Influence of millipedes on litter decomposition, N mineralization, and microbial communities in a coastal forest in British Columbia, Canada

2000 ◽  
Vol 30 (5) ◽  
pp. 817-826 ◽  
Author(s):  
H A Cárcamo ◽  
T A Abe ◽  
C E Prescott ◽  
F B Holl ◽  
C P Chanway
Keyword(s):  
Litter Decomposition ◽  
N Mineralization ◽  
Sitka Spruce ◽  
Douglas Fir ◽  
Picea Sitchensis ◽  
Western Hemlock ◽  
Thuja Plicata ◽  
Coastal Forests ◽  
Western Redcedar ◽  
Litter Consumption

Laboratory experiments were conducted with the millipede Harpaphe haydeniana haydeniana Wood (Polydesmida: Xystodesmidae) to determine (i) its litter feeding preferences, (ii) rates of leaf litter consumption, (iii) feeding effects on available nitrogen, and (iv) functional microbial diversity. The millipede exhibited a preference for Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and, to a lesser extent, Sitka spruce (Picea sitchensis (Bong.) Carrière) litter compared with western hemlock (Tsuga heterophylla (Raf.) Sarg.) and western redcedar (Thuja plicata Donn ex D. Don) litter when given a choice. When only one litter type was provided, millipedes consumed considerably more western redcedar than Douglas-fir, Sitka spruce, or western hemlock. Among the six broadleaf species tested, paper birch (Betula papyrifera Marsh.), bigleaf maple (Acer macrophyllum Pursh), vine maple (Acer circinatum Pursh), and red alder (Alnus rubra Bong.) were consumed at much higher rates than swordfern (Polystichum munitum (Kaulf.) Presl.) or salal (Gaultheria shallon Pursh). Daily rates of conifer litter consumption ranged between 10 and 20% of the millipede's fresh biomass and may translate to 36% of the annual litter fall. Our results suggest that transformation of conifer litter into millipede frass can increase rates of litter decomposition and N mineralization, as well as influence microbial activity and diversity in coastal forests.

Ionic balance and organic acids in western redcedar, western hemlock, and Douglas-fir seedlings grown in low- and high-N soils

1999 ◽  
Vol 29 (6) ◽  
pp. 669-678 ◽  
Author(s):  
J E Graff, Jr. ◽  
R K Hermann ◽  
J B Zaerr
Keyword(s):  
Organic Acids ◽  
Quinic Acid ◽  
Tsuga Heterophylla ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Thuja Plicata ◽  
N Availability ◽  
Ionic Balance ◽  
Total N ◽  
Western Redcedar

Seedlings of western redcedar (Thuja plicata Donn ex. D. Don), western hemlock (Tsuga heterophylla (Raf.) Sarg.), and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) were transplanted into soils with low and high levels of available NO3-(and total N). Current-year foliage was sampled after 10 weeks to determine the effect of N availability on foliar cation-anion balance (C-A) and the concentrations of low molecular weight organic acids of the three species. Carboxylate concentrations were estimated by using the difference between sums of cations and anions (C-A): 750 mequiv.·kg-1for western redcedar, 351 mequiv.·kg-1for western hemlock, and 266 mequiv.·kg-1for Douglas-fir. Quinic acid was a primary constituent, accounting for 40% of the total for western redcedar and 75% for western hemlock and Douglas-fir. Oxalic acid was present in greatest concentration in the foliage of western redcedar (65 mequiv.·kg-1) but was a minor constituent in western hemlock and Douglas-fir. The quantified acids accounted for only 15% of the C-A of western redcedar but >80% of the C-A of western hemlock and Douglas-fir. A considerable portion of the C-A balance not accounted for in redcedar may be associated with the accumulation of CaCO3. Litterfall deposition of CaCO3may lead to the consumption of H+ions and enrichment of exchangeable soil Ca in the rooting zone of long-lived western redcedar trees. No statistically significant differences among the soils were detected with regard to C-A or the concentration of organic acids.

