Characterization of nutrient regimes in some continental subalpine boreal forest soils

1998 ◽  
Vol 78 (3) ◽  
pp. 467-475 ◽  
Author(s):  
H. Y. H. Chen ◽  
K. Klinka ◽  
J. Fons ◽  
P. V. Krestov

To determine whether field-identified soil nutrient regimes (SNRs) can be characterized and segregated by direct soil nutrient measures, we collected samples of forest floor and mineral soil (0 to 30 cm) from a wide range of forest sites throughout the Engelmann Spruce — Subalpine Fir (ESSF) zone of British Columbia. The samples were analyzed for acidity, total C, total N, mineralizable N, and extractable Ca, Mg, K, P, and SO4-S. The study sites were stratified according to an a priori field classification (SNRs) and an a posteriori classification derived from quantitative classification (groups) using all direct measures of nutrients as discriminating variables. The two classification methods had 72% agreement. Regardless of the classification, nitrogen-related variables (C:N ratio, total N, and mineralizable N) in the mineral soil segregated best among SNRs or groups indicating the presence of a steep, N-driven regional soil nutrient gradient. Multiple regression models using SNRs, groups, or direct measures of nutrients together with surrogates of climate (elevation, latitude, and/or longitude) as predictors had the similar accountability for the variation in subalpine fir and Engelmann spruce site index (0.41 ≤ R2 ≤ 0.65). The similarity in the accountability for site index justifies the use of the a priori classification in estimating site quality. Comparison of mineralizable-N values for field-identified SNRs between different climatic regions showed similarities between boreal climates and discrepancies between boreal and cool mesothermal climates. The study gave further evidence that indices of plant-available nitrogen in the upper mineral soil provide useful measures for field-identified SNRs, but indicated that it may be necessary to expand the existing five-class a priori classification to accommodate differences in regional soil nutrient gradients. Key words: Classification, Engelmann spruce, subalpine fir, nitrogen, site index, soil nutrient regime

1994 ◽  
Vol 74 (1) ◽  
pp. 29-38 ◽  
Author(s):  
Karel Klinka ◽  
Gordon J. Kayahara ◽  
Qingli Wang

In order to assess to what extent soil nutrient properties support differentiation of field-identified soil nutrient regimes, composite samples from each forest floor and 0–30 cm of the mineral soil were collected from 116 forest stands in central British Columbia. The samples were analyzed for acidity, total carbon (tC), total nitrogen (tN), mineralizable-N (min-N), and extractable Ca, Mg, K, P, and SO4-S (eCa, eMg, eK, eP, eSO4); and the results were expressed as concentrations on a dry-mass basis. Mineralizable-N of the mineral soil showed (1) the largest amount of variation in the population of sampled soils, (2) significant differences (P < 0.01) among field-identified soil nutrient regimes, and (3) strong correlations with tC, tN, and eCa, eMg, and eK. Using mineral soil min-N as a differentiating characteristic, the following limiting values (mg kg−1) were proposed to provide an objective means of defining soil nutrient regimes: < 2 for very poor, 2–8.9 for poor, 9–27.4 for medium, 27.5–110 for rich, and > 110 for very rich. Site index (height at 50 yr breast height age) of lodge-pole pine (Pinus contorta Dougl. ex Loud) and interior spruce [Picea engelmannii Parry ex Engelmann × P. glauca (Moench) Voss] increased from very poor to very rich soils; however, the differences among site indices of contiguous soil nutrient regimes were largely insignificant. Regression analysis indicated that (1) soil moisture accounts for the largest proportion of the variation in site index, (2) models using C:N ratio of the forest floor and 0–30 cm of the mineral soil had a stronger relationship with site index (0.38 ≤ R2 ≤ 0.43, standard error < 3.0 m) than those using min-N. These results gave further evidence that min-N in the 0–30 mineral soil is a good single measure representing soil nutrient conditions, and justify the use of the existing field procedure for estimating soil nutrient regimes in montane boreal soils. Key words: Boreal soils, soil nutrient regime, quantitative classification, mineralizable-N, site index


