Sarah Jovan

AIR‐QUALITY BIOINDICATION IN THE GREATER CENTRAL VALLEY OF CALIFORNIA, WITH EPIPHYTIC MACROLICHEN COMMUNITIES

Air-quality monitoring in the United States is typically focused on urban areas even though the detrimental effects of pollution often extend into surrounding ecosystems. The purpose of this study was to construct a model, based upon epiphytic macrolichen community data, to indicate air-quality and climate in forested areas throughout the greater Central Valley of California (USA). The structure of epiphytic lichen communities is widely recognized as an effective biological indicator of air-quality as sensitivities to common anthropogenic pollutants vary by species. We used nonmetric multidimensional-scaling ordination to analyze lichen community data from 98 plots. To calibrate the model, a subset of plots was co-located with air-quality monitors that measured ambient levels of ozone, sulfur dioxide, and nitrogen dioxide. Two estimates of ammonia deposition, which is not regularly monitored by any state or federal agency in California, were approximated for all plots using land-use maps and emissions est...

Regional Variation in Epiphytic Macrolichen Communities in Northern and Central California Forests

Abstract We studied epiphytic macrolichen communities in northern and central California to 1) describe how gradients in community composition relate to climate, topography, and stand structure and 2) define subregions of relatively homogeneous lichen communities and environmental conditions. Non-metric multidimensional scaling was used to characterize landscape-level trends in lichen community composition from 211 plots. We found two gradients in lichen community composition that corresponded with macroclimatic gradients: one correlated with temperature variables and elevation, the second with moisture variables. Moist, warm plots supported more cyanolichen species, while warm but dry plots supported a diverse nitrophilous flora. Ammonia pollution, which was not accounted for in the analysis, may also explain spatial patterns in nitrophilous species and deserves further study. Cluster analysis and indicator species analysis were used to divide lichen communities into more homogeneous groups and identify group indicator species. Three groups of plots differing in geography, macroclimate, and community composition were defined: the Greater Central Valley group; the Sierra, Southern Cascades, and Modoc group; and the NW Coast group. Communities in the Greater Central Valley group were typically diverse and dominated by nitrophilous species, averaging 14 species and 40% nitrophiles. Cyanolichens common to this group were mainly diminuitive species from the genera Leptogium and Collema. Indicator species strongly associated with the Greater Central Valley included Melanelia glabra, Candelaria concolor, and Parmelina quercina. Communities from the Sierra, Southern Cascades, and Modoc group had the lowest species richness and total lichen abundance. Cyanolichens were absent, while nitrophiles such as Candelaria concolor and Xanthoria fulva were frequent. Indicator species included Letharia vulpina, L. columbiana, and Nodobryoria abbreviata. The NW Coast group had the highest species richness, cyanolichen diversity, and cyanolichen abundance while nitrophiles were rare. Indicator species included Platismatia glauca, Esslingeriana idahoensis, and Cetraria orbata.

The Forest Inventory and Analysis Database Version 4.0: Database Description and Users Manual for Phase 3

Describes the structure of the Forest Inventory and Analysis Database (FIADB) 4.0 for phase 3 indicators. The FIADB structure provides a consistent framework for storing forest health monitoring data across all ownerships for the entire United States. These data are available to the public.

Lichen-based indices to quantify responses to climate and air pollution across northeastern U.S.A

Abstract Lichens are known to be indicators for air quality; they also respond to climate. We developed indices for lichen response to climate and air quality in forests across the northeastern United States of America (U.S.A.), using 218–250 plot surveys with 145–161 macrolichen taxa from the Forest Inventory and Analysis (FIA) Program of the U.S. Department of Agriculture, Forest Service. Lichen indicator species for response to climate and air quality were selected using Indicator Species Analysis, correlations with environmental variables, and published literature. Ordinations were used to evaluate the strength and relationships of the final indices. The Pollution Index was calculated for a plot from abundances of 12 tolerant and 45 sensitive indicator species standardized by abundance of all lichen species. The Index was correlated with modeled deposition of acidifying sulfur and oxidized nitrogen and with lichen community ordination pollution axes. Analyses suggested separate response of lichens to fertilizing N (weak statistical support). The Climate Index, from abundances of 19 warmer and 47 cooler climate indicator species, was correlated with modeled minimum January and annual maximum temperatures, and with ordination climate axes. The two indices are statistically independent. Repeat sample variability for each index was 7–14.5% (lower with higher quality data), supporting detection of consistent trends of 16–20% change over time or variation across space. Variability of the Climate Index was more affected by data quality than that of the Pollution Index. The continuous gradient of Pollution Index values suggests the cleanest areas may have air pollution above a critical load to fully protect lichen communities. These Indices can be applied to track lichen responses using other data from our study regions; suitability should be tested before use outside of the study area.

