Download or read book Influence of Deciduous Tree Representation on Understory Plant Communities in Pacific Northwest Forests written by Dano Holt and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: While broadleaf deciduous trees are historically a consistent component of forest canopy composition, the ecological importance of these trees has been understudied, in particular their impact on understory plant communities. Broadleaf deciduous trees are a unique source of functional diversity in the Pacific Northwest's conifer dominated forests, and have been shown to alter soil nutrients, precipitation reaching the forest floor, epiphytic communities and provide critical habitat for a number of dependent wildlife species. However, their impact on understory plant communities has remained understudied. In particular, as one of the key functional differences in coniferous and broadleaf trees in the Pacific Northwest is a deciduous leaf habit which increases light transmission in the fall through winter, their impact on light availability to the understory has remained under investigated. It was hypothesized that understory plants growing beneath deciduous trees would be exposed to more light. This study investigated understory plant communities growing under overstory canopies of highly coniferous, low deciduous or highly deciduous compositions. Hypotheses were that 1) understory plant communities will differ significantly from communities under stands with differing overstory percent deciduousness, and that there would be changes to understory plant community diversity and 2) commonly occurring generalist species be acclimated to higher light availability in terms of functional traits, including specific leaf area (SLA), leaf area (LA), rachis angle (in Polystichum munitum), light compensation point (LCP), light response curves, saturation point (K) and intrinsic water use efficiency (iWUE). Understory community composition sampling indicated that canopy composition type had a significant effect on understory community, as indicated by a PERMANOVA test. Additionally, there were a number of species that only occurred under either highly coniferous or highly deciduous canopies. Results from functional trait sampling indicated that for the majority of traits generalist species including Acer circinatum, Berberis nervosa and Polystichum munitum exhibited changes to functional traits indicating that highly deciduous plots were higher light plots. Not only were understory communities growing under highly deciduous canopies significantly differ from those growing beneath low deciduous or highly coniferous canopies, but there were changes to morphology and physiology of plants under differing canopy types. These results suggest that broadleaf deciduous trees in the Pacific Northwest have a functional impact on heterogeneity of the understory environment and consequently the understory plant communities. These results imply that broadleaf deciduous trees play an important role in structuring forests in the Pacific Northwest, and their impact should be assessed in both forest management and conservation purposes.

Download or read book Effects of Variable density Thinning on Understory Diversity and Heterogeneity in Young Douglas fir Forests written by Juliann E. Aukema and published by . This book was released on 2008 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nine years after variable-density thinning (VDT) on the Forest Ecosystem Study, we examined low understory vegetation in 60 plots of eight stands (four pairs of VDT and control). We compared native, exotic, ruderal, and nonforest species richness among the stands. We used clustering, ordination, and indicator species analysis to look for distinctive patches of plant associations. Native, exotic, ruderal, and nonforest plant species diversity were higher in VDT stands compared to control stands for both forests. Differentiation of the understory into multiple distinct vegetation patches was not definitive, but there were trends toward greater heterogeneity in VDT stands.

