The dendroclimatic signal in Douglas-fir and ponderosa pine tree-ring chronologies from the southern Canadian Cordillera

2002 ◽  
Vol 32 (10) ◽  
pp. 1858-1874 ◽  
Author(s):  
Emma Watson ◽  
Brian H Luckman
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Ring Width ◽  
Summer Precipitation ◽  
Severity Index ◽  
Early Summer ◽  
Douglas Fir ◽  
Drought Severity ◽  
Canadian Cordillera ◽  
Pine Tree

A network of 53 ring-width chronologies has been developed from low-elevation stands of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco, n = 40) and ponderosa pine (Pinus ponderosa Dougl. ex P. & C. Laws., n = 13) in the southern Canadian Cordillera. Relationships between the chronologies and monthly, seasonal, and annualized climatic parameters (precipitation, temperature, and Palmer Drought Severity Index (PDSI)) were investigated using correlation analyses. The results indicate that tree growth at the sites is most strongly related to water availability during the growing season months. Although the response of the two species is similar, Douglas-fir show a slightly stronger correlation with seasonalized precipitation for the prior year and early summer whereas ponderosa pine correlate most strongly with current year and late (July) summer precipitation. Maximum correlations for both species occur with annual precipitation totals. The precipitation signal is slightly weaker in the more northerly Douglas-fir chronologies in British Columbia and the higher elevation sites in southwestern Alberta. Correlations with available PDSI records are generally comparable with those from precipitation variables, but the limited number of PDSI records and the availability of more proximal and better correlated precipitation records indicated that annual (summer–summer) precipitation totals provide the best possibilities to develop regional, moisture-related proxy climate records from these data. Analysis of earlywood and latewood chronologies for 28 sites (mainly Douglas-fir) indicates that earlywood width is most consistently and strongly correlated with precipitation in the previous summer (July and August), and latewood width is more strongly related to precipitation in the current summer (June and July). The results of these analyses demonstrate considerable potential for reconstructing annual (and (or) summer) precipitation for sites across the region.

scholarly journals Inferred summer precipitation for southern Ontario back to AD 610, as reconstructed from ring widths of Thuja occidentalis

2004 ◽  
Vol 34 (12) ◽  
pp. 2541-2553 ◽  
Author(s):  
Brendan M Buckley ◽  
Robert JS Wilson ◽  
Peter E Kelly ◽  
Douglas W Larson ◽  
Edward R Cook
Keyword(s):  
Time Scales ◽  
Ring Width ◽  
Principal Component Regression ◽  
Principal Component ◽  
Summer Precipitation ◽  
Severity Index ◽  
Drought Severity ◽  
Southern Ontario ◽  
Thuja Occidentalis ◽  
Decadal Scale

We present a network of seven ring-width chronologies of eastern white-cedar (Thuja occidentalis L.) from the Niagara Escarpment in southern Ontario, Canada. Using principal component regression, a 350-year June-July precipitation reconstruction (SOR) is developed for the region. Prior to the 20th century, the SOR series shows reasonable coherence, particularly at the decadal scale, with an independent tree-ring-based reconstruction of the Palmer drought severity index (PDSI) for roughly the same region. A weakening of the tree-growth – climate relationship in recent decades results in a regression model explaining 21% of the variance in the original climate series when the recent data are used for calibration. We therefore compromise with a model, calibrated for the period 1900–1960, which explains 33% of the variance. The model, while not terribly strong, does pass verification tests, indicating some degree of predictive skill. The longest chronology in our network, the 2787-year Flowerpot Island (FLOW) chronology, also exhibits common variability with the PDSI reconstruction, particularly on decadal and longer time scales and was used to infer hydroclimatic conditions back to AD 610. The combined information of the SOR, PDSI, and FLOW series suggests that dry conditions existed for the periods 1700–1725, 1750–1800, and 1840–1900, and wet conditions for the periods 1675–1700, 1730–1750, and 1810–1840. Over longer time scales, the FLOW chronology shows that summer precipitation was particularly variable during the 7th, 9th, 13th, and 16th centuries.

