T.W. "Doc" Daniel Experimental Forest Copyright (c) 2013 Utah State University All rights reserved. http://digitalcommons.usu.edu/docdan Recent documents in T.W. "Doc" Daniel Experimental Forest en-us Sun, 27 Jan 2013 02:46:16 PST 3600 Selection of Microhabitat by the Red-Backed Vole, <i>Clethrionomys gapperi</i> http://digitalcommons.usu.edu/docdan/117 http://digitalcommons.usu.edu/docdan/117 Thu, 05 Nov 2009 14:58:57 PST Clethrionomys gapperi were captured in microhabitats with greater densities of overall cover than at noncapture or random sites within the study area. Variables describing cover density and distance from free water were selected in a discriminant function analysis to differentiate between vole capture and noncapture sites. Vole capture sites had greater amounts of cover within 4 dm above ground surface and were further from standing water than noncapture sites. The preferential use by C. gapperi of microhabitats with greater densities of cover is in agreement with laboratory and field assessments of habitat use reported in the literature.

]]> Alice P. Wywialowski et al. Fire Frequency and the Vegetation Mosaic of a Spruce-Fir Forest in Northern Utah http://digitalcommons.usu.edu/docdan/116 http://digitalcommons.usu.edu/docdan/116 Thu, 05 Nov 2009 14:52:36 PST Fire scar and vegetative analysis were used to construct a fire history for the Engelmann spruce/subalpine fir (Picea engelmannii/Abies lasciocarpa) vegetation type of Utah State University (USU) T. W. Daniel Experimental Forest. Three distinct periods of fire frequency were established-presettlement (1700-1855), settlement (1856-1909), and suppression (1910-1990). Mean fire interval (MFI) decreased during the settlement period and greatly increased during the suppression era. The difference was attributed to the influx of ignition sources during the settlement of nearby Cache Valley, located 40 km to the west. Logging and livestock grazing appear to have led to the reduced MFI, which in turn worked as a factor to create the vegetative mosaic now observed on the study area. The increase in MFI during the suppression ear permitted the advancement of shade-tolerant species in the understory of the shade-intolerant lodgepole pine (Pinus contorta var. latifolia) and quaking aspen (Populus tremuloides). Continued suppression of disturbance from wildfire will allow the lodgepole pine cover type, which experience the lowest MFI during the settlement period, to be further invaded by shade-intolerant species, decreasing spatial stand diversity and increasing the risk of more intense fires.

]]> Linda Wadleigh et al. Nongame Birds of the Rocky Mountain Spruce- Fir Forests and Their Management http://digitalcommons.usu.edu/docdan/115 http://digitalcommons.usu.edu/docdan/115 Thu, 05 Nov 2009 14:45:57 PST Spruce-fir forests in the Rocky Mountains consist mainly of Engelmann spruce and subalpine fir. The breeding avifaunas in these forests show remarkable consistency in composition along a latitudinal gradient from Montana to Arizona and New Mexico, and with avian communities in the Hudsonian life zone in Washington, Oregon, and California. Woodpeckers, corvids, and seed-eating finches are the most common components. Only the Golden Eagle and a few other raptors are threatened or endangered. Few species winter in these high mountain forests. The distribution of many species is controlled primarily by the vegetation physiognomy, a variable under the control of the forest manager. Fire control and snag management will generally benefit the avifauna, whereas most forest harvesting practices adversely affect, to differing degrees~ the bird communities. It is suggested that the "life-form" approach to avian communities may be easily implemented in these forests. It is recommended that high elevation spruce-fir forests be minimally harvested and used as reservoirs for spruce-fir birds. Lower elevational stands should be managed for harvesting and bird diversity, with special attention given to relic stands.

]]> Kimberly G. Smith Migrational Movements of Blue Jays West of the 100th Meridian http://digitalcommons.usu.edu/docdan/114 http://digitalcommons.usu.edu/docdan/114 Thu, 05 Nov 2009 14:42:41 PST Since the start of the bird-banding program in North America, the movements of Blue Jays (Cyanocitta cristata) have been of great interest. The first report of bird-banding recoveries by the Biological Survey (Lincoln 1924) listed 38 Blue Jay returns, all from the same station at which they were banded. The second Biological Survey report (Lincoln 1927) listed 11 Blue Jays recovered at places removed from the original banding station, although 219 of the 230 reports still were returns at the original station. Seven of these 11 recoveries were within the same state as the original banding station, with the 4 others all showing southward movements during fall. Two of these recoveries constituted movements of over 667 km. Over the next 15 years, many long-distance movements by banded Blue Jays were reported (e.g., Whittle 1928, Anon. 1929, Roberts 1936, Stoner 1936), as were sightings of large mass movements or migrations of Blue Jays (e.g., Sherman 1931, Tyrrell 1934, Cottam 1937, Broun 1941, Lewis 1942).

