Short-term effects of prescribed burning on radial growth of Douglas-fir trees in south central British Columbia

2011 ◽  
Vol 20 (7) ◽  
pp. 876
Author(s):  
M. C. Feller ◽  
W. Klenner
Keyword(s):  
British Columbia ◽  
Tree Growth ◽  
Radial Growth ◽  
Prescribed Burning ◽  
Fire Severity ◽  
Soil Nutrient ◽  
Douglas Fir ◽  
Tree Size ◽  
Radial Increment ◽  
South Central

Radial increment of Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco) trees in uncut and partially cut and grazed and ungrazed dry cool Interior Douglas-fir forests near Isobel Lake in southern central British Columbia was measured for 2-year periods before and after prescribed burning in burned and unburned (control) areas. Parameters thought to influence the effects of prescribed burning on tree growth – characteristics of the tree and its immediate environment, adjacent surface and ladder fuels, and fire effects – were also measured. Burning caused a decrease in tree radial growth. The proportional change in radial tree growth was not related to degree of cutting or the presence of cattle grazing, but was negatively correlated with preburn radial growth, tree size, and also with some fire effect variables, particularly char height, suggesting that an increasing proportional decline in radial growth was associated with increasing tree size and with increasing fire severity. Soil nutrient (N, S, P, K, Mg or Ca) level was not a significant determinant of tree growth. The best prediction model could only explain 23% of the variation in the change in radial growth. Our results show that the effects of fire on Douglas-fir radial growth are complex and difficult to predict with the variables measured.

scholarly journals Fire Exclusion Destroys Habitats for At-Risk Species in a British Columbia Protected Area

Fire ◽  
2019 ◽  
Vol 2 (3) ◽  
pp. 48
Author(s):  
Kira M. Hoffman ◽  
Sara B. Wickham ◽  
William S. McInnes ◽  
Brian M. Starzomski
Keyword(s):  
British Columbia ◽  
Fire History ◽  
Prescribed Burning ◽  
Douglas Fir ◽  
Conifer Encroachment ◽  
Oak Trees ◽  
Composition And Structure ◽  
Fire Exclusion ◽  
History Of

Fire exclusion and suppression has altered the composition and structure of Garry oak and associated ecosystems in British Columbia. The absence of frequent low severity ground fires has been one of the main contributors to dense patches of non-native grasses, shrubs, and encroaching Douglas-fir trees in historical Garry oak dominated meadows. This case study uses remote sensing and dendrochronology to reconstruct the stand dynamics and long-term fire history of a Garry oak meadow situated within Helliwell Provincial Park located on Hornby Island, British Columbia. The Garry oak habitat in Helliwell Park has decreased by 50% since 1950 due to conifer encroachment. Lower densities and mortalities of Garry oak trees were associated with the presence of overstory Douglas-fir trees. To slow conifer encroachment into the remaining Garry oak meadows, we recommend that mechanical thinning of Douglas-fir be followed by a prescribed burning program. Reintroducing fire to Garry oak ecosystems can restore and maintain populations of plants, mammals, and insects that rely on these fire resilient habitats.

Soil disturbance and juvenile Douglas-fir growth following stump removal on moderately coarse textured soils in southwestern British Columbia: 10-year results

2019 ◽  
Vol 49 (7) ◽  
pp. 767-774
Author(s):  
Stefan Zeglen ◽  
Paul J. Courtin
Keyword(s):  
British Columbia ◽  
Tree Growth ◽  
Basal Area ◽  
Soil Disturbance ◽  
Douglas Fir ◽  
Stand Development ◽  
Site Productivity ◽  
Nutrient Analysis ◽  
Armillaria Ostoyae ◽  
Root Diseases

