A5041966197- Tree-ring climate responses
- Plant Water Relations and Carbon Dynamics
- Ecology and Vegetation Dynamics Studies
- Forest ecology and management
- Species Distribution and Climate Change
- Fire effects on ecosystems
- Horticultural and Viticultural Research
- Forest Management and Policy
- Plant responses to water stress
- Forest Ecology and Biodiversity Studies
- Hydrology and Sediment Transport Processes
- Seedling growth and survival studies
- Soil Carbon and Nitrogen Dynamics
- Rangeland and Wildlife Management
- Peatlands and Wetlands Ecology
- Economic and Environmental Valuation
- Ecosystem dynamics and resilience
- Bryophyte Studies and Records
- Invertebrate Taxonomy and Ecology
- Transboundary Water Resource Management
- Climate change and permafrost
- Forest Insect Ecology and Management
- Plant and animal studies
- Geology and Paleoclimatology Research
- Lichen and fungal ecology
University of Maine
2019-2025
Yale University
2016-2021
SUNY College of Environmental Science and Forestry
2015-2019
York University
2016-2019
State University of New York
2016-2019
Purchase College
2015
Under climate change, ecosystems are experiencing novel drought regimes, often in combination with stressors that reduce resilience and amplify drought's impacts. Consequently, appears increasingly likely to push systems beyond important physiological ecological thresholds, resulting substantial changes ecosystem characteristics persisting long after ends (i.e., transformation). In the present article, we clarify how can lead transformation across a wide variety of including forests,...
Climate change is expected to lead upslope shifts in tree species distributions, but the evidence mixed partly due land-use effects and individualistic responses climate. We examined how individual demography varies along elevational climatic gradients across four states northeastern United States determine whether distributions their potential (or downslope) were controlled by climate, legacies (past logging), or soils. characterized demography, microclimate, legacies, soils at 83 sites...
Summary During drought, xylem sap pressures can approach or exceed critical thresholds where gas embolisms form and propagate through the network, leading to systemic hydraulic dysfunction. The vulnerability segmentation hypothesis ( VSH ) predicts that low‐investment organs (e.g. leaf petioles) should be more vulnerable embolism spread compared high‐investment, perennial trunks, stems), as a means of mitigating excessive negative in organs. We tested this by measuring air‐seeding using...
Xylem networks are vulnerable to the formation and spread of gas embolisms that reduce water transport. Embolisms through interconduit pits, but three-dimensional (3D) complexity scale xylem means functional implications intervessel connections not well understood. Here, grapevine (Vitis vinifera L.) were reconstructed from 3D high-resolution X-ray micro-computed tomography (microCT) images. network performance was then modeled simulate loss hydraulic conductivity under increasingly negative...
The earliest vascular plants had stems with a central cylindrical strand of water-conducting xylem, which rapidly diversified into more complex shapes. This diversification is understood to coincide increases in plant body size and branching; however, no selection pressure favoring xylem strand-shape complexity known. We show that incremental changes network organization diverge from the ancestral form lead progressively greater drought resistance by reducing risk hydraulic failure. As...
Abstract Many montane tree species are expected to migrate upslope as climate warms, but it is not clear if forest canopy gaps, which can facilitate seedling recruitment, serve an important mechanism driving range shifts. Patterns of establishment inform us about early stages migrations and critical examine in the context global change. We contrasted elevational distributions seedlings both within outside gaps with conspecific adults saplings across deciduous‐coniferous ecotone on ten...
Summary Tree form can determine biomechanical strategies for attaining maximum height growth. In an earlier paper, tree in five global forest regions was linked to increasing bending stiffness (modulus of elasticity, MOE) and, three those regions, independent strength rupture, MOR), as approximates with slender column buckling theory. But, Latin American and North angiosperm forests, tall trees exhibited a relationship addition the between stiffness. Here we compared characteristics...
Droughts interact with tree phenology to drive declines in growth. As climate change makes drought more likely the Northeastern USA, it is important understand how droughts at different times of year will lead reduced height and diameter growth trees. To determine seasonal may reduce intra-annual growth, we implemented spring, summer or fall on 288 containerized saplings six species (Acer rubrum, Betula papyrifera, Prunus serotina, Juniperus virginiana, Pinus strobus Thuja occidentalis). We...