Postglacial vegetation history of Mitkof Island, Alexander Archipelago, southeastern Alaska

2010 ◽  
Vol 73 (2) ◽  
pp. 259-268 ◽  
Author(s):  
Thomas A. Ager ◽  
Paul E. Carrara ◽  
Jane L. Smith ◽  
Victoria Anne ◽  
Joni Johnson
Keyword(s):  
Pinus Contorta ◽  
Vegetation History ◽  
Regional Climate ◽  
Sitka Spruce ◽  
Tsuga Heterophylla ◽  
Picea Sitchensis ◽  
Thuja Plicata ◽  
Pollen Record ◽  
Coastal Forests ◽  
History Of

An AMS radiocarbon-dated pollen record from a peat deposit on Mitkof Island, southeastern Alaska provides a vegetation history spanning ∼12,900 cal yr BP to the present. Late Wisconsin glaciers covered the entire island; deglaciation occurred > 15,400 cal yr BP. The earliest known vegetation to develop on the island (∼12,900 cal yr BP) was pine woodland (Pinus contorta) with alder (Alnus), sedges (Cyperaceae) and ferns (Polypodiaceae type). By ∼12,240 cal yr BP, Sitka spruce (Picea sitchensis) began to colonize the island while pine woodland declined. By ∼11,200 cal yr BP, mountain hemlock (Tsuga mertensiana) began to spread across the island. Sitka spruce-mountain hemlock forests dominated the lowland landscapes of the island until ∼10,180 cal yr BP, when western hemlock (Tsuga heterophylla) began to colonize, and soon became the dominant tree species. Rising percentages of pine, sedge, and sphagnum after ∼7100 cal yr BP may reflect an expansion of peat bog habitats as regional climate began to shift to cooler, wetter conditions. A decline in alders at that time suggests that coastal forests had spread into the island's uplands, replacing large areas of alder thickets. Cedars (Chamaecyparis nootkatensis, Thuja plicata) appeared on Mitkof Island during the late Holocene.

scholarly journals Seedling Spacing in the Nursery in Relation to Growth, Yield, and Performance of Stock

1984 ◽  
Vol 60 (6) ◽  
pp. 345-355 ◽  
Author(s):  
R. van den Driessche
Keyword(s):  
Dry Weight ◽  
White Spruce ◽  
Sitka Spruce ◽  
Douglas Fir ◽  
Picea Sitchensis ◽  
Thuja Plicata ◽  
Winter Mortality ◽  
Root Collar Diameter ◽  
Collar Diameter ◽  
Root Collar

In three experiments coastal and interior varieties of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco). Sitka spruce (Picea sitchensis (Bong.) Carr), white spruce (Picea glauca (Moench.) Voss), lodgepole pine (Pinus contorta var. latifolia Engelm) and western red cedar (Thuja plicata Donn.) were grown at a range of spacings, within drills 15 cm apart, at four nurseries in coastal British Columbia. In a fourth experiment the frequency distribution of seed spacings achieved with three types of precision seeders was examined.A 1 cm increase in spacing increased seedling dry weight by 0.5–1.5 g and root collar diameter by 0.2–0.25 mm. up to a spacing of about 8–10 cm. Above this spacing response was less. Height of two-year old (2-0) seedlings was increased little, or even decreased by wider spacing. Height:diameter ratios decreased sharply and shoot:root dry weight ratios decreased or remained unchanged with wider spacing. The number of needle primorida in 2-0 Douglas-fir buds increased up to a spacing of 2 cm. The number of first and second order branches was also increased in 2-0 seedlings of this species by wider spacing. Needle dry weight and area measurements suggested Douglas-fir from wider spacing had more sun type needles than those from closer spacing, which had more shade type needles. Only small increases in root growth capacity (RGC) were associated with wider spacing. None of the precision seeders tested achieved anything like perfect precision of seed placement. With irregularity added by 10–20% non-viable seed and winter mortality, truly precision spaced stands of 2-0 seedlings could not be achieved under existing conditions. Increased spacing of 2–5 cm between seedlings, depending on species and nursery, was justified by yield of acceptable seedlings when culling standard was increased to a root collar diameter of about 6 mm.Three years after planting, survival of white spruce was increased 11% by wider spacing in the nursery, and the corresponding value for Sitka spruce two years after planting was 13%. Seedlings of both species from wider spacings maintained a height and diameter advantage over those from close spacing.

