Jesse E D Miller

Stanford University | SU · Department of Biology

Many global ecosystems have undergone shifts in fire regimes in recent decades, such as changes in fire size, frequency, and/or severity. Recent research shows that increases in fire size, frequency, and severity can lead to long‐persisting deforestation, but the consequences of shifting fire regimes for biodiversity of other vegetative organisms (...

Species with unique phenologies have distinct trait syndromes and environmental affinities, yet there has been little exploration of whether community assembly processes differ for plants with different phenologies. In this study, we ask whether early‐ and late‐blooming species differ in the ways that dispersal, persistence and resource acquisition...

Context Encroachment of woody vegetation represents a significant global threat to biodiversity in grasslands, but practices used to reverse encroachment are rarely evaluated comprehensively. Several factors may drive encroachment, such as land use history, alteration of disturbance regimes, and local environment, but their relative importance is p...

Understanding how biotic communities respond to landscape spatial structure is critically important for conservation management as natural landscapes become increasingly fragmented. However, empirical studies of the effects of spatial structure on plant species richness have found inconsistent results, suggesting that more comprehensive approaches...

Forest managers in many parts of the world are charged with protecting rare lichen species, including species growing near their range limits. Rare lichens may be particularly vulnerable to effects of climate change, and conserving lichen diversity necessitates understanding factors that limit species distributions. Habitat suitability envelopes fo...

In 2020 the Beachie Creek Fire burned a large, forested area in the northern Oregon Cascade Range that included public and private land and much of the Opal Creek Wilderness. We compiled a pre-fire baseline data set from various sources of the lichens and allied fungi known to occur before the fire within the fire perimeter. These data are presente...

Wildfire may facilitate climate tracking of forest species moving upslope or north in latitude. For subalpine tree species, for which higher elevation habitat is limited, accelerated replacement by lower elevation montane tree species following fire may hasten extinction risk. We used a dataset of post-fire tree regeneration spanning a broad geogra...

Ecological disturbance regimes across the globe are being altered via direct and indirect human influences. Biodiversity loss at multiple scales can be a direct outcome of these shifts. Fire, especially in dry forests, is an ecological disturbance that is experiencing dramatic changes due to climate change, fire suppression, increased human populat...

In 2020 the Beachie Creek Fire burned a large area of forest in the northern Oregon Cascade Range including public and private land and much of the Opal Creek Wilderness. We compiled a baseline data set from various sources of the lichens known to occur before the fire within this area. These data are presented as an annotated species checklist doc...

Soils derived from ultramafic parent materials (hereafter serpentine) provide habitat for unique plant communities containing species with adaptations to the low nutrient levels, high magnesium: calcium ratios, and high metal content (Ni, Zn) that characterize serpentine. Plants on serpentine have long been studied in evolution and ecology, and pla...

Soils derived from ultramafic parent materials (hereafter serpentine) provide habitat for unique plant communities containing species with adaptations to the low nutrient levels, high magnesium: calcium ratios, and high metal content (Ni, Zn) that characterize serpentine. Plants on serpentine have long been studied in evolution and ecology, and pla...

High severity fire may promote or reduce plant understory diversity in forests. However, few empirical studies test long‐standing theoretical predictions that productivity may help to explain observed variation in post‐fire plant diversity. Support for the influence of productivity on disturbance‐diversity relationships is found predominantly in ex...

Our manuscript “Grazing disturbance promotes exotic annual grasses by degrading soil biocrust communities” (Root et al. 2020) demonstrated that livestock grazing can promote exotic annual grasses indirectly through the disruption of biocrusts, which are disturbance‐sensitive communities (Ponzetti & McCune 2001) that often cover the soil in arid and...

Aim Fire regimes are shifting globally due to climate change, land management practices and population growth, putting species at risk if they are unable to adapt to more frequent or severe wildfires. While many fire‐adapted species may be able to accommodate some amount of change in fire regimes, fire‐sensitive or late‐successional species that co...

Human land-use legacies have long-term effects on plant community composition and ecosystem function. While ancient and historical land use is known to affect biodiversity patterns, it is unknown whether such legacies affect other plant community properties such as the diversity of functional traits. Functional traits are a critical tool for unders...

