Distribution of epiphytic macrolichens in relation to remnant trees in a multiple-age Douglas-fir forest

Alternatives to clear-cutting are being implemented to increase biodiversity of managed forests in the Pacific Northwest. Lichens are an integral component of old growth, but lichen biomass develops slowly in forests. We evaluated the long-term potential of live tree retention for lichen conservation in Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) forests. We sampled lichen litterfall in a 2-ha stand that contained 200- to 600-year-old remnant trees scattered in a forest composed mostly of 100-year-old trees that established following fire. We used association, principal components, and regression analyses to relate lichen litterfall biomass to the proximity of remnant trees. Two epiphytic lichens were strongly associated with remnant trees: the foliose cyanolichen Lobaria oregana (Tuck.) Müll. Arg. and the fruticose green algal lichen Sphaerophorus globosus (Hudson) Vainio. Biomass of both species was highest near remnant trees, and biomass was slightly higher within groves of remnant trees than it was at the edges of these groves or near isolated trees. Lichens appear to have persisted on remnant trees through the last fire and are slowly recolonizing younger trees from this source of propagules. Retention of live trees, maintenance of hardwoods, and longer rotation periods have great potential to maintain old-growth-associated lichens in at least some managed forests.

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Canopy disturbances over the five-century lifetime of an old-growth Douglas-fir stand in the Pacific Northwest

Canadian Journal of Forest Research ◽

10.1139/x02-030 ◽

2002 ◽

Vol 32 (6) ◽

pp. 1057-1070 ◽

Cited By ~ 29

Author(s):

Linda E Winter ◽

Linda B Brubaker ◽

Jerry F Franklin ◽

Eric A Miller ◽

Donald Q DeWitt

Keyword(s):

Pacific Northwest ◽

Variable Density ◽

Tsuga Heterophylla ◽

Douglas Fir ◽

Western Hemlock ◽

Old Growth ◽

The Pacific ◽

History Of ◽

Horizontal Heterogeneity ◽

Restoration Strategies

The history of canopy disturbances over the lifetime of an old-growth Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stand in the western Cascade Range of southern Washington was reconstructed using tree-ring records of cross-dated samples from a 3.3-ha mapped plot. The reconstruction detected pulses in which many western hemlock (Tsuga heterophylla (Raf.) Sarg.) synchronously experienced abrupt and sustained increases in ringwidth, i.e., "growth-increases", and focused on medium-sized or larger ([Formula: see text]0.8 ha) events. The results show that the stand experienced at least three canopy disturbances that each thinned, but did not clear, the canopy over areas [Formula: see text]0.8 ha, occurring approximately in the late 1500s, the 1760s, and the 1930s. None of these promoted regeneration of the shade-intolerant Douglas-fir, all of which established 15001521. The disturbances may have promoted regeneration of western hemlock, but their strongest effect on tree dynamics was to elicit western hemlock growth-increases. Canopy disturbances are known to create patchiness, or horizontal heterogeneity, an important characteristic of old-growth forests. This reconstructed history provides one model for restoration strategies to create horizontal heterogeneity in young Douglas-fir stands, for example, by suggesting sizes of areas to thin in variable-density thinnings.

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Astrosclereids In Needles Of Old-Growth Douglas-Fir Trees

Microscopy and Microanalysis ◽

10.1017/s1431927600019528 ◽

1999 ◽

Vol 5 (S2) ◽

pp. 1240-1241

Author(s):

M. Apple ◽

A. Soeldner ◽

R. Hamill ◽

K. Tiekotfer

Keyword(s):

Pacific Northwest ◽

Cell Walls ◽

Douglas Fir ◽

Old Growth ◽

Mesophyll Cells ◽

Mesophyll Tissue ◽

The Pacific ◽

And Function ◽

Development Structure

Old-growth Douglas-fir trees in the Pacific Northwest are venerable giants that often live for 500 years and reach heights of over 75 meters. Their needles are relatively ephemeral and small but have the important role of interacting with the atmosphere in order to transpire and photosynthesize. Within the photosynthetic mesophyll tissue of Douglas-fir needles, there are large, non-living cells with lignified secondary cell walls that are known as astrosclereids. Apparent channels in the secondary wall may provide a route for exchange or transport of materials between the astrosclereid lumen and mesophyll cells or the vascular cylinder. Astrosclereids may be involvev d in storage of secondary metabolites such as tannin and may develop in response to fungi, mistletoe, or other pathogens. More knowledge is needed about the development, structure and function of astrosclereids.Needles were collected from sapling and old-growth Douglas-fir, Pseudotsuga menziesii, (Mirb.) Franco, trees at the Wind River Canopy Crane in Carson, Washington and from three sites in the Cascade Mountains of Oregon in 1997 and 1998.

