Ecology of Forest Floor Bryophytes in Pseudotsuga Menziesii-Tsuga Heterophylla Stands of Western Oregon PDF Download
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Author: Thomas Roy Rambo
Publisher:
ISBN:
Category : Bryophytes
Languages : en
Pages : 160
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Book Description
Species richness and abundance of forest floor bryophytes, including epiphytes from incorporated litterfall, were assessed at two sites in western Oregon. Bryophyte diversity, abundance, and community composition were compared between sites, and between young forest stands ([approximately] 55 yrs.) and old-growth stands (400+ yrs.) within each site. Relationships of stand structural features to diversity and community composition were assessed by stratifying sampling between "diversity" plots placed in areas of greater structural diversity, such as hardwood openings and remnant old-growth trees, and "matrix" plots situated within the remaining more homogeneous conifer-dominated forest matrix. Bryophyte relationships to substrate and stand age were quantified using the method of Dufrene and Legendre, which combines a species' relative abundance and relative frequency to calculate that species' importance in relation to environmental variables. The resulting "indicator value" describes a species' reliability for indicating the given environmental parameter. Ninety-three bryophyte species were found. Thirty-nine were indicative of either humus, a decay class of coarse woody debris, or stand age. A suite of bryophytes indicated old-growth forest. These were mainly either epiphytes associated with older conifers or liverworts associated with coarse woody debris. Hardwood-associated epiphytes mainly indicated young stands. Richness, particularly for liverworts, was significantly higher in old-growth than young stands, and the two ages differed significantly in community composition Substrate (ground versus coarse woody debris) and overstory (conifers versus hardwoods) were most strongly correlated with variation in bryophyte community composition. Composition changed along the continuum of coarse woody debris decomposition from recently fallen trees with intact bark to forest floor humus. Relatively open hardwood-dominated diversity plots differed in composition from matrix plots. Bryophyte abundance was lower in denser stands and plots, and positively correlated with canopy gaps, percentage of hardwoods, and incident solar radiation. The generality of inferences derived from results is limited by the number of stands studied. Landscape level factors such as topography and prevailing slope and aspect may influence results between sites and ages. However, results suggest that 1) availability of light may limit bryophyte productivity in these stands, 2) bryophyte richness increases with stand continuity, 3) older conifers, hardwoods, and coarse woody debris foster habitat complexity and diversity of bryophytes, and 4) diversity of forest floor bryophytes will be enhanced when a full range of coarse woody debris decay classes is present. Implementation of strategies to protect these biological legacies when thinning managed stands is consistent with an ecosystem approach to forest management.
Author: Thomas Roy Rambo
Publisher:
ISBN:
Category : Bryophytes
Languages : en
Pages : 160
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Book Description
Species richness and abundance of forest floor bryophytes, including epiphytes from incorporated litterfall, were assessed at two sites in western Oregon. Bryophyte diversity, abundance, and community composition were compared between sites, and between young forest stands ([approximately] 55 yrs.) and old-growth stands (400+ yrs.) within each site. Relationships of stand structural features to diversity and community composition were assessed by stratifying sampling between "diversity" plots placed in areas of greater structural diversity, such as hardwood openings and remnant old-growth trees, and "matrix" plots situated within the remaining more homogeneous conifer-dominated forest matrix. Bryophyte relationships to substrate and stand age were quantified using the method of Dufrene and Legendre, which combines a species' relative abundance and relative frequency to calculate that species' importance in relation to environmental variables. The resulting "indicator value" describes a species' reliability for indicating the given environmental parameter. Ninety-three bryophyte species were found. Thirty-nine were indicative of either humus, a decay class of coarse woody debris, or stand age. A suite of bryophytes indicated old-growth forest. These were mainly either epiphytes associated with older conifers or liverworts associated with coarse woody debris. Hardwood-associated epiphytes mainly indicated young stands. Richness, particularly for liverworts, was significantly higher in old-growth than young stands, and the two ages differed significantly in community composition Substrate (ground versus coarse woody debris) and overstory (conifers versus hardwoods) were most strongly correlated with variation in bryophyte community composition. Composition changed along the continuum of coarse woody debris decomposition from recently fallen trees with intact bark to forest floor humus. Relatively open hardwood-dominated diversity plots differed in composition from matrix plots. Bryophyte abundance was lower in denser stands and plots, and positively correlated with canopy gaps, percentage of hardwoods, and incident solar radiation. The generality of inferences derived from results is limited by the number of stands studied. Landscape level factors such as topography and prevailing slope and aspect may influence results between sites and ages. However, results suggest that 1) availability of light may limit bryophyte productivity in these stands, 2) bryophyte richness increases with stand continuity, 3) older conifers, hardwoods, and coarse woody debris foster habitat complexity and diversity of bryophytes, and 4) diversity of forest floor bryophytes will be enhanced when a full range of coarse woody debris decay classes is present. Implementation of strategies to protect these biological legacies when thinning managed stands is consistent with an ecosystem approach to forest management.