Background Ecological disturbance is a major driver of ecosystem structure and evolutionary selection, and theory predicts that the frequency and/or intensity of disturbance should determine its effects on communities. However, adaptations of species pools to different historical disturbance regimes are rarely considered in the search for generaliz...

Fieldwork has played a critical role in the development of landscape ecology, and it remains essential for addressing contemporary challenges such as understanding the landscape ecology of global change. Advances in technology have expanded the scope of fieldwork to include the deployment of drones and other sensors, and in recent years, researcher...

Fieldwork has played a critical role in the development of landscape ecology, and it remains essential for addressing contemporary challenges such as understanding the landscape ecology of global change. Advances in technology have expanded the scope of fieldwork to include the deployment of drones and other sensors, and in recent years, researcher...

Tardigrades live in many ecosystems, but local dispersal mechanisms and the influence of ecological gradients on tardigrade communities are not fully understood. Here we examine tardigrade communities in nests of the red tree vole (Arborimus longicaudus True), an arboreal mammal occupying the canopy of coniferous forests in western Oregon and north...

Commentary On: Oswald, W. W., Foster, D. R., Shuman, B. N., Chilton, E. S., Doucette, D. L., Duranleau, D. L. Conservation implications of limited Native American impacts in pre-contact New England. Nature Sustainability https://doi.org/10.1038/s41893-019-0466-0

Tardigrades live in many ecosystems, but local dispersal mechanisms and the influence of ecological gradients on tardigrade communities are not fully understood. Here we examine tardigrade communities in nests of the red tree vole (Arborimus longicaudus True), an arboreal mammal occupying the canopy of coniferous forests in western Oregon and north...

Evaluating the conservation value of ecological communities is critical for forest management but can be challenging because it is difficult to survey all taxonomic groups of conservation concern. Lichens have long been used as indicators of late successional habitats with particularly high conservation value because lichens are ubiquitous, sensiti...

We update and revise the serpentine affinity database of Safford et al. (2005), which documents levels of plant taxon association with ultramafic ("serpentine") substrates in the California flora. The revised database reflects recent taxonomic changes consistent with the second edition of the Jepson Manual (TJM2) and more recent updates to the Jeps...

Plant traits—the morphological, anatomical, physiological, biochemical and phenological characteristics of plants—determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research sp...

The combination of direct human influences and the effects of climate change are resulting in altered ecological disturbance regimes, and this is especially the case for wildfires. Many regions that historically experienced low–moderate severity fire regimes are seeing increased area burned at high severity as a result of interactions between high...

Exotic invasive plants threaten ecosystem integrity, and their success depends on a combination of abiotic factors, disturbances, and interactions with existing communities. In dryland ecosystems, soil biocrusts (communities of lichens, bryophytes and microorganisms) can limit favorable microsites needed for invasive species establishment, but the...

While climate change has already profoundly influenced biodiversity through local extinctions, range shifts, and altered interactions, its effects on the evolutionary history contained within sets of coexisting species—or phylogenetic community diversity—have yet to be documented. Phylogenetic community diversity may be a proxy for the diversity of...

1. Effects of climate change on plant community functional diversity are of interest since experiments have found functional diversity to predict ecosystem function. Functional diversity has been hypothesized to confer resilience to plant communities (as a “driver” of community change), but in unmanipulated natural communities, it might alternative...

Ecological disturbance is a major driver of ecosystem structure and evolutionary selection, and theory predicts that disturbance frequency and / or intensity should determine its effects on communities. However, adaptations of species pools to different historical disturbance regimes are rarely considered in the search for generalizable community r...

Questions Gradients of fire severity in dry conifer forests can be associated with variation in understory floristic composition. Recent work in dry conifer forests in California, USA , has suggested that more severely burned stands contain more thermophilic taxa (those associated with warmer and drier conditions), and that forest disturbance may t...

1. Of the several approaches that are used to analyze functional trait‐environment relationships, the most popular is community‐weighted mean regressions (CWMr) in which species trait values are averaged at the site level and then regressed against environmental variables. Other approaches include model‐based methods and weighted correlations of di...