A rapid method for landscape assessment of carbon storage and ecosystem function in moss and lichen ground layers

Abstract Mat-forming “ground layers” of mosses and lichens often have functional impacts disproportionate to their biomass, and are responsible for sequestering one-third of the worlds terrestrial carbon as they regulate water tables, cool soils and inhibit microbial decomposition. Without reliable assessment tools, the potential effects of climate and land use changes on these functions remain unclear; therefore, we implemented a novel “Ground Layer Indicator” method as part of the U.S.D.A. Forest Inventory and Analysis (FIA) program. Non-destructive depth and cover measurements were used to estimate biomass, carbon and nitrogen content for nine moss and lichen functional groups among eight contrasted habitat types in Pacific Northwest and subarctic U.S.A. (N  =  81 sites). Ground layer cover, volume, standing biomass, carbon content and functional group richness were greater in boreal forest and tundra habitats of Alaska compared to Oregon forest and steppe. Biomass of up to 22769 ± 2707 kg ha−1 (mean ± SE) in upland Picea mariana forests was nearly double other reports, likely because our method included viable, non-photosynthetic tissues. Functional group richness, which did not directly correspond with biomass, was greatest in lowland Picea mariana forests (7.1 ± 0.4 functional groups per site). Bootstrap resampling revealed that thirty-two microplots per site were adequate for meeting data quality objectives. Here we present a non-destructive, repeatable and efficient method (sampling time: ca. 60 min per site) for gauging ground layer functions and evaluating responses to ecosystem changes. High biomass and functional distinctiveness in Alaskan ground layers highlight the need for increased attention to currently under-sampled boreal and arctic regions, which are projected to be among the most active responders to climate change.

Lichen communities and species indicate climate thresholds in southeast and south-central Alaska, USA

Abstract Because of their unique physiology, lichen communities are highly sensitive to climatic conditions, making them ideal bioindicators for climate change. Southeast and south-central Alaska host diverse and abundant lichen communities and are faced with a more rapidly changing climate than many more southerly latitudes. We develop sensitive lichen-based indicators for tracking the effects of climate change in south-central and southeast Alaska. Using 196 plots, we model community composition and 12 individual species abundances in relation to synthetic climate variables. Both types of lichen indicator are closely related to the climate variable describing a transition from warm, wet oceanic climates to cooler, drier suboceanic climates. Lichen communities and individual species exhibited thresholds associated with average December minimum temperatures between −10.2 and −7.8°C and annual precipitation between 106 and 172 cm, suggesting rapid turnover with relatively small changes within these ranges. These climate conditions occur close to the coast in northern portions of the region and further inland in southeast Alaska. Because lichen communities in the threshold region may be most sensitive to a changing future climate, they should be targeted for monitoring efforts.

Element analysis of two common macrolichens supports bioindication of air pollution and lichen response in rural midwestern U.S.A

Abstract Element analysis was conducted on naturally-growing Flavoparmelia caperata (L.) Hale and Punctelia rudecta (Ach.) Krog (26 sites) in 2003–05 for a 30-year resurvey of forest lichen communities near a power plant in Wisconsin. Cu, Cr, N, and S increased strongly with power plant impact (66 samples, both species) and are good candidate bioindicators for local pollution; Al and Fe increased weakly and are not recommended. Hg is a candidate pollution indicator from comparison with a background site (only F. caperata data: 39 samples, 23 sites). Only N and S were correlated with lichen species abundance and are thus candidate bioindicators for lichen response. Abundance of P. rudecta was lower and that of Phaeophyscia pusilloides (Zahlbr.) Essl. was higher with more N or S in lichens; abundances of F. caperata and large foliose species as a group were lower with higher modeled SO2 from the power plant (no response from four other tested lichen species or groups). Sites in more forested landscapes to the west of the power plant had more lichen species, including disturbance-sensitive taxa. Heathier lichens there may have led to higher concentrations of Al, Cr, and S, plus Li (only F. caperata data). Univariate general linear modeling (GLM) was more useful than regression to test species effect at 7 sites. Element analysis confirmed earlier records of minimal power plant impact on lichens in this area, where no truly pollution-sensitive lichen species have been recorded for decades.

Indicators of climate impacts for forests: recommendations for the US National Climate Assessment indicators system

The Third National Climate Assessment (NCA) process for the United States focused in part on developing a system of indicators to communicate key aspects of the physical climate, climate impacts, vulnerabilities, and preparedness to inform decisionmakers and the public. Initially, 13 active teams were formed to recommend indicators in a range of categories, including forest, agriculture, grassland, phenology, mitigation, and physical climate. This publication describes the work of the Forest Indicators Technical Team. We briefly describe the NCA indicator system effort, propose and explain our conceptual model for the forest system, present our methods, and discuss our recommendations. Climate is only one driver of changes in U.S. forests; other drivers include socioeconomic drivers such as population and culture, and other environmental drivers such as nutrients, light, and disturbance. We offer additional details of our work for transparency and to inform an NCA indicator Web portal. We recommend metrics for 11 indicators of climate impacts on forest, spanning the range of important aspects of forest as an ecological type and as a sector. Some indicators can be reported in a Web portal now; others need additional work for reporting in the near future. Indicators such as budburst, which are important to forest but more relevant to other NCA indicator teams, are identified. Potential indicators that need more research are also presented.