]]> Kimberly G. Smith White-Winged Crossbills Breed in Northern Utah http://digitalcommons.usu.edu/docdan/113 http://digitalcommons.usu.edu/docdan/113 Thu, 05 Nov 2009 14:40:01 PST On 28 June 1977 Stephen B. Vander Wall observed White-winged Crossbills (Loxia leucoptera) at an elevation of 2500 m on the crest of the Bear River Range, 13 km west of Laketown, northern Cache and Rich Cos., Utah. Having censused this area monthly since May 1976, I am certain the species was not present before the last week of June 1977. This occurrence in itself is surprising since only two small flocks had previously been reported in Utah (Worthen 1973, Behle and Perry 1975). Subsequently, I suspected breeding activities in early July and made weekly observations to verify breeding. Also, I captured, examined and banded 19 White-winged Crossbills at a small (<75 >m2) stock pond adjacent to a subalpine meadow on 28 July (7 captured), 6 August (8) and 16 August (4). The pond was the only source of surface water within several km2 during 1977's extreme summer drought in the region. Many species, including Red Crosssbills (L. curvirostra), regularly visited the pond and were easily mist-netted. The nets were baited with salt to attract crossbills (see Samson 1976). Birds stopped visiting the pond in mid-August when it went dry. However, the addition of 200 l of water on 14 August was effective in reattracting many species including crossbills.

]]> Kimberly G. Smith Dinitrogen Fixation in a Montane Forest Sere Determined by 15N2 Assimilation and in situ Acetylene-Reduction Methods http://digitalcommons.usu.edu/docdan/112 http://digitalcommons.usu.edu/docdan/112 Thu, 05 Nov 2009 14:30:22 PST Annual N input rates in a Rocky Mountain forest sere were determined by 15N2 assimilation in an aerobic atmosphere using Swaby-type electrolytic O2-producing incubation flasks, and by in situ enclosures employing C2H2 reduction methods. It was determined that the input in a subalpine meadow was 0.33, in aspen 0.52 and in spruce sites 0.32 kg N ha−1 yr−1, respectively, by combined non-symbiotic and associative-symbiotic fixation. The in situ C2H2 reduction values equated with the 15N2 fixation values if a ratio of 7.5 C2H2 reduced to 1 N2 fixed was used. Symbiotic fixation by a lupine in the aspen site added 0.63 kg N ha−1 yr−1. The associate-symbiotic fixation contributed 14% of the N input in the meadow, 30% in the aspen, and nil in the coniferous stands estimated by the C2H2 reduction method in situ. The results supported the conclusions that the N2 fixation, similar to other microbiological characteristics of the aspen and conifer sites, agrees with the accepted definition of a successional forest sere.

]]> J C. Skujiņš et al. Soil Biological Properties of a Montane Forest Sere: Corroboration of Odum's Postulates http://digitalcommons.usu.edu/docdan/111 http://digitalcommons.usu.edu/docdan/111 Thu, 05 Nov 2009 14:24:59 PST Changes in organic C content, N component pools, Shannon-Weaver diversity index (H′) of microbial populations, nitrification potential, and ATP and dehydrogenase activities were examined in soils along a montane meadow-aspen-fir-spruce sere.

Along the sere organic C increased from 2.15 to 26.8%, total N from 0.13 to 0.98%, C: N ratios from 17 to 27, total NH4+ from 103 to 850 μg g−1, total NH4+:NO3− ratios from 69 to 326, and microbial diversity index, H′, from 0.87 to 1.28. Coefficients of determination, r2, for H′ vs organic C and total N in A-horizons, were 0.99 and 0.98, respectively, and H′ vs combined O- and A-horizons 0.68 and 0.70, respectively, indicating the presence of different microbial communities in the mineral and forest floor soils. Radiocarbon dating of humic acids and humin showed the longest mean residence times (920 and 1050 yr BP) in the meadow soils, suggesting a more efficient organic matter turnover and selective accumulation of recalcitrant organic components than in soils of more mature stages. The ATP content and dehydrogenase activity values were not statistically different in the forest sequence soils. Rates of nitrification potentials measured in vitro increased along the sere in the surface soils.

