LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 3 of total 3

Search options

  1. Article: Variation In Old-Growth Coast Redwood (Sequoia sempervirens) Reference Sites In Mendocino County, California

    Michels, Kristin K / Russell, Will

    Madroño. 2016 July, v. 63, no. 3

    2016  

    Abstract: Restoration and management of old-growth conditions in coast redwood (Sequoia sempervirens [D. Don] Endl.) forests are traditionally based on an idealized set of characteristics that occur in productive stands. We compared three old-growth sites to ... ...

    Abstract Restoration and management of old-growth conditions in coast redwood (Sequoia sempervirens [D. Don] Endl.) forests are traditionally based on an idealized set of characteristics that occur in productive stands. We compared three old-growth sites to quantify variability among remaining reference stands of the central coast redwood range in Mendocino County, California. Two of the sites are protected from coastal influence, have rich alluvial soils, and relatively high visitor usage. The third site is in close proximity to the coast with variable soil conditions and little visitor access. We randomly sampled twenty, 20-meter circular diameter plots in each site to evaluate basal area, tree density, species richness, canopy cover, shrub cover, and herbaceous species cover. We conducted multivariate analyses including nonmetric multidimensional scaling (NMDS), perMANOVA, and indicator species analysis (ISA) to examine the structural clustering and compositional metrics among the sites. Results indicated a strong separation among old-growth reference sites in the NMDS ordination and significant differences in sites using perMANOVA. The inland sites had high tree density, basal area, herbaceous understory cover, and cover of Oxalis oregana Nutt., Adenocaulon bicolor Hook., and Viola glabella Nutt. The coastal site had a high abundance of Trillium ovatum Pursh (an old-growth associated species), high shrub cover in canopy gaps, diverse species assemblages, and relatively high abundance of woodland-adapted perennial species. ISA provided a distinct suite of understory species for each site. The unique characteristics and high variability among these sites may offer a new, and potentially more accurate, standard for restoration and management.
    Keywords Adenocaulon ; alluvial soils ; basal area ; canopy gaps ; coasts ; forests ; indicator species ; multidimensional scaling ; multivariate analysis ; Oxalis ; Sequoia sempervirens ; shrubs ; species diversity ; trees ; Trillium ovatum ; understory ; Viola ; California
    Language English
    Dates of publication 2016-07
    Size p. 258-267.
    Publishing place California Botanical Society, Inc.
    Document type Article
    ZDB-ID 2276951-1
    ISSN 1943-6297 ; 0024-9637
    ISSN (online) 1943-6297
    ISSN 0024-9637
    DOI 10.3120%2F0024-9637-63.3.258
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  2. Article: A new application of change point analysis reveals extensive edge effects on a temperate mixed forest

    Michels, Kristin K / Sara C. Hotchkiss / Erin Jonaitis / Andrew L. Thurman

    Applied vegetation science. 2017 Oct., v. 20, no. 4

    2017  

    Abstract: QUESTIONS: How do landscape changes along edges of protected areas affect forest interiors and stand development? What are the locations, spatial extents and magnitudes of these effects? LOCATION: The 8500‐ha Sylvania Wilderness Area, Michigan's Upper ... ...

