Treesearch

Although snags and coarse woody debris are a small component of ecosystem respiration, disturbances can significantly increase the mass and respiration from these carbon (C) pools. The objectives of this study were to (1) measure respiration rates of snags and coarse woody debris throughout the year in a forest previously defoliated by gypsy moths, (2) develop models for dead stem respiration rates, (3) model stand-level respiration rates of dead stems using forest inventory and analysis data sets and environmental variables predisturbance and postdisturbance, and (4) compare total dead...

Forest inventory estimates of tree volume for large areas are typically calculated by adding model predictions of volumes for individual trees. However, the uncertainty in the model predictions is generally ignored with the result that the precision of the large area volume estimates is overestimated. The primary study objective was to estimate the effects of model residual variability and model parameter uncertainty on large area volume estimates and their uncertainties for a study area in northeastern Minnesota, USA. Monte Carlo simulation approaches were used because of the complexities...

National forest inventories typically estimate individual tree volumes using models that rely on measurements of predictor variables such as tree height and diameter, both of which are subject to measurement error. The aim of this study was to quantify the impacts of these measurement errors on the uncertainty of the model-based tree stem volume estimates. The impacts were investigated using two approaches: the law of propagation of error and Monte Carlo simulation. Estimates of total uncertainty also included variability associated with the model itself. Results for both approaches...

Increased wildfires and temperatures due to climate change are expected to have profound effects on forest productivity and nitrogen (N) cycling. Forecasts about how wildfire and climate change will affect forests seldom consider N availability, which may limit forest response to climate change, particularly in fire-prone landscapes. The overall objective of this study was to examine how wildfire and climate change affect long-term mineral N availability in a fire-prone landscape. We employed a commonly used landscape simulation model (LANDIS-II) in the New Jersey Pine Barrens, a landscape...

Trees remove air pollution by the interception of particulate matter on plant surfaces and the absorption of gaseous pollutants through the leaf stomata. However, the magnitude and value of the effects of trees and forests on air quality and human health across the United States remains unknown. Computer simulations with local environmental data reveal that trees and forests in the conterminous United States removed 17.4 million tonnes (t) of air pollution in 2010 (range: 9.0-23.2 million t), with human health effects valued at 6.8 billion U.S. dollars (range: $1.5-13.0 billion). This...

Monitoring is an important and costly activity in resource man-agement problems such as containing invasive species, protectingendangered species, preventing soil erosion, and regulating con-tracts for environmental services. Recent studies have viewedoptimal monitoring as a Partially Observable Markov Decision Pro-cess (POMDP), which provides a framework for sequential decisionmaking under stochastic resource dynamics and uncertainty aboutthe resource state. We present an overview of the POMDP frame-work and its applications to resource monitoring. We discuss theconcept of the information...

Foresters and futurists share a long-range perspective. The lengthy growing cycle of trees has compelled foresters to plan decades and even hundreds of years ahead, in contrast to the short-term view of most fields. The interconnected nature of forest ecosystems has also given foresters—like futurists—a systems perspective. As the American naturalist John Muir said, "When one tugs at a single thing in nature, he finds it attached to the rest of the world." The world's forests range from sparsely populated wilderness to urban forests, from lush tropical rain forests to the vast...

The urban environment offers significant opportunities to improve sustainability and optimize water resources. Historically, research and software applications have been focused on the built environment (buildings). Cost-effective, practical tools that can assess the impact of different landscape configurations and their interactions with buildings have not been widely deployed. ecoSmart Landscapes (eSL) is a unique SaaS-based platform that helps to bridge this gap. It incorporates modelling and planning tools for the integrated assessment of carbon, water, energy, and fire impacts of...

Purpose This study seeks to answer the question, “Will the Million Trees LA (Million Trees Los Angeles, MTLA) program be a carbon dioxide (CO2) sink or source?” Because there has never been a full accounting of CO2 emissions, it is unclear if urban tree planting initiatives (TPIs) are likely to be effective means for reaching local reduction targets. Methods Using surveys, interviews, field sampling, and computer simulation of tree growth and survival over a 40-year time period, we developed the first process-based life cycle inventory of CO2 for a large TPI. CO2 emissions and reductions...

Regression models developed in the upper Midwest (United States) to predict drought-induced tree mortality from measures of drought (Palmer Drought Severity Index) were tested in the northeastern United States and found inadequate. The most likely cause of this result is that long drought events were rare in the Northeast during the period when inventory data were available. Therefore, new predictive models of drought mortality for the Northeast were built using USDA Forest Service inventory data and national climate data from 1969 to 2007. The Standardized Precipitation Index was better...