Comparison of the chemical properties of forest floors, decaying wood, and fine roots in three ecosystems on Vancouver Island

1981 ◽  
Vol 11 (2) ◽  
pp. 216-218 ◽  
Author(s):  
H. J. Quesnel ◽  
L M. Lavkulich
Keyword(s):  
Forest Floor ◽  
Fine Roots ◽  
Chemical Properties ◽  
Nutrient Status ◽  
Vancouver Island ◽  
Loss On Ignition ◽  
Elemental Concentrations ◽  
Red Cedar ◽  
Forest Floors ◽  
Decaying Wood

Elemental concentrations were measured and compared for LF horizons, H horizons, decaying wood, and fine (< 2 mm) roots of three ecosystems on northern Vancouver Island. The principal tree species of these ecosystems were western hemlock (Tsugaheterophylla (Raf.) Sarg.), amabilis fir (Abiesamabilis (Dougl.) Forbes), and western red cedar (Thujaplicata Donn.). The H horizons had greater Mg and Na values than the LF horizons, while the opposite result was found for K and loss on ignition (LOI). The decaying wood represents a significant accumulation of nutrient-deficient biomass that could immobilize N. The decomposing fine roots will temporarily immobilize N while possibly increasing the concentration of elements such as Fe, Al, and Mn. These materials should be separated from forest floor samples in order to represent more accurately the nutrient status of forest floor horizons.

Mass and nutrient content of woody debris and forest floor in western red cedar and western hemlock forests on northern Vancouver Island

1993 ◽  
Vol 23 (6) ◽  
pp. 1052-1059 ◽  
Author(s):  
Rodney J. Keenan ◽  
Cindy E. Prescott ◽  
J.P. Hamish Kimmins
Keyword(s):  
Forest Floor ◽  
Forest Type ◽  
Woody Debris ◽  
Nutrient Content ◽  
Vancouver Island ◽  
Western Hemlock ◽  
N Availability ◽  
Red Cedar ◽  
The Mean ◽  
Western Red Cedar

Biomass and C, N, P, and K contents of woody debris and the forest floor were surveyed in adjacent stands of old-growth western red cedar (Thujaplicata Donn)–western hemlock (Tsugaheterophylla (Raf.) Sarg.) (CH type), and 85-year-old, windstorm-derived, second-growth western hemlock–amabilis fir (Abiesamabilis (Dougl.) Forbes) (HA type) at three sites on northern Vancouver Island. Carbon concentrations were relatively constant across all detrital categories (mean = 556.8 mg/g); concentrations of N and P generally increased, and K generally decreased, with increasing degree of decomposition. The mean mass of woody debris was 363 Mg/ha in the CH and 226 Mg/ha in the HA type. The mean forest floor mass was 280 Mg/ha in the CH and 211 Mg/ha in the HA stands. Approximately 60% of the forest floor mass in each forest type was decaying wood. Dead woody material above and within the forest floor represented a significant store of biomass and nutrients in both forest types, containing 82% of the aboveground detrital biomass, 51–59% of the N, and 58–61% of the detrital P. Forest floors in the CH and HA types contained similar total quantities of N, suggesting that the lower N availability in CH forests is not caused by greater immobilization in detritus. The large accumulation of forest floor and woody debris in this region is attributed to slow decomposition in the cool, wet climate, high rates of detrital input following windstorms, and the large size and decay resistance of western red cedar boles.