Underplanted conifer seedling survival and growth in thinned Douglas-fir stands

2001 ◽  
Vol 31 (2) ◽  
pp. 302-312 ◽  
Author(s):  
Thomas J Brandeis ◽  
Michael Newton ◽  
Elizabeth C Cole
Keyword(s):  
Seedling Survival ◽  
Tsuga Heterophylla ◽  
Douglas Fir ◽  
Understory Vegetation ◽  
Western Hemlock ◽  
Thuja Plicata ◽  
Herbicide Application ◽  
Western Redcedar ◽  
Second Growth ◽  
Conifer Seedling

In a multilevel study to determine limits to underplanted conifer seedling growth, Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), grand fir (Abies grandis (Dougl. ex D. Don) Lindl.), western redcedar (Thuja plicata Donn ex D. Don), and western hemlock (Tsuga heterophylla (Raf.) Sarg.) seedlings were planted beneath second-growth Douglas-fir stands that had been thinned to basal areas ranging from 16 to 31 m2/ha. Understory vegetation was treated with a broadcast herbicide application prior to thinning, a directed release herbicide application 2 years later, or no treatment beyond harvest disturbance. Residual overstory density was negatively correlated with percent survival for all four species. Broadcast herbicide application improved survival of grand fir and western hemlock. Western redcedar, grand fir, and western hemlock stem volumes were inversely related to overstory tree density, and this effect increased over time. There was a strong indication that this was also the case for Douglas-fir. Reduction of competing understory vegetation resulted in larger fourth-year stem volumes in grand fir and western hemlock.

Tenth-year survival and size of underplanted seedlings in the Oregon Coast Range

2009 ◽  
Vol 39 (3) ◽  
pp. 580-595 ◽  
Author(s):  
Elizabeth Cole ◽  
Michael Newton
Keyword(s):  
Stand Structure ◽  
Site Preparation ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Thuja Plicata ◽  
Coast Range ◽  
Oregon Coast Range ◽  
Western Redcedar ◽  
Oregon Coast ◽  
Forest Stand Structure

This study initiated a two-aged forest stand structure by underplanting 50-year-old stands, primarily of Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco var. menziesii) and Douglas-fir – western hemlock ( Tsuga heterophylla (Raf.) Sarg.), thinned to 19–33 m2/ha on interior and coastal sites in the Oregon Coast Range. Douglas-fir, grand fir ( Abies grandis (Dougl. ex D. Don) Lindl.) (interior site only), western hemlock, and western redcedar ( Thuja plicata Donn ex D. Don) were planted following thinning either uniformly or in gaps of 0.06 or 0.1 ha. Understory vegetation treatments included (i) a preharvest site preparation herbicide application and an untreated control at both sites and (ii) a postharvest herbicide release treatment at the interior site. Planting conditions and stock at the interior site were not ideal, so survival was adjusted for first-year mortality. Adjusted 10 year survival ranged from 27% to 56% for Douglas-fir, 47% to 65% for western hemlock, 61% to 80% for grand fir, and 78% to 96% for western redcedar. Tenth-year survival at the coastal site ranged from 79% to 92% for Douglas-fir, 61% to 75% for western hemlock, and 67% to 86% for western redcedar. All species grew moderately well beneath the lowest-density overstories, and size was better within gaps than matrices for most species. Understory site preparation improved size for most species. Browsing on Douglas-fir and western redcedar impacted size on both sites.