Author:
Publisher: DIANE Publishing
ISBN: 9781422324868
Category :
Languages : en
Pages : 100
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Book Description
Author: Nathan Jeremy Poage
Publisher:
ISBN:
Category : Forest management
Languages : en
Pages : 50
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Book Description
We review 12 large-scale silviculture experiments (LSSEs) in western Washington and Oregon with which the Pacific Northwest Research Station of the USDA Forest Service is substantially involved. We compiled and arrayed information about the LSSEs as a series of matrices in a relational database, which is included on the compact disc published with this report and available online at http://www.fs.fed.us/pnw/research/lsse. The LSSEs are both spatially and temporally large scale, with experimental treatment units between 5 and 100 acres and proposed study durations of 20 to 200 years. A defining characteristic of the LSSEs is that a broad range of response variables are measured to characterize the response of forest ecosystems to experimental treatments. We discuss the general value and limitations of the LSSEs and highlight some possible roles that can be played by the LSSEs in addressing management issues emerging at the beginning of the 21st century.
Author: Heather T. Root
Publisher:
ISBN:
Category : Bryophytes
Languages : en
Pages : 111
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Book Description
I focus on addressing knowledge gaps relating to management of cryptogams in Oregon's public lands in Pseudotsuga menziesii-Tsuga heterophylla forests on the west side of the Cascade Range and dryland steppe in the Cascade Range's rainshadow. While a great deal of research has illustrated the importance of late-successional forests for maintaining biodiversity in the Pacific Northwest of North America, over 76% of the forests in the region are less than 100 years old. To preserve landscape-level biodiversity, forest managers are increasingly interested in how young stands can be manipulated to favor late-successional species. At two sites in moist conifer forests of western Oregon, lichen community monitoring plots were established prior to treatment and resampled approximately 10 years after alternative thinning treatments aimed at promoting late-successional strucural characteristics. At both sites, hardwood gaps and open-grown trees were positively associated with cyanolichen species richness. At one site, thinned plots hosted more Bryoria, Candelaria concolor, Leptogium polycarpum, Peltigera collina, Nephroma laevigatum and Physcia tenella than had been observed prior to thinning. I concluded that thinning treatments retaining remnants, open-grown trees and hardwood gaps have potential to favor lichen communities rich in cyanolichen and alectorioid species. In the same sites, I sought to understand how stand-level gradients in canopy structure relate to dominant forest floor bryophyte and lichen species composition and abundance. At the one site, I found no strong associations between forest floor communities and stand structural characteristics. At the the other, lichens, particularly Cladonia, were negatively associated with canopy cover whereas bryophyte abundance was positively associated with Tsuga basal area. This relationship was stronger in the thinned stands, which had a different community composition than those left unthinned. Overall, the forest floor communities were fairly homogeneous at both sites and relationships with stand structural variables were subtle, indicating that thinning did not have a strong impact. Biological soil crusts are ecosystem engineers in arid and semi-arid habitats; they affect soil chemistry, stability, and vegetation. Little is known about regional variation in biotic crust communities of North America. I explored how biotic crust lichen community composition and richness related to vascular plant, soil and climate characteristics in Oregon. In 59 0.4-ha plots, I found 99 biotic crust lichen taxa, one-third of which were observed only once, 33 of which occurred in only one plot and seven of which were new to Oregon. I compiled records from herbaria and other studies to evaluate the rarity of 124 biotic crust lichen species and conclude that 37 are rare or uncommon. Many of these appear to be associated with calcareous substrates. I modeled occurrences in relation to climate and soil variables for four