Availability of N and P in the forest floors of adjacent stands of western red cedar–western hemlock and western hemlock–amabilis fir on northern Vancouver Island

1993 ◽  
Vol 23 (4) ◽  
pp. 605-610 ◽  
Author(s):  
C. E. Prescott ◽  
M.A. McDonald ◽  
G.F. Weetman
Keyword(s):  
Forest Floor ◽  
Forest Type ◽  
Western Hemlock ◽  
Red Cedar ◽  
Floor Layer ◽  
Second Growth ◽  
Extractable P ◽  
Western Red Cedar ◽  
Forest Floors ◽  
Floor Material

Availability of N and P was compared in the forest floors of old-growth forests of western red cedar (Thujaplicata Donn)and western hemlock (Tsugaheterophylla (Raf.) Sarg.) (CH forests), and second-growth forests of western hemlock and amabilis fir (Abiesamabilis (Dougl.) Forbes) (HA forests) of windthrow origin. Five samples of each forest floor layer (litter, fermentation (woody and nonwoody), and humus (woody and nonwoody)) were collected from three forests of each type (CH and HA). All layers of CH forest floors had smaller concentrations of total and extractable N and mineralized less N during 40-day aerobic incubations in the laboratory. Total and extractable P was lower in the litter layer of CH forest floors. Seedlings of western red cedar, Sitka spruce (Piceasitchensis (Bong.) Carr.), western hemlock, and amabilis fir grown from seed in forest floor material from CH forests grew more slowly and took up less N and P than did seedlings grown in HA forest floor material. The low supply of N and P in CH forest floors may contribute to the nutrient supply problems encountered by regenerating trees on cutovers of this forest type.

Endomycorrhizal status of sugar maple in relation to tree decline and foliar, fine-roots, and soil chemistry in the Beauce region, Quebec

1995 ◽  
Vol 73 (8) ◽  
pp. 1168-1175 ◽  
Author(s):  
Rock Ouimet ◽  
Claude Camiré ◽  
Valentin Furlan
Keyword(s):  
Soil Chemistry ◽  
Fine Roots ◽  
Acer Saccharum ◽  
Sugar Maple ◽  
Root Colonization ◽  
Fine Root ◽  
Chemical Properties ◽  
Nutrient Status ◽  
Nutrient Content ◽  
Tree Decline

The Beauce region of Quebec has been relentlessly affected by sugar maple (Acer saccharum Marsh.) tree decline since the late 1970s. Nutrient disturbances are generally associated with maple decline, but the severity of decline symptoms can vary quite dramatically between individuals within a stand. Possible causes of this variability were investigated, including soil chemistry and endomycorrhization. Within 18 mature sugar maple stands, a comparative study of fine root colonization rate by endomycorrhizal fungi, and foliar, fine-roots, and soil-nutrient status between healthy and declining sugar maple trees was carried out. Three individuals showing a very low degree of decline symptoms (healthy) and three individuals in the vicinity exhibiting severe decline symptoms (declining) were selected in each stand. Although trees of both health classes were K and Ca deficient, the diagnosis revealed that those in the declining group were experiencing a more severe nutrient stress and lower stem radial growth than those in the healthy group. The percent colonization by endomycorrhizal fungi in fine roots of sugar maple varied from 8 to 40% among stands, with an average of 23%. However, the endomycorrhization rate was not related to tree health status. The frequency of endomycorrhization was positively correlated to soil pH and soil exchangeable Mg saturation, but negatively to the proportion of H + Al held on the soil exchange complex. Also, the rate of endomycorrhization was correlated positively to foliar and root Ca content, but negatively to foliar and root N content. Foliar N, P, K, Ca, Mg, and Mn contents were positively correlated to corresponding nutrient content in fine roots. Fine-root chemistry was only partly related to soil chemistry. Declining trees had a lower foliar K content and a lower P and Ca content in fine roots than healthy ones. The results do not support the hypothesis that sugar maple decline and its disturbed nutrient status is associated with lower colonization by endomycorrhizal fungi in fine roots. They suggest, however, that soil chemical properties, particularly the soil composition in cations, regulates fine-root colonization by endomycorrhizal fungi and sugar maple nutrition and health. These results can neither confirm nor invalidate the hypothesis according to which a deleterious microbial population may have colonized the soil under declining trees. Key words: Acer saccharum, soil cation saturation, forest decline, nutrient status, fine root, endomycorrhizae.