What influences the long-term development of mixtures in British forests?

2020 ◽  
Vol 93 (4) ◽  
pp. 545-556 ◽  
Author(s):  
W L Mason ◽  
T Connolly
Keyword(s):  
Functional Traits ◽  
Scots Pine ◽  
Shade Tolerance ◽  
Basal Area ◽  
Sitka Spruce ◽  
Picea Sitchensis ◽  
Silver Birch ◽  
Western Hemlock ◽  
Larix Kaempferi ◽  
Pure Stand

Abstract Six experiments were established between 1955 and 1962 in different parts of northern and western Britain which used replicated randomized block designs to compare the performance of two species 50:50 mixtures with pure stands of the component species. The species involved were variously lodgepole pine (Pinus contorta Dougl.), Japanese larch (Larix kaempferi Lamb. Carr.), Scots pine (Pinus sylvestris L.), silver birch (Betula pendula Roth.), Sitka spruce (Picea sitchensis Bong. Carr.) and western hemlock (Tsuga heterophylla Raf. Sarg.). The first four species are light demanding, while Sitka spruce is of intermediate shade tolerance and western hemlock is very shade tolerant: only Scots pine and silver birch are native to Great Britain. In three experiments (Bickley, Ceannacroc, Hambleton), the mixtures were of two light-demanding species, while at the other three sites, the mixture tested contained species of different shade tolerance. The experiments were followed for around 50 years, similar to a full rotation of even-aged conifer stands in Britain. Five experiments showed a tendency for one species to dominate in mixture, possibly reflecting differences in the shade tolerance or other functional traits of the component species. In the three experiments, the basal area of the mixtures at the last assessment was significantly higher than predicted based on the performance of the pure stands (i.e. the mixture ‘overyielded’). In two of these cases, the mixture had had a higher basal area than found in the more productive pure stand indicating ‘transgressive overyielding’. Significant basal area differences were generally more evident at the later assessment date. The exception was in a Scots pine: western hemlock mixture where greater overyielding at the earlier date indicated a nursing (‘facilitation’) effect. In the remaining experiments, the performance of the mixture conformed to predictions from the growth of the component species in pure stands. Taken overall, the results suggest that functional traits can be used to interpret the performance of mixtures but prediction of the outcome will require better understanding of the interplay between species and site characteristics plus the influence of silvicultural interventions.

scholarly journals Porcupine Feeding Damage in Precommercially Thinned Conifer Stands of Central Southeast Alaska

1997 ◽  
Vol 12 (4) ◽  
pp. 115-121 ◽  
Author(s):  
Andris Eglitis ◽  
Paul E. Hennon
Keyword(s):  
Host Selection ◽  
Sitka Spruce ◽  
Tsuga Heterophylla ◽  
Picea Sitchensis ◽  
Western Hemlock ◽  
Feeding Damage ◽  
Southeast Alaska ◽  
Erethizon Dorsatum ◽  
Young Growth

Abstract This study describes feeding damage by porcupines (Erethizon dorsatum) in precommercially thinned young growth stands of Sitka spruce (Picea sitchensis) and western hemlock (Tsuga heterophylla) on Mitkof Island in central southeast Alaska. We examined 641 trees from 54 sampling plots along transect lines in three 12 to 20 yr old stands. Porcupine feeding was monitored each spring and fall from 1985 to 1987. Four categories of feeding damage are described: complete girdling of the bole, partial girdling (bole scars), branch clipping, and "tasting wounds" (small basal bole scars). Sitka spruce, the primary crop tree in these thinned stands, sustained significantly higher damage (52% of trees affected) than western hemlock (26% of trees affected). Porcupine feeding was greater on taller than shorter Sitka spruce. Although only 8 of 59 trees initially girdled in 1985 were killed, many later sustained additional feeding damage. Following the 1987 season 3 yr after thinning, nearly 30% of the spruce and 14% of the western hemlock crop trees had been partially or completely girdled. Issues deserving future attention include the role of thinning in predisposing stands to porcupine damage, methods of population assessment, and mechanisms of host selection by porcupines. West. J. Appl. For. 12(4):115-121.