1980 ◽  
Vol 56 (2) ◽  
pp. 55-57 ◽  
Author(s):  
L. J. Herring ◽  
R. G. McMinn

The mean height of Engelmann spruce (Picea engelmanni Parry) advance growth 21 years after release by overstorey harvesting and residual tree felling, was eight times that of natural regeneration established following brush blade scarification. Subalpine fir (Abies lasiocarpa (Hook.) Nutt.) advance growth was nine times taller than natural regeneration established on scarified soil. Mean current annual height increment of Engelmann spruce and subalpine fir advance growth was 39 and 34 cm, respectively, compared with only 7 cm for natural regeneration on scarified soil. The performance gap does not appear to be narrowing. The poor performance of natural regeneration on mineral soil exposed by blade scarification is attributed to removal of organic and top mineral soil horizons beyond the immediate reach of seedlings. These soil layers remained available to the advance growth. Consideration should be given to preserving advance growth when scarification may be inappropriate.


1987 ◽  
Vol 17 (12) ◽  
pp. 1565-1571 ◽  
Author(s):  
R. D. Kabzems ◽  
K. Klinka

Relationships between soil properties, understory vegetation, foliar properties, and site index were examined in some Douglas-fir ecosystems on Vancouver Island. Multivariate summaries of variation in understory vegetation and foliar properties were highly correlated with the soil properties (mineralizable N, total N, and exchangeable Ca and Mg) that best characterized soil nutrient regimes of the ecosystems. The increases in soil nutrient availability were correlated with increased foliar N concentrations of the current year foliage. A consistent correlation was found between increased soil nutrient availability (particularly N, Mg, Ca) and decreased foliar Mn and Al. Site index of Douglas-fir was significantly greater on sites with greater quantities of most nutrients (particularly N, Mg, Ca) when sites with equivalent soil moisture regime were compared.


2003 ◽  
Vol 33 (11) ◽  
pp. 2210-2220 ◽  
Author(s):  
Cindy E Prescott ◽  
Graeme D Hope ◽  
Leandra L Blevins

Possible mitigation of nitrate losses associated with clearcuts through harvesting smaller gaps was tested in a high-elevation forest of Engelmann spruce (Picea engelmannii Parry ex Engelm.) and subalpine fir (Abies lasiocarpa (Hook.) Nutt.). We measured concentrations of ammonium and nitrate after 6-week buried bag incubations of forest floor and mineral soil samples in replicated plots of uncut forest and gaps of 10, 1.0, and 0.1 ha and single-tree removal for 7 years after harvest. Nitrate concentrations in forest floor and mineral soil were elevated 3–7 years after harvesting in gaps of 0.1 ha and larger. Removal of the same proportion of trees as single trees did not result in increased nitrate concentrations, suggesting that nitrate losses could be reduced by harvesting single trees rather than creating gaps. Greater N availability was not associated with faster rates of decomposition of litter and forest floor, which were similar in gaps of all sizes (0–10 ha). Reciprocal transplant of forest floor and soil from the 10-ha gaps and the uncut forests indicated that changes in the nature of the forest floor or soil following harvest had a greater influence on nitrate concentrations than the changes in environmental conditions in the gaps.


1996 ◽  
Vol 72 (2) ◽  
pp. 193-198 ◽  
Author(s):  
K. Klinka ◽  
H. Y. H. Chen ◽  
Q. Wang ◽  
R. E. Carter