Litter production and nutrient resorption in western red cedar and western hemlock forests on northern Vancouver Island, British Columbia

1995 ◽  
Vol 25 (11) ◽  
pp. 1850-1857 ◽  
Author(s):  
Rodney J. Keenan ◽  
Cindy E. Prescott ◽  
J.P. (Hamish) Kimmins
Keyword(s):  
Nutrient Availability ◽  
Forest Floor ◽  
Forest Type ◽  
Vancouver Island ◽  
The Other ◽  
Western Hemlock ◽  
Litter Fall ◽  
Red Cedar ◽  
N Concentration ◽  
Nutrient Use

Fine litter fall and concentrations of N and P in green foliage and foliar litter were measured in three species over 1 year in two forest types at three sites on northern Vancouver Island to explore the hypothesis that differences in nutrient use and cycling between the dominant tree species on each forest type contribute to differences in forest floor nutrient availability. Total annual aboveground fine litter fall was significantly higher in second-growth, windstorm-derived 85-year-old stands of western hemlock (Tsugaheterophylla (Raf.) Sarg.) and amabilis fir (Abiesamabilis (Dougl.) Forbes) forests (4137 kg•ha−1) than in adjacent old-growth forests of western red cedar (Thujaplicata Donn) and western hemlock (3094 kg•ha−1) occurring on similar sites. Cedar had significantly lower N concentration in green foliage (9.3 mg•g−1) and litter (4.3 mg•g−1) than the other species in each forest type. Hemlock had a higher litter N concentration in the hemlock–amabilis fir type (8.3 mg•g−1) than in the cedar–hemlock type (6.4 mg•g−1). Cedar resorbed a significantly higher percentage of N during leaf senescence (76%), than hemlock in the cedar–hemlock type (64%), hemlock in the hemlock–amabilis fir type (51%), or amabilis fir (18%). Nitrogen-use efficiency (litter-fall mass/litter N) was considerably higher in cedar (235 kg litter/kg N) than in the other species in either forest type (90–156 kg litter/kg N). These results suggest that differences within and between species in the two types in nutrient use and the amount of nutrients cycling through the litter fall and internal redistribution pathways are contributing to lower rates of nutrient cycling and forest floor nutrient availability in the cedar–hemlock type.

NUTRIENT VARIABILITY OF FOREST FLOORS NEAR PORT HARDY, BRITISH COLUMBIA, CANADA

1980 ◽  
Vol 60 (3) ◽  
pp. 565-573 ◽  
Author(s):  
H. J. QUESNEL ◽  
L. M. LAVKULICH
Keyword(s):  
Forest Floor ◽  
Chemical Properties ◽  
Sampling Procedure ◽  
Exchange Capacity ◽  
Forest Sites ◽  
Exchangeable Ca ◽  
Allowable Error ◽  
Forest Floors ◽  
Nutrient Variability ◽  
Physical And Chemical

The variability of forest floor properties over short distances and the number of samples required to achieve desired levels of precision for estimation of property means have received little attention. The importance of the forest floor for forest management is well known and increasingly forest floor characteristics are being used to classify forest sites. Highly variable forest floor properties require more intensive sampling and often have less predictive value for characterization and classification purposes. A study site at Port Hardy was used to characterize forest floors for selected physical and chemical properties. The three sites chosen represented xeric, mesic and hygric positions along a hygrotopic gradient. A stratified random sampling procedure was used to obtain 15 samples at each site. Fifteen samples were adequate to characterize the means at 10% allowable error with a 95% confidence level for total nitrogen, organic carbon, pH and cation exchange capacity. Greater than 15 samples were required for exchangeable bases and forest floor thickness for the same level of accuracy and confidence. Even at 25% allowable error and 90% confidence, 40 samples and 16 samples, respectively, were required for exchangeable Ca and Mg.