A field experiment informs expected patterns of conifer regeneration after disturbance under changing climate conditions

2015 ◽  
Vol 45 (11) ◽  
pp. 1607-1616 ◽  
Author(s):  
Monica T. Rother ◽  
Thomas T. Veblen ◽  
Luke G. Furman
Keyword(s):  
Field Experiment ◽  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Douglas Fir ◽  
Tree Regeneration ◽  
Colorado Front Range ◽  
Front Range ◽  
Average Growth ◽  
Growth And Survival ◽  
Treatment Type

Climate change may inhibit tree regeneration following disturbances such as wildfire, altering post-disturbance vegetation trajectories. We implemented a field experiment to examine the effects of manipulations of temperature and water on ponderosa pine (Pinus ponderosa Douglas ex P. Lawson & C. Lawson) and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings planted in a low-elevation, recently disturbed setting of the Colorado Front Range. We implemented four treatments: warmed only (Wm), watered only (Wt), warmed and watered (WmWt), and control (Co). We found that measures of growth and survival varied significantly by treatment type. Average growth and survival was highest in the Wt plots, followed by the Co, WmWt, and Wm plots, respectively. This general trend was observed for both conifer species, although average growth and survival was generally higher in ponderosa pine than in Douglas-fir. Our findings suggest that warming temperatures and associated drought are likely to inhibit post-disturbance regeneration of ponderosa pine and Douglas-fir in low-elevation forests of the Colorado Front Range and that future vegetation composition and structure may differ notably from historic patterns in some areas. Our findings are relevant to other forested ecosystems in which a warming climate may similarly inhibit regeneration by dominant tree species.

scholarly journals An 854-Year Tree-Ring Chronology of Scots Pine for South-West Finland

2014 ◽  
Vol 31 (1) ◽  
pp. 61-68 ◽  
Author(s):  
Samuli Helama ◽  
Jari Holopainen ◽  
Mauri Timonen ◽  
Kari Mielikäinen
Keyword(s):  
Tree Ring ◽  
Ring Width ◽  
Summer Precipitation ◽  
Total Sample ◽  
Early Summer ◽  
The South ◽  
Tree Ring Chronology ◽  
The North ◽  
South West ◽  
The North Atlantic Oscillation

Abstract A near-millennial tree-ring chronology (AD 1147-2000) is presented for south-west Finland and analyzed using dendroclimatic methods. This is a composite chronology comprising samples both from standing pine trees (Pinus sylvestris L.) and subfossil trunks as recovered from the lake sediments, with a total sample size of 189 tree-ring sample series. The series were dendrochronologically cross-dated to exact calendar years to portray variability in tree-ring widths on inter-annual and longer scales. Al though the studied chronology correlates statistically significantly with other long tree-ring width chronologies from Finland over their common period (AD 1520-1993), the south-west chronology did not exhibit similarly strong mid-summer temperature or spring/early-summer precipitation signals in comparison to published chronologies. On the other hand, the south-west chronology showed highest correlations to the North Atlantic Oscillation indices in winter/spring months, this association following a dendroclimatic feature common to pine chronologies over the region and adjacent areas. Paleoclimatic comparison showed that tree-rings had varied similarly to central European spring temperatures. It is postulated that the collected and dated tree-ring material could be studied for wood surface reflectance (blue channel light intensity) and stable isotopes, which both have recently shown to correlate notably well with summer temperatures.

scholarly journals Root Volume and Growth of Ponderosa Pine and Douglas-Fir Seedlings: A Summary of Eight Growing Seasons

1997 ◽  
Vol 12 (3) ◽  
pp. 69-73 ◽  
Author(s):  
R. Rose ◽  
D. L. Haase ◽  
F. Kroiher ◽  
T. Sabin
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Douglas Fir ◽  
Stem Volume ◽  
Coast Range ◽  
Root Volume ◽  
Growth And Survival ◽  
Growing Seasons ◽  
Early Results

