Biology subjects

Laflower, D.

Publications and source records attributed to Laflower, D..

5 recordsLinked to original sources

bioRxiv2023

Hurricanes Pose Substantial Risk to New England Forest Carbon Stocks

Nature-based climate solutions are championed as a primary tool to mitigate climate change, especially in forested regions capable of storing and sequestering vast amounts of carbon. New England is one of the most heavily forested regions in the United States (>75% forested by land area), and forest carbon is a significant component of regional climate mitigation strategies. Large infrequent disturbances, such as hurricanes, are a major source of uncertainty and risk for policies that rely on forest carbon for climate mitigation, especially as climate change is projected to alter the intensity and geographic extent of hurricanes. To date, most research into disturbance impacts on forest carbon stocks has focused on fire. Here we show that a single hurricane in the region can down between 121-250 MMTCO2e or 4.6-9.4% of the total aboveground forest carbon, much greater than the carbon sequestered annually by New Englands forests (16 MMTCO2e yr-1). However, the emissions from the storms are not instantaneous; it takes approximately 19 years for the downed carbon to become a net emission, and 100 years for 90% of the downed carbon to be emitted. Using hurricane reconstructions across a range of historical and projected wind speeds, we find that an 8% and 16% increase in hurricane wind speeds leads to a 10.7 and 24.8 fold increase in the extent of high-severity damaged areas (widespread tree mortality). Increased wind speed also leads to unprecedented geographical shifts in damage; both inland and northward into heavily forested regions traditionally unaffected by hurricanes. Given that a single hurricane can emit the equivalent of 10+ years of carbon sequestered by forests in New England, the status of these forests as a durable carbon sink is uncertain. Understanding the risks to forest carbon stocks from large infrequent disturbances is necessary for decision-makers relying on forests as a nature-based climate solution.

ecology↗

bioRxiv2021

Does land use matter? Carbon consequences of alternative land use futures in New England

Globally, forests play an important role in climate change mitigation. However, land-use impacts the ability of forests to sequester and store carbon. Here we quantify the impacts of five divergent future land-use scenarios on aboveground forest carbon stocks and fluxes throughout New England. These scenarios, four co-designed with stakeholders from throughout the region and the fifth a continuation of recent trends in land use, were simulated by coupling a land cover change model with a mechanistic forest growth model to produce estimates of aboveground carbon over 50 years. Future carbon removed through harvesting and development was tracked using a standard carbon accounting methodology, modified to fit our modeling framework. Of the simulated changes in land use, changes in harvesting had the most profound and immediate impacts on carbon stocks and fluxes. In one of the future land-use scenarios including a rapid expansion of harvesting for biomass energy, this changed New Englands forests from a net carbon sink to a net carbon source in 2060. Also in these simulations, relatively small reductions in harvest intensities (e.g., 10% reduction), coupled with an increased percent of wood going into longer-term storage, led to substantial reductions in net carbon emissions (909 MMtCO2eq) as compared to a continuation of recent trends in land use. However, these projected gains in carbon storage and reduction in emissions from less intense harvesting regimes can only be realized if it is paired with a reduction in the consumption of the timber products, and their replacements, that otherwise would result in additional emissions from leakage and substitution.

ecology↗

bioRxiv2019

Potential impacts of insect-induced harvests in the mixed forests of New England

Forest insects and pathogens (FIPs) have significant impacts on U.S. forests, each year affecting an area nearly three times the area of wildfires and timber harvesting combined. We surveyed family forest owners (FFOs) in the northeastern U.S. and 84% of respondents indicated they would harvest in at least one of the presented FIP infestation scenarios. This harvest response represents a potentially significant shift in the timing, extent, and species selection of harvesting in the Northeast. Here we used the landowner survey, regional forest inventory data, and characteristics of the emerald ash borer (EAB, Agrilus planipennis) invasion to examine the potential for a rapidly spreading FIP to alter harvest regimes and affect regional forest conditions. Twenty-five percent of the FFO parcels in the Connecticut River Watershed in New England are likely to be harvested in response to EAB within 10 years. This prediction represents an increase in harvest frequencies, from 2.9%/yr (historically) to 3.7%/yr, on FFO woodlands. At typical harvest intensities, this would result in 13% of the total aboveground biomass removed through these harvests, with 81% of that biomass from species other than ash, creating a forest disturbance that is over twice the magnitude of the disturbance from EAB alone.

ecology↗

bioRxiv2019

Landowner Functional Types to Characterize Response to Forest Insects

Forest insects and pathogens (FIPs) play an important role in the complex interactions between woodland owners and the ecosystems they manage. Understanding the specifics of woodland owner decision-making with regard to trees impacted by FIPs can facilitate projections of future forest conditions and insect spread. Our first objective is to: (i) characterize agent functional types (AFTs) of New England family forest owners (FFOs) using a set of contingent behavior questions contained in a mail survey of FFOs concerning response to FIPs. We establish AFTs as a form of dimension reduction, effectively assigning individual FFOs to particular decision-making classes, each with distinct probabilities of behavior with respect to the harvest of impacted trees. Our second objective is to: (ii) model AFT membership to predict the distribution of AFTs across the landscape. Predictors are chosen from a set of survey, geographic, and demographic features. Accomplishing (i) establishes three functional classes of landowners: cutters (46% of respondents; highly likely to cut timber impacted by FIPs), responsive cutters (42% of respondents; sensitive to pest severity), and non-cutters (12% of respondents; highly unlikely to cut). Fulfilling (ii) provides a high-resolution probability surface of AFTs across the landscape, delivering key input for simulation models of forest and land cover change in New England. Predictors in our best model of AFT membership include parcel size (hectares of forest), region, and town-level forested fraction.

ecology↗

bioRxiv2019

Compounding the disturbance: Family forest owner reactions to invasive forest insects

Invasive forest insect and pathogens (FIP) are having significant, direct, adverse impacts. Interactions between FIPs and forest owners have the potential to create ecosystem impacts that compound direct impacts. We assessed family forest owners responses to numerous contingent behavior, FIP-outbreak scenarios in the northeastern U.S. based on FIP outbreak attributes. Sixty-two percent of scenario responses (n=2,752) reflected a harvest intent as a result of FIPs; 84% of respondents (n=688) would consider harvesting in at least one of the four hypothetical scenarios presented to them. Harvest intention increased with greater FIP-related tree mortality and decreased with delayed total tree mortality. Owners with larger holdings, who had previously harvested forest products, and live on their forestland had greater intentions to harvest in response to FIPs. Results suggest that FIPs could transform the regional harvest regime with socio-ecological impacts that are distinct from those caused by FIPs or harvesting alone.

ecology↗