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Abstract (from http://www.bioone.org/doi/abs/10.3417/2017006): The Earth system is undergoing rapid, profound anthropogenic change. The primary axes of change include not only the climate system, but also the spread of invasive species, altered biogeochemical and hydrological cycles, modified disturbance regimes, and land degradation and conversion. These factors are influencing the distribution of species and the structure and function of ecosystems worldwide, interacting with climatic stressors that may preclude the persistence of many current species distributions and communities. Ecological disturbances such as wildfires and insect outbreaks can interact with climate variability to precipitate abrupt change...
Abstract (from ESA): Estimating population size and resource selection functions (RSFs) are common approaches in applied ecology for addressing wildlife conservation and management objectives. Traditionally such approaches have been undertaken separately with different sources of data. Spatial capture–recapture (SCR) provides a hierarchical framework for jointly estimating density and multi‐scale resource selection, and data integration techniques provide opportunities for improving inferences from SCR models. Despite the added benefits, there have been few applications of SCR‐RSF integration, potentially due to complexities of specifying and fitting such models. Here, we extend a previous integrated SCR‐RSF model...
Abstract (from AGU 100): This study investigates snowmelt and streamflow responses to cloudiness variability across the mountainous parts of the western United States. Twenty years (1996–2015) of Geostationary Operational Environmental Satellite‐derived cloud cover indices (CC) with 4‐km spatial and daily temporal resolutions are used as a proxy for cloudiness. The primary driver of nonseasonal fluctuations in daily mean solar insolation is the fluctuating cloudiness. We find that CC fluctuations are related to snowmelt and snow‐fed streamflow fluctuations, to some extent (correlations of <0.5). Multivariate linear regression models of daily snowmelt (MELT) and streamflow (ΔQ) variations are constructed for each...
This project consisted of two principal components: (1) A climatological analysis of burn conditions (2) A forum to discuss fire risk and management practices The climatological study included seasonality and inter-annual variability and potential changes due to increasing temperatures. The regional forum engaged stakeholders in a discussion of the use of prescribed fire in a safe and effective manner.
Severe droughts cause widespread tree mortality and decreased growth in forests across the globe. Forest managers are seeking strategies to increase forest resistance (minimizing negative impacts during the drought) and resilience (maximizing recovery rates following drought). Limited experimental evidence suggests that forests with particular structural characteristics have greater capacity to resist change and or recover ecosystem function in the face of drought. However, the applicability of these results to practical forest conservation and management remains unclear. This project utilized an existing network of eight long-term, operational-scale, forest management experiments from Arizona to Maine to examine...
Exposure (vulnerability) index for the future time period (2061-2080) representing projected climate conditions from the Meteorological Research Institute's Coupled Atmosphere-Ocean General Circulation Model, version 3, and the rcp85 emissions scenario. The exposure model uses LANDFIRE vegetation data and Worldclim climate data .The raster values represent exposure scores for the corresponding vegetation type. The modeled vegetation types can be spatially associated with the exposure values by overlaying them with the "landfire_veg_sw_300m.tif" raster.Exposure values represent where the location falls in climate space relative to its recent historical distribution:5 (core 5% of historical climate space); 10 (5 -...
The responses of individual species to environmental changes can be manifested at multiple levels that range from individual-level (i.e., behavioral responses) to population-level (i.e., demographic) impacts. Major environmental changes that ultimately result in population level impacts are often first detected as individual-level responses. For example, herbivores respond to limited forage availability during drought periods by increasing the duration of foraging periods and expanding home range areas to compensate for the reduction in forage. However, if the individual-level responses are not sufficient to compensate for reduced forage availability, reduced survival and reproductive rates may result. We studied...
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To assess the current topography of the tidal marshes we conducted survey-grade elevation surveys at all sites between 2009 and 2013 using a Leica RX1200 Real Time Kinematic (RTK)Global Positioning System (GPS) rover (±1 cm horizontal, ±2 cm vertical accuracy; Leica Geosystems Inc., Norcross, GA; Figure 4). At sites with RTK network coverage (San Pablo, Petaluma, Pt. Mugu, and Newport), rover positions were received in real time from the Leica Smartnet system via a CDMA modem (www.lecia-geosystems.com). At sites without network coverage (Humboldt, Bolinas, Morro and Tijuana), rover positions were received in real time from a Leica GS10 antenna base station via radio link. When using the base station, we adjusted...
