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Filters: Tags: Monitoring 1-Changes in Plant and Animal Distribution: Flora (X)

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Tree-ring analyses and an interpolated climate model (ClimateBC) were used to compare radial growth responses to climate variables among three coexisting, ecologically distinct conifer species, including interior spruce (Picea glauca x Picea Engelmannii ), lodgepole pine ( Pinus contorta var. latifolia ) and subalpine fir (Abies lasiocarpa ) across a range of climate conditions in western Canada, and altitudinal treelines in the Engelmann Spruce-Subalpine Fir forests in central British Columbia (BC). Ring-width chronologies were developed and correlated with site-specific climate data in the past 50 years from 1953-2002. Spruce ring-width chronologies were mainly correlated with June-July temperatures across the...
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Increased fire severity in boreal forests of Interior Alaska is shifting forest canopy composition from black spruce (Picea mariana) to deciduous species, including trembling aspen (Populus tremuloides) and Alaska paper birch (Betula neoalaskana). Because deciduous trees are less flammable than black spruce, the dominant disturbance regime in deciduous forests could move away from fire to one of gap disturbances. In this study, we quantified forest gap characteristics and vegetation within eight mature (62–119-yr-old) deciduous stands in Interior Alaska. Canopy gaps were generally small (true gap area <50 m2), formed by the mortality of 4–16 gap makers (which were always deciduous trees), and occupied ∼17–29% of...
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A reconnaissance inventory of the vascular plant flora of Denali National Park and Preserve was conducted during the period 1998-2001. The primary goal of this project was to synthesize existing floristic information with the results of targeted original inventory field work in order to produce a voucher-based list of the vascular plant species that occur within the Park. In order to accomplish this fundamental goal of documenting the flora of Denali National Park and Preserve there were five major objectives that needed to be met: 1) to assemble all available pre-existing floristic data into a highly functional database; 2) to assess the strengths and weaknesses of this existing data set and identify geographic...
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Abstract. We compared the species composition and species density of vascular plants in the understorey vegetation of boreal forest between Picea mariana (Black spruce) and Populus tremuloides (Trembling aspen) stands in British Columbia, Canada, and related differences in species composition and species density between the two forest types to dominant canopy tree species as well as a wide variety of environmental factors. We analysed 231 stands, distributed in three different climatic regions representing drier, wetter, and milder variations of montane boreal climate. Of these stands 118 were dominated by P. mariana and 113 by P. tremuloides. P. tremuloides stands had higher species density than P. mariana stands...
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The litter-bag technique has become common in the estimation of the rates of decomposition, but in many cases the bags are incubated for only a short period, raising the issue of the extent to which short-term incubations represent long-term litter decomposition. We addressed this using 12 years of data from the CIDET study.
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Ectomycorrhizal (ECM) fungi, like wood and litter decaying fungi, are believed to produce extracellular oxidative enzymes. Oxidative enzymes associated with lignin degradation have been demonstrated to effectively degrade recalcitrant organic compounds, including chlorinated pesticides and polycyclic aromatic hydrocarbons (PAHs). This thesis describes a suite of experiments investigating ECM fungi lignolytic enzymes and the fate of organochlorine pesticide in Alaskan ECM fungal cultures. In this study, molecular techniques were employed to assess the potential of Alaskan ECM fungal cultures to produce the lignolytic enzymes lignin peroxidase (LiP), manganese peroxidase (MnP), and laccase (Lac). ECM mycelia were...
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Pinus contorta Douglas ex Loudon var. yukonensis W. L Strong (Yukon pine), a new variety, is described from south?central Yukon, Canada. It is a stout tree with long lower branches, often with paired lower and forked upper stems, and weakly platy to smooth gray bark on the lower stem, when < 70 years old; with bark on the lower stem becoming furrowed and platy on older trees. This contrasts with the narrow columnar habit, simple stem, and scaly bark associated with the more common inland var. latifolia. In several respects, var. yukonensis is more similar to var. contorta (a coastal variant), although occupying a different ecological regime and spatially disjunct (i.e., a high latitude and high elevation variant)....