Information obtained from seral soil variables supported hypothesized successional trends relating to organic matter content, species diversity, nutrient cycling, nutrient exchange rate and nutrient conservation. Nitrification potentials of soils, however, contradicted the postulate that nutrient conservation increases as an ecosystem matures.

]]> J Skujins et al. Insect Communities and Faunas of a Rocky Mountain Subalpine Sere http://digitalcommons.usu.edu/docdan/110 http://digitalcommons.usu.edu/docdan/110 Thu, 05 Nov 2009 14:19:31 PST Insect faunas and communities are characterized for herbaceous and tree canopy layers in meadow, aspen, and spruce/fir stages of a northern Utah sere. A greater percentage of species were in Thysanoptera in both aspen strata, and a greater percentage of individuals were in Lepidoptera in aspen canopy. Our sites were quite similar to a wide variety of other terrestrial sites in their distribution of species or individuals among orders or metamorphosis categories. Insects/m2 peaked in the aspen stage, but declined in the herbaceous layer with succession. Insects/plant biomass in the herbaceous layer increased with succession. Insects/m2 and insects/foliar biomass were higher in aspen canopies than in conifer canopies. Insect species/m2 peaked in the aspen stage. This statistic was comparable in meadow and aspen understory, and lower in conifer understory. Insects/m2 in the tree canopies were similar to the values in their respective understories. Insect species/plant biomass increased in the herbaceous layer with succession, but decreased in tree canopies with succession. Species evenness in both strata increased with succession. Adult body length was greatest for meadow species, least for conifer species. Adult body length per individual was greatest in aspen. Life cycle complexity was greatest in aspen. Insects on trees were more likely to have complex life cycles than those on herbs.

]]> David J. Schimpf et al. Some Aspects of Succession in the Spruce-Fir Forest Zone of Northern Utah http://digitalcommons.usu.edu/docdan/109 http://digitalcommons.usu.edu/docdan/109 Thu, 05 Nov 2009 14:17:48 PST A site in the Rocky Mountain subalpine forest zone with which a series of hypotheses concerning ecosystem succession was tested is characterized. Succession from herb-dominated meadows to climax forests of Engelmann spruce and subalpine fir can follow at least four identified pathways. After fire, spruce and fir may reinvade a site directly, follow invasion by aspen, or follow invasion by lodgepole pine, the pathway depending on a combination of physical and biotic factors. In other cases, succession begins with long-established meadows which do not owe their existence to fire. In this latter pathway, aspen invades meadows by suckering and changes the environment near the soil surface so as to facilitate establishment of the climax tree species. The biota and soils of four characteristic seral stages (meadow, aspen, fir, spruce-fir) in this latter pathway are described.

]]> David J. Schimpf et al. Reproductive Attributes of Some Rocky Mountain Subalpine Herbs in Successional Context http://digitalcommons.usu.edu/docdan/108 http://digitalcommons.usu.edu/docdan/108 Thu, 05 Nov 2009 14:16:07 PST Selected reproductive attributes of herbaceous plant species were compared among three stages of a sere in the subalpine zone of Utah’s Wasatch Mountains: herbaceous meadow, aspen grove, spruce-fir forest. No successional trends in seed size or inferred mode of seed dispersal were detected. We ascribe the deviation of these findings from those of most other studies to differences in climate, life-form composition, or community age between our sere and those of other studies. A variety of flower colors were found in the meadow stage, grading into a predominance of white flowers under conifers. Animal vectors of pollen, capable of effecting plant outcrossing, were most abundant in the meadows and an order of magnitude less abundant under aspen.