Summary Tree‐growth responses to environmental change could provide early detection of shifts in forest composition and help facilitate ecosystem management conservation. We studied tree recent trends climate acidic deposition using analyses rings long‐term climate, plot data along an elevational climatic gradient the northeastern United States. analysed how (i) individual growth dominant species ( Picea rubens , Abies balsamea ) (ii) spatial distributions all species, changed with elevation...
Acid rain in eastern North America contributed to the widespread decline of red spruce high-elevation spruce-fir forests. With recent reductions acid deposition and a warming climate, resurgence growth has been reported some mountain areas. Based on an extensive tree-ring sampling network established across elevations (600 1200 m above sea level) forests 10 mountains northeastern US (New York, Vermont, New Hampshire, Maine), we investigated whether this was specific only or if it occurred...
Abstract Aim The forest moss layer plays an important role in water retention, nutrient cycling and regeneration. We quantified broad‐scale latitudinal patterns environmental drivers of cover extratropical upland forests where such information has been missing. Location One thousand, nine hundred seventy‐seven sites outside the tropical belt (i.e., beyond 26° N S) across longitudes (from 154° W to 140° E) elevations 0 3,950 m a.s.l.). Time period Current (1969–2016). Major taxa studied Moss...
Deciduous angiosperm trees transport xylem sap through trunks and branches in vessels within annual growth rings. Utilizing previous rings for could increase vessel network size redundancy but may expose new to residual air embolisms the network. Despite important role of networks drought resistance, our understanding cross-ring connections between species is limited.We studied four temperate deciduous using dye staining X-ray microcomputed tomography (microCT) detect connectivity across...
Abstract Understanding the influence of post‐disturbance forest management on tree regeneration is critical for assessing ecosystem recovery and guiding future responses. In particular, influx elevated coarse woody material (CWM) following wind disturbance, if left in situ, may impede herbivore access, thereby protecting saplings from browsing damage through a natural ‘exclosure effect’. 2013, tornado northcentral Maine, United States subsequent salvage logging operations created three clear...
Abstract Climate change is raising concerns about how forests will respond to extreme droughts, heat waves and their co-occurrence. In this greenhouse study, we tested carbon water relations relate seedling growth mortality of northeastern US trees during after drought, warming, combined drought warming. We compared the response our focal species red spruce (Picea rubens Sarg.) with a common associate (paper birch, Betula papyrifera Marsh.) expected increase abundance in region climate...
Lowland northern white-cedar (Thuja occidentalis L.) forests are increasingly exposed to extreme droughts and floods that cause tree mortality. However, it is not clear the extent which these events may differentially affect regeneration of cedar its common associate, balsam fir (Abies balsamea (L.) Mill.). To test this, we measured how seedlings were able avoid, resist recover from experimental drought flood treatments different lengths (8 66 days). Overall, found exhibited a strategy...
PREMISE OF THE STUDY: Despite the strong influence of frequency and distribution vessel endings on both hydraulic safety efficiency, detailed anatomical descriptions or measurements these structures are generally lacking. METHODS: Here we used high‐resolution x‐ray microcomputed tomography (microCT) to identify describe xylem within Acer rubrum root segments (1.0–2.1 mm diameter, ∼2 long). We then compared vessel‐lumen pit density, element length, perforation plate angle between non‐ending...
Silvicultural thinning can lead to rapid microclimatic changes for residual trees. Despite the benefits of decreased competition, may induce “thinning shock”—temporary negative physiological responses as trees acclimate new conditions. We examined impact on microclimate and physiology residual, previously shaded red spruce ( Picea rubens Sarg.) relative non-thinned controls. Both daily maximum temperature vapor pressure deficit increased post thinning, with larger increases observed hotter...
Non-native earthworms can cause abrupt changes in forest ecosystems by altering soil properties and depleting or redistributing carbon (C) stocks. The forests of Northern Maine are often perceived as having winters that too harsh to support earthworm populations restricted more southerly regions. In this study, we report the discovery European at two research sites Maine. At one site, were only found across a portion forest, median organic (O) horizon C stock area with was 34% less than...
Abstract Private woodland owners (PWOs) face an increasing number of considerations for climate change adaptation and mitigation activities in their forest management. Evidence suggests there may be a disconnect between PWOs’ perceptions behaviors, which can limit implementation. We conducted seventeen semistructured interviews Maine to develop typological framework PWOs based on climate-induced threats efficacy. Our results produced three types PWOs: the steady-as-they-go landowner (low...