A New Model For Simulating Climate Change and Carbon Dynamics in Forested Landscapes

Journal of Ecosystems & Management vol. 13 no. 2 2012 news brief

Carbon Sequestration in Managed Temperate Coniferous Forests Under Climate Change

Management of temperate forests has the potential to increase carbon sinks and mitigate climate change. However, those opportunities may be confounded by negative climate change impacts. We therefore need a better understanding of climate change alterations to temperate forest carbon dynamics before developing mitigation strategies. The purpose of this project was to investigate the interactions of species composition, fire, management, and climate change in the Copper–Pine Creek valley, a temperate coniferous forest with a wide range of growing conditions. To do so, we used the LANDIS-II modelling framework including the new Forest Carbon Succession extension to simulate forest ecosystems under four different productivity scenarios, with and without climate change effects, until 2050. Significantly, the new extension allowed us to calculate the net sector productivity, a carbon accounting metric that integrates aboveground and belowground carbon dynamics, disturbances, and the eventual fate of forest products. The model output was validated against literature values. The results implied that the species optimum growing conditions relative to current and future conditions strongly influenced future carbon dynamics. Warmer growing conditions led to increased carbon sinks and storage in the colder and wetter ecoregions but not necessarily in the others. Climate change impacts varied among species and site conditions, and this indicates that both of these components need to be taken into account when considering climate change mitigation activities and adaptive management. The introduction of a new carbon indicator, net sector productivity, promises to be useful in assessing management effectiveness and mitigation activities

Presence of low virulence chytrid fungi could protect European amphibians from more deadly strains

Wildlife diseases are contributing to the current Earth’s sixth mass extinction; one disease, chytridiomycosis, has caused mass amphibian die-offs. While global spread of a hypervirulent lineage of the fungus Batrachochytrium dendrobatidis (BdGPL) causes unprecedented loss of vertebrate diversity by decimating amphibian populations, its impact on amphibian communities is highly variable across regions. Here, we combine field data with in vitro and in vivo trials that demonstrate the presence of a markedly diverse variety of low virulence isolates of BdGPL in northern European amphibian communities. Pre-exposure to some of these low virulence isolates protects against disease following subsequent exposure to highly virulent BdGPL in midwife toads (Alytes obstetricans) and alters infection dynamics of its sister species B. salamandrivorans in newts (Triturus marmoratus), but not in salamanders (Salamandra salamandra). The key role of pathogen virulence in the complex host-pathogen-environment interaction supports efforts to limit pathogen pollution in a globalized world

Models for tent caterpillar-virus interactions

Many species of forest Lepidoptera show eight to twelve year population cycles which may involve viral disease. To examine possible interactions between viral disease and population cycles of forest Lepidoptera I explored some models for insect-virus dynamics. All of the models produced population oscillations in their original form. However, after they were modified to conform more closely to the tent caterpillar system, none of the models produced realistic cycles. I then developed a new model specifically for the tent caterpillar system that included important features such as: reduced fecundity of individuals that had been exposed to the disease, transmission of the disease from mother to progeny, a free-living infective stage of the virus, and a horizontal transmission rate that varied with the larval stage, the number of individuals, and amount of virus present. Cyclic dynamics resulted from some simulations. The parameters producing the cycles were similar to actual data. However, unlike natural populations of tent caterpillars, in the simulated population the average fecundity decreased before the population started to decline and survival decreased at approximately the same time as the population. Important further research in the field should include investigation of the distribution and survival of free-living virus and factors that would reduce caterpillar survival at peak populations but not affect fecundity.Science, Faculty ofZoology, Department ofGraduat

Carbon budget implications of the transition from natural to manged disturbance regimes in forest landscapes

Canada, carbon fluxes, carbon content, harvesting, land-use change, wild fire,

A Proposal to Improve Performance of the Forest Vegetation Simulator - Fire and Fuels Extension

The Forest Vegetation Simulator (FVS) and its associated Fire and Fuels Extension (FFE) have been used to provide information required by larger software systems like the Interagency Fuels Treatment - Decision Support System (IFT-DSS). Interacting with FVS in an automated fashion has been difficult, and simulations with very large numbers of stands, such as those necessary for landscape analyses for fire planning, could take a significant amount of time to process. This project was designed to: (A) develop a requirements document considering Service Oriented Architecture and how that may apply to FVS, and how FVS will be used interactively; (B) profile the FVS code to evaluate what takes the most processing time and identify possible areas for program optimization; (C) while optimizing and reducing the size of code, migrate FVS to a modern development framework such as Intel Fortran and the Visual Studio IDE; (D) identify platforms and systems that meet needs of the JFSP and other stakeholders, such as creating dynamic link libraries (DLL); and (E) specify and define the use of new technologies in the next phase of software development, such as OpenMP directives, thus implementing multithreading in the base FVS executables or extensions to take advantage of increased computing power of multicore processors