Mechanized treatment for root diseases such as Coniferiporia sulphurascens (Pilát) L. W. Zhou & Y. C. Dai (syn. Phellinus sulphurascens Pilát) and Armillaria ostoyae (Romagn.) Herink (syn. Armillaria solidipes Peck) is often avoided due to cost or the perception that removal of stumps creates detrimental soil disturbance or degradation that hinders site productivity. Our study tested five diseased stands that were treated by extracting stumps following harvesting and replanted with susceptible Douglas-fir. Soil disturbance surveys were conducted in treated and untreated plots, and individual planted spots were assessed and categorized for soil disturbance using existing and proposed new categories specific to disturbance caused by the stump removal. Tree measurements were taken at intervals over the first 10 years of stand development, and foliage was sampled for nutrient analysis. The percentage of total and counted disturbance was 20%–46% and 8%–11% greater, respectively, in treated versus untreated plots; however, mean tree growth in height and diameter was not statistically different between treatments and was more positive for treated plots at all sites but one. Tree nutrition and survival to age 10 was not negatively affected by stump removal. Total site productivity represented by basal area and tree volume differed widely between sites but was not significantly different between treatments.

THE NATURE OF THE ASSOCIATION OF EUROPHIUM TRINACRIFORME WITH POLE BLIGHT LESIONS

1957 ◽  
Vol 35 (6) ◽  
pp. 845-856 ◽  
Author(s):  
A. K. Parker
Keyword(s):  
British Columbia ◽  
Radial Growth ◽  
Growth Analysis ◽  
Radial Increment ◽  
White Pine ◽  
Histological Studies ◽  
Stem Section ◽  
Western White Pine ◽  
General Reduction

Europhium trinacriforme Parker was isolated from 11% of the lesions on western white pine affected with pole blight in the Interior of British Columbia and from 84% of the lesions on white pine on the Coast. This fungus was the only organism isolated more than twice from pole blight lesions and found to be pathogenic to white pine. However, it was unable to cause the pole blight condition within a period of 4 years after inoculation into healthy white pine. When this fungus was placed in wounds on white pine, lesions resulted which were similar to pole blight lesions in shape and in ability to cause resin exudation, but were otherwise dissimilar. On the basis of radial growth analysis it was evident that lesions occur following a general reduction in radial increment, and at the same time, or shortly after, the first crown symptoms of pole blight appear. Radial growth beneath lesions was nearly always less than in other parts of the stem section, indicating that both the position and extent of lesions are determined before they occur. Examinations of the number and size of lesions on pole blighted trees and the results of inoculations, isolations, and histological studies indicated that E. trinacriforme most likely gains entrance to lesions that are already formed from other causes and extends them.

Tree mortality and radial growth losses caused by the western spruce budworm in a Douglas-fir stand in British Columbia

1982 ◽  
Vol 12 (4) ◽  
pp. 780-787 ◽  
Author(s):  
R. I. Alfaro ◽  
G. A. Van Sickle ◽  
A. J. Thomson ◽  
E. Wegwitz
Keyword(s):  
Radial Growth ◽  
Tree Mortality ◽  
Small Diameter ◽  
Basal Area ◽  
Spruce Budworm ◽  
Douglas Fir ◽  
Radial Increment ◽  
Western Spruce Budworm ◽  
Number Of Stems ◽  
The Relationship

The effects of defoliation by western spruce budworm (Choristoneuraoccidentalis (Freeman)), on Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) radial growth at breast height and tree mortality are given. Four hundred and twenty trees were marked in an 81-year-old stand, and their defoliation levels were recorded annually from 1970 to 1980 in an outbreak that lasted from 1970 to 1974, inclusive. Forty-one trees were felled and dissected in 1977, 3 years after recovery began. The number of stems per hectare was reduced by 39.3% and basal area by 11.6% through mortality, most occurring among the small diameter, suppressed, and intermediate trees. Relationships were established between mortality and defoliation. Radial increments were examined, and the presence of four outbreaks during the life of the stand was detected. The combined effect of these infestations amounted to a loss of about 12% of the estimated potential diameter had not the insects been active. The most recent outbreak (1970–1974) caused a total of 10 years of subnormal growth, including 5 years due to defoliation and 5 years of recovery. The relationship between radial increment losses and defoliation intensity and duration is studied and quantified.