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Normalized difference vegetation index (NDVI) derived from AVHRR and MODIS satellitesensors is summarized in five northern Alaskan National Park Service units dominated by arctictundra. NDVI is an index of vegetation productivity that is closely related to the warmth ofsummer growing seasons in the arctic. Mean NDVI for ecological sections (broad landscapescalemapping units) is highest for densely vegetated lowlands, lowest in sparsely vegetated highmountain areas, and intermediate in lowlands with significant area of lakes. NDVI during greenup(June) varies 20 to 40% between years, while peak NDVI and late-season NDVI vary 10 to20% between years. These short-term variations are closely linked to current-year variations...
Here we quantitatively summarize the conservation ecology of one group of dead-wood-dependent organisms, the polyporous fungi, in boreal Europe. At the substrate scale, the decay stage is the strongest determinant of species richness, with large (>20 cm diameter) downed logs hosting more species than other dead-wood types. At the stand scale, the amount of dead wood is the strongest determinant of polypore species richness; the minimum average amount of dead wood for the occurrence of rare polypores appears to be 20–40 m3/ha. Species-area analysis shows that in mature boreal forests species accumulation levels off at around 20–30 ha. This leads us to suggest a heuristic 20/20/20 rule of thumb: a 20 ha stand, with...
List of 67 rare plants (Alaska Natural Heritage Program state rank <= 3)for Wrangell-St. Elias National Park and Preserve as of July 24 2000. List includes rank, number of occurrences, habitat and park distribution.
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Long-term experiments provide a way to test presumed causes of successional or environmentally driven vegetation changes. Early-successional nitrogen (N)-fixing plants are widely thought to facilitate productivity and vegetation development on N-poor sites, thus accounting for observed vegetation patterns later in succession. We tested this facilitative impact on vegetation development in a 23-yr field experiment on an Interior Alaska ( USA) floodplain. On three replicate early-successional silt bars, we planted late-successional white spruce ( Picea glauca) seedlings in the presence and absence of planted seedlings of an early-successional N-fixing shrub, thinleaf alder ( Alnus incana). Alder initially facilitated...
map background search result map search result map Understorey vegetation in boreal Picea mariana and Populus tremuloides stands in British Columbia Pinus contorta var. yukonensis var. nov. (Pinaceae) from south-central Yukon, Canada A newly described plant disease complex involving two distinct viruses in a native Alaskan lily, Streptopus amplexifolius Clonal and nonclonal genetic structure of subarctic black spruce (Picea mariana) populations in Yukon territory Botanical Survey of Selected Sites in the White Mountains National Recreation Area and the Steese National Conservation Area, Yukon-Tanana Uplands, Alaska    The Community Ecological Monitoring Program Annual Report 2008 Satellite greenness data summary for the Arctic Inventory and Monitoring Network, 1990-2009 The Vascular Plant Floristics of Denali National Park and Preserve: A Summary, Including the Results of Plant Inventory Fieldwork 1998-2001 A first comprehensive census of fungi in soil reveals both hyperdiversity and fine-scale niche partitioning Can short-term litter-bag measurements predict long-term decomposition in northern forests? Forest recovery trends derived from Landsat time series for North American boreal forests Gap regeneration within mature deciduous forests of Interior Alaska: Implications for future forest change Absence of net long-term successional facilitation by alder in a boreal Alaska floodplain Absence of net long-term successional facilitation by alder in a boreal Alaska floodplain Can short-term litter-bag measurements predict long-term decomposition in northern forests? A first comprehensive census of fungi in soil reveals both hyperdiversity and fine-scale niche partitioning Clonal and nonclonal genetic structure of subarctic black spruce (Picea mariana) populations in Yukon territory Botanical Survey of Selected Sites in the White Mountains National Recreation Area and the Steese National Conservation Area, Yukon-Tanana Uplands, Alaska    A newly described plant disease complex involving two distinct viruses in a native Alaskan lily, Streptopus amplexifolius The Vascular Plant Floristics of Denali National Park and Preserve: A Summary, Including the Results of Plant Inventory Fieldwork 1998-2001 Satellite greenness data summary for the Arctic Inventory and Monitoring Network, 1990-2009 Pinus contorta var. yukonensis var. nov. (Pinaceae) from south-central Yukon, Canada The Community Ecological Monitoring Program Annual Report 2008 Gap regeneration within mature deciduous forests of Interior Alaska: Implications for future forest change Understorey vegetation in boreal Picea mariana and Populus tremuloides stands in British Columbia Forest recovery trends derived from Landsat time series for North American boreal forests