Abstract This is the final summary of two studies on the relationship between root volume and seedling growth; early results were published previously. Survival, growth, and stem volume were determined for 2+0 ponderosa pine (Pinus ponderosa) and Douglas-fir (Pseudotsuga menziesii) seedlings after 8 growing seasons. For each species, seedlings from three seedlots were assigned to one of three root-volume categories [<4.5 cm3 (RV1), 4.5-7 cm3 (RV2), and >7 cm3 (RV3) for ponderosa pine; <9 cm3 (RV1), 9-13 cm3 (RV2), and >13 cm3 (RV3) for Douglas-fir]. On a dry harsh ponderosa pine site on the eastern slopes of Mt. Hood in Oregon, where gopher and cattle damage decreased the number of seedlings, more seedlings in the highest root-volume category survived (70%) than in the smaller root-volume categories (62% and 50%). Douglas-fir on a good site in the Coast Range of Oregon showed significantly greater height and stem volume for the largest root-volume category, whereas annual shoot growth and survival did not differ. Root volume is one of several potentially useful criteria for predicting long-term growth and survival after outplanting. West. J. Appl. For. 12(3):69-73.

Diversity and host specificity of ectomycorrhizal fungi retrieved from three adjacent forest sites by five host species

1999 ◽  
Vol 77 (8) ◽  
pp. 1053-1076 ◽  
Author(s):  
H B Massicotte ◽  
R Molina ◽  
L E Tackaberry ◽  
J E Smith ◽  
M P Amaranthus
Keyword(s):  
Pseudotsuga Menziesii ◽  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Host Species ◽  
Ectomycorrhizal Fungus ◽  
Douglas Fir ◽  
Abies Grandis ◽  
Forest Sites ◽  
Fungal Propagules ◽  
Arbutus Menziesii

Seedlings of Abies grandis (Dougl.) Lindl. (grand fir), Lithocarpus densiflora (Hook. & Arn.) Rehd. (tanoak), Pinus ponderosa Dougl. ex Laws. (ponderosa pine), Pseudotsuga menziesii (Mirb.) Franco (Douglas-fir), and Arbutus menziesii Pursh (madrone) were planted in mixture and monoculture in soil collected from three adjacent forest sites in southwestern Oregon (a clearcut area, a 25-year-old Douglas-fir plantation, and a mature 90- to 160-year-old Douglas-fir - pine forest) to determine the effect of host tree diversity on retrieval of ectomycorrhizal morphotypes. In this greenhouse bioassay, 18 morphotypes of mycorrhizae were recognized overall from all soils with a total of 55 host-fungus combinations: 14 types with ponderosa pine, 14 with Douglas-fir, 10 with tanoak, 10 with grand fir, and 7 for madrone. Four genus-specific morphotypes were retrieved (three on ponderosa pine and one on Douglas-fir), even in mixture situations, demonstrating selectivity of some fungal propagules by their respective host. Five types were detected on all hosts, but not necessarily in soils from all sites. The remaining nine types were associated with two, three, or four hosts, which indicates a wide potential for interspecific hyphal linkages between trees. More morphotypes were retrieved from the monoculture treatments compared with the mixture treatments, although the differences were not significant. Several examples of acropetal replacement of one fungus by another (interpreted as succession) were recorded on all hosts during the course of the experiment. These results illustrate the importance of different host species in maintaining ectomycorrhizal fungus diversity, especially fungi with restricted host range, and the strong potential for fungal linkages between trees in forest ecosystems.Key words: fungal succession, fungal communities, compatibility, Arbutus menziesii, Pseudotsuga menziesii, Pinus ponderosa, Abies grandis, Lithocarpus densiflora.

Effects of fuel morphology on ember generation characteristics at the tree scale

2020 ◽  
Vol 29 (11) ◽  
pp. 1042
Author(s):  
Tyler R. Hudson ◽  
Ryan B. Bray ◽  
David L. Blunck ◽  
Wesley Page ◽  
Bret Butler
Keyword(s):  
Mass Loss ◽  
Pseudotsuga Menziesii ◽  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Douglas Fir ◽  
Biological Factors ◽  
Abies Grandis ◽  
Western Juniper ◽  
Juniperus Occidentalis ◽  
Spot Fires