Effects of fertilization on the nutrition and growth of a slow-growing Engelmann spruce plantation in south central British Columbia

1992 ◽  
Vol 22 (11) ◽  
pp. 1617-1622 ◽  
Author(s):  
R.P. Brockley
Keyword(s):  
British Columbia ◽  
Tree Growth ◽  
Nitrogen Nutrition ◽  
Ferrous Sulphate ◽  
Nutrient Deficiencies ◽  
Height Increment ◽  
Growth Responses ◽  
Poor Growth ◽  
Engelmann Spruce ◽  
South Central

A study was undertaken to investigate the effects of ground and foliar fertilizer applications on the growth of a 15-year-old Engelmann spruce (Piceaengelmannii Parry) plantation in the south central interior of British Columbia. The site had been broadcast burned prior to plantation establishment, and poor growth performance and pretreatment foliar analyses indicated that multiple nutrient deficiencies were likely growth limiting. Fertilization has had a very strong positive influence on height increment and branch elongation. Although growth responses were minimal in the 1st year after treatment, cumulative increases in height increment over the next 2 years averaged 41 cm (range 28–48 cm) greater than those recorded in unfertilized trees. In relative terms, these responses averaged 102% (range 90–120%). Improvements in branch increment over this 2-year period also averaged 102% (range 85–115%). Results indicate that the majority of the growth response has been due to improved nitrogen nutrition. Combined ground applications of nitrogen and a "complete mix" fertilizer were no better than nitrogen alone in stimulating tree growth. The effectiveness of 2% ferrous sulphate and sodium sulphate sprays was probably adversely affected by foliar scorching following spray application. However, despite foliar burning, results indicate that trees may respond favourably to iron applications if accompanied by ground applications of nitrogen and other deficient nutrients (likely sulphur). Because the study design did not allow distinction of cause and effect, with respect to the consequences of the prior broadcast burn, it cannot be stated conclusively that burning is responsible for inadequate stand nutrition and poor tree growth on this site. However, when combined with evidence of impaired nutrition following slash burning from other studies, it may be safely inferred that burning will exacerbate existing nutritional problems and that fertilization under these conditions may at least temporarily improve plantation performance.

scholarly journals Monthly Radial Growth Model of Chinese Fir (Cunninghamia lanceolata (Lamb.) Hook.), and the Relationships between Radial Increment and Climate Factors

Forests ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 757
Author(s):  
Yaqi Huang ◽  
Xiangwen Deng ◽  
Zhonghui Zhao ◽  
Wenhua Xiang ◽  
Wende Yan ◽  
...  
Keyword(s):  
Growth Rate ◽  
Social Status ◽  
Growth Model ◽  
Tree Growth ◽  
Radial Growth ◽  
Chinese Fir ◽  
Cunninghamia Lanceolata ◽  
Radial Increment ◽  
Climate Factors ◽  
Temperature And Precipitation

Chinese fir (Cunninghamia lanceolata (Lamb.) Hook) is the most commonly grown afforestation species in subtropical China. It is essential that we understand the response of radial tree growth to climate factors, yet most experiments have been conducted based on total annual growth and not on monthly dynamics, which alone can detail the influence of climatic factors. In this study, we aimed to: (i) construct a monthly growth model and compare the growth rate of different social statuses of trees, and (ii) determine the response of radial increments of different social statuses to climate factors. The radial growth was monitored monthly during four years using manual band dendrometers (MBD). The data were fitted using the Gompertz function. Within-stand differences in the social status of Chinese firs resulted in growing period and growth rate length variations. The radial growth began in March, and suppressed trees—especially groups of AS1 and BS1 (suppressed trees of classes I in sites A and B)—stopped in September, whereas dominant and intermediate trees were delayed and stopped in November. The periodic monthly increment curve showed double peaks, and the maximum growth rate occurred in April and August. The peak values were affected by social status, which showed that dominant trees had the greatest radial growth rates. S-shaped Gompertz meant that monthly increment models were successfully fitted to our data, which explained more than 98% of the variation in increment data and passed the uncertainty test. Temperature and precipitation had a significant influence on radial growth, and the correlation between radial growth and air temperature was the highest. Our results also revealed that temperatures explain the double-peak features of Chinese fir. The limiting factors of radial growth changed with the seasons and were mainly affected by temperature and precipitation, which should be considered in predicting the response of tree growth to climate change.

