaged research, this paper describes the beginning development of such a tool in fall 2012—the creation of a baseline of community well-being against which mining-induced change can be identified. Its development owes much to the remarkable and sustained contribution of many key members of the Naskapi Nation. If on-going surveying is completed based on the chosen indicators, the Nation will be better positioned to recognize shifts in its well-being and to communicate these shifts to its partners. In addition, long-term monitoring will allow the Naskapi Nation to contribute to more universal understanding of the impacts of mining for Indigenous peoples.

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