Abstract (from http://link.springer.com/article/10.1007/s11069-016-2376-z): Drought is among the most insidious types of natural disasters and can have devastating economic and human health impacts. This research analyzes the relationship between two readily accessible drought indices—the Palmer Drought Severity Index (PDSI) and Palmer Hydrologic Drought Index (PHDI)—and the damage incurred by such droughts in terms of monetary loss, over the 1975–2010 time period on monthly basis, for five states in the south-central USA. Because drought damage in the Spatial Hazards Events and Losses Database for the United States (SHELDUS™) is reported at the county level, statistical downscaling techniques were used to estimate...
A new method for automatic detection of atmospheric rivers (ARs) is developed and applied to an atmospheric reanalysis, yielding an extensive catalog of ARs land-falling along the west coast of North America during 1948–2017. This catalog provides a large array of variables that can be used to examine AR cases and their climate-scale variability in exceptional detail. The new record of AR activity, as presented, validated and examined here, provides a perspective on the seasonal cycle and the interannual-interdecadal variability of AR activity affecting the hydroclimate of western North America. Importantly, AR intensity does not exactly follow the climatological pattern of AR frequency. Strong links to hydroclimate...
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The South Central U.S. is one of the main agricultural regions in North America: annual agricultural production is valued at more than $44 billion dollars. However, as climate conditions change, the region is experiencing more frequent and severe droughts, with significant impacts on agriculture and broader consequences for land management. For example, in 2011 drought caused an estimated $7.6 billion in agricultural losses in Texas and an additional $1.6 billion in Oklahoma. Although there are many drought monitoring tools available, most of these tools were developed without input from the stakeholders, such as farmers and ranchers, who are intended to use them. The goal of this project was to assess the information...
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The South Central U.S. encompasses a wide range of ecosystem types and precipitation patterns. Average annual precipitation is less than 10 inches in northwest New Mexico but can exceed 60 inches further east in Louisiana. Much of the region relies on warm-season convective precipitation – that is, highly localized brief but intense periods of rainfall that are common in the summer. This type of precipitation is a significant driver of climate and ecosystem function in the region, but it is also notoriously difficult to predict since it occurs at such small spatial and temporal scales. While global climate models are helpful for understanding and predicting large-scale precipitation trends, they often do not capture...
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The sky island forests of the southwestern United States are one of the most diverse temperate forest ecosystems in the world, providing key habitat for migrating and residential species alike. Black bear, bighorn sheep, mule deer, and wild turkey are just a few of the species found in these isolated mountain ecosystems that rise out of the desert landscape. However, recent droughts have crippled these ecosystems, causing significant tree death. Climate predictions suggest that this region will only face hotter and drier conditions in the future, potentially stressing these ecosystems even further. Simple models predict that vegetation will move to cooler and wetter locations in response to this warming. However,...
A warming climate, fire exclusion, and land cover changes are altering the conditions that produced historical fire regimes and facilitating increased recent wildfire activity in the northwestern United States. Understanding the impacts of changing fire regimes on forest recruitment and succession, species distributions, carbon cycling, and ecosystem services is critical, but challenging across broad spatial scales. One important and understudied aspect of fire regimes is the unburned area within fire perimeters; these areas can function as fire refugia across the landscape during and after wildfire by providing habitat and seed sources. With increasing fire activity, there is speculation that fire intensity and...
Wildfire refugia are forest patches that are minimally-impacted by fire and provide critical habitats for fire-sensitive species and seed sources for post-fire forest regeneration. Wildfire refugia are relatively understudied, particularly concerning the impacts of subsequent fires on existing refugia. We opportunistically re-visited 122 sites classified in 1994 for a prior fire refugia study, which were burned by two wildfires in 2012 in the Cascade mountains of central Washington, USA. We evaluated the fire effects for historically persistent fire refugia and compared them to the surrounding non-refugial forest matrix. Of 122 total refugial (43 plots) and non-refugial (79 plots) sites sampled following the 2012...


map background search result map search result map Predicting Sky Island Forest Vulnerability to Climate Change: Fine Scale Climate Variability, Drought Tolerance, and Fire Response Improving Representation of Extreme Precipitation Events in Regional Climate Models Developing Effective Drought Monitoring Tools for Farmers and Ranchers in the South Central U.S. Tijuana: Tidal Marsh Digital Elevation Model Tijuana: Tidal Marsh Digital Elevation Model Predicting Sky Island Forest Vulnerability to Climate Change: Fine Scale Climate Variability, Drought Tolerance, and Fire Response Improving Representation of Extreme Precipitation Events in Regional Climate Models Developing Effective Drought Monitoring Tools for Farmers and Ranchers in the South Central U.S.