scholarly journals Characterization of western spruce budworm outbreak regions in the British Columbia Interior

2018 ◽  
Vol 48 (7) ◽  
pp. 783-802 ◽  
Author(s):  
Lorraine E. Maclauchlan ◽  
Lori D. Daniels ◽  
Janice C. Hodge ◽  
Julie E. Brooks
Keyword(s):  
British Columbia ◽  
Spruce Budworm ◽  
Growth Suppression ◽  
Douglas Fir ◽  
Western North America ◽  
Western Spruce Budworm ◽  
The North ◽  
South Central ◽  
Ecosystem Classification

The western spruce budworm (WSB; Choristoneura freemani Razowski) shapes Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) forests throughout western North America with periodic, severe landscape-level defoliation events. The largest and most continuous recorded defoliation occurred in the 2000s, largely centered in the Williams Lake and 100 Mile House WSB outbreak regions, peaking in 2007 at 847 000 ha defoliated in British Columbia (B.C.). Unique WSB outbreak regions in south-central B.C. are described using biogeoclimatic ecosystem classification, geography, 106 years of documented defoliation, and 46 stand-level Douglas-fir host tree-ring chronologies. Since the 1980s, recorded defoliation in B.C. has shifted from coastal ecosystems and become a dominant disturbance in drier, colder, interior Douglas-fir ecosystems. Defoliation records demarcate four outbreaks from 1950–2012 and up to three growth suppression events from 1937–2012. Outbreak duration was shorter in the north and far south of B.C., with recovery periods (no trees showing growth suppression) shorter over all WSB outbreak regions in the 2000s, suggesting that trees may be increasingly susceptible to each successive defoliation event. Knowing the regional outbreak periodicity may facilitate early detection of incipient WSB populations, which is critical for management as many of our low-elevation Douglas-fir forests become more stressed with changing and unpredictable climate regimes.

Mixed-severity fire regimes in dry forests of southern interior British Columbia, Canada

2012 ◽  
Vol 42 (1) ◽  
pp. 88-98 ◽  
Author(s):  
Emily K. Heyerdahl ◽  
Ken Lertzman ◽  
Carmen M. Wong
Keyword(s):  
British Columbia ◽  
Ponderosa Pine ◽  
Fire Regime ◽  
Fire Severity ◽  
Fire Regimes ◽  
Douglas Fir ◽  
Dry Forests ◽  
Ponderosa Pine Forests ◽  
Fire Scar ◽  
High Severity

Historical fire severity is poorly characterized for dry forests in the interior west of North America. We inferred a multicentury history of fire severity from tree rings in Douglas-fir ( Pseudotsuga menziesii var. glauca (Beissn.) Franco) – ponderosa pine ( Pinus ponderosa Douglas ex P. Lawson & C. Lawson) forests in the southern interior of British Columbia, Canada. In 2 ha plots distributed systematically over 1105 ha, we determined the dates of fire scars, indicators of low-severity fire, from 125 trees and inferred dates of even-aged cohorts, potential indicators of high-severity fire, from establishment dates of 1270 trees. Most (76%) of the 41 plots contained fire-scarred trees with a mean plot-composite fire scar interval of 21 years (1700–1900). Most (76%) also contained one or two cohorts. At the plot scale, we inferred that the fire regime at most plots was of mixed severity through time (66%) and at the remaining plots of low (20%), high (10%), or unknown (4%) severity through time. We suggest that across our study area, the fire regime was mixed severity over the past several centuries, with low-severity fires most common and often extensive but small, high-severity disturbances also occasionally occurred. Our results present strong evidence for the importance of mixed-severity fire regimes in which low-severity fires dominate in interior Douglas-fir – ponderosa pine forests in western Canada.

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