Some climatic aspects of biomass productivity of white spruce stem wood

1987 ◽  
Vol 17 (9) ◽  
pp. 1075-1079 ◽  
Author(s):  
L. A. Jozsa ◽  
J. M. Powell

Biomass productivity was determined for white spruce (Piceaglauca (Moench) Voss) in the boreal forests of Alberta, the Northwest Territories, and Manitoba. Comparisons were made between southern and northern locations, between eastern and western transect locations, and between older (200 + years) and younger (110 years) trees. At 13 sampling locations, X-ray densitometric tree ring data were obtained from the base of the stem, breast height, and from five points equidistant along the stem. Markedly higher stem wood biomass productivity was found for the 110-year-old trees than for the 210-year-old trees in Alberta; average ring weights were 3.8 and 1.2 g for the first 100 years of growth in 1 cm thick disks at breast height. These results suggest that climatic warming since the end of the Little Ice Age (ca. 1850) has resulted in higher biomass productivity in the Canadian boreal forest.

1988 ◽  
Vol 18 (9) ◽  
pp. 1182-1185 ◽  
Author(s):  
Josefina S. Gonzalez ◽  
Jane Richards

Selection age for wood density in vigorous coastal Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) was determined by examining the following: strength of the correlation between total-stem wood density of 50-year-old trees and their breast-height density when the trees were 5 through 30 years old (breast-height age); efficiency in terms of gain per year of tree improvement effort by selecting at ages 5 through 30, relative to selecting at age 50. The linear regression and rank correlation between total-stem and breast-height densities improved as age increased from 5 to 15 years, but showed no significant improvement from 15 to 30 years. Densities of early-growth rings fluctuated considerably and their exclusion from the calculation of breast-height density enhanced the linear regression with total-stem density. Efficiency estimates in terms of gain per year showed an optimum value at age 15, but the estimates for ages 10–14 were nearly as efficient.


2004 ◽  
Vol 34 (7) ◽  
pp. 1538-1542 ◽  
Author(s):  
Heidi Steltzer

Soil carbon (C) and nitrogen (N) pools were measured under the canopy of 29 white spruce (Picea glauca (Moench) Voss) trees and in the surrounding tundra 3 and 6 m away from each tree at three sites of recent forest expansion along the Agashashok River in northwestern Alaska. The aim was to characterize the potential for forest expansion to lead to increased soil C pools across diverse tundra types. Soil C beneath the trees correlated positively with tree age, suggesting that tree establishment has led to C storage in the soils under their canopy at a rate of 18.5 ± 4.6 g C·m–2·year–1. Soil C in the surrounding tundra did not differ from those under the trees and showed no relationship to tree age. This characterization of the soil C pools at the 3-m scale strengthens the assertion that the pattern associated with the trees is an effect of the trees, because tree age cannot explain variation among tundra sampling locations at this scale. Potential mechanisms by which these white spruce trees could increase soil C pools include greater production and lower litter quality.


2016 ◽  
Vol 12 (7) ◽  
pp. 1485-1498 ◽  
Author(s):  
Liangjun Zhu ◽  
Yuandong Zhang ◽  
Zongshan Li ◽  
Binde Guo ◽  
Xiaochun Wang