]]> David J. Schimpf et al. Production Efficiency of <i>Abies lasiocarpa</i>: Influence of Vertical Distribution of Leaf Area http://digitalcommons.usu.edu/docdan/106 http://digitalcommons.usu.edu/docdan/106 Thu, 05 Nov 2009 14:01:26 PST A simple conceptual model is proposed concerning how leaf area efficiency (stemwood growth per unit leaf area) changes with leaf area for trees within a stand. Greater leaf area is generally associated with (i) improved light environment due to greater height and (ii) a lower ratio of photosynthetic to nonphotosynthetic tissue. Greater height and improved light environment result in higher photosynthetic production, which should increase leaf area efficiency. A lower ratio of photosynthetic to nonphotosynthetic tissue suggests that the ratio of respiration to photosynthesis increases, which should decrease leaf area efficiency. In relatively small trees, the influence of increased height (associated with greater leaf area) should more than offset the influence of the increased respiration:photosynthesis ratio; as a result, leaf area efficiency should increase with leaf area. In large trees, further increases in leaf area are associated with minimal increases in height, and leaf area efficiency should decline as the respiration:photosynthesis ratio increases. Predictions from this conceptual model were examined with data from stands of subalpine fir (Abieslasiocarpa (Hook.) Nutt.).

]]> Scott D. Roberts et al. Analysis of Stand Density Effects on Canopy Structure: A Conceptual Approach http://digitalcommons.usu.edu/docdan/107 http://digitalcommons.usu.edu/docdan/107 Thu, 05 Nov 2009 14:01:26 PST A few assumptions were used to generate a series of specific, quantitative predictions for the relationships between stand density and various dimensional measures of canopy structure. The predictions, each indicating an increase in mean crown size as density decreased, appeared to be reasonable and intuitive. Predictions were compared to data for two conifer species with different crown forms, Pinus contorta var. latifolia and Abies lasiocarpa. Results of these comparisons were mixed — the linear, directly measured dimensions were consistent with predicted relationships, but dimensions calculated from the linear measures were not. Re-examination of the original assumptions indicated that the model should account for crown shyness (engagement/disengagement) to adequately reflect the influence of stand density on canopy structure. The results also indicated a strong association between stand height and measures of mean crown size. Mean crown size of lodgepole pine was altered much more by density than was mean crown size of subalpine fir, due primarily to the different relative shade tolerances of the two species. Some of the observed differences between species may also reflect the range of densities examined and uneven spacing in the unmanaged natural stands.

]]> Steven B. Jack et al. The Occurrence of Non-Ring Producing Branches in <i>Abies lasiocarpa</i> http://digitalcommons.usu.edu/docdan/105 http://digitalcommons.usu.edu/docdan/105 Thu, 05 Nov 2009 13:53:36 PST Lack of annual growth ring production at the base of branches in the lower portion of the crown is a commonly observed phenomenon. In this study, branches with missing rings were found on 47 of 49 Abies lasiocarpa trees sampled. The number of missing rings on the lowest live branch in the crown averaged 12, and ranged as high as 28. The lower one-third of the live crown tended to consist of branches without rings; these branches contained an average of 30% of the total crown leaf area. The ratio of foliage weight to total branch weight, in combination with position of the branch in the canopy, was an effective discriminator of non-ring producing branches. This suggests that both structural and environmental factors influence the cessation of ring production. The potential ecological implications of branches that fail to produce rings are discussed.

]]> Scott D. Roberts Intra- and Interspecific Tests of Some Indicators of Relative Tolerance http://digitalcommons.usu.edu/docdan/103 http://digitalcommons.usu.edu/docdan/103 Thu, 05 Nov 2009 13:37:06 PST Community ecologists and foresters commonly view relative tolerance as the capacity of a species to survive in the understory of an established plant community. Diverse individual- and population-level attributes are commonly cited as indirect indicators of relative tolerance. Eight of these putative indicators of relative tolerance were tested for their ability in discriminating between species representing differing levels of relative tolerance; of these, only five were found to be valid. The indicators were even less accurate in discriminating between presumed intraspecific differences in relative tolerance. The species characteristics that appeared to have the greatest potential as indicators of relative tolerance involved stand density, leaf-area index and foliage retention time.

]]> Joy N. Parker et al. An Organism-Centered Approach to Some Community and Ecosystem Concepts http://digitalcommons.usu.edu/docdan/102 http://digitalcommons.usu.edu/docdan/102 Thu, 05 Nov 2009 13:30:01 PST We present a discussion of the ecological concept of the niche based on the perspective of the individual organism, rather than that of a population or species. This discussion is then expanded to include other related ecological concepts such as guild, environment, habitat and functional group.

Using the individual as the focus permits the development of a system of concepts which, we believe, approximate the way that ecological interactions occur in nature.