    Abstract QUESTIONS: How do landscape changes along edges of protected areas affect forest interiors and stand development? What are the locations, spatial extents and magnitudes of these effects? LOCATION: The 8500‐ha Sylvania Wilderness Area, Michigan's Upper Peninsula, USA. METHODS: We conducted vegetation surveys in 202 plots in ten transects crossing the Sylvania Wilderness border in 2013 and 2014. We recorded characteristics of forest structure, trees, shrubs, saplings, seedlings and herbaceous species. We constructed GLMM to estimate the location, spatial extent and magnitude of change of edge effects on Sylvania with a range of possible edge effect locations and widths of effect. We selected best‐fit models that minimized the AIC and applied likelihood ratio tests to assess the statistical significance of each edge effect. RESULTS: Overall, evidence of edge effects occurred up to 625 m into the Sylvania Wilderness, with most significant changes occurring within 400 m of the wilderness border. Wide zones of change occurred across the wilderness border, while zones of change farther from the edge tended to be narrower, suggesting that distinct environments are established beyond the transitional habitats surrounding the border region. Canopy‐level and understorey‐level variables exhibited the largest magnitudes and steepest gradients of change, indicating these communities are strongly influenced by edge effects in this forest system. Canopy‐level heterogeneity also increased approaching the internal core area of Sylvania. CONCLUSIONS: In this case study, we applied a linear change point model and found a minimum buffer zone of 400 m to mitigate edge effects in an old‐growth temperate mixed forest. Regionally, land managers could implement this buffer to existing edges of protected areas or negotiate this buffer zone in land acquisitions. A more stringent buffer zone of 625 m internal and 250 m external to old‐growth forests would be ideal. This application of change point analysis provides a simple, efficient method to establish effective buffer zones and to identify functional groups or ecosystem attributes for which edge effects are of greatest conservation concern. We recommend modifying our open‐source change point package to estimate local edge effects that take into account regional characteristics.
    Keywords case studies ; conservation areas ; ecosystems ; edge effects ; habitats ; landscapes ; mixed forests ; models ; moieties ; old-growth forests ; saplings ; seedlings ; shrubs ; stand development ; surveys ; wilderness ; Michigan
    Language English
    Dates of publication 2017-10
    Size p. 651-661.
    Publishing place John Wiley & Sons, Ltd
    Document type Article
    Note JOURNAL ARTICLE
    ZDB-ID 1445659-x
    ISSN 1402-2001
    ISSN 1402-2001
    DOI 10.1111/avsc.12325
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

    In stock of ZB MED Bonn / Germany

    Z 7002: Show issues

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  3. Article: Advantages of Live Microscope Video for Laboratory and Teaching Applications

    Michels, Kristin K / Hotchkiss, Sara C / Michels, Zachary D

    Journal of natural resources and life sciences education. 2016 Dec., v. 45, no. 1

    2016  

    Abstract: Although spatial reasoning and penetrative thinking skills are essential for many disciplines, these concepts are difficult for students to comprehend. In microscopy, traditional educational materials (i.e., photographs) are static. Conversely, video- ... ...

    Abstract Although spatial reasoning and penetrative thinking skills are essential for many disciplines, these concepts are difficult for students to comprehend. In microscopy, traditional educational materials (i.e., photographs) are static. Conversely, video-based training methods convey dimensionality. We implemented a real-time digital video imaging system (VIS) in a collegiate-level directed study environment to assess the efficacy of live video in microscope pedagogy. We subsequently investigated the utility of live microscope videos by surveying 150 undergraduate and continuing education University of Wisconsin-Madison students in an introductory biology laboratory course that relies on video technology. In directed study, using a VIS effectively increased student learning by actively engaging both instructors and students while collectively viewing live microscope feeds in real time. The live videos conveyed microscopy concepts, reinforced quality microscope techniques, enhanced penetrative thinking and mental rotation skills, and increased student understanding of multi-dimensional, microscopic specimens. Survey results indicated that early-career students also benefited from similar technology and helped students understand complex microscopic structures. We conclude that the application of a VIS in directed study and in classroom-scale introductory laboratory courses enhances student learning of difficult concepts involving spatial reasoning.
    Keywords continuing education ; educational materials ; feeds ; image analysis ; learning ; microscopy ; photographs ; students ; surveys ; teachers
    Language English
    Dates of publication 2016-12
    Publishing place American Society of Agronomy
    Document type Article
    Note epub
    ZDB-ID 1112701-6
    ISSN 1539-1582 ; 1059-9053
    ISSN (online) 1539-1582
    ISSN 1059-9053
    DOI 10.4195/nse2015.0018
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

    In stock of ZB MED Bonn / Germany

    Z 3651: Show issues

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

To top