Download or read book Forested Plant Associations of the Oregon East Cascades written by Michael Simpson and published by . This book was released on 2007 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Patterns in Understory Vegetation Communities Across Canopy Gaps in Young Douglas fir Forests of Western Oregon written by Robert T. Fahey and published by . This book was released on 2005 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: Canopy gap formation is a major factor contributing to maintenance of overstory species diversity and stand structure in forests and may be integral to development of understory shrub and herb layers as well. Acknowledgement of gap formation as a fundamental feature of natural forests has led to consideration of gaps as an option in forest management regimes. This study examined understory vegetation communities across canopy gaps created as a part of the Density Management Study (DMS), which investigates the effectiveness of a thinning regime in promoting late-successional habitat development in young Douglas-fir forests of western Oregon. Patterns in understory vegetation community composition in and around 0.1 and 0.4ha gaps created as a part of the DMS treatment were investigated. The primary goal of this research was to investigate the potential role of canopy gap creation in fostering heterogeneity in understory vegetation communities, and to examine the extent of gap influence on the surrounding thinned forest matrix. Tree species distributions have been shown to partition across gaps in tropical forest systems through differential responses of species to gradients in resource availability, a pattern known as gap partitioning. In temperate forests, understory vegetation communities are much more diverse than the overstories, and display a greater array of habitat requirements. Therefore, understory communities may be more likely than overstories to exhibit gap partitioning in these forests. Patterns in understory community composition across gaps suggest that gap partitioning has occurred. The strength of this partitioning effect appears to differ between gap sizes, as smaller gaps showed a less powerful effect. Abundance of ruderal species was strongly related to gap partitioning in larger gaps, while smaller gaps were dominated by competitor species. Partitioning may be related to an interactive relationship between harvest-related ground disturbance and resource gradients. Therefore, considerations of gap partitioning processes should take into account intensity and spatial distribution of ground disturbance in relation to resource gradients. In addition, conditions necessary for the expression of gap partitioning in understory vegetation communities may be rare in natural gaps in this region. The influence of gaps on understory vegetation communities in the surrounding forest appears to be relatively small. This small influence extent may help explain the lack of a stand level response to gap formation in these stands. Larger gaps exhibit a slight influence on the understory plant community in the surrounding forest to the north of the gap. In small gaps, there seemed to be an influence of the surrounding forest on gap interiors, resulting in an area of influence smaller than the physical gap area. This relationship may indicate that the area of gap influence on understory vegetation may not scale linearly with physical gap size. Species diversity was higher in gap interiors than in surrounding thinned forests. However this effect was partially due to the presence of exotic species, which showed an affinity for gap interiors. Late successional associated species were negatively related to gap interiors, but only in the larger gap size. Gap creation appears to be promoting small scale species diversity in these stands, but creation of large gaps may also promote the establishment of exotic species and may have a negative effect on late successional associated species. However, any and all of these effects may be transient, as understory communities will be strongly affected by overstory re-establishment, and related changes in resource availability. In general, gap formation may influence small-scale stand heterogeneity as evidenced by understory plant communities, but this effect may rely strongly on the nature of gap formation and intensity of disturbance related to this formation.

Download or read book Field Guide to the Forested Plant Associations of Southwestern Oregon written by and published by . This book was released on 1996 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Forested Plant Associations of the Colville National Forest written by Clinton K. Williams and published by . This book was released on 1990 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book BPA Puget Power Northwest Washington Transmission Project written by United States. Bonneville Power Administration and published by . This book was released on 1995 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book General Technical Report PNW GTR written by and published by . This book was released on 2002 with total page 928 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Spatial Distribution of Understory Vegetation in Tree Canopy Gaps of the Pacific Northwest written by Sharon Gail London and published by . This book was released on 1999 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understory vegetation in artificially created tree canopy gaps in the Pacific Northwest was studied to determine 1) variation in understory vegetation cover between gap edges and gap centers, as well as between control and treatment plots, 2) spatial patterns of biomass and difference in biomass patterns among plots, 3) individual species responses to gap creation and 4) the relationships between species dominance and diversity by site and treatment. Data were collected in 1990 and 1997 in 16 plots (two controls and two treatments at each of four study sites: the H.J. Andrews Experimental Forest and Martha Creek, Panther Creek, and Trout Creek in the Wind River Experimental Forest). Two of the sites are oldgrowth stands (250-500 years old), while the other two sites are mature stands (90- 150 years old). Six growing seasons after gap creation, average percent cover of understory vegetation was greater within gaps than at gap edges. Vegetation cover had increased significantly in all artificial gaps, and it had increased more in gaps than in controls. Vegetation cover increased more at Martha Creek, a mature stand, than at H.J. Andrews and Trout Creek, the two old-growth stands, or at Panther Creek, a mature stand. Understory biomass increased more in gaps than in controls and the amount of increase varied by site. Initial understory biomass was highest in Panther Creek and Martha Creek, but the magnitude of biomass increase was greatest in Trout Creek and H.J. Andrews. Biomass patterns in 1990 and 1997 were more patchy in old-growth stands than in mature stands. Vegetation cover of most understory species increased from 1990 to 1997 in artificial gaps, but species' responses were often site specific. In some cases, species with advantageous dispersal mechanisms (such as rhizomes, stolons, or clonal growth, e.g. Rubus ursinus, or Acer cinncinatum) increased in cover and biomass more than species without such advantageous dispersal mechanisms. Cover of weedy species such as Epilobium angustfolium and Lactuca muralis increased dramatically (up to 25 times) in artificial gaps, but weedy species represented less than two percent of the total average cover in 1997. Species dominance and diversity did not respond consistently following gap creation. Species dominance was relatively high (species with highest dominance was 30 g/m2) and diversity relatively low (38 species) at Martha Creek, a mature stand, whereas species dominance was low and diversity high at H.J. Andrews (9 g/m2, 51 species), an old-growth site. Panther Creek, a mature stand, and Trout Creek, an old growth stand, had intermediate dominance and high diversity (17 g/m2, 57 species at Panther Creek and 18 g/m2, 41 species at Trout Creek).