]]> James A. MacMahon et al. Canopy Development and Leaf Area Efficiency: Links between Production Ecology and Density Management http://digitalcommons.usu.edu/docdan/101 http://digitalcommons.usu.edu/docdan/101 Thu, 05 Nov 2009 13:20:28 PST The generally positive relationships between PAI and LAI and between mean PAI and mean leaf area are modified as leaf area efficiency decreases in trees with large crowns. Relative density indices, such as SDI, are effective indicators of growing stock because they incorporate mean leaf area as well as LAI.

]]> J N. Long et al. Estimating Leaf Area of <i>Abies lasiocarpa</i> Across Ranges of Stand Density and Site Quality http://digitalcommons.usu.edu/docdan/100 http://digitalcommons.usu.edu/docdan/100 Thu, 05 Nov 2009 13:18:21 PST For a given species, differences in the relation between leaf area and sapwood cross-sectional area at breast height have been attributed to the effects of varying stand density and site quality. When leaf area of Abieslasiocarpa (Hook.) Nutt. is estimated as a function of sapwood cross-sectional area at breast height and distance from breast height to the midpoint of the crown, the apparent effects of stand density and site quality are eliminated. A comparison of these results with those for Pinuscontorta Dougl. suggests this model form should provide unbiased estimates of leaf area for a variety of species and stand conditions.

]]> James N. Long et al. Leaf Area-Sapwood Area Relations of Lodgepole Pine as Influenced by Stand Density and Site Index http://digitalcommons.usu.edu/docdan/99 http://digitalcommons.usu.edu/docdan/99 Thu, 05 Nov 2009 13:17:05 PST Leaf area to sapwood area ratios for a given species are believed to vary with factors such as site quality, stand density, early stand growth rates, and crown class. Based on data from 55 mature lodgepole pine trees (Pinuscontorta var. latifolia Dougl.) from 10 plots in southeastern Wyoming, we conclude that putative density and site effects on leaf area - sapwood area relations are actually a consequence of the increase in the leaf area to sapwood area ratio with increasing sapwood area. When leaf area is estimated with a nonlinear model that includes tree size and distance to the live crown, the apparent effects of stand density and site index disappear. We consider a constant ratio of leaf area and sapwood cross-sectional area to be inappropriate for the estimation of leaf area across the range of stand conditions included in most studies of forest ecology.

]]> James N. Long et al. The Effects of Silvicultural Treatments on Occurrence of Mycorrhizal Sporocarps in a Pinus contorta Forest: A Preliminary Study http://digitalcommons.usu.edu/docdan/98 http://digitalcommons.usu.edu/docdan/98 Thu, 05 Nov 2009 13:09:58 PST A preliminary survey was conducted to evaluate the effects of thinning and clearcutting, followed by replanting, on mycorrhizal fungi. A total of 48 species of mycorrhizal fungi was recorded for the study site. Suillus brevipes and S. tomentosus were the dominant species. Data from the survey indicate that thinning reduced the total number of species as compared to an undisturbed stand. Some fungi were adversely affected by thinning while others were positively affected. Members of the Hygrophoraceae appeared to be most susceptible to mild disturbance such as thinning. While clearcutting had a negative impact on the total number of sporocarps of mycorrhizal fungi, Suillus brevipes increased in percent abundance as severity of disturbance increased.

]]> Bradley R. Kropp et al. ATP Concentration and Soil Respiration at Reduced Water Potentials in Arid Soils http://digitalcommons.usu.edu/docdan/97 http://digitalcommons.usu.edu/docdan/97 Thu, 05 Nov 2009 13:07:50 PST Adenosine triphosphate (ATP) concentrations and soil respiration rates of two arid and one subalpine forest soil were evaluated as a function of water potential (ψw) in the range −2 to −100 bars. Water potential was determined by thermocouple psychrometry, CO2 release from soil by titrimetry; ATP was extracted from soil with cold sulfuric acid and assayed by luciferin-luciferase methology. ATP concentrations increased in the ψw range −2 to −20 bars in the arid soils and was negatively correlated (r^2 = 0.92) with exponential decreases in respiration rates for the same ψw range. In the subalpine forest soil, the highest ATP concentration was at the highest measured water potential (−2 bars) and decreased with decreasing respiration rates (r^2 = 0.93) and decreasing ψw values. It was concluded that the soil microflora may exhibit diverse physiological responses to water and, consequently, to available carbon-source induced stresses in soils from environmentally different areas.

]]> W G. Knight et al.