uncommon biotic crust lichens: Acarospora schleicheri, Fuscopannaria cyanolepra, Rhizocarpon diploschistidina, and Texosporium sancti-jacobi. Based on climate and soils, I mapped regions of Oregon that may support new populations of these species and overlay habitats unsuitable for biotic crusts due to development and agriculture. These species, except Fuscopannaria cyanolepra, are strongly associated with the fine soils along the Columbia and Treasure Valleys that are most intensively used for agriculture. Biotic crust lichen communities rich in cyanolichens characterized Juniperus stands whereas warm grasslands were home to regionally uncommon species including Texosporium sancti-jacobi and Rhizocarpon diploschistidina. I discerned biotic crust communities in sandy Artemisia tridentata ssp. wyomingensis sites from those loamy A. arbuscula sites. Hotspots of biotic crust diversity were geographically scattered, weakly negatively associated with abundance of shrubs of disturbed sites, Gutierrezia and Chrysothamnus. The poorest sites for biotic crust lichen richness were heavily grazed, burned plots with Gutierrezia in the grassy north, unstable steep talus slopes at the center, and sandy, grazed sites with Chrysothamnus in the southern portion of our region. Overall, regional patterns in biotic crust lichen communities were strongly associated with vegetation, soils, and climate. I hope that my findings will promote intentional management of epiphytic and forest floor cryptogams of western Oregon forests and monitoring of biotic lichen communities in eastern Oregon.
Author:
Publisher:
ISBN:
Category : Forests and forestry
Languages : en
Pages : 720
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Book Description
Author:
Publisher:
ISBN:
Category : Buffer zones (Ecosystem management)
Languages : en
Pages : 160
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Book Description
Author:
Publisher:
ISBN:
Category : Biodiversity
Languages : en
Pages : 92
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Book Description
Author:
Publisher:
ISBN:
Category : Ecology
Languages : en
Pages : 594
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Book Description
Coverage: 1982- current; updated: monthly. This database covers current ecology research across a wide range of disciplines, reflecting recent advances in light of growing evidence regarding global environmental change and destruction. Major ares of subject coverage include: Algae/lichens, Animals, Annelids, Aquatic ecosystems, Arachnids, Arid zones, Birds, Brackish water, Bryophytes/pteridophytes, Coastal ecosystems, Conifers, Conservation, Control, Crustaceans, Ecosyst em studies, Fungi, Grasses, Grasslands, High altitude environments, Human ecology, Insects, Legumes, Mammals, Management, Microorganisms, Molluscs, Nematodes, Paleo-ecology, Plants, Pollution studies, Reptiles, River basins, Soil, TAiga/tundra, Terrestrial ecosystems, Vertebrates, Wetlands, Woodlands.
Author:
Publisher:
ISBN:
Category : Botany
Languages : en
Pages : 694
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Book Description
Author:
Publisher:
ISBN:
Category : Forest management
Languages : en
Pages : 406
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Book Description
Balancing Ecosystem Values: Innovative Experiments for Sustainable Forestry is a compendium of more than 40 contributions from Asia, Europe, and North America. The theme encompasses experiments implemented at an operational scale to test ecological, social, or economic responses to silvicultural treatments designed to balance the complex set of objectives currently targeted in sustainable forest management. Several invited and plenary papers emphasize the variety of outcomes demanded by the public, as well as the essential role that these long-term studies will play in allowing natural resource managers to make better-informed, science-based decisions. A broad spectrum of silvicultural treatments and systems are covered, as are simulation runs with different types of models and discussion about design challenges for scaling up from stands to landscapes. Diverse forest ecosystems, stand structures and plant, animal, and fungal species are also considered. The conference included 2 days in the field where participants saw several types of the comprehensive field experiments firsthand. The conference concluded with a critique from state, private, and public land managers.
