-
Temporal dynamics of a commensal network of cavity-nesting vertebrates: increased diversity during an insect outbreak
-
Network analysis offers insight into the structure and function of ecological
communities, but little is known about how empirical networks change over time during
perturbations. ‘‘Nest webs’’ are commensal networks that link secondary cavity-nesting
vertebrates (e.g., bluebirds, ducks, and squirrels, which depend on tree cavities for nesting)
with the excavators (e.g., woodpeckers) that produce cavities. In central British Columbia,
Canada, Northern Flicker (Colaptes auratus) is considered a keystone excavator, providing
most cavities for secondary cavity-nesters. However, roles of species in the network, and
overall network architecture, are expected to vary with population fluctuations. Many
excavator species increased in abundance in association with a pulse of food (adult and larval
beetles) during an outbreak of mountain pine beetle (Dendroctonus ponderosae), which peaked
in 2003–2004. We studied nest-web dynamics from 1998 to 2011 to determine how network
architecture changed during this resource pulse.Cavity availability increased at the onset of the beetle outbreak and peaked in 2005. During and after the outbreak, secondary cavity-nesters increased their use of cavities made by five species of beetle-eating excavators, and decreased their use of flicker cavities. We found low link turnover, with 74% of links conserved from year to year. Nevertheless, the network
increased in evenness and diversity of interactions, and declined slightly in nestedness and
niche overlap. These patterns remained evident seven years after the beetle outbreak,
suggesting a legacy effect. In contrast to previous snapshot studies of nest webs, our dynamic approach reveals how the role of each cavity producer, and thus quantitative network architecture, can vary over
time. The increase in interaction diversity with the beetle outbreak adds to growing evidence
that insect outbreaks can increase components of biodiversity in forest ecosystems at various
temporal scales. The observed changes in (quantitative) network architecture contrast with the
relatively stable (qualitative) architecture of empirical mutualistic networks that have been
studied to date. However, they are consistent with recent theory on the importance of
population fluctuations in driving network architecture. Our results support the view that
models should allow for the possibility of rewiring (species switching partners) to avoid
overestimation of secondary extinction risk.
Located in
Resources
/
Climate Science Documents
-
THE COST OF INACTION: RECOGNISING THE VALUE AT RISK FROM CLIMATE CHANGE
-
The asset management industry—and thus the wider community of investors of all sizes— is facing the prospect of significant losses from the effects of climate change. Assets can be directly damaged by floods, droughts and severe storms, but portfolios can also be harmed indirectly, through weaker growth and lower asset returns. Climate change is a long-term, probably irreversible problem beset by substantial uncertainty. Crucially, however, climate change is a problem of extreme risk: this means that the average losses to be expected are not the only source of concern; on the contrary, the outliers, the particularly extreme scenarios, may matter most of all.
Located in
Resources
/
Climate Science Documents
-
The Nature Conservancy Releases Country-Level Temperature and Precipitation Data for Climate Resilience and Adaptation Planning
-
The Nature Conservancy has released a new country-level dataset for its online Climate Wizard mapping tool that enables users to visualize future climate conditions using the most recent modeled data from the Intergovernmental Panel on Climate Change (IPCC).
Located in
News & Events
-
The State of Greenhouse Gases in the Atmosphere Based on Global Observations through 2013
-
The WMO Global Atmosphere Watch (GAW) coordinates observations of the most important contributors to climate change: long-lived greenhouse gases(LLGHG). In the figure, their radiative forcing (RF) is plotted along with a simple illustration of the impacts on future RF of different emission reduction scenarios. Analysis of GAW observations shows that a reduction in RF from its current level (2.92 W·m–2 in
2013)[1] requires significant reductions in anthropogenic emissions of all major greenhouse gases (GHGs).
Located in
Resources
/
Climate Science Documents
-
Thomas, Richard Neil
-
Located in
Expertise Search
-
Uncertainty in the response of transpiration to CO2 and implications for climate change
-
While terrestrial precipitation is a societally highly relevant climate variable, there is little consensus among climate models about its projected 21st century changes. An important source of precipitable water over land is plant transpiration. Plants control transpiration by opening and closing their stomata. The sensitivity of this process to increasing CO2 concentrations is uncertain. To assess the impact of this uncertainty on future climate, we perform experiments with an intermediate complexity Earth System Climate Model (UVic ESCM) for a range of model-imposed transpiration- sensitivities to CO2. Changing the sensitivity of transpiration to CO2 causes simulated terrestrial precipitation to change by −10% to +27% by 2100 under a high emission scenario. This study emphasises the importance of an improved assessment of the dynamics of environmental impact on vegetation to better predict future changes of the terrestrial hydrological and carbon cycles.
Located in
Resources
/
Climate Science Documents
-
USFS Landscape Science Webinar
-
When the past cannot predict the future: Using process-based landscape models to predict forest dynamics in a changing world.
Located in
News & Events
/
Events
-
USGS-NOAA: Climate Change Impacts to U.S. Coasts Threaten Public Health, Safety and Economy
-
According to a new technical report, the effects of climate change will continue to threaten the health and vitality of U.S. coastal communities' social, economic and natural systems.
Located in
News & Events
-
Virginia’s Climate Modeling and Species Vulnerability Assessment
-
The National Wildlife Federation (NWF) is excited to announce the publication of Virginia’s Climate Modeling and Species Vulnerability Assessment: How Climate Data Can Inform Management and Conservation. This report is the culmination of over 4 years of effort by NWF, Virginia Department of Game and Inland Fisheries (DGIF), Conservation Management Institute, and Kutztown University to downscale climate data for Virginia and use that in a species modeling effort to project how a selections of species (wildlife, fish, and plants) may change their distribution across the landscape based on climate change.
Located in
News & Events
-
What are Future Climate Projections for Precipitation and Temperature for Your County?
-
For the first time, maps and summaries of historical and projected temperature and precipitation changes for the 21st century for the continental U.S. are accessible at a county-by-county level on a website developed by the U.S. Geological Survey in collaboration with the College of Earth, Oceanic and Atmospheric Sciences at Oregon State University.
Located in
News & Events
