Populus tremuloides seedling establishment: An underexplored vector for forest type conversion after multiple disturbances

Trees are often well adapted to periodic physical disturbances such as fires or floods. However, I investigated forest response to an extremely unusual disturbance event. Following heavy rain in June 1995 a catastrophic debris flow from Vimy Peak in the Canadian Rocky Mountains terminated as an alluvial debris fan that plowed through a trembling aspen (Populus tremuloides Michx.) grove. I analyzed the site over a decade to monitor forest response and determine whether there would be recolonization to the prior forest type. In contrast to my expectation, aspen recolonization did not occur; instead, black cottonwoods (Populus trichocarpa Torr. & Gray) colonized the site. These originated from seedlings and not through clonal propagation, and by 2004, black cottonwoods composed 99% of the saplings and were typically 0.61.4 m tall with a density of about 1/m2. The debris fan dramatically changed the physical environment, which partly resembled a floodplain depositional zone and was colonized by the regionally dominant riparian tree. I propose the concept of foreign disturbance to recognize an unusual disturbance that an organism would very rarely experience and thus to which it is unlikely to be adapted. In this example the disturbance produced an abrupt transition to an alternative forest type and this response may provide insight into forest response to other unusual disturbances, such as extreme weather events, that might increase with climate change.

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Soil properties and aspen development five years after compaction and forest floor removal

Canadian Journal of Soil Science ◽

10.4141/s97-026 ◽

1998 ◽

Vol 78 (1) ◽

pp. 51-58 ◽

Cited By ~ 40

Author(s):

Douglas M. Stone ◽

John D. Elioff

Keyword(s):

Organic Matter ◽

Soil Properties ◽

Populus Tremuloides ◽

Soil Compaction ◽

Forest Floor ◽

Forest Type ◽

Woody Species ◽

Stand Development ◽

Site Productivity ◽

Organic Matter Removal

Forest management activities that decrease soil porosity and remove organic matter have been associated with declines in site productivity. In the northern Lake States region, research is in progress in the aspen (Populus tremuloides Michx. and P. grandidentata Michx.) forest type to determine effects of soil compaction and organic matter removal on soil properties and growth of aspen suckers, associated woody species, herbaceous vegetation, and on stand development. Four treatments: (1) total tree harvest (TTH); (2) TTH plus soil compaction (CPT); (3) TTH plus forest floor removal (FFR); and (4) TTH plus CPT + FFR were applied after winter-harvest of a 70-yr-old aspen stand growing on a loamy sand with a site index(age50) of 20.7 m. The CPT treatment significantly increased bulk density and soil strength of the surface 30 cm of soil and neither have recovered during the 5 yr since treatment. The CPT plots had 19.6 thousand (k) suckers ha−1, less than half that of the TTH and FFR treatments; mean diameter (19.4 mm) and height (271 cm) were greatest on the TTH plots. The disturbance treatments (CPT, FFR, and CPT + FFR) each reduced biomass of foliage, stems, and total suckers compared with the TTH treatment. Total aboveground biomass (herbs + shrubs + suckers) was less than half that of TTH plots. There were 5.0 k saplings (suckers >2.5 cm DBH) ha−1 on the TTH plots, but fewer than 1.0 k ha−1 in the other treatments. The disturbance treatments decreased 5-yr growth of potential crop trees, delayed early stand development, and temporarily reduced stockability and site productivity of an aspen ecosystem. Key words: Soil compaction, organic matter removal, site productivity, stand development

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Studies in the Ecology of Nothofagus Cunninghamii Oerst. i Natural Regeneration on the Mt. Donna Buang Massif, Victoria

Australian Journal of Botany ◽

10.1071/bt9730067 ◽

1973 ◽

Vol 21 (1) ◽

pp. 67 ◽

Cited By ~ 37

Author(s):

TM Howard

Keyword(s):

Seedling Establishment ◽

Natural Regeneration ◽

Forest Type ◽

Canopy Gaps ◽

Surface Soils ◽

Mature Forest ◽

Soil Failure ◽

Closed Forest ◽

Dry Out

On the southern slopes of the Mt. Donna Buang massif, Nothofagus cunninghamii occurs within the 60 in. isohyet between 1500 and 4000 ft. The occurrence of N. cunninghamii as an understorey to eucalypts of various ages has been interpreted as a post-fire succession towards a climax closed forest. The ability of N. cunninghamii to coppice after fire is important in the re-establishment of this forest type. Regeneration of N. cunninghamii in the mature forest is dependent on seedling establishment under canopy gaps on decayed logs or firm soil. Failure of seedlings to establish is related to loose surface soils which rapidly dry out, especially in open situations; to inadequate illumination; and to the soil-scratching activities of lyrebirds.