Download or read book Distribution of Understory Species in Relation to Maximum and Minimum Tree Influence in the Montane Forest of the Central Oregon Cascades written by Andrew Frederick Robinson (Jr) and published by . This book was released on 1969 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: Twenty sites of uniform topography and soil were select ed in the montane forest found on the East flank of the Central Oregon Cascades. These sites were located along a vegetational gradient composed of five plant communities: Abies/Pachistima, Pinus/Ceanothus, Pinus Arctostaphylos-Purshia, Pinus/Purshia/Festuca, and Juniperus Festuca. An attempt was made to relate the distributional pattern of understory species to six aspects of tree influence (overhead cover, amount of shade, daily differences in shading, seasonal differences in shading, amount of litter deposit, and species of tree depositing the litter) understory species' competition, and plot location. Cole's index and hierarchical classification analysis were statistical methods used to correlate the understory species' pattern to tree influence, understory species' competition, and plot location. From frequency data of the 63 species analyzed by Cole's index, only two showed an inconsistent distributional pattern in relation to tree influence. Similarly, three distributional patterns were noted. (1) Species were distributed at random in the area of maximum tree influence regardless where the species occurred along the gradient. (2) Species were distributed at random in the area of minimum tree influence and were absent in the area of maximum tree influence regardless where the species occurred along the gradient. (3) Species at a point along the gradient were distributed at random in areas of maximum and minimum tree influence; but on more xeric plots the species were distributed similar to pattern 1, and on more mesic plots species were distributed similar to pattern 2. In pattern 3, the point along the gradient where the species were distributed at random to areas of maximum and minimum tree influence may suggest an optimum point along the gradient where the effect from tree layer influence is minimal. This point provides a basis for comparing the environmental tolerances of the species and ordinating the stands. When the species' density data were analyzed by hierarchial classification to determine what factors of maximum and minimum tree influence effected the density distribution of the species, the following patterns were noted. Normally, species with highest densities in areas of maximum insolation or sparse litter were prominent on the xeric end of the gradient, and those species with maximum densities in areas of low insolation or deep litter were prominent on the mesic end of the gradient. Chamaephyte species sampled had highest densities in areas underneath the trees and usually near the me sic end of the gradient. Therophyte species sampled had highest densities in open areas usually near the xeric end of the gradient. Thus, a theoretical model was constructed using data obtained from this structural analysis of internal distributional patterns of understory species. The distribution of the species is much wider according to the theoretical model than was actually found by constancy data, but the differences when statistically analyzed are not great enough to reject the model at the 1% significance level. The model suggests predictable patterns of species' distribution within the five community types and may reflect the relative stability of these species within the community types.