Stem analysis data from even-aged Engelmann spruce (Picea engelmannii Parry ex Engelm.) and subalpine fir [Abies lasiocarpa (Hook.) Nutt.] stands on zonal sites in the Engelmann Spruce—Subalpine Fir biogeoclimatic zone of British Columbia were used to examine the relationships of site index and height growth and elevation, latitude, and longitude. Elevation and latitude were found to be strongly negatively correlated with site index of both study species. Spruce site index (bh age 50) was predicted to decrease 2.9 m and fir site index 2.5 m with every 100 m and 1° increase in elevation and latitude, respectively; however, (i) site index of both species appeared to decline faster with increasing latitude than elevation, and (ii) decrease appeared to be faster for spruce than for fir. Comparison of height growth curves for stands on zonal and azonal sites with similar site index from different elevations and latitudes suggested that there are probably inconsequential differences between the shape of curves for either species. These findings imply that (i) subalpine fir is better adapted to subalpine boreal climates than Engelmann spruce and (ii) development of polymorphic site index curves for estimating site index of both species may be appropriate. Key words: elevation, latitude, longitude, site index, height growth, Abies lasiocarpa, Picea engelmannii, Engelmann Spruce—Subalpine Fir zone


1987 ◽  
Vol 17 (12) ◽  
pp. 1557-1564 ◽  
Author(s):  
R. D. Kabzems ◽  
K. Klinka

Previous attempts to characterize soil nutrient regimes of forest ecosystems have been qualitative evaluations utilizing vegetation and (or) topographic features, morphological soil properties, and mineralogy of soil parent materials. The objective of this study was to describe and provide initial data for quantitative classification of soil nutrient regimes in some Douglas-fir ecosystems on southern Vancouver Island. A multivariate classification using forest floor plus mineral soil mineralizable N and exchangeable Mg quantities was proposed for the four nutrient regimes (poor, medium, rich, and very rich) recognized in this study. Significant differences in mineralizable and total N existed between the four identified soil nutrient regimes. The previous N fertilization of two study sites did not seem to change soil N status sufficiently to alter the classification. The differences in nutrient availability were more distinct when forest floor and mineral soil properties, expressed on an areal basis, were summed. There were no significant differences in exchangeable Ca and Mg for the poor and medium soil nutrient regimes. The humus form of the forest floor was an important characteristic for identifying soil nutrient regimes in the field; however, the nutrient quantities of the forest floor reflected differences in bulk density and depth and did not effectively distinguish between regimes.


1999 ◽  
Vol 29 (2) ◽  
pp. 187-193 ◽  
Author(s):  
Jianwen Zhong ◽  
Bart J van der Kamp

Unstratified seed of Engelmann spruce (Picea engelmannii Parry) and subalpine fir (Abies lasiocarpa (Hook.) Nutt.) in nylon mesh bags was placed on various natural and disturbed forest floor seed beds in the Engelmann Spruce - Subalpine Fir Zone in the southern interior of British Columbia in September 1995 and recovered just before snow melt in June 1996. Fifty-two and 86% of the viable spruce and fir seed, respectively, had germinated before snowmelt. Germination under snow may be an adaptation of these high-elevation species to short cool growing seasons. Seed viability at recovery was significantly lower on undisturbed forest floor seed beds (spruce, 13%; fir, 12%) than on exposed mineral soil (spruce, 57%; fir, 42%). Viability of seed placed on nurse logs was 38 and 23% for spruce and fir, respectively. Isolation from ungerminated seed yielded a Rhizoctonia sp., an as yet unidentified black mold at high frequencies, and several other seed pathogens at low frequency. Multiple linear regression of the frequency of isolation of Rhizoctonia and black mold on seed viability was highly significant for both tree species. Seed pathogens appear to cause a major loss of seed and seedlings in these forests, and this may explain both the common occurrence of regeneration on nurse logs and the requirement of mineral soil seed beds for adequate regeneration.