Abstract. We present a reconstruction of July–August mean maximum temperature variability based on a chronology of tree-ring widths over the period AD 1646–2013 in the northern part of the northwestern Sichuan Plateau (NWSP), China. A regression model explains 37.1 % of the variance of July–August mean maximum temperature during the calibration period from 1954 to 2012. Compared with nearby temperature reconstructions and gridded land surface temperature data, our temperature reconstruction had high spatial representativeness. Seven major cold periods were identified (1708–1711, 1765–1769, 1818–1821, 1824–1828, 1832–1836, 1839–1842, and 1869–1877), and three major warm periods occurred in 1655–1668, 1719–1730, and 1858–1859 from this reconstruction. The typical Little Ice Age climate can also be well represented in our reconstruction and clearly ended with climatic amelioration at the late of the 19th century. The 17th and 19th centuries were cold with more extreme cold years, while the 18th and 20th centuries were warm with less extreme cold years. Moreover, the 20th century rapid warming was not obvious in the NWSP mean maximum temperature reconstruction, which implied that mean maximum temperature might play an important and different role in global change as unique temperature indicators. Multi-taper method (MTM) spectral analysis revealed significant periodicities of 170-, 49–114-, 25–32-, 5.7-, 4.6–4.7-, 3.0–3.1-, 2.5-, and 2.1–2.3-year quasi-cycles at a 95 % confidence level in our reconstruction. Overall, the mean maximum temperature variability in the NWSP may be associated with global land–sea atmospheric circulation (e.g., ENSO, PDO, or AMO) as well as solar and volcanic forcing.


2008 ◽  
Vol 54 (184) ◽  
pp. 125-130 ◽  
Author(s):  
Satoru Yamaguchi ◽  
Renji Naruse ◽  
Takayuki Shiraiwa

AbstractBased on the field data at Koryto glacier, Kamchatka Peninsula, Russia, we constructed a one-dimensional numerical glacier model which fits the behaviour of the glacier. The analysis of meteorological data from the nearby station suggests that the recent rapid retreat of the glacier since the mid-20th century is likely to be due to a decrease in winter precipitation. Using the geographical data of the glacier terminus variations from 1711 to 1930, we reconstructed the fluctuation in the equilibrium-line altitude by means of the glacier model. With summer temperatures inferred from tree-ring data, the model suggests that the winter precipitation from the mid-19th to the early 20th century was about 10% less than that at present. This trend is close to consistent with ice-core results from the nearby ice cap in the central Kamchatka Peninsula.


1981 ◽  
Vol 57 (4) ◽  
pp. 169-173 ◽  
Author(s):  
I. S. Alemdag ◽  
K. W. Horton

Ovendry mass of single trees of trembling aspen, largetooth aspen, and white birch in the Great Lakes — St. Lawrence and Boreal forest regions in Ontario was studied in relation to stem dimensions. Mass equations for tree components based on diameter at breast height outside bark and tree height were developed. Results were found more dependable for stem wood and the whole tree than for stem bark, live branches, and twigs plus leaves. Ovendry mass values were slightly higher than those reported for New York and northern Minnesota.


2010 ◽  
Vol 34 (2) ◽  
pp. 84-90 ◽  
Author(s):  
Michael J. Aspinwall ◽  
Bailian Li ◽  
Steven E. McKeand ◽  
Fikret Isik ◽  
Marcia L. Gumpertz

Abstract Models were developed for predicting whole-stem α-cellulose yield, lignin content, and wood density in 14- and 20-year-old loblolly pine across three different sites. Also, the relationships between juvenile-, transition-, and mature-wood α-cellulose yield, lignin content, and wood density at breast-height and overall whole-stem wood property values were examined. Whole-stem wood property weighted averages were calculated by taking 12-mm core samples at breast height and at 2.4-m incremental heights up each tree, and breast-height wood property values were then used to predict whole-stem weighted averages. Despite large differences in growth across sites and both ages, whole-stem models based on whole cores taken at breast height were not significantly different among sites, and coefficients of determination (R2) were 0.87, 0.74, and 0.78 for α-cellulose, lignin, and wood density, respectively. Generally, whole-stem prediction models based on sections of wood at breast height were not significantly different among sites and were less effective than cores as predictors, explaining between 39 and 82% of the variation in whole-stem wood traits. The results of this study indicate that the relationship between breast height and whole-stem wood chemical properties (and density) is predictable and consistent across sites in both juvenile and mature loblolly pine.


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.


Forests ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 1002
Author(s):  
Rafael M. Navarro-Cerrillo ◽  
Antonio Gazol ◽  
Carlos Rodríguez-Vallejo ◽  
Rubén D. Manzanedo ◽  
Guillermo Palacios-Rodríguez ◽  
...  