This work reports characteristics of embers generated by torching trees and seeks to identify the important physical and biological factors involved. The size of embers, number flux and propensity to ignite spot fires (i.e. number flux of ‘hot’ embers) are reported for several tree species under different combinations of number (one, three or five) and moisture content (11–193%). Douglas-fir (Pseudotsuga menziesii), grand fir (Abies grandis), western juniper (Juniperus occidentalis) and ponderosa pine (Pinus ponderosa) trees were evaluated. Embers were collected on an array of fire-resistant fabric panels and trays filled with water. Douglas-fir trees generated the highest average ember flux per kilogram of mass loss during torching, whereas grand fir trees generated the highest ‘hot’ ember flux per kilogram of mass loss. Western juniper produced the largest fraction of ‘hot’ embers, with ~30% of the embers generated being hot enough to leave char marks. In contrast, only 6% of the embers generated by ponderosa pine were hot enough to leave char marks. Results from this study can be used to help understand the propensity of different species of tree to produce embers and the portion of embers that may be hot enough to start a spot fire.

scholarly journals A 424-year tree-ring-based Palmer Drought Severity Index reconstruction of <i>Cedrus deodara</i> D. Don from the Hindu Kush range of Pakistan: linkages to ocean oscillations

2020 ◽  
Vol 16 (2) ◽  
pp. 783-798
Author(s):  
Sarir Ahmad ◽  
Liangjun Zhu ◽  
Sumaira Yasmeen ◽  
Yuandong Zhang ◽  
Zongshan Li ◽  
...  
Keyword(s):  
Tree Ring ◽  
Palmer Drought Severity Index ◽  
Southern Oscillation ◽  
Ring Width ◽  
Severity Index ◽  
Drought Severity ◽  
Mountain Range ◽  
Cedrus Deodara ◽  
Hindu Kush ◽  
Drought Severity Index

Abstract. The rate of global warming has led to persistent drought. It is considered to be the preliminary factor affecting socioeconomic development under the background of the dynamic forecasting of the water supply and forest ecosystems in West Asia. However, long-term climate records in the semiarid Hindu Kush range are seriously lacking. Therefore, we developed a new tree-ring width chronology of Cedrus deodara spanning the period of 1537–2017. We reconstructed the March–August Palmer Drought Severity Index (PDSI) for the past 424 years, going back to 1593 CE. Our reconstruction featured nine dry periods (1593–1598, 1602–1608, 1631–1645, 1647–1660, 1756–1765, 1785–1800, 1870–1878, 1917–1923, and 1981–1995) and eight wet periods (1663–1675, 1687–1708, 1771–1773, 1806–1814, 1844–1852, 1932–1935, 1965–1969, and 1990–1999). This reconstruction is consistent with other dendroclimatic reconstructions in West Asia, thereby confirming its reliability. The multi-taper method and wavelet analysis revealed drought variability at periodicities of 2.1–2.4, 3.3, 6.0, 16.8, and 34.0–38.0 years. The drought patterns could be linked to the large-scale atmospheric–oceanic variability, such as the El Niño–Southern Oscillation, Atlantic Multidecadal Oscillation, and solar activity. In terms of current climate conditions, our findings have important implications for developing drought-resistant policies in communities on the fringes of the Hindu Kush mountain range in northern Pakistan.

Seasonal and diurnal trends of heat pulse velocity in Douglas-fir and ponderosa pine

1986 ◽  
Vol 16 (4) ◽  
pp. 814-821 ◽  
Author(s):  
W. Lopushinsky
Keyword(s):  
Soil Moisture ◽  
Ponderosa Pine ◽  
Heat Pulse ◽  
Pulse Velocity ◽  
Early Summer ◽  
Douglas Fir ◽  
Evaporative Demand ◽  
Maximum Heat ◽  
Weather Patterns ◽  
Summer Maximum