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Montane zone vegetation of the Alsek River region, southwestern Yukon

Canadian Journal of Botany ◽

10.1139/b74-327 ◽

1974 ◽

Vol 52 (12) ◽

pp. 2505-2532 ◽

Cited By ~ 37

Author(s):

George W. Douglas

Keyword(s):

Populus Tremuloides ◽

Forest Type ◽

Vegetation Diversity ◽

Artemisia Frigida ◽

Forest Region ◽

Montane Vegetation ◽

River Region ◽

Montane Zone ◽

Community Types ◽

Salix Glauca

A rapid reconnaissance technique was used to sample montane vegetation in the Alsek River region, southwest Yukon. Twenty-one major community types are described from 223 sample stands. The forest vegetation of the region is interspersed with numerous shrub and herb vegetation types. This vegetation diversity is extraordinarily rich for a forest region and is due primarily to the variable climate (both local and regional) and the frequency of disturbance by fire and geomorphological processes.Ten communities, within four forest types, are distinguished in the region. The most widespread forest type is dominated by Picea glauea. The remaining three are dominated by Populus tremuloides, P. balsamifera, and Salix scouleriana. Shrub communities recognized include the Betula glandulosa – Festuca altaica, Salix glauca, Juniperus communis – Arctostaphylos uva-ursi, Artemisia frigida – Poa glauca, Artemisia alaskana, and Salix setchelliana – Oxytropis campestris types. Herb communities distinguished include the Carex sabulosa, Hedysarum boreale – Agropyron yukonense, Calamagrostis, and Agropyron yukonense types.Examination of diversity and its components during succession in the Alsek River region indicates that, in general, richness and general diversity increase and dominance decreases until the later stages of succession, when these trends are subsequently reversed. Evenness, while somewhat more variable, showed trends similar to that of the dominance component. Deviations from these trends occurred when the habitat was either extremely homogeneous or extremely heterogeneous.The flora of the region is relatively rich and derived from many North Temperate elements. The largest segment (64%) is derived from the more northern (Circumarctic-alpine, Circumboreal-montane, Amphi-beringian, Amphi-atlantic) elements.

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Changes in bird communities throughout succession following fire and harvest in boreal forests of western North America: literature review and meta-analyses

Canadian Journal of Forest Research ◽

10.1139/x06-017 ◽

2006 ◽

Vol 36 (5) ◽

pp. 1299-1318 ◽

Cited By ~ 86

Author(s):

Jim Schieck ◽

Samantha J Song

Keyword(s):

North America ◽

Populus Tremuloides ◽

Boreal Forests ◽

Large Scale ◽

Forest Type ◽

Bird Species ◽

Bird Communities ◽

Forest Birds ◽

Western North America ◽

Meta Analyses

Within boreal forests of western North America, the dominant large-scale natural disturbance is wildfire. Thus, harvesting that is as similar as possible to fire is expected to best maintain natural bird communities. We reviewed studies of birds (mainly grouse, woodpeckers, and songbirds) from boreal forests of western North America and conducted meta-analyses to compare the similarity of bird communities occurring postfire versus postharvest. We compared the bird communities at five seral stages and also summarized the effects of retaining large live trees at harvest. Bird communities immediately postharvest differed greatly from those postfire. Differences between disturbance types disappeared as the forest regenerated, and both disturbance types became dominated by relatively few bird species in 31- to 75-year-old forests. During the period 76125 years postdisturbance, old-forest birds became present and bird species richness increased. However, the trajectory of forest succession during this period influenced bird communities; old aspen (Populus tremuloides Michx.), old mixedwood, and old white spruce (Picea glauca Moench (Voss)) forests all had different bird communities. Retention of large live trees in cutblocks resulted in their use by many old-forest birds, but results were not consistent among studies. Although most bird species had clear peaks in abundance in a specific forest type, no species with more than five detections was limited to a single forest type.