Selected biological and chemical properties of forest floors across bedrock types on the north coast of British Columbia

2000 ◽  
Vol 30 (6) ◽  
pp. 971-981 ◽  
Author(s):  
J M Kranabetter ◽  
A Banner
Keyword(s):  
British Columbia ◽  
Forest Floor ◽  
Chemical Properties ◽  
Canopy Cover ◽  
North Coast ◽  
Available Phosphorus ◽  
Northern Coast ◽  
Turnover Rates ◽  
The North ◽  
Forest Floors

We examined some of the factors related to nutrient availability of forest floors developed over saprolitic and colluvial mineral soils of four bedrock types (granodiorite, gneissic diorite, schist, and limestone) on the outer northern coast of British Columbia. All sites were relatively well drained with old-growth coniferous forests. Forest floor morphology was quite similar across sites, with friable, moderately aggregated horizons dominating the profile. There were significant differences in concentrations of total nitrogen, available phosphorus, total sulphur, and condensed tannins across bedrock types. We found detritivores such as sowbugs, millipedes, and potworms across all sites. We could not detect differences in turnover rates (via laboratory respiration) of organic matter between bedrock types. Turnover rates instead were negatively correlated with forest floor carbon and total canopy cover. Overall, forest floor properties were quite similar across the range in parent materials because of the strong influence of climate and vegetation on soil development.

Growth of western red cedar seedlings in relation to microtopography, forest floor nutrient status, and fireweed and salal on clear-cut sites in coastal British Columbia

1992 ◽  
Vol 22 (3) ◽  
pp. 273-278 ◽  
Author(s):  
Christian Messier ◽  
James P. Kimmins
Keyword(s):  
British Columbia ◽  
Forest Floor ◽  
Nutrient Status ◽  
Ecological Significance ◽  
Total N ◽  
Cellulose Decomposition ◽  
Clear Cut ◽  
Red Cedar ◽  
Western Red Cedar ◽  
Coastal British Columbia

The growth of western red cedar (Thujaplicata Donn) seedlings was studied in relation to microtopography, to forest floor nutrient status, and to fireweed (Epilobiumangustifolium L.) and salal (Gaultheriashallon Pursh) abundance on 4-year-old logged and burned sites dominated by salal on northern Vancouver Island, British Columbia. These relationships were sought to determine some possible factors at the microsite level that influence the growth of western red cedar on recently clear-cut sites. Western red cedar growth and fireweed abundance and height were significantly greater in depressions than on flats and mounds, but these differences were not related to any major differences in forest floor pH, cellulose decomposition, total N and P, and available NH4+, NO3−, and phosphate P as measured using resin bags. The ecological significance of and possible reasons for the lack of correlation found between (i) western red cedar and fireweed growth and (ii) many measures of forest floor nutrient status are discussed.

Nitrogen mineralization and decomposition in forest floors in adjacent plantations of western red cedar, western hemlock, and Douglas-fir

1994 ◽  
Vol 24 (12) ◽  
pp. 2424-2431 ◽  
Author(s):  
C.E. Prescott ◽  
C.M. Preston
Keyword(s):  
Mass Loss ◽  
N Mineralization ◽  
Forest Floor ◽  
Douglas Fir ◽  
Western Hemlock ◽  
N Availability ◽  
Net N Mineralization ◽  
Red Cedar ◽  
Western Red Cedar ◽  
Forest Floors

To determine if western red cedar (Thujaplicata Donn) litter contributes to low N availability in cedar–hemlock forests, we measured concentrations of N and rates of net N mineralization in forest floors from single-species plantations of cedar, western hemlock (Tsugaheterophylla (Raf.) Sarg.), and Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) on the same site in coastal British Columbia. Concentrations of total and extractable N and rates of net N mineralization during laboratory incubations were lowest in the cedar forest floor and highest in Douglas-fir. Less C was mineralized in the cedar forest floor during incubation, and the amount of N mineralized per unit C was least in cedar. Rates of mass loss of foliar litter of the three species were similar during the first 50 weeks of a 70-week laboratory incubation, but cedar lost mass more quickly during the final 20 weeks. Rates of net N mineralization in the forest floors were significantly correlated with the initial percent N, C/N, % Klason lignin, and lignin/N of foliar litter. Foliar litter of cedar had lower concentrations of N and greater proportions of alkyl C (based on 13C NMR spectroscopy) than Douglas-fir litter. These characteristics of cedar litter may contribute to low N availability in cedar–hemlock forest floors. Concentrations of alkyl C (waxes and cutin) may be better than lignin for predicting rates of mass loss and N mineralization from litter.

