Paul Rogers

Historical Patterns in Lichen Communities of Montane Quaking Aspen Forests

Paul C. Rogers et al. — Fri, 25 Jan 2013 13:55:44 PST

Resilience in Quaking Aspen: Recent Advances and Future Needs

Paul C. Rogers et al. — Fri, 25 Jan 2013 13:55:43 PST

Quaking Aspen (Populus tremuloides) sustainability is a topic of intense interest in forest ecology. Reports range from declines to persisting or increasing coverage in some areas. Moreover, there is little agreement on ultimate factors driving changes. Low aspen recruitment has been attributed to climate patterns, past management, herbivore increases, competitive interactions with conifers, predator and beaver extirpation, and livestock grazing. Several of these potential causes result from direct or indirect actions of human agency. On June 27–28, 2012 a group of leading aspen ecologists from diverse backgrounds convened at the High Lonesome Ranch in western Colorado to address the state of aspen science under the title, Resilience in Quaking Aspen: restoring ecosystem processes through applied science. The purposes of this meeting were to: (a) present disciplinary updates on recent developments; (b) focus our collective understanding on determining key research gaps; and, to the extent possible, (c) develop a plan to communicate both advances and science gaps to wider audiences. Presentations and group discussions were framed mainly in the geographic context of the western US. The symposium addressed dual central themes—historical aspen cover change and ungulate herbivory—both of which have important ramifications for future aspen resilience. We also found emergent themes in disturbance, climate work, and genetic innovation. This paper presents a brief review of the state of aspen science and a synopsis of issues and needs identified at the symposium. Detailed treatments of topics mentioned here are found in accompanying articles of this volume. A key recommendation from researchers here is that there are many ‘‘aspen types’’ and novel, landscape- or aspen type-specific, approaches will be required to appropriately address this regional diversity. We further emphasize needed interdisciplinary work addressing changing climates, altered disturbance patterns, intensive herbivory, and human drivers of ecological change.

Landscape assessment of a stable aspen community in southern Utah, USA

Paul C. Rogers et al. — Fri, 25 Jan 2013 13:55:42 PST

Recent reports of rapid die-off of aspen (Populus tremuloides), coupled with vigorous debate over longterm reduction of aspen cover in western North America, has prompted considerable research given the importance of this forest type for economic and non-economic interests. Despite this interest, indicators of aspen conditions are poorly understood, and there is a lack of systematic monitoring of stable aspen landscapes. Stable aspen are defined here as being predominantly aspen overstorey (>80% basal area) with little or no conifer regeneration. We examined a putative stable aspen landscape in southern Utah and addressed (1) stand structure and (2) indicators of decline. We sampled 83 aspen-dominated stands within a 275 km2 landscape using established forest healthmonitoring protocols. Eighty-four percent of sample stands on Cedar Mountain exhibited stable aspen characteristics. Principal findings include: (1) a relatively uniform age of adults within the study area; (2) approximately 10% crown dieback on half of the plots sampled; (3) roughly 50% of the study plots had greater than 50% of the trees with damage to the bole; (4) about 25% of the adult basal area was dead; and (5) over half the plots had few sub-canopy individuals and/or limited regeneration. Physiographic variables including elevation, slope, and aspect were generally not strong indicators of aspen condition, typically explaining less than 15% of the variation in basal area, mortality, dieback, or damage. Healthy stands were rarely observed in the most drought prone locations, though the inverse was not necessarily true; healthy and unhealthy stands were found in more mesic settings. Principal components analysis identified two clusters of plots that differed considerably in regeneration; however, no other variables differed between these groupings.We suggest exogenous factors such as land-use history or altered disturbance regimes and endogenous factors such as soils and geology influence aspen condition on this landscape. Further research is necessary to test these hypotheses.

Landscape Assessment of a Stable Aspen Community in Southern Utah, USA

Paul C. Rogers et al. — Fri, 25 Jan 2013 13:55:41 PST

Recent reports of rapid die-off of aspen (Populus tremuloides), coupled with vigorous debate over long-term reduction of aspen cover in western North America, has prompted considerable research given the importance of this forest type for economic and non-economic interests. Despite this interest, indicators of aspen conditions are poorly understood, and there is a lack of systematic monitoring of stable aspen landscapes. Stable aspen are defined here as being predominantly aspen overstorey (>80% basal area) with little or no conifer regeneration. We examined a putative stable aspen landscape in southern Utah and addressed (1) stand structure and (2) indicators of decline. We sampled 83 aspen-dominated stands within a 275 km² landscape using established forest health monitoring protocols. Eighty-four percent of sample stands on Cedar Mountain exhibited stable aspen characteristics. Principal findings include: (1) a relatively uniform age of adults within the study area; (2) approximately 10% crown dieback on half of the plots sampled; (3) roughly 50% of the study plots had greater than 50% of the trees with damage to the bole; (4) about 25% of the adult basal area was dead; and (5) over half the plots had few sub-canopy individuals and/or limited regeneration. Physiographic variables including elevation, slope, and aspect were generally not strong indicators of aspen condition, typically explaining less than 15% of the variation in basal area, mortality, dieback, or damage. Healthy stands were rarely observed in the most drought prone locations, though the inverse was not necessarily true; healthy and unhealthy stands were found in more mesic settings. Principal components analysis identified two clusters of plots that differed considerably in regeneration; however, no other variables differed between these groupings. We suggest exogenous factors such as land-use history or altered disturbance regimes and endogenous factors such as soils and geology influence aspen condition on this landscape. Further research is necessary to test these hypotheses.