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Forest diversity as a factor influencing Engelmann spruce resistance to beetle outbreaks

Canadian Journal of Forest Research ◽

10.1139/cjfr-2014-0236 ◽

2014 ◽

Vol 44 (11) ◽

pp. 1369-1375 ◽

Cited By ~ 7

Author(s):

Lafe G. Conner ◽

Michael C. Bunnell ◽

Richard A. Gill

Keyword(s):

Populus Tremuloides ◽

Tree Species ◽

Forest Type ◽

Stand Density ◽

Douglas Fir ◽

Tree Diversity ◽

Phylogenetic Distance ◽

Associational Resistance ◽

Engelmann Spruce ◽

White Fir

Tree mortality because of beetle outbreaks has become substantial and widespread in conifer forests in western North America. A number of environmental and physiological factors influence patterns of mortality. Tree diversity may reduce the severity and extent of insect damage to host trees by providing associational resistance, but the existence and importance of associational resistance varies by forest type and by tree and insect species. We assessed whether plot-level tree diversity contributed to survival of Engelmann spruce (Picea engelmannii Parry ex Engelm.) following a spruce beetle (Dendroctonus rufipennis Kirby) epidemic. Our study plots comprised 2 to 5 tree species including Engelmann spruce, subalpine fir (Abies lasiocarpa (Hook) Nutt.), Douglas-fir (Pseudostuga menziesii (Mirb.) Franco), quaking aspen (Populus tremuloides Michx.), and white fir (Abies concolor (Gordon & Glend.) Hildebr.). We used a model-selection analysis to compare the importance of tree diversity with other known factors that influence spruce survival. We found lower rates of spruce survival in stands where spruce was the dominant tree species (by percent of stand density index) and higher survival in stands where nonspruce conifers (Douglas-fir, subalpine, and white fir) were dominant. We also found that tree diversity (Shannon index) did not show a positive correlation to spruce survival and that there was no additional benefit derived from the presence of aspen, which has higher phylogenetic distance from Engelmann spruce than the other trees in this study. The relationship between diversity and survival is complicated by factors that naturally co-vary with diversity, such as elevation, aspect, and stand density of spruce. Our results best support an explanation that if associational resistance does increase spruce survival during a beetle epidemic, it is due to host or resource dilution, which may be an indirect effect of higher stand diversity.

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Breeding bird communities of the western and northern Canadian boreal forest: relationship to forest type

Canadian Journal of Zoology ◽

10.1139/z96-193 ◽

1996 ◽

Vol 74 (9) ◽

pp. 1749-1770 ◽

Cited By ~ 51

Author(s):

David A. Kirk ◽

Antony W. Diamond ◽

Keith A. Hobson ◽

Alan R. Smith

Keyword(s):

Boreal Forest ◽

Populus Tremuloides ◽

Geographical Variation ◽

Deciduous Forest ◽

Forest Type ◽

Black Spruce ◽

Detrended Correspondence Analysis ◽

Bird Communities ◽

Habitat Associations ◽

Stand Age

We examined the distribution of 80 species of breeding birds across 67 census plots from a variety of sources in the boreal forest of western and northern Canada to obtain information on bird habitat associations for forest management. The sites ranged from upland black spruce (Picea mariana) to riverine deciduous forests and wet, marshy bogs. Axis 1 of an ordination (detrended correspondence analysis) demonstrated a gradient in bird communities from dry to wet sites; axis 2 may have been a black spruce (nutrient poor) to mixed deciduous forest gradient (nutrient rich). Hierarchical classification (twinspan) identified five groups of sites according to their bird communities. Despite geographical variation in bird communities and possible geographical variation in habitat associations, sites were classified according to their forest types rather than regional affinities. Yellow-rumped warblers (Dendroica coronata) and dark-eyed juncos (Junco hyemalis) showed a pronounced gradient of increased abundance from deciduous to coniferous sites. White-throated sparrows (Zonotrichia albicollis) and alder flycatchers (Empidonax alnorum) showed a reverse gradient. In 22 sites of known-age aspen (Populus tremuloides) – mixedwood forests from central Saskatchewan, an ordination indicated a strong relationship between stand age (and thus the proportion of coniferous cover) and bird community structure. The highest combined densities of Neotropical migrants occurred in old forests, whereas short-distance migrants were most abundant in young forests. The highest abundance of upper-canopy gleaners was found in old forests, whereas ground foragers were most abundant in early successional forests. These findings have important implications for management of boreal forests.