Forest floor chemistry under seven tree species along a soil fertility gradient

1998 ◽  
Vol 28 (11) ◽  
pp. 1636-1647 ◽  
Author(s):  
Lars Vesterdal ◽  
Karsten Raulund-Rasmussen
Keyword(s):  
Soil Fertility ◽  
Tree Species ◽  
Forest Floor ◽  
Mineral Soil ◽  
Nutrient Status ◽  
Nutrient Ratios ◽  
Fertility Gradient ◽  
Soil Fertility Gradient ◽  
Element Contents ◽  
Forest Floors

Forest floor chemistry, i.e., C/nutrient ratios, pH, and element contents, were determined in stands of two deciduous species and five conifer species replicated at seven sites along a soil fertility gradient. There were consistent differences between forest floors of the tree species. Lodgepole pine (Pinus contorta Dougl.) forest floors had highest C/nutrient ratios, lowest pH, and the greatest element contents, whereas oak (Quercus robur L.) forest floors had low C/nutrient ratios and the lowest element contents of all species. Differences in forest floor C/nutrient ratios, pH, and element contents between sites of low nutrient status and sites of intermediate to high nutrient status were also great. Forest floor pH was related to mineral soil pH, and C/P, C/Ca, and C/K ratios were related to mineral soil nutrient concentrations. Forest floor C content was negatively related to most mineral soil fertility variables and was closest related to texture, pH, and concentrations of P and Ca. The C content of lodgepole pine and oak forest floors tended to be less affected by the soil fertility gradient. The results suggest that C storage and immobilization of nutrients in forest floors may be managed along an extensive soil gradient by selection of the proper tree species.

Vertical fine root distributions of western redcedar, western hemlock, and salal in old-growth cedar–hemlock forests on northern Vancouver Island

2002 ◽  
Vol 32 (7) ◽  
pp. 1208-1216 ◽  
Author(s):  
Jennifer N Bennett ◽  
Ben Andrew ◽  
Cindy E Prescott
Keyword(s):  
Forest Floor ◽  
Fine Roots ◽  
Fine Root ◽  
Mineral Soil ◽  
Vancouver Island ◽  
Western Hemlock ◽  
Old Growth ◽  
Total N ◽  
Western Redcedar ◽  
Vertical Distributions

The vertical distributions of fine roots of western hemlock (Tsuga heterophylla (Raf.) Sarg.) western redcedar (Thuja plicata Donn ex D. Don), and salal (Gaultheria shallon Pursh) were characterized in old-growth cedar–hemlock forests on northern Vancouver Island. Total biomasses of cedar, hemlock, and salal roots in the forest floor and upper mineral soil were 817, 620, and 187 g·m–2, respectively. Hemlock and salal fine roots were concentrated in the upper forest floor, while cedar fine roots were evenly distributed through the profile. Salal and hemlock fine root densities (g·m–3) in the forest floor and mineral soil were positively correlated, as were salal and cedar root biomass distributions (g·m–2). Only salal and hemlock root densities were significantly correlated with N concentrations. Hemlock root densities were negatively correlated with total N, and salal root densities were negatively correlated with total N and soluble organic N. Based on fine root densities, hemlock and salal probably compete for resources in the upper forest floor, whereas cedar accesses resources in the lower organic and mineral soil horizons. The differences in the vertical distributions of cedar, hemlock, and salal fine roots may partly explain the co-occurrence and different productivities of the three species in cedar-hemlock forests.

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