Several California Lichen Society members and friends explored the lichen communities of coastal San Luis Obispo County, California, on a foray in March, 2018. Lichen observations were focused on two areas: the University of California Ken Norris Rancho Marino Reserve in Cambria, California, and the Los Osos Oaks State Natural Reserve near Morro Ba...

Branches and boles of trees in wet forests are often carpeted with lichens and bryophytes capable of providing periodically saturated habitat suitable for microfauna, animals that include tardigrades, rotifers, nematodes, mites, and springtails. Although resident microfauna likely exhibit habitat preferences structured by fine-scale environmental f...

White oak (Quercus garryana) plant communities are one of the most threatened habitat types in the Pacific Northwest, and often host diverse and characteristic epiphyte communities. In order to better understand the diversity and floristic patterns of epiphytic macrolichens of these habitats in the Klamath-Siskiyou region we studied lichen communit...

Context: Encroachment of woody vegetation represents a significant global threat to biodiversity in grasslands, but practices used to reverse encroachment are rarely evaluated comprehensively. Several factors may drive encroachment, such as land use history, alteration of disturbance regimes, and local environment, but their relative importance is...

A central focus of ecology is identifying the factors that shape spatial patterns of species diversity and this is particularly relevant in an era of global change. Positive relationships between plant and consumer diversity are common, but could be driven by direct responses of each trophic level to underlying environmental gradients, or indirectl...

Sandstone glades in the Ozark highlands contain unique communities of vascular plants, including several species of conservation concern, as well as abundant communities of terricolous cryptogams-collectively termed biological soil crusts. Biological soil crusts have important ecological roles in grassland systems, such as preventing erosion and re...

Changes in landscape spatial structure—specifically, reductions in habitat area and connectivity—are thought to be a primary cause of pollinator declines across North America. However, the mechanisms by which landscape structure influences pollinator diversity are not well understood. Because flowering plants and pollinators are generally mutualist...

Identifying processes that drive epiphytic lichen diversity and succession is important for directing conservation efforts and developing forest management plans for the maintenance of biodiversity and forest health. Stand age has been implicated as a key factor in driving epiphytic species diversity and community composition. However, understandin...

Background/Question/Methods Plant species richness can be influenced by multiple factors including local environment, landscape connectivity, and disturbance history, but understanding the relative importance of these factors for plant communities remains a challenge for ecologists. Previous studies of the effects of habitat spatial structure on...

Background/Question/Methods Biological soil crusts play important ecological roles in communities where they occur, but factors that control their distribution as well as their effects on vascular plant community assembly processes remain poorly understood. Biological soil crusts are known to have both positive and negative effects on vascular pla...

Biological soil crusts are ecosystem engineers in arid and semi-arid habitats; they affect soil chemistry, stability, and vegetation. Their ecosystem functions may vary depending on species composition; however, lichen species diversity is poorly known in the Pacific Northwestern drylands of North America. We sampled 59 random and 20 intuitive plot...

Several notable lichens were found in the South Slough area near Coos Bay, Oregon, on a foray sponsored by the Northwest Lichenologists. A new record for Bryoria bicolor extends its southern range on the Pacific coast of North America, and information is presented on several other species, including Scoliciosporum sp., a little-reported, undescribe...

We present a lichen checklist of 141 species from the Lawrence Memorial Grassland Preserve and nearby lands in Wasco County, Oregon, based on collections made in the 1970s and 1990s. Collections include epiphytic, lignicolous, saxicolous, muscicolous, and terricolous species. One of these collections is the type specimen for a recently described sp...

The Usnea rigida group, which is uncommon to rare in California and the Pacific Northwest, has historically been recognized as a complex of morphologically similar species that are distinguished by chemistry. However, some researchers have recently recognized North American members of this group as a single species with multiple chemotypes. Sources...

On April 17th seven CALS members met at the Horseshoe Ranch Wildlife Area (HRWA) in Siskiyou County to collect and catalog the lichens of the area. A list of lichens present at the site are given. Notable lichens encountered include Lecanora neodegelii, Squamarina lentigera, Lobathallia alphoplaca and Umbillicara phaea var. coccinea.