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Decomposition of broadleaf and needle litter in forests of British Columbia: influences of litter type, forest type, and litter mixtures

Canadian Journal of Forest Research ◽

10.1139/x00-097 ◽

2000 ◽

Vol 30 (11) ◽

pp. 1742-1750 ◽

Cited By ~ 186

Author(s):

C E Prescott ◽

L M Zabek ◽

C L Staley ◽

R Kabzems

Keyword(s):

British Columbia ◽

Populus Tremuloides ◽

Picea Glauca ◽

Boreal Forests ◽

Forest Type ◽

Douglas Fir ◽

Coniferous Forests ◽

Coastal Forests ◽

Mixedwood Forests ◽

Needle Litter

We measured rates of decomposition at three sites representing the major mixedwood forest types of British Columbia: (i) boreal forests of white spruce (Picea glauca (Moench) Voss) and trembling aspen (Populus tremuloides Michx.); (ii) coastal forests of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and red alder (Alnus rubra Bong.); and (iii) a wet interior forest of Douglas-fir, paper birch (Betula papyrifera Marsh.), and lodgepole pine (Pinus contorta Doug. ex Loud.). Mass loss of litter of each species (both pure and in combination with the other species) was measured for 2-5 years in forests of each species to determine (i) if broadleaf litter decomposed faster than needle litter, (ii) if litter decomposed faster in broadleaf or mixedwood forests than in coniferous forests, and (iii) if mixing with broadleaf hastened decomposition of needle litter. The broadleaf litters decomposed faster than needles during the first year but, thereafter, decomposed more slowly, so differences were small after 3 years. Litter tended to decompose faster in the broadleaf forests than in the coniferous forests. There was either no effect or a slight suppression of decomposition when litters were mixed; thus, there was no evidence that addition of broadleaf litter hastened decomposition of needle litter. The results clearly indicate that the mixing of needle litter with broadleaf litter is unlikely to hasten decomposition in mixedwood forests of British Columbia. The main influence of broadleaves was more rapid decomposition in broadleaf or mixedwood forest floors, which does not appear to be simply an effect of litter quality or litter mixing.

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Trembling aspen seedling establishment, growth and response to fertilization on contrasting soils used in oil sands reclamation

Canadian Journal of Soil Science ◽

10.4141/cjss2011-004 ◽

2012 ◽

Vol 92 (1) ◽

pp. 143-151 ◽

Cited By ~ 40

Author(s):

Bradley D. Pinno ◽

Simon M. Landhäusser ◽

M. Derek MacKenzie ◽

Sylvie A. Quideau ◽

Pak S. Chow

Keyword(s):

Populus Tremuloides ◽

Seedling Establishment ◽

Oil Sands ◽

Land Reclamation ◽

N Fertilizer ◽

Initial Growth ◽

Trembling Aspen ◽

Organic Mineral ◽

Foliar Phosphorus ◽

Oil Sands Reclamation

Pinno, B. D., Landhäusser, S. M., MacKenzie, M. D., Quideau, S. A. and Chow, P. S. 2012. Trembling aspen seedling establishment, growth and response to fertilization on contrasting soils used in oil sands reclamation. Can. J. Soil Sci. 92: 143–151. Trembling aspen (Populus tremuloides) is an important tree species for land reclamation. This study determined trembling aspen germination, establishment, initial growth and response to fertilizer on contrasting oil sands reclamation soils. In a greenhouse, eight soils varying in total nitrogen and available phosphorus were treated with no fertilizer (control), phosphorus and potassium (PK), nitrogen (N) and all three (NPK). Soil had the greatest impact on aspen growth when no fertilizer was applied with the best growth occurring on organic-mineral material soils where growth was positively correlated with extractable and foliar potassium but not to nitrogen or phosphorus. With PK and N fertilizer, growth increases were positively correlated with foliar phosphorus concentrations of the corresponding controls. NPK fertilizer caused greater growth, bud set and root:leaf mass ratio compared with PK or N fertilizer. Soil type had little impact on germination and establishment, indicating natural aspen seedlings can potentially regenerate on all of these soils. In oil sands mining reclamation where these soils are used as surface materials, organic-mineral mixes had the greatest potential without fertilizer. With fertilizer, NPK provided maximum growth and developmental benefits.

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