1999 ◽  
Vol 75 (3) ◽  
pp. 467-472 ◽  
Author(s):  
Alan Vyse

The Sicamous Creek Project was established as part of the British Columbia Provincial Silvicultural Systems program in 1990 to investigate the effects of clearcutting and other practices on a high elevation forested ecosystem. The objective is to provide the forestry community with information on the ecology of high elevation forests in the Southern Interior, and the probable responses to a wide range of disturbance. After a period of planning by a team of scientists and foresters from several agencies, a site in subalpine fir-Engelmann spruce forest at 1530 m to 1830 m elevation near the town of Sicamous in the south central interior of British Columbia was logged in the winter of 1994–95. A range of treatments was created by logging one third of the forest in 30 ha experimental units using a range of opening sizes (individual tree selection, 1/10 ha, 1 ha, and 10 ha) and a no-logging control. Within these experimental units, smaller areas (0.08 ha) have been treated to create a range of soil disturbance conditions (no disturbance, burning, complete organic soil removal, mounding). A wide range of studies has been conducted on the site by a team of scientists before and after treatment and those studies are continuing. The project is long-term, (at least 30 years), the main treatments are sufficiently large to have operational significance, and the supported studies are intended to be interdisciplinary in scientific method and scope. Support for the project is strong within the operational forestry community because information on logging costs, safety issues and snags, windthrow, bark beetle management, wildlife habitat and small streams has already been made available to them. Studies of stand structure and wildlife habitat suggest that in future much greater emphasis should be placed on the silviculture of fir than spruce. Key words: silviculture systems, clearcutting, opening size, Engelmann spruce, subalpine fir, long term research, interdisciplinary research


2000 ◽  
Vol 15 (2) ◽  
pp. 62-69 ◽  
Author(s):  
Han Y. H. Chen ◽  
Karel Klinka

Abstract To estimate potential productivity of the high-elevation Engelmann Spruce and Subalpine Fir (ESSF) zone of British Columbia forests, the height growth models developed from low-elevation forests are currently used to estimate site indices of subalpine fir (Abies lasiocarpa), Engelmann spruce (Picea engelmannii), and lodgepole pine (Pinus contorta). Whether these models are adequate to describe height growth of high-elevation forests is of concern. We sampled a total of 319 naturally established, even-aged, and undamaged stands with breast height age ≥50 yr (165 for subalpine fir, 87 for Engelmann spruce, and 67 for lodgepole pine) ranging widely in climate and available soil moisture and nutrients. In each sampled stand, three dominant trees were destructively sampled for stem analysis. Height growth models developed from fitting data to a conditioned logistic function explained > 97% variation in height for all three study species. Examined by residual analysis, no models showed lack of fit. These models provided more accurate estimates of site index than the currently used models developed from low-elevation stands or different species. It is recommended that the models developed in this study be applied to estimate site index of the three species in the ESSF zone in British Columbia. West. J. Appl. For. 15(2):62-69.


2003 ◽  
Vol 33 (12) ◽  
pp. 2321-2330 ◽  
Author(s):  
C SM Washburn ◽  
M A Arthur

Established species have been shown to affect soil nutrient availability, but the effects of "native invasive" species on soil nutrient availability are relatively unknown. Oak-dominated forests in the eastern deciduous forest are dynamic in their species composition, with increasing dominance of red maple (Acer rubrum L.) in the midstory and overstory. We hypothesized that higher quality red maple litter within a litter matrix dominated by oaks would accelerate N turnover, increase nutrient availability in the soil, and result in a thinner and less massive O horizon. We examined nutrient availability in soils under three overstory tree species (Quercus prinus L., A. rubrum, and Pinus echinata Mill. or Pinus rigida Mill.), under a shrub (Vaccinium spp.), and in locations without tree stems ("no tree"). Ex tract able nutrients (P, K, Mg, Ca) and total and available N were quantified in the O horizon and upper mineral soil at 0.5 m and 1.0 m from the base of individual trees or from the center of Vaccinium and no-tree locations. Despite low lignin concentration in red maple litter and low lignin/N ratio, the lowest N mineralization rates were found in red maple microsites; the highest N mineralization rates were found under oak. Extractable cations were generally highest under red maple and lowest under pines, and red maple had the highest levels of total N (but not NO3or NH4) in the upper mineral soil. Shifting species composition towards red maple and away from pines in these forests may alter nutrient cycling by increasing surface soil cation availability, but reducing soil N mineralization.


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