Seasonal trends of heat pulse velocity in the trunks of 55-year-old ponderosa pine (Pinusponderosa Dougl. ex Laws.) and Douglas-fir (Pseudotsugamenziesii var. glauca (Beissn.) Franco) trees showed large yearly variations related to weather patterns. Onset of sap movement in the spring, seasonal variations, and summer declines in response to decreasing moisture were similar for Douglas-fir and ponderosa pine. When soil moisture was not limiting, rates of heat pulse velocity in both species were significantly related to air temperature, solar radiation, and vapor pressure deficit. As soil moisture decreased during the summer, rates of heat pulse velocity no longer followed evaporative demand. In both species, sap movement also occurred at night. Diurnal trends of heat pulse velocity also were similar in both species. During early summer, maximum heat pulse velocity occurred at midday; in the fall, maximum rates occurred earlier. The similarity of seasonal and diurnal trends of heat pulse velocity and responses to variation in site conditions suggest that on the site studied, transpiration behavior in ponderosa pine and Douglas-fir trees generally is similar.

Conifer seed predation in harvested and burned dry Douglas-fir forests in southern British Columbia

2009 ◽  
Vol 39 (8) ◽  
pp. 1548-1556 ◽  
Author(s):  
David J. Huggard ◽  
André Arsenault
Keyword(s):  
Pinus Ponderosa ◽  
Seed Predation ◽  
Ponderosa Pine ◽  
Natural Regeneration ◽  
Woody Debris ◽  
Survival Rates ◽  
Forest Litter ◽  
Douglas Fir ◽  
Burned Area ◽  
Clear Cut

Consumption of seeds of Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco) and ponderosa pine ( Pinus ponderosa Dougl. ex P. & C. Laws.) was measured in dry Douglas-fir forest at the Opax Mountain Silvicultural Systems site and a nearby burned area as one component of understanding limited natural regeneration in these sites. Seeds were placed in plots surrounded by a physical barrier to invertebrates, enclosed in mesh impermeable to small mammals, covered by litter, or unprotected in clear-cut, partially harvested, uncut, and burned areas and monitored for three several-day sessions in 2 years. Daily survival rates of unprotected seeds of both species were equally low: 0.63 in uncut forest, 0.45 in partially harvested and clear-cut sites, and 0.03 in the burned area. Experimental reductions of coarse woody debris reduced seed predation moderately in patch cuts but not in uncut forest. Litter cover or selective exclosure of ground-dwelling invertebrates reduced seed losses only slightly, whereas small mammal exclosures eliminated most seed loss. Deer mice ( Peromyscus maniculatus Wagner) are likely the most important seed predators. High rates of seed predation in dry Douglas-fir forests likely limit natural regeneration in harvested and burned stands.

scholarly journals Moisture and Temperature Covariability over the Southeastern Tibetan Plateau during the Past Nine Centuries

2020 ◽  
Vol 33 (15) ◽  
pp. 6583-6598
Author(s):  
Jianglin Wang ◽  
Bao Yang ◽  
Fredrik Charpentier Ljungqvist
Keyword(s):  
Tibetan Plateau ◽  
Climate Model ◽  
Severity Index ◽  
Early Summer ◽  
Convective Precipitation ◽  
Drought Severity ◽  
The Tibetan Plateau ◽  
Low Frequencies ◽  
The Past ◽  
Spatial Coverage

AbstractAccurate projections of moisture variability across the Tibetan Plateau (TP) are crucial for managing regional water resources, ecosystems, and agriculture in densely populated downstream regions. Our understanding of how moisture conditions respond to increasing temperatures over the TP is still limited, due to the short length of instrumental data and the limited spatial coverage of high-resolution paleoclimate proxy records in this region. This study presents a new, early-summer (May–June) self-calibrating Palmer drought severity index (scPDSI) reconstruction for the southeastern TP (SETP) covering 1135–2010 CE using 14 tree-ring records based on 1669 individual width sample series. The new reconstruction reveals that the SETP experienced the longest period of pluvial conditions in 1154–75 CE, and the longest droughts during the periods 1262–80 and 1958–76 CE. The scPDSI reconstruction shows stable and significant in-phase relationships with temperature at both high and low frequencies throughout the past 900 years. This supports the hypothesis that climatic warming may increase moisture by enhancing moisture recycling and convective precipitation over the SETP; it is also consistent with climate model projections of wetter conditions by the late twenty-first century in response to global warming.

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