Systematic forest networks of health monitoring have been established to follow changes in tree vigor and mortality. These networks often lack long-term growth data, but they could be complemented with tree ring data, since both defoliation and radial growth are proxies of changes in tree vigor. For instance, a severe water shortage should reduce growth and increase tree defoliation in drought-prone areas. However, the effects of climatic stress and drought on growth and defoliation could also depend on tree age. To address these issues, we compared growth and defoliation data with recent climate variability and drought severity in Abies pinsapo old and young trees sampled in Southern Spain, where a systematic health network (Andalucía Permanent Plot Network) was established. Our aims were: (i) to assess the growth sensitivity of old and young A. pinsapo trees and (ii) to test if relative changes in radial growth were related with recent defoliation, for instance, after severe droughts. We also computed the resilience indices to quantify how old and young trees recovered growth after recent droughts. Wet-cool conditions during the prior autumn and the current early summer improved the growth of old trees, whereas late-spring wet conditions enhanced the growth of young trees. Old trees were more sensitive to wet and sunny conditions in the early summer than young trees. Old and young trees were more responsive to the Standardized Precipitation-Evapotranspiration Index drought index of June–July and July–August calculated at short (one–three months) and mid (three–six months) time scales, respectively. Old trees presented a higher resistance to a severe drought in 1995 than young trees. A positive association was found between stand defoliation and relative growth. Combining monitoring and tree ring networks is useful for the detection of early warning signals of dieback in similar drought-prone forests.


1993 ◽  
Vol 23 (5) ◽  
pp. 846-853 ◽  
Author(s):  
D.C. West ◽  
T.W. Doyle ◽  
M.L. Tharp ◽  
J.J. Beauchamp ◽  
W.J. Platt ◽  
...  

Longleaf pine (Pinuspalustris Mill.) tree-ring data were obtained from an old-growth stand located in Thomas County, Georgia. The tree-ring chronology from the pine stand is composed of a collection of cores extracted from 26 trees ranging in age from approximately 100 to 400 years. These cores were prepared, dated, and measured, and the resulting data were examined with dendrochronological and statistical techniques. Beginning in approximately 1950 and continuing to the present, annual increments of all age classes examined in this study have increased, resulting in an average annual ring increment approximately 40% greater in 1987 than in 1950. When compared with expected annual increment, the increase for 100- to 150-year-old trees is approximately 45%, while the increase for 200- to 400-year-old trees is approximately 35%. In terms of stand-level aboveground biomass accumulation, the increased growth has resulted in approximately 5% more biomass than expected. The increased growth cannot be explained by disturbance; stand history; or trends in precipitation, temperature, or Palmer drought severity index over the last 57 years. Increased atmospheric CO2 is a possible explanation for initiation of the observed trend, while SOx and NOx may be augmenting continuation of this phenomenon.


1996 ◽  
Vol 28 (4) ◽  
pp. 315-330 ◽  
Author(s):  
Håkon Holien

AbstractThe distribution of crustose Caliciales has been surveyed in 100 spruce forest patches in Sør-Trøndelag, central Norway. Relationships between occurrence of the species and a number of site and stand variables were analysed by detrended correspondence analysis (DCA) and direct gradient analysis. Species diversity7 was significantly higher in old forests and in forests at higher altitudes compared to young forests and forests at lower altitudes. Old trees and snags are considered to be the most important structural components in old forests promoting species diversity of the Caliciales. Threatened or vulnerable species, such as Chaenotheca gracilliina, Cybebe gracilenta, Sclerophora coniophaea and S. peronella were confined to forest on rich soils showing no correlation with forest stand age. Chaenotheca brachypoda and C. trichialis were found to be the most typical old forest species among the Caliciales. Humidiphilous species are considered to be less affected by forestry in a humid climate. A change in forestry practice towards methods imitating the natural dynamic processes is considered necessary to maintain species diversity of the Caliciales in boreal forests.


Sign in / Sign up

Export Citation Format

Share Document