Effects on understory biomass and forage 8–10 years after precommercial thinning of Sitka spruce – western hemlock stands in southeast Alaska

2020 ◽  
Vol 50 (2) ◽  
pp. 215-225
Author(s):  
Justin S. Crotteau ◽  
Annelise Z. Rue-Johns ◽  
Jeffrey C. Barnard
Keyword(s):  
Forest Type ◽  
Sitka Spruce ◽  
Picea Sitchensis ◽  
Wildlife Habitat ◽  
Western Hemlock ◽  
Stand Age ◽  
Southeast Alaska ◽  
Precommercial Thinning ◽  
Clear Cutting ◽  
Understory Biomass

In southeast Alaska, United States, multiple-use forest management objectives include both timber production and wildlife habitat. Following stand-replacing disturbances such as clear-cutting, Sitka spruce (Picea sitchensis (Bong.) Carrière) and western hemlock (Tsuga heterophylla (Raf.) Sarg.) naturally regenerate and competitively dominate resources, excluding understory biomass and biodiversity. Thinning may mitigate the effects of canopy closure and permit understory development, but evidence of the effect on understories 8–10 years after thinning is lacking. We report results 4–5 and 8–10 years after thinning experiments on the Tongass National Forest to demonstrate the effects of precommercial thinning (thinned versus control), stand age (15–25, 25–35, and 35–50 years), and weather on understory dynamics and Sitka black-tailed deer (Odocoileus hemionus sitkensis Merriam, 1898) forage availability. Stand density negatively affected understory biomass, whereas temperature and precipitation positively interacted to increase biomass. Thinning had an enduring effect on understories, with biomass at least twice as great in thinned versus unthinned stands through year 10. We identified compositional differences from thinning as stand age class increased. Deer forage responded similarly to biomass, but thinning-induced differences faded with increased winter snowfall scenarios, especially in older stands. This study aids the understanding of stand overstory and understory development following silvicultural treatments in the coastal temperate rain forest of Alaska and suggests management implications and applications for balancing objectives throughout the forest type.

Ectomycorrhizal mushroom response to partial cutting in a western hemlock - western redcedar forest

2001 ◽  
Vol 31 (6) ◽  
pp. 978-987 ◽  
Author(s):  
J M Kranabetter ◽  
P Kroeger
Keyword(s):  
Stand Structure ◽  
Basal Area ◽  
Tsuga Heterophylla ◽  
Western Hemlock ◽  
Thuja Plicata ◽  
Soil Conditions ◽  
Taxon Richness ◽  
Partial Cutting ◽  
Western Redcedar ◽  
Significant Block

We examined epigeous ectomycorrhizal mushroom richness and productivity after partial cutting in a western hemlock (Tsuga heterophylla (Raf.) Sarg.) - western redcedar (Thuja plicata Donn ex D. Don in Lamb.) forest of northwestern British Columbia. Mushrooms were collected throughout the fruiting season (July to October) for 3 years, starting 5 years after partial cutting, from plots with mesic soil conditions and residual basal areas ranging from 23 to 69 m2/ha for western hemlock and 0 to 26 m2/ha for western redcedar. Partial cutting had no apparent effect on mushroom phenology over the 3 years. Significant block interactions demonstrated that reductions in basal area of western hemlock could lead to positive, neutral, and negative responses in mushroom richness, biomass, and number of fruiting bodies. These responses were related to stand structure and the potential differences in tree vigour after partial cutting. In addition, there was weak evidence that western redcedar, a host for vesicular-arbuscular mycorrhiza, had a negative effect on average taxon richness. The study demonstrated that partial-cutting systems could allow some timber removal without necessarily reducing ectomycorrhizal mushroom communities.

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