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The role of epiphytes in rainfall interception by forests in the Pacific Northwest. I. Laboratory measurements of water storage

Canadian Journal of Forest Research ◽

10.1139/x05-298 ◽

2006 ◽

Vol 36 (4) ◽

pp. 809-818 ◽

Cited By ~ 42

Author(s):

Thomas G Pypker ◽

Michael H Unsworth ◽

Barbara J Bond

Keyword(s):

Pacific Northwest ◽

Water Storage ◽

Dry Mass ◽

Douglas Fir ◽

P Value ◽

Epiphytic Lichens ◽

Old Growth ◽

Water Fraction ◽

Large Populations ◽

External Water

Old-growth Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) forests frequently contain large populations of epiphytic lichens and bryophytes. To determine the effect these epiphytes have on canopy hydrology we measured the maximum water fraction (f(x)max; maximum mass of internal and external water stored by an epiphyte divided by its tissue dry mass) of common lichens, bryophytes, and dead branches in the laboratory and the water storage and interception efficiency (pi) (the rainfall stored on a branch divided by the rainfall intercepted by the branch) of whole epiphyte-laden branches under a rainfall simulator at three intensities (11.3, 16.1, and 39.8 mm·h1). The f(x)max values for epiphytic fruticose lichens, foliose lichens, and bryophytes were 2.2 ± 0.4, 3.4 ± 0.6, and 10.0 ± 0.5, respectively. The water stored by an epiphyte-laden branch during and after exposure to simulated rainfall could be predicted if the biomass of epiphytic lichens and bryophytes on the branch was known (R2 = 0.8, p value < 0.0001). For all three rainfall intensities, the branches required >6 mm of rainfall to saturate. Values of pi averaged between 0.5 and 0.7 after 2 mm of rainfall and did not differ among the three intensities (all p values > 0.05). We conclude that epiphytes increase the canopy water storage of a typical old growth Douglas-fir forest by >1.3 mm.

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Interim definitions for old growth Douglas-fir and mixed-conifer forests in the Pacific Northwest and California.

10.2737/pnw-rn-447 ◽

1986 ◽

Cited By ~ 6

Author(s):

J.F. Franklin ◽

F. Hall ◽

W. Laudenslayer ◽

C. Maser ◽

J. Nunan ◽

...

Keyword(s):

Pacific Northwest ◽

Douglas Fir ◽

Conifer Forests ◽

Mixed Conifer ◽

Old Growth ◽

Mixed Conifer Forests ◽

The Pacific

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Litter decomposition contrasts in second- and old-growth Douglas-fir forests of the Pacific Northwest, USA

Plant Ecology ◽

10.1007/s11258-007-9339-0 ◽

2007 ◽

Vol 196 (1) ◽

pp. 123-133 ◽

Cited By ~ 4

Author(s):

Jeffrey M. Klopatek

Keyword(s):

Pacific Northwest ◽

Litter Decomposition ◽

Douglas Fir ◽

Old Growth ◽

The Pacific

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Initiation of an old-growth Douglas-fir stand in the Pacific Northwest: a reconstruction from tree-ring records

Canadian Journal of Forest Research ◽

10.1139/x02-031 ◽

2002 ◽

Vol 32 (6) ◽

pp. 1039-1056 ◽

Cited By ~ 48

Author(s):

Linda E Winter ◽

Linda B Brubaker ◽

Jerry F Franklin ◽

Eric A Miller ◽

Donald Q DeWitt

Keyword(s):

Pacific Northwest ◽

Tree Ring ◽

Tsuga Heterophylla ◽

Douglas Fir ◽

Western Hemlock ◽

Old Growth ◽

The Pacific ◽

Closed Forest ◽

Initial Spacing ◽

Epicormic Branching

We used tree-ring records to reconstruct the stand initiation of an old-growth Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stand in the western Cascade Range of southern Washington. All tree-ring samples were prepared and crossdated. Following a stand-replacing fire, the stand initiation period lasted from 1500 to 1540, with gradual filling-in of growing space over this period. All sampled Douglas-fir were initial colonizers, establishing (at stump-height) 15001521 under open conditions. A small number of the sampled western hemlock (Tsuga heterophylla (Raf.) Sarg.) were also initial colonizers. Growing space filled as tree crowns widened, and by 1540, closed forest conditions had developed. At this time, Douglas-fir were spaced about 3.5 m from equivalent competitors (ca. 800 trees/ha). In the centuries following canopy closure, considerable natural thinning of the initial colonizers occurred, but the canopy never opened enough again to allow further Douglas-fir establishment. Surviving Douglas-fir developed deep crowns despite the narrow initial spacing, and without epicormic branching from the bole. Most western hemlock that were canopy trees in 1992 established after 1540, originating in the understory. This reconstruction provides an example that may be useful where management policies emphasize the development of old-growth structures.

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