Lichen Communities Indicator Results from Idaho: Baseline Sampling

P. Neitlich et al. — Thu, 15 Dec 2011 15:16:23 PST

Lichen Communities for Forest Health Monitoring in Colorado, USA

B. McCune et al. — Thu, 15 Dec 2011 15:16:19 PST

Forest Resources of the Apache-Sitgreaves National Forest

Paul C. Rogers — Thu, 15 Dec 2011 15:16:16 PST

Wyoming Forest Health Report: A Baseline Assessment, 1995-1998

L. Koch et al. — Thu, 15 Dec 2011 15:16:13 PST

Aspen in the Sierra Nevada: Regional Conservation of a Continental Species

Paul C. Rogers et al. — Thu, 15 Dec 2011 15:16:09 PST

Health of Idaho’s Forests: A Summary of Conditions, Issues and Implications

D. Atkins et al. — Thu, 15 Dec 2011 15:16:06 PST

Monitoring the Health of Selected Eastern Arc Forests in Tanzania

S. Madoffe et al. — Thu, 15 Dec 2011 15:16:02 PST

Technical Reporting Plan: Guidelines for Annual Regional Reports

Paul C. Rogers et al. — Thu, 15 Dec 2011 15:15:59 PST

FHM Lichen Community Results from Wyoming, 1997: A Preliminary Summary

P. Neitlich et al. — Thu, 15 Dec 2011 15:15:55 PST

Ecology, Biodiversity, Management, and Restoration of Aspen in the Sierra Nevada

W. Shepperd et al. — Thu, 15 Dec 2011 15:15:52 PST

Forest Health Monitoring in the Ngangao Forest, Taita Hills, Kenya: A Five Year Assessment of Change

Paul C. Rogers et al. — Thu, 15 Dec 2011 15:15:49 PST

Summary and Abstracts from Sudden Aspen Decline (SAD) Meeting

Paul C. Rogers — Thu, 15 Dec 2011 15:15:45 PST

Don’t Miss the Invasions! A Note on Forest Health Monitoring in the Taita Hills, Kenya

Paul C. Rogers — Thu, 15 Dec 2011 15:15:43 PST

Guidelines for aspen restoration on the National Forests in Utah

Mary O'Brien et al. — Thu, 15 Dec 2011 15:15:40 PST

These guidelines are a working document and will be tested within the Utah National Forests on dif- ferent aspen types.

Historical patterns in lichen communities of montane quaking aspen forests

Paul C. Rogers et al. — Thu, 15 Dec 2011 15:15:37 PST

Climate shifts and resource exploitation in Rocky Mountain forests have caused profound changes in quaking aspen (Populus tremuloides Michx.) structure and function since Euro-American settlement. It therefore seems likely that commensurate shifts in dependent epiphytes would follow major ecological transitions. In the current study, we merge several lines of inquiry to investigate historical changes using lichens as bioindicators of forest structure, air quality, and community composition. Though lichens are well known for their sensitivity to air borne pollutants, recent utilization in the monitoring realm has lead to novel uses as indicators of biodiversity and stand composition. A landscape- level investigation in northern Utah and southern Idaho, USA, was implemented to track contemporary and long-term impacts of humans on aspen forests and their dependent macrolichens. We use historical sources, climate data, fire records, and passive ammonia sensors alongside forest and lichen monitoring techniques to gain further insight into aspen and epiphytic lichen community change over the past 150 years. Our research shows that historic drought conditions correlated closely with pulses of aspen regeneration during this period. Aspen initiation was closely aligned with large-scale resource impacts of the late 19th century. During the 20th century a moist climate pattern generally favored shade-tolerant conifers. Additionally, results from nonmetric multidimensional scaling (NMS) ordination indicate a primary successional gradient in determining lichen communities, but also revealed a significant gradient of more recent impacts from nitrogen loading originating from local ammonia (NH3) sources. While advancing succession generally favors lichen diversity, our findings suggest that medium-distance transport (10-50 km) of local air pollutants is already contributing to altered lichen communities. Overall, there are strong ties between landscape-level disturbance history and present aspen-dependent species assemblages. Effects on the epiphytic community are viewed as symptomatic of greater biodiversity and ecosystem impacts.

Reporting Plan for the Forest Health Monitoring Program of the USDA Forest Service: Guidelines for State, Multi-State and National Reports

J. Steinman et al. — Thu, 15 Dec 2011 15:15:35 PST