Download or read book Biotic and Abiotic Processes of Eastside Ecosystems written by and published by . This book was released on 1994 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effects of Variable density Thinning on Understory Diversity and Heterogeneity in Young Douglas fir Forests written by Juliann E. Aukema and published by . This book was released on 2007 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Understory Diversity and Succession on Coarse Woody Debris in a Coastal Old growth Forest Oregon written by and published by . This book was released on 2013 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research examines the relationship between understory plant diversity and logs in a Pacific Northwest (PNW) Sitka spruce (Picea sitchensis)-western hemlock (Tsuga heterophylla) old-growth, coastal forest. These forests are renowned for their high forest productivity, frequent wind storms, and slow log decomposition rates that produce unmatched accumulations of coarse woody debris (CWD) yet few studies have examined the relationship between CWD and understory vegetation ecology. My research addressed this topic by comparing understory plant census data between paired fallen log and forest floor sites (n=20 pairs). My objectives were to: 1) determine the influence of substrate type on community composition and diversity, and 2) examine successional pathways and species assemblage patterns on CWD in various stages of decomposition. To meet these objectives I employed non-metric multidimensional scaling (NMDS) ordinations and unsupervised cluster analyses to identify and compare community assemblages on both substrates. These methods revealed similar species diversity and evenness between log and forest floor sites with compositional differences within and between substrates corresponding to habitat availability for colonization and light and moisture gradients. My results also suggest understory successional pathways related to decay class and characterized by an initial abundance of bryophytes, forbs, and seedlings followed by woody shrubs. Understory communities developing on logs also experienced increasing diversity, evenness, and divergence from forest floor communities consistent with log decomposition. These results differ from findings for boreal forests that reveal increasing similarity between substrate communities with increasing decay class. Recommendations for future research include the employment of a more robust sample size and direct measurements of environmental variables. Additional comparator studies are also needed to confirm the effects of forest type and decomposition on the relationship between CWD and forest understory communities. This study demonstrates how fine-scale wind disturbance fosters biodiversity through the creation of CWD substrate. My results and future research are essential for the development of silvicultural models designed to promote biodiversity in PNW coastal forests.

Download or read book Real Gardens Grow Natives written by Eileen M Stark and published by Mountaineers Books. This book was released on 2014-09-24 with total page 645 pages. Available in PDF, EPUB and Kindle. Book excerpt: CLICK HERE to download sample native plants from Real Gardens Grow Natives For many people, the most tangible and beneficial impact they can have on the environment is right in their own yard. Aimed at beginning and veteran gardeners alike, Real Gardens Grow Natives is a stunningly photographed guide that helps readers plan, implement, and sustain a retreat at home that reflects the natural world. Gardening with native plants that naturally belong and thrive in the Pacific Northwest’s climate and soil not only nurtures biodiversity, but provides a quintessential Northwest character and beauty to yard and neighborhood! For gardeners and conservationists who lack the time to read through lengthy design books and plant lists or can’t afford a landscape designer, Real Gardens Grow Natives is accessible yet comprehensive and provides the inspiration and clear instruction needed to create and sustain beautiful, functional, and undemanding gardens. With expert knowledge from professional landscape designer Eileen M. Stark, Real Gardens Grow Natives includes: * Detailed profiles of 100 select native plants for the Pacific Northwest west of the Cascades, plus related species, helping make plant choice and placement. * Straightfoward methods to enhance or restore habitat and increase biodiversity * Landscape design guidance for various-sized yards, including sample plans * Ways to integrate natives, edibles, and nonnative ornamentals within your garden * Specific planting procedures and secrets to healthy soil * Techniques for propagating your own native plants * Advice for easy, maintenance using organic methods

Download or read book Influences on Understory Plant Communities in Mesic Uplands of the Chequamegon National Forest Wisconsin written by Helana L. Nelson and published by . This book was released on 2011 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Influence of Artificial Canopy Gaps on Wildlife and Understory in Young Coastal Temperate Coniferous Forests of the Pacific Northwest written by Landon James Charlo and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Wildland Fire in Ecosystems written by and published by . This book was released on 2000 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: