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• 1. [Article] Non-parametric methods reveal non-linear functional trait variation of lichens along environmental and fire age gradients

  To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article is copyrighted by International Association ...

  Citation × Citation Citation Abstract Copy Title: Non-parametric methods reveal non-linear functional trait variation of lichens along environmental and fire age gradients Author: Roland, Carl, Nelson, Peter R., Stehn, Sarah, McCune, Bruce To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article is copyrighted by International Association for Vegetation Science and published by John Wiley & Sons Ltd. It can be found at: http://onlinelibrary.wiley.com/journal/10.1111/%28ISSN%291654-1103 Title: Non-parametric methods reveal non-linear functional trait variation of lichens along environmental and fire age gradients Author: Roland, Carl, Nelson, Peter R., Stehn, Sarah, McCune, Bruce To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article is copyrighted by International Association for Vegetation Science and published by John Wiley & Sons Ltd. It can be found at: http://onlinelibrary.wiley.com/journal/10.1111/%28ISSN%291654-1103 Close

• 2. [Article] Cryptogam communities in forest and steppe ecosystems of Oregon, USA

  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 ...

  Citation × Citation Citation Abstract Copy Title: Cryptogam communities in forest and steppe ecosystems of Oregon, USA Author: Root, Heather T. 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. Title: Cryptogam communities in forest and steppe ecosystems of Oregon, USA Author: Root, Heather T. 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. Close

• 3. [Article] Detecting continuous lichen abundance for mapping winter caribou forage at landscape spatial scales

  To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Elsevier ...

  Citation × Citation Citation Abstract Copy Title: Detecting continuous lichen abundance for mapping winter caribou forage at landscape spatial scales Author: Roland, Carl, Macander, Matthew J., Nelson, Peter R., McCune, Bruce To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Elsevier and can be found at: http://www.elsevier.com/. Title: Detecting continuous lichen abundance for mapping winter caribou forage at landscape spatial scales Author: Roland, Carl, Macander, Matthew J., Nelson, Peter R., McCune, Bruce To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Elsevier and can be found at: http://www.elsevier.com/. Close

• 4. [Article] Community gradients of Arctic macrolichens in relation to succession, grazing and the environment

  The purpose of this dissertation was to define macrolichen community gradients in relation to succession, grazing and the environment. First, species scores indicating when macrolichen species appeared ...

  Citation × Citation Citation Abstract Copy Title: Community gradients of Arctic macrolichens in relation to succession, grazing and the environment Author: Holt, Emily A. The purpose of this dissertation was to define macrolichen community gradients in relation to succession, grazing and the environment. First, species scores indicating when macrolichen species appeared following disturbance were derived from the literature. Weighted averaging of these data with a community matrix created a successional score for each sample unit of interest. These scores are surrogates for community age for subsequent analyses. I then described lichen community structure and its relation to the environment in the Bering Land Bridge National Preserve (BELA) in northwestern Alaska. Two primary gradients in lichen community composition were related to habitat rockiness and a substrate-topographic gradient. Next, I sought impacts of grazing by reindeer and caribou on lichen communities. I found lightly grazed areas had taller lichens, greater total lichen cover and minor but significant changes in community structure than heavily grazed sites. Lichen species richness, however, did not differ by grazing status. To create a generalized recovery model, I used plots in burned areas and found total lichen and bryophyte cover varied with time since fire (range 4-49 yrs since fire), while vascular plant cover showed no trend. I then compared these patterns to BELA, an area of unknown disturbance history. Low lichen cover in BELA may not necessarily reflect disturbance but rather site or climatic differences. Lastly, I found that all 17 GIS variables separated lichen communities to some degree. Separation of lichen communities by variable ranged from strong (Alaska Subsections, soil and surficial geology variables) to weak (Watersheds and Reindeer Ownership). The quality of the underlying relationships, how finely the groups are divided and the average patch size of each variable also contribute to differences in how clearly lichen communities were separated. This work will serve as a baseline for future comparisons to understand implications of climate and land use change on lichen communities. My grazing results may inform managers of the implications of heavy grazing and underscore protection and monitoring of prolific and diverse sites. In addition, this work contributes a new method to age tundra communities and a list of GIS variable successful at separating lichen communities. Title: Community gradients of Arctic macrolichens in relation to succession, grazing and the environment Author: Holt, Emily A. The purpose of this dissertation was to define macrolichen community gradients in relation to succession, grazing and the environment. First, species scores indicating when macrolichen species appeared following disturbance were derived from the literature. Weighted averaging of these data with a community matrix created a successional score for each sample unit of interest. These scores are surrogates for community age for subsequent analyses. I then described lichen community structure and its relation to the environment in the Bering Land Bridge National Preserve (BELA) in northwestern Alaska. Two primary gradients in lichen community composition were related to habitat rockiness and a substrate-topographic gradient. Next, I sought impacts of grazing by reindeer and caribou on lichen communities. I found lightly grazed areas had taller lichens, greater total lichen cover and minor but significant changes in community structure than heavily grazed sites. Lichen species richness, however, did not differ by grazing status. To create a generalized recovery model, I used plots in burned areas and found total lichen and bryophyte cover varied with time since fire (range 4-49 yrs since fire), while vascular plant cover showed no trend. I then compared these patterns to BELA, an area of unknown disturbance history. Low lichen cover in BELA may not necessarily reflect disturbance but rather site or climatic differences. Lastly, I found that all 17 GIS variables separated lichen communities to some degree. Separation of lichen communities by variable ranged from strong (Alaska Subsections, soil and surficial geology variables) to weak (Watersheds and Reindeer Ownership). The quality of the underlying relationships, how finely the groups are divided and the average patch size of each variable also contribute to differences in how clearly lichen communities were separated. This work will serve as a baseline for future comparisons to understand implications of climate and land use change on lichen communities. My grazing results may inform managers of the implications of heavy grazing and underscore protection and monitoring of prolific and diverse sites. In addition, this work contributes a new method to age tundra communities and a list of GIS variable successful at separating lichen communities. Close